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!function(e){if("object"==typeof exports&&"undefined"!=typeof module)module.exports=e();else if("function"==typeof define&&define.amd)define([],e);else{var f;"undefined"!=typeof window?f=window:"undefined"!=typeof global?f=global:"undefined"!=typeof self&&(f=self),f.dagre=e()}}(function(){var define,module,exports;return (function e(t,n,r){function s(o,u){if(!n[o]){if(!t[o]){var a=typeof require=="function"&&require;if(!u&&a)return a(o,!0);if(i)return i(o,!0);var f=new Error("Cannot find module '"+o+"'");throw f.code="MODULE_NOT_FOUND",f}var l=n[o]={exports:{}};t[o][0].call(l.exports,function(e){var n=t[o][1][e];return s(n?n:e)},l,l.exports,e,t,n,r)}return n[o].exports}var i=typeof require=="function"&&require;for(var o=0;o 0; --i) {
        entry = buckets[i].dequeue();
        if (entry) {
          results = results.concat(removeNode(g, buckets, zeroIdx, entry, true));
          break;
        }
      }
    }
  }

  return results;
}

function removeNode(g, buckets, zeroIdx, entry, collectPredecessors) {
  var results = collectPredecessors ? [] : undefined;

  _.each(g.inEdges(entry.v), function(edge) {
    var weight = g.edge(edge),
        uEntry = g.node(edge.v);

    if (collectPredecessors) {
      results.push({ v: edge.v, w: edge.w });
    }

    uEntry.out -= weight;
    assignBucket(buckets, zeroIdx, uEntry);
  });

  _.each(g.outEdges(entry.v), function(edge) {
    var weight = g.edge(edge),
        w = edge.w,
        wEntry = g.node(w);
    wEntry["in"] -= weight;
    assignBucket(buckets, zeroIdx, wEntry);
  });

  g.removeNode(entry.v);

  return results;
}

function buildState(g, weightFn) {
  var fasGraph = new Graph(),
      maxIn = 0,
      maxOut = 0;

  _.each(g.nodes(), function(v) {
    fasGraph.setNode(v, { v: v, "in": 0, out: 0 });
  });

  // Aggregate weights on nodes, but also sum the weights across multi-edges
  // into a single edge for the fasGraph.
  _.each(g.edges(), function(e) {
    var prevWeight = fasGraph.edge(e.v, e.w) || 0,
        weight = weightFn(e),
        edgeWeight = prevWeight + weight;
    fasGraph.setEdge(e.v, e.w, edgeWeight);
    maxOut = Math.max(maxOut, fasGraph.node(e.v).out += weight);
    maxIn  = Math.max(maxIn,  fasGraph.node(e.w)["in"]  += weight);
  });

  var buckets = _.range(maxOut + maxIn + 3).map(function() { return new List(); });
  var zeroIdx = maxIn + 1;

  _.each(fasGraph.nodes(), function(v) {
    assignBucket(buckets, zeroIdx, fasGraph.node(v));
  });

  return { graph: fasGraph, buckets: buckets, zeroIdx: zeroIdx };
}

function assignBucket(buckets, zeroIdx, entry) {
  if (!entry.out) {
    buckets[0].enqueue(entry);
  } else if (!entry["in"]) {
    buckets[buckets.length - 1].enqueue(entry);
  } else {
    buckets[entry.out - entry["in"] + zeroIdx].enqueue(entry);
  }
}

},{"./data/list":5,"./graphlib":7,"./lodash":10}],9:[function(require,module,exports){
"use strict";

var _ = require("./lodash"),
    acyclic = require("./acyclic"),
    normalize = require("./normalize"),
    rank = require("./rank"),
    normalizeRanks = require("./util").normalizeRanks,
    parentDummyChains = require("./parent-dummy-chains"),
    removeEmptyRanks = require("./util").removeEmptyRanks,
    nestingGraph = require("./nesting-graph"),
    addBorderSegments = require("./add-border-segments"),
    coordinateSystem = require("./coordinate-system"),
    order = require("./order"),
    position = require("./position"),
    util = require("./util"),
    Graph = require("./graphlib").Graph;

module.exports = layout;

function layout(g, opts) {
  var time = opts && opts.debugTiming ? util.time : util.notime;
  time("layout", function() {
    var layoutGraph = time("  buildLayoutGraph",
                               function() { return buildLayoutGraph(g); });
    time("  runLayout",        function() { runLayout(layoutGraph, time); });
    time("  updateInputGraph", function() { updateInputGraph(g, layoutGraph); });
  });
}

function runLayout(g, time) {
  time("    makeSpaceForEdgeLabels", function() { makeSpaceForEdgeLabels(g); });
  time("    removeSelfEdges",        function() { removeSelfEdges(g); });
  time("    acyclic",                function() { acyclic.run(g); });
  time("    nestingGraph.run",       function() { nestingGraph.run(g); });
  time("    rank",                   function() { rank(util.asNonCompoundGraph(g)); });
  time("    injectEdgeLabelProxies", function() { injectEdgeLabelProxies(g); });
  time("    removeEmptyRanks",       function() { removeEmptyRanks(g); });
  time("    nestingGraph.cleanup",   function() { nestingGraph.cleanup(g); });
  time("    normalizeRanks",         function() { normalizeRanks(g); });
  time("    assignRankMinMax",       function() { assignRankMinMax(g); });
  time("    removeEdgeLabelProxies", function() { removeEdgeLabelProxies(g); });
  time("    normalize.run",          function() { normalize.run(g); });
  time("    parentDummyChains",      function() { parentDummyChains(g); });
  time("    addBorderSegments",      function() { addBorderSegments(g); });
  time("    order",                  function() { order(g); });
  time("    insertSelfEdges",        function() { insertSelfEdges(g); });
  time("    adjustCoordinateSystem", function() { coordinateSystem.adjust(g); });
  time("    position",               function() { position(g); });
  time("    positionSelfEdges",      function() { positionSelfEdges(g); });
  time("    removeBorderNodes",      function() { removeBorderNodes(g); });
  time("    normalize.undo",         function() { normalize.undo(g); });
  time("    fixupEdgeLabelCoords",   function() { fixupEdgeLabelCoords(g); });
  time("    undoCoordinateSystem",   function() { coordinateSystem.undo(g); });
  time("    translateGraph",         function() { translateGraph(g); });
  time("    assignNodeIntersects",   function() { assignNodeIntersects(g); });
  time("    reversePoints",          function() { reversePointsForReversedEdges(g); });
  time("    acyclic.undo",           function() { acyclic.undo(g); });
}

/*
 * Copies final layout information from the layout graph back to the input
 * graph. This process only copies whitelisted attributes from the layout graph
 * to the input graph, so it serves as a good place to determine what
 * attributes can influence layout.
 */
function updateInputGraph(inputGraph, layoutGraph) {
  _.each(inputGraph.nodes(), function(v) {
    var inputLabel = inputGraph.node(v),
        layoutLabel = layoutGraph.node(v);

    if (inputLabel) {
      inputLabel.x = layoutLabel.x;
      inputLabel.y = layoutLabel.y;

      if (layoutGraph.children(v).length) {
        inputLabel.width = layoutLabel.width;
        inputLabel.height = layoutLabel.height;
      }
    }
  });

  _.each(inputGraph.edges(), function(e) {
    var inputLabel = inputGraph.edge(e),
        layoutLabel = layoutGraph.edge(e);

    inputLabel.points = layoutLabel.points;
    if (_.has(layoutLabel, "x")) {
      inputLabel.x = layoutLabel.x;
      inputLabel.y = layoutLabel.y;
    }
  });

  inputGraph.graph().width = layoutGraph.graph().width;
  inputGraph.graph().height = layoutGraph.graph().height;
}

var graphNumAttrs = ["nodesep", "edgesep", "ranksep", "marginx", "marginy"],
    graphDefaults = { ranksep: 50, edgesep: 20, nodesep: 50, rankdir: "tb" },
    graphAttrs = ["acyclicer", "ranker", "rankdir", "align"],
    nodeNumAttrs = ["width", "height"],
    nodeDefaults = { width: 0, height: 0 },
    edgeNumAttrs = ["minlen", "weight", "width", "height", "labeloffset"],
    edgeDefaults = {
      minlen: 1, weight: 1, width: 0, height: 0,
      labeloffset: 10, labelpos: "r"
    },
    edgeAttrs = ["labelpos"];

/*
 * Constructs a new graph from the input graph, which can be used for layout.
 * This process copies only whitelisted attributes from the input graph to the
 * layout graph. Thus this function serves as a good place to determine what
 * attributes can influence layout.
 */
function buildLayoutGraph(inputGraph) {
  var g = new Graph({ multigraph: true, compound: true }),
      graph = canonicalize(inputGraph.graph());

  g.setGraph(_.merge({},
    graphDefaults,
    selectNumberAttrs(graph, graphNumAttrs),
    _.pick(graph, graphAttrs)));

  _.each(inputGraph.nodes(), function(v) {
    var node = canonicalize(inputGraph.node(v));
    g.setNode(v, _.defaults(selectNumberAttrs(node, nodeNumAttrs), nodeDefaults));
    g.setParent(v, inputGraph.parent(v));
  });

  _.each(inputGraph.edges(), function(e) {
    var edge = canonicalize(inputGraph.edge(e));
    g.setEdge(e, _.merge({},
      edgeDefaults,
      selectNumberAttrs(edge, edgeNumAttrs),
      _.pick(edge, edgeAttrs)));
  });

  return g;
}

/*
 * This idea comes from the Gansner paper: to account for edge labels in our
 * layout we split each rank in half by doubling minlen and halving ranksep.
 * Then we can place labels at these mid-points between nodes.
 *
 * We also add some minimal padding to the width to push the label for the edge
 * away from the edge itself a bit.
 */
function makeSpaceForEdgeLabels(g) {
  var graph = g.graph();
  graph.ranksep /= 2;
  _.each(g.edges(), function(e) {
    var edge = g.edge(e);
    edge.minlen *= 2;
    if (edge.labelpos.toLowerCase() !== "c") {
      if (graph.rankdir === "TB" || graph.rankdir === "BT") {
        edge.width += edge.labeloffset;
      } else {
        edge.height += edge.labeloffset;
      }
    }
  });
}

/*
 * Creates temporary dummy nodes that capture the rank in which each edge's
 * label is going to, if it has one of non-zero width and height. We do this
 * so that we can safely remove empty ranks while preserving balance for the
 * label's position.
 */
function injectEdgeLabelProxies(g) {
  _.each(g.edges(), function(e) {
    var edge = g.edge(e);
    if (edge.width && edge.height) {
      var v = g.node(e.v),
          w = g.node(e.w),
          label = { rank: (w.rank - v.rank) / 2 + v.rank, e: e };
      util.addDummyNode(g, "edge-proxy", label, "_ep");
    }
  });
}

function assignRankMinMax(g) {
  var maxRank = 0;
  _.each(g.nodes(), function(v) {
    var node = g.node(v);
    if (node.borderTop) {
      node.minRank = g.node(node.borderTop).rank;
      node.maxRank = g.node(node.borderBottom).rank;
      maxRank = _.max(maxRank, node.maxRank);
    }
  });
  g.graph().maxRank = maxRank;
}

function removeEdgeLabelProxies(g) {
  _.each(g.nodes(), function(v) {
    var node = g.node(v);
    if (node.dummy === "edge-proxy") {
      g.edge(node.e).labelRank = node.rank;
      g.removeNode(v);
    }
  });
}

function translateGraph(g) {
  var minX = Number.POSITIVE_INFINITY,
      maxX = 0,
      minY = Number.POSITIVE_INFINITY,
      maxY = 0,
      graphLabel = g.graph(),
      marginX = graphLabel.marginx || 0,
      marginY = graphLabel.marginy || 0;

  function getExtremes(attrs) {
    var x = attrs.x,
        y = attrs.y,
        w = attrs.width,
        h = attrs.height;
    minX = Math.min(minX, x - w / 2);
    maxX = Math.max(maxX, x + w / 2);
    minY = Math.min(minY, y - h / 2);
    maxY = Math.max(maxY, y + h / 2);
  }

  _.each(g.nodes(), function(v) { getExtremes(g.node(v)); });
  _.each(g.edges(), function(e) {
    var edge = g.edge(e);
    if (_.has(edge, "x")) {
      getExtremes(edge);
    }
  });

  minX -= marginX;
  minY -= marginY;

  _.each(g.nodes(), function(v) {
    var node = g.node(v);
    node.x -= minX;
    node.y -= minY;
  });

  _.each(g.edges(), function(e) {
    var edge = g.edge(e);
    _.each(edge.points, function(p) {
      p.x -= minX;
      p.y -= minY;
    });
    if (_.has(edge, "x")) { edge.x -= minX; }
    if (_.has(edge, "y")) { edge.y -= minY; }
  });

  graphLabel.width = maxX - minX + marginX;
  graphLabel.height = maxY - minY + marginY;
}

function assignNodeIntersects(g) {
  _.each(g.edges(), function(e) {
    var edge = g.edge(e),
        nodeV = g.node(e.v),
        nodeW = g.node(e.w),
        p1, p2;
    if (!edge.points) {
      edge.points = [];
      p1 = nodeW;
      p2 = nodeV;
    } else {
      p1 = edge.points[0];
      p2 = edge.points[edge.points.length - 1];
    }
    edge.points.unshift(util.intersectRect(nodeV, p1));
    edge.points.push(util.intersectRect(nodeW, p2));
  });
}

function fixupEdgeLabelCoords(g) {
  _.each(g.edges(), function(e) {
    var edge = g.edge(e);
    if (_.has(edge, "x")) {
      if (edge.labelpos === "l" || edge.labelpos === "r") {
        edge.width -= edge.labeloffset;
      }
      switch (edge.labelpos) {
        case "l": edge.x -= edge.width / 2 + edge.labeloffset; break;
        case "r": edge.x += edge.width / 2 + edge.labeloffset; break;
      }
    }
  });
}

function reversePointsForReversedEdges(g) {
  _.each(g.edges(), function(e) {
    var edge = g.edge(e);
    if (edge.reversed) {
      edge.points.reverse();
    }
  });
}

function removeBorderNodes(g) {
  _.each(g.nodes(), function(v) {
    if (g.children(v).length) {
      var node = g.node(v),
          t = g.node(node.borderTop),
          b = g.node(node.borderBottom),
          l = g.node(_.last(node.borderLeft)),
          r = g.node(_.last(node.borderRight));

      node.width = Math.abs(r.x - l.x);
      node.height = Math.abs(b.y - t.y);
      node.x = l.x + node.width / 2;
      node.y = t.y + node.height / 2;
    }
  });

  _.each(g.nodes(), function(v) {
    if (g.node(v).dummy === "border") {
      g.removeNode(v);
    }
  });
}

function removeSelfEdges(g) {
  _.each(g.edges(), function(e) {
    if (e.v === e.w) {
      var node = g.node(e.v);
      if (!node.selfEdges) {
        node.selfEdges = [];
      }
      node.selfEdges.push({ e: e, label: g.edge(e) });
      g.removeEdge(e);
    }
  });
}

function insertSelfEdges(g) {
  var layers = util.buildLayerMatrix(g);
  _.each(layers, function(layer) {
    var orderShift = 0;
    _.each(layer, function(v, i) {
      var node = g.node(v);
      node.order = i + orderShift;
      _.each(node.selfEdges, function(selfEdge) {
        util.addDummyNode(g, "selfedge", {
          width: selfEdge.label.width,
          height: selfEdge.label.height,
          rank: node.rank,
          order: i + (++orderShift),
          e: selfEdge.e,
          label: selfEdge.label
        }, "_se");
      });
      delete node.selfEdges;
    });
  });
}

function positionSelfEdges(g) {
  _.each(g.nodes(), function(v) {
    var node = g.node(v);
    if (node.dummy === "selfedge") {
      var selfNode = g.node(node.e.v),
          x = selfNode.x + selfNode.width / 2,
          y = selfNode.y,
          dx = node.x - x,
          dy = selfNode.height / 2;
      g.setEdge(node.e, node.label);
      g.removeNode(v);
      node.label.points = [
        { x: x + 2 * dx / 3, y: y - dy },
        { x: x + 5 * dx / 6, y: y - dy },
        { x: x +     dx    , y: y },
        { x: x + 5 * dx / 6, y: y + dy },
        { x: x + 2 * dx / 3, y: y + dy },
      ];
      node.label.x = node.x;
      node.label.y = node.y;
    }
  });
}

function selectNumberAttrs(obj, attrs) {
  return _.mapValues(_.pick(obj, attrs), Number);
}

function canonicalize(attrs) {
  var newAttrs = {};
  _.each(attrs, function(v, k) {
    newAttrs[k.toLowerCase()] = v;
  });
  return newAttrs;
}

},{"./acyclic":2,"./add-border-segments":3,"./coordinate-system":4,"./graphlib":7,"./lodash":10,"./nesting-graph":11,"./normalize":12,"./order":17,"./parent-dummy-chains":22,"./position":24,"./rank":26,"./util":29}],10:[function(require,module,exports){
/* global window */

var lodash;

if (typeof require === "function") {
  try {
    lodash = require("lodash");
  } catch (e) {}
}

if (!lodash) {
  lodash = window._;
}

module.exports = lodash;

},{"lodash":51}],11:[function(require,module,exports){
var _ = require("./lodash"),
    util = require("./util");

module.exports = {
  run: run,
  cleanup: cleanup
};

/*
 * A nesting graph creates dummy nodes for the tops and bottoms of subgraphs,
 * adds appropriate edges to ensure that all cluster nodes are placed between
 * these boundries, and ensures that the graph is connected.
 *
 * In addition we ensure, through the use of the minlen property, that nodes
 * and subgraph border nodes to not end up on the same rank.
 *
 * Preconditions:
 *
 *    1. Input graph is a DAG
 *    2. Nodes in the input graph has a minlen attribute
 *
 * Postconditions:
 *
 *    1. Input graph is connected.
 *    2. Dummy nodes are added for the tops and bottoms of subgraphs.
 *    3. The minlen attribute for nodes is adjusted to ensure nodes do not
 *       get placed on the same rank as subgraph border nodes.
 *
 * The nesting graph idea comes from Sander, "Layout of Compound Directed
 * Graphs."
 */
function run(g) {
  var root = util.addDummyNode(g, "root", {}, "_root"),
      depths = treeDepths(g),
      height = _.max(depths) - 1,
      nodeSep = 2 * height + 1;

  g.graph().nestingRoot = root;

  // Multiply minlen by nodeSep to align nodes on non-border ranks.
  _.each(g.edges(), function(e) { g.edge(e).minlen *= nodeSep; });

  // Calculate a weight that is sufficient to keep subgraphs vertically compact
  var weight = sumWeights(g) + 1;

  // Create border nodes and link them up
  _.each(g.children(), function(child) {
    dfs(g, root, nodeSep, weight, height, depths, child);
  });

  // Save the multiplier for node layers for later removal of empty border
  // layers.
  g.graph().nodeRankFactor = nodeSep;
}

function dfs(g, root, nodeSep, weight, height, depths, v) {
  var children = g.children(v);
  if (!children.length) {
    if (v !== root) {
      g.setEdge(root, v, { weight: 0, minlen: nodeSep });
    }
    return;
  }

  var top = util.addBorderNode(g, "_bt"),
      bottom = util.addBorderNode(g, "_bb"),
      label = g.node(v);

  g.setParent(top, v);
  label.borderTop = top;
  g.setParent(bottom, v);
  label.borderBottom = bottom;

  _.each(children, function(child) {
    dfs(g, root, nodeSep, weight, height, depths, child);

    var childNode = g.node(child),
        childTop = childNode.borderTop ? childNode.borderTop : child,
        childBottom = childNode.borderBottom ? childNode.borderBottom : child,
        thisWeight = childNode.borderTop ? weight : 2 * weight,
        minlen = childTop !== childBottom ? 1 : height - depths[v] + 1;

    g.setEdge(top, childTop, {
      weight: thisWeight,
      minlen: minlen,
      nestingEdge: true
    });

    g.setEdge(childBottom, bottom, {
      weight: thisWeight,
      minlen: minlen,
      nestingEdge: true
    });
  });

  if (!g.parent(v)) {
    g.setEdge(root, top, { weight: 0, minlen: height + depths[v] });
  }
}

function treeDepths(g) {
  var depths = {};
  function dfs(v, depth) {
    var children = g.children(v);
    if (children && children.length) {
      _.each(children, function(child) {
        dfs(child, depth + 1);
      });
    }
    depths[v] = depth;
  }
  _.each(g.children(), function(v) { dfs(v, 1); });
  return depths;
}

function sumWeights(g) {
  return _.reduce(g.edges(), function(acc, e) {
    return acc + g.edge(e).weight;
  }, 0);
}

function cleanup(g) {
  var graphLabel = g.graph();
  g.removeNode(graphLabel.nestingRoot);
  delete graphLabel.nestingRoot;
  _.each(g.edges(), function(e) {
    var edge = g.edge(e);
    if (edge.nestingEdge) {
      g.removeEdge(e);
    }
  });
}

},{"./lodash":10,"./util":29}],12:[function(require,module,exports){
"use strict";

var _ = require("./lodash"),
    util = require("./util");

module.exports = {
  run: run,
  undo: undo
};

/*
 * Breaks any long edges in the graph into short segments that span 1 layer
 * each. This operation is undoable with the denormalize function.
 *
 * Pre-conditions:
 *
 *    1. The input graph is a DAG.
 *    2. Each node in the graph has a "rank" property.
 *
 * Post-condition:
 *
 *    1. All edges in the graph have a length of 1.
 *    2. Dummy nodes are added where edges have been split into segments.
 *    3. The graph is augmented with a "dummyChains" attribute which contains
 *       the first dummy in each chain of dummy nodes produced.
 */
function run(g) {
  g.graph().dummyChains = [];
  _.each(g.edges(), function(edge) { normalizeEdge(g, edge); });
}

function normalizeEdge(g, e) {
  var v = e.v,
      vRank = g.node(v).rank,
      w = e.w,
      wRank = g.node(w).rank,
      name = e.name,
      edgeLabel = g.edge(e),
      labelRank = edgeLabel.labelRank;

  if (wRank === vRank + 1) return;

  g.removeEdge(e);

  var dummy, attrs, i;
  for (i = 0, ++vRank; vRank < wRank; ++i, ++vRank) {
    edgeLabel.points = [];
    attrs = {
      width: 0, height: 0,
      edgeLabel: edgeLabel, edgeObj: e,
      rank: vRank
    };
    dummy = util.addDummyNode(g, "edge", attrs, "_d");
    if (vRank === labelRank) {
      attrs.width = edgeLabel.width;
      attrs.height = edgeLabel.height;
      attrs.dummy = "edge-label";
      attrs.labelpos = edgeLabel.labelpos;
    }
    g.setEdge(v, dummy, { weight: edgeLabel.weight }, name);
    if (i === 0) {
      g.graph().dummyChains.push(dummy);
    }
    v = dummy;
  }

  g.setEdge(v, w, { weight: edgeLabel.weight }, name);
}

function undo(g) {
  _.each(g.graph().dummyChains, function(v) {
    var node = g.node(v),
        origLabel = node.edgeLabel,
        w;
    g.setEdge(node.edgeObj, origLabel);
    while (node.dummy) {
      w = g.successors(v)[0];
      g.removeNode(v);
      origLabel.points.push({ x: node.x, y: node.y });
      if (node.dummy === "edge-label") {
        origLabel.x = node.x;
        origLabel.y = node.y;
        origLabel.width = node.width;
        origLabel.height = node.height;
      }
      v = w;
      node = g.node(v);
    }
  });
}

},{"./lodash":10,"./util":29}],13:[function(require,module,exports){
var _ = require("../lodash");

module.exports = addSubgraphConstraints;

function addSubgraphConstraints(g, cg, vs) {
  var prev = {},
      rootPrev;

  _.each(vs, function(v) {
    var child = g.parent(v),
        parent,
        prevChild;
    while (child) {
      parent = g.parent(child);
      if (parent) {
        prevChild = prev[parent];
        prev[parent] = child;
      } else {
        prevChild = rootPrev;
        rootPrev = child;
      }
      if (prevChild && prevChild !== child) {
        cg.setEdge(prevChild, child);
        return;
      }
      child = parent;
    }
  });

  /*
  function dfs(v) {
    var children = v ? g.children(v) : g.children();
    if (children.length) {
      var min = Number.POSITIVE_INFINITY,
          subgraphs = [];
      _.each(children, function(child) {
        var childMin = dfs(child);
        if (g.children(child).length) {
          subgraphs.push({ v: child, order: childMin });
        }
        min = Math.min(min, childMin);
      });
      _.reduce(_.sortBy(subgraphs, "order"), function(prev, curr) {
        cg.setEdge(prev.v, curr.v);
        return curr;
      });
      return min;
    }
    return g.node(v).order;
  }
  dfs(undefined);
  */
}

},{"../lodash":10}],14:[function(require,module,exports){
var _ = require("../lodash");

module.exports = barycenter;

function barycenter(g, movable) {
  return _.map(movable, function(v) {
    var inV = g.inEdges(v);
    if (!inV.length) {
      return { v: v };
    } else {
      var result = _.reduce(inV, function(acc, e) {
        var edge = g.edge(e),
            nodeU = g.node(e.v);
        return {
          sum: acc.sum + (edge.weight * nodeU.order),
          weight: acc.weight + edge.weight
        };
      }, { sum: 0, weight: 0 });

      return {
        v: v,
        barycenter: result.sum / result.weight,
        weight: result.weight
      };
    }
  });
}


},{"../lodash":10}],15:[function(require,module,exports){
var _ = require("../lodash"),
    Graph = require("../graphlib").Graph;

module.exports = buildLayerGraph;

/*
 * Constructs a graph that can be used to sort a layer of nodes. The graph will
 * contain all base and subgraph nodes from the request layer in their original
 * hierarchy and any edges that are incident on these nodes and are of the type
 * requested by the "relationship" parameter.
 *
 * Nodes from the requested rank that do not have parents are assigned a root
 * node in the output graph, which is set in the root graph attribute. This
 * makes it easy to walk the hierarchy of movable nodes during ordering.
 *
 * Pre-conditions:
 *
 *    1. Input graph is a DAG
 *    2. Base nodes in the input graph have a rank attribute
 *    3. Subgraph nodes in the input graph has minRank and maxRank attributes
 *    4. Edges have an assigned weight
 *
 * Post-conditions:
 *
 *    1. Output graph has all nodes in the movable rank with preserved
 *       hierarchy.
 *    2. Root nodes in the movable layer are made children of the node
 *       indicated by the root attribute of the graph.
 *    3. Non-movable nodes incident on movable nodes, selected by the
 *       relationship parameter, are included in the graph (without hierarchy).
 *    4. Edges incident on movable nodes, selected by the relationship
 *       parameter, are added to the output graph.
 *    5. The weights for copied edges are aggregated as need, since the output
 *       graph is not a multi-graph.
 */
function buildLayerGraph(g, rank, relationship) {
  var root = createRootNode(g),
      result = new Graph({ compound: true }).setGraph({ root: root })
                  .setDefaultNodeLabel(function(v) { return g.node(v); });

  _.each(g.nodes(), function(v) {
    var node = g.node(v),
        parent = g.parent(v);

    if (node.rank === rank || node.minRank <= rank && rank <= node.maxRank) {
      result.setNode(v);
      result.setParent(v, parent || root);

      // This assumes we have only short edges!
      _.each(g[relationship](v), function(e) {
        var u = e.v === v ? e.w : e.v,
            edge = result.edge(u, v),
            weight = !_.isUndefined(edge) ? edge.weight : 0;
        result.setEdge(u, v, { weight: g.edge(e).weight + weight });
      });

      if (_.has(node, "minRank")) {
        result.setNode(v, {
          borderLeft: node.borderLeft[rank],
          borderRight: node.borderRight[rank]
        });
      }
    }
  });

  return result;
}

function createRootNode(g) {
  var v;
  while (g.hasNode((v = _.uniqueId("_root"))));
  return v;
}

},{"../graphlib":7,"../lodash":10}],16:[function(require,module,exports){
"use strict";

var _ = require("../lodash");

module.exports = crossCount;

/*
 * A function that takes a layering (an array of layers, each with an array of
 * ordererd nodes) and a graph and returns a weighted crossing count.
 *
 * Pre-conditions:
 *
 *    1. Input graph must be simple (not a multigraph), directed, and include
 *       only simple edges.
 *    2. Edges in the input graph must have assigned weights.
 *
 * Post-conditions:
 *
 *    1. The graph and layering matrix are left unchanged.
 *
 * This algorithm is derived from Barth, et al., "Bilayer Cross Counting."
 */
function crossCount(g, layering) {
  var cc = 0;
  for (var i = 1; i < layering.length; ++i) {
    cc += twoLayerCrossCount(g, layering[i-1], layering[i]);
  }
  return cc;
}

function twoLayerCrossCount(g, northLayer, southLayer) {
  // Sort all of the edges between the north and south layers by their position
  // in the north layer and then the south. Map these edges to the position of
  // their head in the south layer.
  var southPos = _.zipObject(southLayer,
                             _.map(southLayer, function (v, i) { return i; }));
  var southEntries = _.flatten(_.map(northLayer, function(v) {
    return _.chain(g.outEdges(v))
            .map(function(e) {
              return { pos: southPos[e.w], weight: g.edge(e).weight };
            })
            .sortBy("pos")
            .value();
  }), true);

  // Build the accumulator tree
  var firstIndex = 1;
  while (firstIndex < southLayer.length) firstIndex <<= 1;
  var treeSize = 2 * firstIndex - 1;
  firstIndex -= 1;
  var tree = _.map(new Array(treeSize), function() { return 0; });

  // Calculate the weighted crossings
  var cc = 0;
  _.each(southEntries.forEach(function(entry) {
    var index = entry.pos + firstIndex;
    tree[index] += entry.weight;
    var weightSum = 0;
    while (index > 0) {
      if (index % 2) {
        weightSum += tree[index + 1];
      }
      index = (index - 1) >> 1;
      tree[index] += entry.weight;
    }
    cc += entry.weight * weightSum;
  }));

  return cc;
}

},{"../lodash":10}],17:[function(require,module,exports){
"use strict";

var _ = require("../lodash"),
    initOrder = require("./init-order"),
    crossCount = require("./cross-count"),
    sortSubgraph = require("./sort-subgraph"),
    buildLayerGraph = require("./build-layer-graph"),
    addSubgraphConstraints = require("./add-subgraph-constraints"),
    Graph = require("../graphlib").Graph,
    util = require("../util");

module.exports = order;

/*
 * Applies heuristics to minimize edge crossings in the graph and sets the best
 * order solution as an order attribute on each node.
 *
 * Pre-conditions:
 *
 *    1. Graph must be DAG
 *    2. Graph nodes must be objects with a "rank" attribute
 *    3. Graph edges must have the "weight" attribute
 *
 * Post-conditions:
 *
 *    1. Graph nodes will have an "order" attribute based on the results of the
 *       algorithm.
 */
function order(g) {
  var maxRank = util.maxRank(g),
      downLayerGraphs = buildLayerGraphs(g, _.range(1, maxRank + 1), "inEdges"),
      upLayerGraphs = buildLayerGraphs(g, _.range(maxRank - 1, -1, -1), "outEdges");

  var layering = initOrder(g);
  assignOrder(g, layering);

  var bestCC = Number.POSITIVE_INFINITY,
      best;

  for (var i = 0, lastBest = 0; lastBest < 4; ++i, ++lastBest) {
    sweepLayerGraphs(i % 2 ? downLayerGraphs : upLayerGraphs, i % 4 >= 2);

    layering = util.buildLayerMatrix(g);
    var cc = crossCount(g, layering);
    if (cc < bestCC) {
      lastBest = 0;
      best = _.cloneDeep(layering);
      bestCC = cc;
    }
  }

  assignOrder(g, best);
}

function buildLayerGraphs(g, ranks, relationship) {
  return _.map(ranks, function(rank) {
    return buildLayerGraph(g, rank, relationship);
  });
}

function sweepLayerGraphs(layerGraphs, biasRight) {
  var cg = new Graph();
  _.each(layerGraphs, function(lg) {
    var root = lg.graph().root;
    var sorted = sortSubgraph(lg, root, cg, biasRight);
    _.each(sorted.vs, function(v, i) {
      lg.node(v).order = i;
    });
    addSubgraphConstraints(lg, cg, sorted.vs);
  });
}

function assignOrder(g, layering) {
  _.each(layering, function(layer) {
    _.each(layer, function(v, i) {
      g.node(v).order = i;
    });
  });
}

},{"../graphlib":7,"../lodash":10,"../util":29,"./add-subgraph-constraints":13,"./build-layer-graph":15,"./cross-count":16,"./init-order":18,"./sort-subgraph":20}],18:[function(require,module,exports){
"use strict";

var _ = require("../lodash");

module.exports = initOrder;

/*
 * Assigns an initial order value for each node by performing a DFS search
 * starting from nodes in the first rank. Nodes are assigned an order in their
 * rank as they are first visited.
 *
 * This approach comes from Gansner, et al., "A Technique for Drawing Directed
 * Graphs."
 *
 * Returns a layering matrix with an array per layer and each layer sorted by
 * the order of its nodes.
 */
function initOrder(g) {
  var visited = {},
      simpleNodes = _.filter(g.nodes(), function(v) {
        return !g.children(v).length;
      }),
      maxRank = _.max(_.map(simpleNodes, function(v) { return g.node(v).rank; })),
      layers = _.map(_.range(maxRank + 1), function() { return []; });

  function dfs(v) {
    if (_.has(visited, v)) return;
    visited[v] = true;
    var node = g.node(v);
    layers[node.rank].push(v);
    _.each(g.successors(v), dfs);
  }

  var orderedVs = _.sortBy(simpleNodes, function(v) { return g.node(v).rank; });
  _.each(orderedVs, dfs);

  return layers;
}

},{"../lodash":10}],19:[function(require,module,exports){
"use strict";

var _ = require("../lodash");

module.exports = resolveConflicts;

/*
 * Given a list of entries of the form {v, barycenter, weight} and a
 * constraint graph this function will resolve any conflicts between the
 * constraint graph and the barycenters for the entries. If the barycenters for
 * an entry would violate a constraint in the constraint graph then we coalesce
 * the nodes in the conflict into a new node that respects the contraint and
 * aggregates barycenter and weight information.
 *
 * This implementation is based on the description in Forster, "A Fast and
 * Simple Hueristic for Constrained Two-Level Crossing Reduction," thought it
 * differs in some specific details.
 *
 * Pre-conditions:
 *
 *    1. Each entry has the form {v, barycenter, weight}, or if the node has
 *       no barycenter, then {v}.
 *
 * Returns:
 *
 *    A new list of entries of the form {vs, i, barycenter, weight}. The list
 *    `vs` may either be a singleton or it may be an aggregation of nodes
 *    ordered such that they do not violate constraints from the constraint
 *    graph. The property `i` is the lowest original index of any of the
 *    elements in `vs`.
 */
function resolveConflicts(entries, cg) {
  var mappedEntries = {};
  _.each(entries, function(entry, i) {
    var tmp = mappedEntries[entry.v] = {
      indegree: 0,
      "in": [],
      out: [],
      vs: [entry.v],
      i: i
    };
    if (!_.isUndefined(entry.barycenter)) {
      tmp.barycenter = entry.barycenter;
      tmp.weight = entry.weight;
    }
  });

  _.each(cg.edges(), function(e) {
    var entryV = mappedEntries[e.v],
        entryW = mappedEntries[e.w];
    if (!_.isUndefined(entryV) && !_.isUndefined(entryW)) {
      entryW.indegree++;
      entryV.out.push(mappedEntries[e.w]);
    }
  });

  var sourceSet = _.filter(mappedEntries, function(entry) {
    return !entry.indegree;
  });

  return doResolveConflicts(sourceSet);
}

function doResolveConflicts(sourceSet) {
  var entries = [];

  function handleIn(vEntry) {
    return function(uEntry) {
      if (uEntry.merged) {
        return;
      }
      if (_.isUndefined(uEntry.barycenter) ||
          _.isUndefined(vEntry.barycenter) ||
          uEntry.barycenter >= vEntry.barycenter) {
        mergeEntries(vEntry, uEntry);
      }
    };
  }

  function handleOut(vEntry) {
    return function(wEntry) {
      wEntry["in"].push(vEntry);
      if (--wEntry.indegree === 0) {
        sourceSet.push(wEntry);
      }
    };
  }

  while (sourceSet.length) {
    var entry = sourceSet.pop();
    entries.push(entry);
    _.each(entry["in"].reverse(), handleIn(entry));
    _.each(entry.out, handleOut(entry));
  }

  return _.chain(entries)
          .filter(function(entry) { return !entry.merged; })
          .map(function(entry) {
            return _.pick(entry, ["vs", "i", "barycenter", "weight"]);
          })
          .value();
}

function mergeEntries(target, source) {
  var sum = 0,
      weight = 0;

  if (target.weight) {
    sum += target.barycenter * target.weight;
    weight += target.weight;
  }

  if (source.weight) {
    sum += source.barycenter * source.weight;
    weight += source.weight;
  }

  target.vs = source.vs.concat(target.vs);
  target.barycenter = sum / weight;
  target.weight = weight;
  target.i = Math.min(source.i, target.i);
  source.merged = true;
}

},{"../lodash":10}],20:[function(require,module,exports){
var _ = require("../lodash"),
    barycenter = require("./barycenter"),
    resolveConflicts = require("./resolve-conflicts"),
    sort = require("./sort");

module.exports = sortSubgraph;

function sortSubgraph(g, v, cg, biasRight) {
  var movable = g.children(v),
      node = g.node(v),
      bl = node ? node.borderLeft : undefined,
      br = node ? node.borderRight: undefined,
      subgraphs = {};

  if (bl) {
    movable = _.filter(movable, function(w) {
      return w !== bl && w !== br;
    });
  }

  var barycenters = barycenter(g, movable);
  _.each(barycenters, function(entry) {
    if (g.children(entry.v).length) {
      var subgraphResult = sortSubgraph(g, entry.v, cg, biasRight);
      subgraphs[entry.v] = subgraphResult;
      if (_.has(subgraphResult, "barycenter")) {
        mergeBarycenters(entry, subgraphResult);
      }
    }
  });

  var entries = resolveConflicts(barycenters, cg);
  expandSubgraphs(entries, subgraphs);

  var result = sort(entries, biasRight);

  if (bl) {
    result.vs = _.flatten([bl, result.vs, br], true);
    if (g.predecessors(bl).length) {
      var blPred = g.node(g.predecessors(bl)[0]),
          brPred = g.node(g.predecessors(br)[0]);
      if (!_.has(result, "barycenter")) {
        result.barycenter = 0;
        result.weight = 0;
      }
      result.barycenter = (result.barycenter * result.weight +
                           blPred.order + brPred.order) / (result.weight + 2);
      result.weight += 2;
    }
  }

  return result;
}

function expandSubgraphs(entries, subgraphs) {
  _.each(entries, function(entry) {
    entry.vs = _.flatten(entry.vs.map(function(v) {
      if (subgraphs[v]) {
        return subgraphs[v].vs;
      }
      return v;
    }), true);
  });
}

function mergeBarycenters(target, other) {
  if (!_.isUndefined(target.barycenter)) {
    target.barycenter = (target.barycenter * target.weight +
                         other.barycenter * other.weight) /
                        (target.weight + other.weight);
    target.weight += other.weight;
  } else {
    target.barycenter = other.barycenter;
    target.weight = other.weight;
  }
}

},{"../lodash":10,"./barycenter":14,"./resolve-conflicts":19,"./sort":21}],21:[function(require,module,exports){
var _ = require("../lodash"),
    util = require("../util");

module.exports = sort;

function sort(entries, biasRight) {
  var parts = util.partition(entries, function(entry) {
    return _.has(entry, "barycenter");
  });
  var sortable = parts.lhs,
      unsortable = _.sortBy(parts.rhs, function(entry) { return -entry.i; }),
      vs = [],
      sum = 0,
      weight = 0,
      vsIndex = 0;

  sortable.sort(compareWithBias(!!biasRight));

  vsIndex = consumeUnsortable(vs, unsortable, vsIndex);

  _.each(sortable, function (entry) {
    vsIndex += entry.vs.length;
    vs.push(entry.vs);
    sum += entry.barycenter * entry.weight;
    weight += entry.weight;
    vsIndex = consumeUnsortable(vs, unsortable, vsIndex);
  });

  var result = { vs: _.flatten(vs, true) };
  if (weight) {
    result.barycenter = sum / weight;
    result.weight = weight;
  }
  return result;
}

function consumeUnsortable(vs, unsortable, index) {
  var last;
  while (unsortable.length && (last = _.last(unsortable)).i <= index) {
    unsortable.pop();
    vs.push(last.vs);
    index++;
  }
  return index;
}

function compareWithBias(bias) {
  return function(entryV, entryW) {
    if (entryV.barycenter < entryW.barycenter) {
      return -1;
    } else if (entryV.barycenter > entryW.barycenter) {
      return 1;
    }

    return !bias ? entryV.i - entryW.i : entryW.i - entryV.i;
  };
}

},{"../lodash":10,"../util":29}],22:[function(require,module,exports){
var _ = require("./lodash");

module.exports = parentDummyChains;

function parentDummyChains(g) {
  var postorderNums = postorder(g);

  _.each(g.graph().dummyChains, function(v) {
    var node = g.node(v),
        edgeObj = node.edgeObj,
        pathData = findPath(g, postorderNums, edgeObj.v, edgeObj.w),
        path = pathData.path,
        lca = pathData.lca,
        pathIdx = 0,
        pathV = path[pathIdx],
        ascending = true;

    while (v !== edgeObj.w) {
      node = g.node(v);

      if (ascending) {
        while ((pathV = path[pathIdx]) !== lca &&
               g.node(pathV).maxRank < node.rank) {
          pathIdx++;
        }

        if (pathV === lca) {
          ascending = false;
        }
      }

      if (!ascending) {
        while (pathIdx < path.length - 1 &&
               g.node(pathV = path[pathIdx + 1]).minRank <= node.rank) {
          pathIdx++;
        }
        pathV = path[pathIdx];
      }

      g.setParent(v, pathV);
      v = g.successors(v)[0];
    }
  });
}

// Find a path from v to w through the lowest common ancestor (LCA). Return the
// full path and the LCA.
function findPath(g, postorderNums, v, w) {
  var vPath = [],
      wPath = [],
      low = Math.min(postorderNums[v].low, postorderNums[w].low),
      lim = Math.max(postorderNums[v].lim, postorderNums[w].lim),
      parent,
      lca;

  // Traverse up from v to find the LCA
  parent = v;
  do {
    parent = g.parent(parent);
    vPath.push(parent);
  } while (parent &&
           (postorderNums[parent].low > low || lim > postorderNums[parent].lim));
  lca = parent;

  // Traverse from w to LCA
  parent = w;
  while ((parent = g.parent(parent)) !== lca) {
    wPath.push(parent);
  }

  return { path: vPath.concat(wPath.reverse()), lca: lca };
}

function postorder(g) {
  var result = {},
      lim = 0;

  function dfs(v) {
    var low = lim;
    _.each(g.children(v), dfs);
    result[v] = { low: low, lim: lim++ };
  }
  _.each(g.children(), dfs);

  return result;
}

},{"./lodash":10}],23:[function(require,module,exports){
"use strict";

var _ = require("../lodash"),
    Graph = require("../graphlib").Graph,
    util = require("../util");

/*
 * This module provides coordinate assignment based on Brandes and Köpf, "Fast
 * and Simple Horizontal Coordinate Assignment."
 */

module.exports = {
  positionX: positionX,
  findType1Conflicts: findType1Conflicts,
  findType2Conflicts: findType2Conflicts,
  addConflict: addConflict,
  hasConflict: hasConflict,
  verticalAlignment: verticalAlignment,
  horizontalCompaction: horizontalCompaction,
  alignCoordinates: alignCoordinates,
  findSmallestWidthAlignment: findSmallestWidthAlignment,
  balance: balance
};

/*
 * Marks all edges in the graph with a type-1 conflict with the "type1Conflict"
 * property. A type-1 conflict is one where a non-inner segment crosses an
 * inner segment. An inner segment is an edge with both incident nodes marked
 * with the "dummy" property.
 *
 * This algorithm scans layer by layer, starting with the second, for type-1
 * conflicts between the current layer and the previous layer. For each layer
 * it scans the nodes from left to right until it reaches one that is incident
 * on an inner segment. It then scans predecessors to determine if they have
 * edges that cross that inner segment. At the end a final scan is done for all
 * nodes on the current rank to see if they cross the last visited inner
 * segment.
 *
 * This algorithm (safely) assumes that a dummy node will only be incident on a
 * single node in the layers being scanned.
 */
function findType1Conflicts(g, layering) {
  var conflicts = {};

  function visitLayer(prevLayer, layer) {
    var
      // last visited node in the previous layer that is incident on an inner
      // segment.
      k0 = 0,
      // Tracks the last node in this layer scanned for crossings with a type-1
      // segment.
      scanPos = 0,
      prevLayerLength = prevLayer.length,
      lastNode = _.last(layer);

    _.each(layer, function(v, i) {
      var w = findOtherInnerSegmentNode(g, v),
          k1 = w ? g.node(w).order : prevLayerLength;

      if (w || v === lastNode) {
        _.each(layer.slice(scanPos, i +1), function(scanNode) {
          _.each(g.predecessors(scanNode), function(u) {
            var uLabel = g.node(u),
                uPos = uLabel.order;
            if ((uPos < k0 || k1 < uPos) &&
                !(uLabel.dummy && g.node(scanNode).dummy)) {
              addConflict(conflicts, u, scanNode);
            }
          });
        });
        scanPos = i + 1;
        k0 = k1;
      }
    });

    return layer;
  }

  _.reduce(layering, visitLayer);
  return conflicts;
}

function findType2Conflicts(g, layering) {
  var conflicts = {};

  function scan(south, southPos, southEnd, prevNorthBorder, nextNorthBorder) {
    var v;
    _.each(_.range(southPos, southEnd), function(i) {
      v = south[i];
      if (g.node(v).dummy) {
        _.each(g.predecessors(v), function(u) {
          var uNode = g.node(u);
          if (uNode.dummy &&
              (uNode.order < prevNorthBorder || uNode.order > nextNorthBorder)) {
            addConflict(conflicts, u, v);
          }
        });
      }
    });
  }


  function visitLayer(north, south) {
    var prevNorthPos = -1,
        nextNorthPos,
        southPos = 0;

    _.each(south, function(v, southLookahead) {
      if (g.node(v).dummy === "border") {
        var predecessors = g.predecessors(v);
        if (predecessors.length) {
          nextNorthPos = g.node(predecessors[0]).order;
          scan(south, southPos, southLookahead, prevNorthPos, nextNorthPos);
          southPos = southLookahead;
          prevNorthPos = nextNorthPos;
        }
      }
      scan(south, southPos, south.length, nextNorthPos, north.length);
    });

    return south;
  }

  _.reduce(layering, visitLayer);
  return conflicts;
}

function findOtherInnerSegmentNode(g, v) {
  if (g.node(v).dummy) {
    return _.find(g.predecessors(v), function(u) {
      return g.node(u).dummy;
    });
  }
}

function addConflict(conflicts, v, w) {
  if (v > w) {
    var tmp = v;
    v = w;
    w = tmp;
  }

  var conflictsV = conflicts[v];
  if (!conflictsV) {
    conflicts[v] = conflictsV = {};
  }
  conflictsV[w] = true;
}

function hasConflict(conflicts, v, w) {
  if (v > w) {
    var tmp = v;
    v = w;
    w = tmp;
  }
  return _.has(conflicts[v], w);
}

/*
 * Try to align nodes into vertical "blocks" where possible. This algorithm
 * attempts to align a node with one of its median neighbors. If the edge
 * connecting a neighbor is a type-1 conflict then we ignore that possibility.
 * If a previous node has already formed a block with a node after the node
 * we're trying to form a block with, we also ignore that possibility - our
 * blocks would be split in that scenario.
 */
function verticalAlignment(g, layering, conflicts, neighborFn) {
  var root = {},
      align = {},
      pos = {};

  // We cache the position here based on the layering because the graph and
  // layering may be out of sync. The layering matrix is manipulated to
  // generate different extreme alignments.
  _.each(layering, function(layer) {
    _.each(layer, function(v, order) {
      root[v] = v;
      align[v] = v;
      pos[v] = order;
    });
  });

  _.each(layering, function(layer) {
    var prevIdx = -1;
    _.each(layer, function(v) {
      var ws = neighborFn(v);
      if (ws.length) {
        ws = _.sortBy(ws, function(w) { return pos[w]; });
        var mp = (ws.length - 1) / 2;
        for (var i = Math.floor(mp), il = Math.ceil(mp); i <= il; ++i) {
          var w = ws[i];
          if (align[v] === v &&
              prevIdx < pos[w] &&
              !hasConflict(conflicts, v, w)) {
            align[w] = v;
            align[v] = root[v] = root[w];
            prevIdx = pos[w];
          }
        }
      }
    });
  });

  return { root: root, align: align };
}

function horizontalCompaction(g, layering, root, align, reverseSep) {
  // This portion of the algorithm differs from BK due to a number of problems.
  // Instead of their algorithm we construct a new block graph and do two
  // sweeps. The first sweep places blocks with the smallest possible
  // coordinates. The second sweep removes unused space by moving blocks to the
  // greatest coordinates without violating separation.
  var xs = {},
      blockG = buildBlockGraph(g, layering, root, reverseSep);

  // First pass, assign smallest coordinates via DFS
  var visited = {};
  function pass1(v) {
    if (!_.has(visited, v)) {
      visited[v] = true;
      xs[v] = _.reduce(blockG.inEdges(v), function(max, e) {
        pass1(e.v);
        return Math.max(max, xs[e.v] + blockG.edge(e));
      }, 0);
    }
  }
  _.each(blockG.nodes(), pass1);

  var borderType = reverseSep ? "borderLeft" : "borderRight";
  function pass2(v) {
    if (visited[v] !== 2) {
      visited[v]++;
      var node = g.node(v);
      var min = _.reduce(blockG.outEdges(v), function(min, e) {
        pass2(e.w);
        return Math.min(min, xs[e.w] - blockG.edge(e));
      }, Number.POSITIVE_INFINITY);
      if (min !== Number.POSITIVE_INFINITY && node.borderType !== borderType) {
        xs[v] = Math.max(xs[v], min);
      }
    }
  }
  _.each(blockG.nodes(), pass2);

  // Assign x coordinates to all nodes
  _.each(align, function(v) {
    xs[v] = xs[root[v]];
  });

  return xs;
}


function buildBlockGraph(g, layering, root, reverseSep) {
  var blockGraph = new Graph(),
      graphLabel = g.graph(),
      sepFn = sep(graphLabel.nodesep, graphLabel.edgesep, reverseSep);

  _.each(layering, function(layer) {
    var u;
    _.each(layer, function(v) {
      var vRoot = root[v];
      blockGraph.setNode(vRoot);
      if (u) {
        var uRoot = root[u],
            prevMax = blockGraph.edge(uRoot, vRoot);
        blockGraph.setEdge(uRoot, vRoot, Math.max(sepFn(g, v, u), prevMax || 0));
      }
      u = v;
    });
  });

  return blockGraph;
}

/*
 * Returns the alignment that has the smallest width of the given alignments.
 */
function findSmallestWidthAlignment(g, xss) {
  return _.min(xss, function(xs) {
    var min = _.min(xs, function(x, v) { return x - width(g, v) / 2; }),
        max = _.max(xs, function(x, v) { return x + width(g, v) / 2; });
    return max - min;
  });
}

/*
 * Align the coordinates of each of the layout alignments such that
 * left-biased alignments have their minimum coordinate at the same point as
 * the minimum coordinate of the smallest width alignment and right-biased
 * alignments have their maximum coordinate at the same point as the maximum
 * coordinate of the smallest width alignment.
 */
function alignCoordinates(xss, alignTo) {
  var alignToMin = _.min(alignTo),
      alignToMax = _.max(alignTo);

  _.each(["u", "d"], function(vert) {
    _.each(["l", "r"], function(horiz) {
      var alignment = vert + horiz,
          xs = xss[alignment],
          delta;
      if (xs === alignTo) return;

      delta = horiz === "l" ? alignToMin - _.min(xs) : alignToMax - _.max(xs);

      if (delta) {
        xss[alignment] = _.mapValues(xs, function(x) { return x + delta; });
      }
    });
  });
}

function balance(xss, align) {
  return _.mapValues(xss.ul, function(ignore, v) {
    if (align) {
      return xss[align.toLowerCase()][v];
    } else {
      var xs = _.sortBy(_.pluck(xss, v));
      return (xs[1] + xs[2]) / 2;
    }
  });
}

function positionX(g) {
  var layering = util.buildLayerMatrix(g),
      conflicts = _.merge(findType1Conflicts(g, layering),
                          findType2Conflicts(g, layering));

  var xss = {},
      adjustedLayering;
  _.each(["u", "d"], function(vert) {
    adjustedLayering = vert === "u" ? layering : _.values(layering).reverse();
    _.each(["l", "r"], function(horiz) {
      if (horiz === "r") {
        adjustedLayering = _.map(adjustedLayering, function(inner) {
          return _.values(inner).reverse();
        });
      }

      var neighborFn = _.bind(vert === "u" ? g.predecessors : g.successors, g);
      var align = verticalAlignment(g, adjustedLayering, conflicts, neighborFn);
      var xs = horizontalCompaction(g, adjustedLayering,
                                    align.root, align.align,
                                    horiz === "r");
      if (horiz === "r") {
        xs = _.mapValues(xs, function(x) { return -x; });
      }
      xss[vert + horiz] = xs;
    });
  });

  var smallestWidth = findSmallestWidthAlignment(g, xss);
  alignCoordinates(xss, smallestWidth);
  return balance(xss, g.graph().align);
}

function sep(nodeSep, edgeSep, reverseSep) {
  return function(g, v, w) {
    var vLabel = g.node(v),
        wLabel = g.node(w),
        sum = 0,
        delta;

    sum += vLabel.width / 2;
    if (_.has(vLabel, "labelpos")) {
      switch (vLabel.labelpos.toLowerCase()) {
        case "l": delta = -vLabel.width / 2; break;
        case "r": delta = vLabel.width / 2; break;
      }
    }
    if (delta) {
      sum += reverseSep ? delta : -delta;
    }
    delta = 0;

    sum += (vLabel.dummy ? edgeSep : nodeSep) / 2;
    sum += (wLabel.dummy ? edgeSep : nodeSep) / 2;

    sum += wLabel.width / 2;
    if (_.has(wLabel, "labelpos")) {
      switch (wLabel.labelpos.toLowerCase()) {
        case "l": delta = wLabel.width / 2; break;
        case "r": delta = -wLabel.width / 2; break;
      }
    }
    if (delta) {
      sum += reverseSep ? delta : -delta;
    }
    delta = 0;

    return sum;
  };
}

function width(g, v) {
  return g.node(v).width;
}

},{"../graphlib":7,"../lodash":10,"../util":29}],24:[function(require,module,exports){
"use strict";

var _ = require("../lodash"),
    util = require("../util"),
    positionX = require("./bk").positionX;

module.exports = position;

function position(g) {
  g = util.asNonCompoundGraph(g);

  positionY(g);
  _.each(positionX(g), function(x, v) {
    g.node(v).x = x;
  });
}

function positionY(g) {
  var layering = util.buildLayerMatrix(g),
      rankSep = g.graph().ranksep,
      prevY = 0;
  _.each(layering, function(layer) {
    var maxHeight = _.max(_.map(layer, function(v) { return g.node(v).height; }));
    _.each(layer, function(v) {
      g.node(v).y = prevY + maxHeight / 2;
    });
    prevY += maxHeight + rankSep;
  });
}


},{"../lodash":10,"../util":29,"./bk":23}],25:[function(require,module,exports){
"use strict";

var _ = require("../lodash"),
    Graph = require("../graphlib").Graph,
    slack = require("./util").slack;

module.exports = feasibleTree;

/*
 * Constructs a spanning tree with tight edges and adjusted the input node's
 * ranks to achieve this. A tight edge is one that is has a length that matches
 * its "minlen" attribute.
 *
 * The basic structure for this function is derived from Gansner, et al., "A
 * Technique for Drawing Directed Graphs."
 *
 * Pre-conditions:
 *
 *    1. Graph must be a DAG.
 *    2. Graph must be connected.
 *    3. Graph must have at least one node.
 *    5. Graph nodes must have been previously assigned a "rank" property that
 *       respects the "minlen" property of incident edges.
 *    6. Graph edges must have a "minlen" property.
 *
 * Post-conditions:
 *
 *    - Graph nodes will have their rank adjusted to ensure that all edges are
 *      tight.
 *
 * Returns a tree (undirected graph) that is constructed using only "tight"
 * edges.
 */
function feasibleTree(g) {
  var t = new Graph({ directed: false });

  // Choose arbitrary node from which to start our tree
  var start = g.nodes()[0],
      size = g.nodeCount();
  t.setNode(start, {});

  var edge, delta;
  while (tightTree(t, g) < size) {
    edge = findMinSlackEdge(t, g);
    delta = t.hasNode(edge.v) ? slack(g, edge) : -slack(g, edge);
    shiftRanks(t, g, delta);
  }

  return t;
}

/*
 * Finds a maximal tree of tight edges and returns the number of nodes in the
 * tree.
 */
function tightTree(t, g) {
  function dfs(v) {
    _.each(g.nodeEdges(v), function(e) {
      var edgeV = e.v,
          w = (v === edgeV) ? e.w : edgeV;
      if (!t.hasNode(w) && !slack(g, e)) {
        t.setNode(w, {});
        t.setEdge(v, w, {});
        dfs(w);
      }
    });
  }

  _.each(t.nodes(), dfs);
  return t.nodeCount();
}

/*
 * Finds the edge with the smallest slack that is incident on tree and returns
 * it.
 */
function findMinSlackEdge(t, g) {
  return _.min(g.edges(), function(e) {
    if (t.hasNode(e.v) !== t.hasNode(e.w)) {
      return slack(g, e);
    }
  });
}

function shiftRanks(t, g, delta) {
  _.each(t.nodes(), function(v) {
    g.node(v).rank += delta;
  });
}

},{"../graphlib":7,"../lodash":10,"./util":28}],26:[function(require,module,exports){
"use strict";

var rankUtil = require("./util"),
    longestPath = rankUtil.longestPath,
    feasibleTree = require("./feasible-tree"),
    networkSimplex = require("./network-simplex");

module.exports = rank;

/*
 * Assigns a rank to each node in the input graph that respects the "minlen"
 * constraint specified on edges between nodes.
 *
 * This basic structure is derived from Gansner, et al., "A Technique for
 * Drawing Directed Graphs."
 *
 * Pre-conditions:
 *
 *    1. Graph must be a connected DAG
 *    2. Graph nodes must be objects
 *    3. Graph edges must have "weight" and "minlen" attributes
 *
 * Post-conditions:
 *
 *    1. Graph nodes will have a "rank" attribute based on the results of the
 *       algorithm. Ranks can start at any index (including negative), we'll
 *       fix them up later.
 */
function rank(g) {
  switch(g.graph().ranker) {
    case "network-simplex": networkSimplexRanker(g); break;
    case "tight-tree": tightTreeRanker(g); break;
    case "longest-path": longestPathRanker(g); break;
    default: networkSimplexRanker(g);
  }
}

// A fast and simple ranker, but results are far from optimal.
var longestPathRanker = longestPath;

function tightTreeRanker(g) {
  longestPath(g);
  feasibleTree(g);
}

function networkSimplexRanker(g) {
  networkSimplex(g);
}

},{"./feasible-tree":25,"./network-simplex":27,"./util":28}],27:[function(require,module,exports){
"use strict";

var _ = require("../lodash"),
    feasibleTree = require("./feasible-tree"),
    slack = require("./util").slack,
    initRank = require("./util").longestPath,
    preorder = require("../graphlib").alg.preorder,
    postorder = require("../graphlib").alg.postorder,
    simplify = require("../util").simplify;

module.exports = networkSimplex;

// Expose some internals for testing purposes
networkSimplex.initLowLimValues = initLowLimValues;
networkSimplex.initCutValues = initCutValues;
networkSimplex.calcCutValue = calcCutValue;
networkSimplex.leaveEdge = leaveEdge;
networkSimplex.enterEdge = enterEdge;
networkSimplex.exchangeEdges = exchangeEdges;

/*
 * The network simplex algorithm assigns ranks to each node in the input graph
 * and iteratively improves the ranking to reduce the length of edges.
 *
 * Preconditions:
 *
 *    1. The input graph must be a DAG.
 *    2. All nodes in the graph must have an object value.
 *    3. All edges in the graph must have "minlen" and "weight" attributes.
 *
 * Postconditions:
 *
 *    1. All nodes in the graph will have an assigned "rank" attribute that has
 *       been optimized by the network simplex algorithm. Ranks start at 0.
 *
 *
 * A rough sketch of the algorithm is as follows:
 *
 *    1. Assign initial ranks to each node. We use the longest path algorithm,
 *       which assigns ranks to the lowest position possible. In general this
 *       leads to very wide bottom ranks and unnecessarily long edges.
 *    2. Construct a feasible tight tree. A tight tree is one such that all
 *       edges in the tree have no slack (difference between length of edge
 *       and minlen for the edge). This by itself greatly improves the assigned
 *       rankings by shorting edges.
 *    3. Iteratively find edges that have negative cut values. Generally a
 *       negative cut value indicates that the edge could be removed and a new
 *       tree edge could be added to produce a more compact graph.
 *
 * Much of the algorithms here are derived from Gansner, et al., "A Technique
 * for Drawing Directed Graphs." The structure of the file roughly follows the
 * structure of the overall algorithm.
 */
function networkSimplex(g) {
  g = simplify(g);
  initRank(g);
  var t = feasibleTree(g);
  initLowLimValues(t);
  initCutValues(t, g);

  var e, f;
  while ((e = leaveEdge(t))) {
    f = enterEdge(t, g, e);
    exchangeEdges(t, g, e, f);
  }
}

/*
 * Initializes cut values for all edges in the tree.
 */
function initCutValues(t, g) {
  var vs = postorder(t, t.nodes());
  vs = vs.slice(0, vs.length - 1);
  _.each(vs, function(v) {
    assignCutValue(t, g, v);
  });
}

function assignCutValue(t, g, child) {
  var childLab = t.node(child),
      parent = childLab.parent;
  t.edge(child, parent).cutvalue = calcCutValue(t, g, child);
}

/*
 * Given the tight tree, its graph, and a child in the graph calculate and
 * return the cut value for the edge between the child and its parent.
 */
function calcCutValue(t, g, child) {
  var childLab = t.node(child),
      parent = childLab.parent,
      // True if the child is on the tail end of the edge in the directed graph
      childIsTail = true,
      // The graph's view of the tree edge we're inspecting
      graphEdge = g.edge(child, parent),
      // The accumulated cut value for the edge between this node and its parent
      cutValue = 0;

  if (!graphEdge) {
    childIsTail = false;
    graphEdge = g.edge(parent, child);
  }

  cutValue = graphEdge.weight;

  _.each(g.nodeEdges(child), function(e) {
    var isOutEdge = e.v === child,
        other = isOutEdge ? e.w : e.v;

    if (other !== parent) {
      var pointsToHead = isOutEdge === childIsTail,
          otherWeight = g.edge(e).weight;

      cutValue += pointsToHead ? otherWeight : -otherWeight;
      if (isTreeEdge(t, child, other)) {
        var otherCutValue = t.edge(child, other).cutvalue;
        cutValue += pointsToHead ? -otherCutValue : otherCutValue;
      }
    }
  });

  return cutValue;
}

function initLowLimValues(tree, root) {
  if (arguments.length < 2) {
    root = tree.nodes()[0];
  }
  dfsAssignLowLim(tree, {}, 1, root);
}

function dfsAssignLowLim(tree, visited, nextLim, v, parent) {
  var low = nextLim,
      label = tree.node(v);

  visited[v] = true;
  _.each(tree.neighbors(v), function(w) {
    if (!_.has(visited, w)) {
      nextLim = dfsAssignLowLim(tree, visited, nextLim, w, v);
    }
  });

  label.low = low;
  label.lim = nextLim++;
  if (parent) {
    label.parent = parent;
  } else {
    // TODO should be able to remove this when we incrementally update low lim
    delete label.parent;
  }

  return nextLim;
}

function leaveEdge(tree) {
  return _.find(tree.edges(), function(e) {
    return tree.edge(e).cutvalue < 0;
  });
}

function enterEdge(t, g, edge) {
  var v = edge.v,
      w = edge.w;

  // For the rest of this function we assume that v is the tail and w is the
  // head, so if we don't have this edge in the graph we should flip it to
  // match the correct orientation.
  if (!g.hasEdge(v, w)) {
    v = edge.w;
    w = edge.v;
  }

  var vLabel = t.node(v),
      wLabel = t.node(w),
      tailLabel = vLabel,
      flip = false;

  // If the root is in the tail of the edge then we need to flip the logic that
  // checks for the head and tail nodes in the candidates function below.
  if (vLabel.lim > wLabel.lim) {
    tailLabel = wLabel;
    flip = true;
  }

  var candidates = _.filter(g.edges(), function(edge) {
    return flip === isDescendant(t, t.node(edge.v), tailLabel) &&
           flip !== isDescendant(t, t.node(edge.w), tailLabel);
  });

  return _.min(candidates, function(edge) { return slack(g, edge); });
}

function exchangeEdges(t, g, e, f) {
  var v = e.v,
      w = e.w;
  t.removeEdge(v, w);
  t.setEdge(f.v, f.w, {});
  initLowLimValues(t);
  initCutValues(t, g);
  updateRanks(t, g);
}

function updateRanks(t, g) {
  var root = _.find(t.nodes(), function(v) { return !g.node(v).parent; }),
      vs = preorder(t, root);
  vs = vs.slice(1);
  _.each(vs, function(v) {
    var parent = t.node(v).parent,
        edge = g.edge(v, parent),
        flipped = false;

    if (!edge) {
      edge = g.edge(parent, v);
      flipped = true;
    }

    g.node(v).rank = g.node(parent).rank + (flipped ? edge.minlen : -edge.minlen);
  });
}

/*
 * Returns true if the edge is in the tree.
 */
function isTreeEdge(tree, u, v) {
  return tree.hasEdge(u, v);
}

/*
 * Returns true if the specified node is descendant of the root node per the
 * assigned low and lim attributes in the tree.
 */
function isDescendant(tree, vLabel, rootLabel) {
  return rootLabel.low <= vLabel.lim && vLabel.lim <= rootLabel.lim;
}

},{"../graphlib":7,"../lodash":10,"../util":29,"./feasible-tree":25,"./util":28}],28:[function(require,module,exports){
"use strict";

var _ = require("../lodash");

module.exports = {
  longestPath: longestPath,
  slack: slack
};

/*
 * Initializes ranks for the input graph using the longest path algorithm. This
 * algorithm scales well and is fast in practice, it yields rather poor
 * solutions. Nodes are pushed to the lowest layer possible, leaving the bottom
 * ranks wide and leaving edges longer than necessary. However, due to its
 * speed, this algorithm is good for getting an initial ranking that can be fed
 * into other algorithms.
 *
 * This algorithm does not normalize layers because it will be used by other
 * algorithms in most cases. If using this algorithm directly, be sure to
 * run normalize at the end.
 *
 * Pre-conditions:
 *
 *    1. Input graph is a DAG.
 *    2. Input graph node labels can be assigned properties.
 *
 * Post-conditions:
 *
 *    1. Each node will be assign an (unnormalized) "rank" property.
 */
function longestPath(g) {
  var visited = {};

  function dfs(v) {
    var label = g.node(v);
    if (_.has(visited, v)) {
      return label.rank;
    }
    visited[v] = true;

    var rank = _.min(_.map(g.outEdges(v), function(e) {
      return dfs(e.w) - g.edge(e).minlen;
    }));

    if (rank === Number.POSITIVE_INFINITY) {
      rank = 0;
    }

    return (label.rank = rank);
  }

  _.each(g.sources(), dfs);
}

/*
 * Returns the amount of slack for the given edge. The slack is defined as the
 * difference between the length of the edge and its minimum length.
 */
function slack(g, e) {
  return g.node(e.w).rank - g.node(e.v).rank - g.edge(e).minlen;
}

},{"../lodash":10}],29:[function(require,module,exports){
"use strict";

var _ = require("./lodash"),
    Graph = require("./graphlib").Graph;

module.exports = {
  addDummyNode: addDummyNode,
  simplify: simplify,
  asNonCompoundGraph: asNonCompoundGraph,
  successorWeights: successorWeights,
  predecessorWeights: predecessorWeights,
  intersectRect: intersectRect,
  buildLayerMatrix: buildLayerMatrix,
  normalizeRanks: normalizeRanks,
  removeEmptyRanks: removeEmptyRanks,
  addBorderNode: addBorderNode,
  maxRank: maxRank,
  partition: partition,
  time: time,
  notime: notime
};

/*
 * Adds a dummy node to the graph and return v.
 */
function addDummyNode(g, type, attrs, name) {
  var v;
  do {
    v = _.uniqueId(name);
  } while (g.hasNode(v));

  attrs.dummy = type;
  g.setNode(v, attrs);
  return v;
}

/*
 * Returns a new graph with only simple edges. Handles aggregation of data
 * associated with multi-edges.
 */
function simplify(g) {
  var simplified = new Graph().setGraph(g.graph());
  _.each(g.nodes(), function(v) { simplified.setNode(v, g.node(v)); });
  _.each(g.edges(), function(e) {
    var simpleLabel = simplified.edge(e.v, e.w) || { weight: 0, minlen: 1 },
        label = g.edge(e);
    simplified.setEdge(e.v, e.w, {
      weight: simpleLabel.weight + label.weight,
      minlen: Math.max(simpleLabel.minlen, label.minlen)
    });
  });
  return simplified;
}

function asNonCompoundGraph(g) {
  var simplified = new Graph({ multigraph: g.isMultigraph() }).setGraph(g.graph());
  _.each(g.nodes(), function(v) {
    if (!g.children(v).length) {
      simplified.setNode(v, g.node(v));
    }
  });
  _.each(g.edges(), function(e) {
    simplified.setEdge(e, g.edge(e));
  });
  return simplified;
}

function successorWeights(g) {
  var weightMap = _.map(g.nodes(), function(v) {
    var sucs = {};
    _.each(g.outEdges(v), function(e) {
      sucs[e.w] = (sucs[e.w] || 0) + g.edge(e).weight;
    });
    return sucs;
  });
  return _.zipObject(g.nodes(), weightMap);
}

function predecessorWeights(g) {
  var weightMap = _.map(g.nodes(), function(v) {
    var preds = {};
    _.each(g.inEdges(v), function(e) {
      preds[e.v] = (preds[e.v] || 0) + g.edge(e).weight;
    });
    return preds;
  });
  return _.zipObject(g.nodes(), weightMap);
}

/*
 * Finds where a line starting at point ({x, y}) would intersect a rectangle
 * ({x, y, width, height}) if it were pointing at the rectangle's center.
 */
function intersectRect(rect, point) {
  var x = rect.x;
  var y = rect.y;

  // Rectangle intersection algorithm from:
  // http://math.stackexchange.com/questions/108113/find-edge-between-two-boxes
  var dx = point.x - x;
  var dy = point.y - y;
  var w = rect.width / 2;
  var h = rect.height / 2;

  if (!dx && !dy) {
    throw new Error("Not possible to find intersection inside of the rectangle");
  }

  var sx, sy;
  if (Math.abs(dy) * w > Math.abs(dx) * h) {
    // Intersection is top or bottom of rect.
    if (dy < 0) {
      h = -h;
    }
    sx = h * dx / dy;
    sy = h;
  } else {
    // Intersection is left or right of rect.
    if (dx < 0) {
      w = -w;
    }
    sx = w;
    sy = w * dy / dx;
  }

  return { x: x + sx, y: y + sy };
}

/*
 * Given a DAG with each node assigned "rank" and "order" properties, this
 * function will produce a matrix with the ids of each node.
 */
function buildLayerMatrix(g) {
  var layering = _.map(_.range(maxRank(g) + 1), function() { return []; });
  _.each(g.nodes(), function(v) {
    var node = g.node(v),
        rank = node.rank;
    if (!_.isUndefined(rank)) {
      layering[rank][node.order] = v;
    }
  });
  return layering;
}

/*
 * Adjusts the ranks for all nodes in the graph such that all nodes v have
 * rank(v) >= 0 and at least one node w has rank(w) = 0.
 */
function normalizeRanks(g) {
  var min = _.min(_.map(g.nodes(), function(v) { return g.node(v).rank; }));
  _.each(g.nodes(), function(v) {
    var node = g.node(v);
    if (_.has(node, "rank")) {
      node.rank -= min;
    }
  });
}

function removeEmptyRanks(g) {
  // Ranks may not start at 0, so we need to offset them
  var offset = _.min(_.map(g.nodes(), function(v) { return g.node(v).rank; }));

  var layers = [];
  _.each(g.nodes(), function(v) {
    var rank = g.node(v).rank - offset;
    if (!layers[rank]) {
      layers[rank] = [];
    }
    layers[rank].push(v);
  });

  var delta = 0,
      nodeRankFactor = g.graph().nodeRankFactor;
  _.each(layers, function(vs, i) {
    if (_.isUndefined(vs) && i % nodeRankFactor !== 0) {
      --delta;
    } else if (delta) {
      _.each(vs, function(v) { g.node(v).rank += delta; });
    }
  });
}

function addBorderNode(g, prefix, rank, order) {
  var node = {
    width: 0,
    height: 0
  };
  if (arguments.length >= 4) {
    node.rank = rank;
    node.order = order;
  }
  return addDummyNode(g, "border", node, prefix);
}

function maxRank(g) {
  return _.max(_.map(g.nodes(), function(v) {
    var rank = g.node(v).rank;
    if (!_.isUndefined(rank)) {
      return rank;
    }
  }));
}

/*
 * Partition a collection into two groups: `lhs` and `rhs`. If the supplied
 * function returns true for an entry it goes into `lhs`. Otherwise it goes
 * into `rhs.
 */
function partition(collection, fn) {
  var result = { lhs: [], rhs: [] };
  _.each(collection, function(value) {
    if (fn(value)) {
      result.lhs.push(value);
    } else {
      result.rhs.push(value);
    }
  });
  return result;
}

/*
 * Returns a new function that wraps `fn` with a timer. The wrapper logs the
 * time it takes to execute the function.
 */
function time(name, fn) {
  var start = _.now();
  try {
    return fn();
  } finally {
    console.log(name + " time: " + (_.now() - start) + "ms");
  }
}

function notime(name, fn) {
  return fn();
}

},{"./graphlib":7,"./lodash":10}],30:[function(require,module,exports){
module.exports = "0.7.4";

},{}],31:[function(require,module,exports){
/**
 * Copyright (c) 2014, Chris Pettitt
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions are met:
 *
 * 1. Redistributions of source code must retain the above copyright notice, this
 * list of conditions and the following disclaimer.
 *
 * 2. Redistributions in binary form must reproduce the above copyright notice,
 * this list of conditions and the following disclaimer in the documentation
 * and/or other materials provided with the distribution.
 *
 * 3. Neither the name of the copyright holder nor the names of its contributors
 * may be used to endorse or promote products derived from this software without
 * specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND
 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
 * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
 * DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE
 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
 * SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
 * CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
 * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
 * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 */

var lib = require("./lib");

module.exports = {
  Graph: lib.Graph,
  json: require("./lib/json"),
  alg: require("./lib/alg"),
  version: lib.version
};

},{"./lib":47,"./lib/alg":38,"./lib/json":48}],32:[function(require,module,exports){
var _ = require("../lodash");

module.exports = components;

function components(g) {
  var visited = {},
      cmpts = [],
      cmpt;

  function dfs(v) {
    if (_.has(visited, v)) return;
    visited[v] = true;
    cmpt.push(v);
    _.each(g.successors(v), dfs);
    _.each(g.predecessors(v), dfs);
  }

  _.each(g.nodes(), function(v) {
    cmpt = [];
    dfs(v);
    if (cmpt.length) {
      cmpts.push(cmpt);
    }
  });

  return cmpts;
}

},{"../lodash":49}],33:[function(require,module,exports){
var _ = require("../lodash");

module.exports = dfs;

/*
 * A helper that preforms a pre- or post-order traversal on the input graph
 * and returns the nodes in the order they were visited. This algorithm treats
 * the input as undirected.
 *
 * Order must be one of "pre" or "post".
 */
function dfs(g, vs, order) {
  if (!_.isArray(vs)) {
    vs = [vs];
  }

  var acc = [],
      visited = {};
  _.each(vs, function(v) {
    if (!g.hasNode(v)) {
      throw new Error("Graph does not have node: " + v);
    }

    doDfs(g, v, order === "post", visited, acc);
  });
  return acc;
}

function doDfs(g, v, postorder, visited, acc) {
  if (!_.has(visited, v)) {
    visited[v] = true;

    if (!postorder) { acc.push(v); }
    _.each(g.neighbors(v), function(w) {
      doDfs(g, w, postorder, visited, acc);
    });
    if (postorder) { acc.push(v); }
  }
}

},{"../lodash":49}],34:[function(require,module,exports){
var dijkstra = require("./dijkstra"),
    _ = require("../lodash");

module.exports = dijkstraAll;

function dijkstraAll(g, weightFunc, edgeFunc) {
  return _.transform(g.nodes(), function(acc, v) {
    acc[v] = dijkstra(g, v, weightFunc, edgeFunc);
  }, {});
}

},{"../lodash":49,"./dijkstra":35}],35:[function(require,module,exports){
var _ = require("../lodash"),
    PriorityQueue = require("../data/priority-queue");

module.exports = dijkstra;

var DEFAULT_WEIGHT_FUNC = _.constant(1);

function dijkstra(g, source, weightFn, edgeFn) {
  return runDijkstra(g, String(source),
                     weightFn || DEFAULT_WEIGHT_FUNC,
                     edgeFn || function(v) { return g.outEdges(v); });
}

function runDijkstra(g, source, weightFn, edgeFn) {
  var results = {},
      pq = new PriorityQueue(),
      v, vEntry;

  var updateNeighbors = function(edge) {
    var w = edge.v !== v ? edge.v : edge.w,
        wEntry = results[w],
        weight = weightFn(edge),
        distance = vEntry.distance + weight;

    if (weight < 0) {
      throw new Error("dijkstra does not allow negative edge weights. " +
                      "Bad edge: " + edge + " Weight: " + weight);
    }

    if (distance < wEntry.distance) {
      wEntry.distance = distance;
      wEntry.predecessor = v;
      pq.decrease(w, distance);
    }
  };

  g.nodes().forEach(function(v) {
    var distance = v === source ? 0 : Number.POSITIVE_INFINITY;
    results[v] = { distance: distance };
    pq.add(v, distance);
  });

  while (pq.size() > 0) {
    v = pq.removeMin();
    vEntry = results[v];
    if (vEntry.distance === Number.POSITIVE_INFINITY) {
      break;
    }

    edgeFn(v).forEach(updateNeighbors);
  }

  return results;
}

},{"../data/priority-queue":45,"../lodash":49}],36:[function(require,module,exports){
var _ = require("../lodash"),
    tarjan = require("./tarjan");

module.exports = findCycles;

function findCycles(g) {
  return _.filter(tarjan(g), function(cmpt) {
    return cmpt.length > 1 || (cmpt.length === 1 && g.hasEdge(cmpt[0], cmpt[0]));
  });
}

},{"../lodash":49,"./tarjan":43}],37:[function(require,module,exports){
var _ = require("../lodash");

module.exports = floydWarshall;

var DEFAULT_WEIGHT_FUNC = _.constant(1);

function floydWarshall(g, weightFn, edgeFn) {
  return runFloydWarshall(g,
                          weightFn || DEFAULT_WEIGHT_FUNC,
                          edgeFn || function(v) { return g.outEdges(v); });
}

function runFloydWarshall(g, weightFn, edgeFn) {
  var results = {},
      nodes = g.nodes();

  nodes.forEach(function(v) {
    results[v] = {};
    results[v][v] = { distance: 0 };
    nodes.forEach(function(w) {
      if (v !== w) {
        results[v][w] = { distance: Number.POSITIVE_INFINITY };
      }
    });
    edgeFn(v).forEach(function(edge) {
      var w = edge.v === v ? edge.w : edge.v,
          d = weightFn(edge);
      results[v][w] = { distance: d, predecessor: v };
    });
  });

  nodes.forEach(function(k) {
    var rowK = results[k];
    nodes.forEach(function(i) {
      var rowI = results[i];
      nodes.forEach(function(j) {
        var ik = rowI[k];
        var kj = rowK[j];
        var ij = rowI[j];
        var altDistance = ik.distance + kj.distance;
        if (altDistance < ij.distance) {
          ij.distance = altDistance;
          ij.predecessor = kj.predecessor;
        }
      });
    });
  });

  return results;
}

},{"../lodash":49}],38:[function(require,module,exports){
module.exports = {
  components: require("./components"),
  dijkstra: require("./dijkstra"),
  dijkstraAll: require("./dijkstra-all"),
  findCycles: require("./find-cycles"),
  floydWarshall: require("./floyd-warshall"),
  isAcyclic: require("./is-acyclic"),
  postorder: require("./postorder"),
  preorder: require("./preorder"),
  prim: require("./prim"),
  tarjan: require("./tarjan"),
  topsort: require("./topsort")
};

},{"./components":32,"./dijkstra":35,"./dijkstra-all":34,"./find-cycles":36,"./floyd-warshall":37,"./is-acyclic":39,"./postorder":40,"./preorder":41,"./prim":42,"./tarjan":43,"./topsort":44}],39:[function(require,module,exports){
var topsort = require("./topsort");

module.exports = isAcyclic;

function isAcyclic(g) {
  try {
    topsort(g);
  } catch (e) {
    if (e instanceof topsort.CycleException) {
      return false;
    }
    throw e;
  }
  return true;
}

},{"./topsort":44}],40:[function(require,module,exports){
var dfs = require("./dfs");

module.exports = postorder;

function postorder(g, vs) {
  return dfs(g, vs, "post");
}

},{"./dfs":33}],41:[function(require,module,exports){
var dfs = require("./dfs");

module.exports = preorder;

function preorder(g, vs) {
  return dfs(g, vs, "pre");
}

},{"./dfs":33}],42:[function(require,module,exports){
var _ = require("../lodash"),
    Graph = require("../graph"),
    PriorityQueue = require("../data/priority-queue");

module.exports = prim;

function prim(g, weightFunc) {
  var result = new Graph(),
      parents = {},
      pq = new PriorityQueue(),
      v;

  function updateNeighbors(edge) {
    var w = edge.v === v ? edge.w : edge.v,
        pri = pq.priority(w);
    if (pri !== undefined) {
      var edgeWeight = weightFunc(edge);
      if (edgeWeight < pri) {
        parents[w] = v;
        pq.decrease(w, edgeWeight);
      }
    }
  }

  if (g.nodeCount() === 0) {
    return result;
  }

  _.each(g.nodes(), function(v) {
    pq.add(v, Number.POSITIVE_INFINITY);
    result.setNode(v);
  });

  // Start from an arbitrary node
  pq.decrease(g.nodes()[0], 0);

  var init = false;
  while (pq.size() > 0) {
    v = pq.removeMin();
    if (_.has(parents, v)) {
      result.setEdge(v, parents[v]);
    } else if (init) {
      throw new Error("Input graph is not connected: " + g);
    } else {
      init = true;
    }

    g.nodeEdges(v).forEach(updateNeighbors);
  }

  return result;
}

},{"../data/priority-queue":45,"../graph":46,"../lodash":49}],43:[function(require,module,exports){
var _ = require("../lodash");

module.exports = tarjan;

function tarjan(g) {
  var index = 0,
      stack = [],
      visited = {}, // node id -> { onStack, lowlink, index }
      results = [];

  function dfs(v) {
    var entry = visited[v] = {
      onStack: true,
      lowlink: index,
      index: index++
    };
    stack.push(v);

    g.successors(v).forEach(function(w) {
      if (!_.has(visited, w)) {
        dfs(w);
        entry.lowlink = Math.min(entry.lowlink, visited[w].lowlink);
      } else if (visited[w].onStack) {
        entry.lowlink = Math.min(entry.lowlink, visited[w].index);
      }
    });

    if (entry.lowlink === entry.index) {
      var cmpt = [],
          w;
      do {
        w = stack.pop();
        visited[w].onStack = false;
        cmpt.push(w);
      } while (v !== w);
      results.push(cmpt);
    }
  }

  g.nodes().forEach(function(v) {
    if (!_.has(visited, v)) {
      dfs(v);
    }
  });

  return results;
}

},{"../lodash":49}],44:[function(require,module,exports){
var _ = require("../lodash");

module.exports = topsort;
topsort.CycleException = CycleException;

function topsort(g) {
  var visited = {},
      stack = {},
      results = [];

  function visit(node) {
    if (_.has(stack, node)) {
      throw new CycleException();
    }

    if (!_.has(visited, node)) {
      stack[node] = true;
      visited[node] = true;
      _.each(g.predecessors(node), visit);
      delete stack[node];
      results.push(node);
    }
  }

  _.each(g.sinks(), visit);

  if (_.size(visited) !== g.nodeCount()) {
    throw new CycleException();
  }

  return results;
}

function CycleException() {}

},{"../lodash":49}],45:[function(require,module,exports){
var _ = require("../lodash");

module.exports = PriorityQueue;

/**
 * A min-priority queue data structure. This algorithm is derived from Cormen,
 * et al., "Introduction to Algorithms". The basic idea of a min-priority
 * queue is that you can efficiently (in O(1) time) get the smallest key in
 * the queue. Adding and removing elements takes O(log n) time. A key can
 * have its priority decreased in O(log n) time.
 */
function PriorityQueue() {
  this._arr = [];
  this._keyIndices = {};
}

/**
 * Returns the number of elements in the queue. Takes `O(1)` time.
 */
PriorityQueue.prototype.size = function() {
  return this._arr.length;
};

/**
 * Returns the keys that are in the queue. Takes `O(n)` time.
 */
PriorityQueue.prototype.keys = function() {
  return this._arr.map(function(x) { return x.key; });
};

/**
 * Returns `true` if **key** is in the queue and `false` if not.
 */
PriorityQueue.prototype.has = function(key) {
  return _.has(this._keyIndices, key);
};

/**
 * Returns the priority for **key**. If **key** is not present in the queue
 * then this function returns `undefined`. Takes `O(1)` time.
 *
 * @param {Object} key
 */
PriorityQueue.prototype.priority = function(key) {
  var index = this._keyIndices[key];
  if (index !== undefined) {
    return this._arr[index].priority;
  }
};

/**
 * Returns the key for the minimum element in this queue. If the queue is
 * empty this function throws an Error. Takes `O(1)` time.
 */
PriorityQueue.prototype.min = function() {
  if (this.size() === 0) {
    throw new Error("Queue underflow");
  }
  return this._arr[0].key;
};

/**
 * Inserts a new key into the priority queue. If the key already exists in
 * the queue this function returns `false`; otherwise it will return `true`.
 * Takes `O(n)` time.
 *
 * @param {Object} key the key to add
 * @param {Number} priority the initial priority for the key
 */
PriorityQueue.prototype.add = function(key, priority) {
  var keyIndices = this._keyIndices;
  key = String(key);
  if (!_.has(keyIndices, key)) {
    var arr = this._arr;
    var index = arr.length;
    keyIndices[key] = index;
    arr.push({key: key, priority: priority});
    this._decrease(index);
    return true;
  }
  return false;
};

/**
 * Removes and returns the smallest key in the queue. Takes `O(log n)` time.
 */
PriorityQueue.prototype.removeMin = function() {
  this._swap(0, this._arr.length - 1);
  var min = this._arr.pop();
  delete this._keyIndices[min.key];
  this._heapify(0);
  return min.key;
};

/**
 * Decreases the priority for **key** to **priority**. If the new priority is
 * greater than the previous priority, this function will throw an Error.
 *
 * @param {Object} key the key for which to raise priority
 * @param {Number} priority the new priority for the key
 */
PriorityQueue.prototype.decrease = function(key, priority) {
  var index = this._keyIndices[key];
  if (priority > this._arr[index].priority) {
    throw new Error("New priority is greater than current priority. " +
        "Key: " + key + " Old: " + this._arr[index].priority + " New: " + priority);
  }
  this._arr[index].priority = priority;
  this._decrease(index);
};

PriorityQueue.prototype._heapify = function(i) {
  var arr = this._arr;
  var l = 2 * i,
      r = l + 1,
      largest = i;
  if (l < arr.length) {
    largest = arr[l].priority < arr[largest].priority ? l : largest;
    if (r < arr.length) {
      largest = arr[r].priority < arr[largest].priority ? r : largest;
    }
    if (largest !== i) {
      this._swap(i, largest);
      this._heapify(largest);
    }
  }
};

PriorityQueue.prototype._decrease = function(index) {
  var arr = this._arr;
  var priority = arr[index].priority;
  var parent;
  while (index !== 0) {
    parent = index >> 1;
    if (arr[parent].priority < priority) {
      break;
    }
    this._swap(index, parent);
    index = parent;
  }
};

PriorityQueue.prototype._swap = function(i, j) {
  var arr = this._arr;
  var keyIndices = this._keyIndices;
  var origArrI = arr[i];
  var origArrJ = arr[j];
  arr[i] = origArrJ;
  arr[j] = origArrI;
  keyIndices[origArrJ.key] = i;
  keyIndices[origArrI.key] = j;
};

},{"../lodash":49}],46:[function(require,module,exports){
"use strict";

var _ = require("./lodash");

module.exports = Graph;

var DEFAULT_EDGE_NAME = "\x00",
    GRAPH_NODE = "\x00",
    EDGE_KEY_DELIM = "\x01";

// Implementation notes:
//
//  * Node id query functions should return string ids for the nodes
//  * Edge id query functions should return an "edgeObj", edge object, that is
//    composed of enough information to uniquely identify an edge: {v, w, name}.
//  * Internally we use an "edgeId", a stringified form of the edgeObj, to
//    reference edges. This is because we need a performant way to look these
//    edges up and, object properties, which have string keys, are the closest
//    we're going to get to a performant hashtable in JavaScript.

function Graph(opts) {
  this._isDirected = _.has(opts, "directed") ? opts.directed : true;
  this._isMultigraph = _.has(opts, "multigraph") ? opts.multigraph : false;
  this._isCompound = _.has(opts, "compound") ? opts.compound : false;

  // Label for the graph itself
  this._label = undefined;

  // Defaults to be set when creating a new node
  this._defaultNodeLabelFn = _.constant(undefined);

  // Defaults to be set when creating a new edge
  this._defaultEdgeLabelFn = _.constant(undefined);

  // v -> label
  this._nodes = {};

  if (this._isCompound) {
    // v -> parent
    this._parent = {};

    // v -> children
    this._children = {};
    this._children[GRAPH_NODE] = {};
  }

  // v -> edgeObj
  this._in = {};

  // u -> v -> Number
  this._preds = {};

  // v -> edgeObj
  this._out = {};

  // v -> w -> Number
  this._sucs = {};

  // e -> edgeObj
  this._edgeObjs = {};

  // e -> label
  this._edgeLabels = {};
}

/* Number of nodes in the graph. Should only be changed by the implementation. */
Graph.prototype._nodeCount = 0;

/* Number of edges in the graph. Should only be changed by the implementation. */
Graph.prototype._edgeCount = 0;


/* === Graph functions ========= */

Graph.prototype.isDirected = function() {
  return this._isDirected;
};

Graph.prototype.isMultigraph = function() {
  return this._isMultigraph;
};

Graph.prototype.isCompound = function() {
  return this._isCompound;
};

Graph.prototype.setGraph = function(label) {
  this._label = label;
  return this;
};

Graph.prototype.graph = function() {
  return this._label;
};


/* === Node functions ========== */

Graph.prototype.setDefaultNodeLabel = function(newDefault) {
  if (!_.isFunction(newDefault)) {
    newDefault = _.constant(newDefault);
  }
  this._defaultNodeLabelFn = newDefault;
  return this;
};

Graph.prototype.nodeCount = function() {
  return this._nodeCount;
};

Graph.prototype.nodes = function() {
  return _.keys(this._nodes);
};

Graph.prototype.sources = function() {
  return _.filter(this.nodes(), function(v) {
    return _.isEmpty(this._in[v]);
  }, this);
};

Graph.prototype.sinks = function() {
  return _.filter(this.nodes(), function(v) {
    return _.isEmpty(this._out[v]);
  }, this);
};

Graph.prototype.setNodes = function(vs, value) {
  var args = arguments;
  _.each(vs, function(v) {
    if (args.length > 1) {
      this.setNode(v, value);
    } else {
      this.setNode(v);
    }
  }, this);
  return this;
};

Graph.prototype.setNode = function(v, value) {
  if (_.has(this._nodes, v)) {
    if (arguments.length > 1) {
      this._nodes[v] = value;
    }
    return this;
  }

  this._nodes[v] = arguments.length > 1 ? value : this._defaultNodeLabelFn(v);
  if (this._isCompound) {
    this._parent[v] = GRAPH_NODE;
    this._children[v] = {};
    this._children[GRAPH_NODE][v] = true;
  }
  this._in[v] = {};
  this._preds[v] = {};
  this._out[v] = {};
  this._sucs[v] = {};
  ++this._nodeCount;
  return this;
};

Graph.prototype.node = function(v) {
  return this._nodes[v];
};

Graph.prototype.hasNode = function(v) {
  return _.has(this._nodes, v);
};

Graph.prototype.removeNode =  function(v) {
  var self = this;
  if (_.has(this._nodes, v)) {
    var removeEdge = function(e) { self.removeEdge(self._edgeObjs[e]); };
    delete this._nodes[v];
    if (this._isCompound) {
      this._removeFromParentsChildList(v);
      delete this._parent[v];
      _.each(this.children(v), function(child) {
        this.setParent(child);
      }, this);
      delete this._children[v];
    }
    _.each(_.keys(this._in[v]), removeEdge);
    delete this._in[v];
    delete this._preds[v];
    _.each(_.keys(this._out[v]), removeEdge);
    delete this._out[v];
    delete this._sucs[v];
    --this._nodeCount;
  }
  return this;
};

Graph.prototype.setParent = function(v, parent) {
  if (!this._isCompound) {
    throw new Error("Cannot set parent in a non-compound graph");
  }

  if (_.isUndefined(parent)) {
    parent = GRAPH_NODE;
  } else {
    // Coerce parent to string
    parent += "";
    for (var ancestor = parent;
         !_.isUndefined(ancestor);
         ancestor = this.parent(ancestor)) {
      if (ancestor === v) {
        throw new Error("Setting " + parent+ " as parent of " + v +
                        " would create create a cycle");
      }
    }

    this.setNode(parent);
  }

  this.setNode(v);
  this._removeFromParentsChildList(v);
  this._parent[v] = parent;
  this._children[parent][v] = true;
  return this;
};

Graph.prototype._removeFromParentsChildList = function(v) {
  delete this._children[this._parent[v]][v];
};

Graph.prototype.parent = function(v) {
  if (this._isCompound) {
    var parent = this._parent[v];
    if (parent !== GRAPH_NODE) {
      return parent;
    }
  }
};

Graph.prototype.children = function(v) {
  if (_.isUndefined(v)) {
    v = GRAPH_NODE;
  }

  if (this._isCompound) {
    var children = this._children[v];
    if (children) {
      return _.keys(children);
    }
  } else if (v === GRAPH_NODE) {
    return this.nodes();
  } else if (this.hasNode(v)) {
    return [];
  }
};

Graph.prototype.predecessors = function(v) {
  var predsV = this._preds[v];
  if (predsV) {
    return _.keys(predsV);
  }
};

Graph.prototype.successors = function(v) {
  var sucsV = this._sucs[v];
  if (sucsV) {
    return _.keys(sucsV);
  }
};

Graph.prototype.neighbors = function(v) {
  var preds = this.predecessors(v);
  if (preds) {
    return _.union(preds, this.successors(v));
  }
};

/* === Edge functions ========== */

Graph.prototype.setDefaultEdgeLabel = function(newDefault) {
  if (!_.isFunction(newDefault)) {
    newDefault = _.constant(newDefault);
  }
  this._defaultEdgeLabelFn = newDefault;
  return this;
};

Graph.prototype.edgeCount = function() {
  return this._edgeCount;
};

Graph.prototype.edges = function() {
  return _.values(this._edgeObjs);
};

Graph.prototype.setPath = function(vs, value) {
  var self = this,
      args = arguments;
  _.reduce(vs, function(v, w) {
    if (args.length > 1) {
      self.setEdge(v, w, value);
    } else {
      self.setEdge(v, w);
    }
    return w;
  });
  return this;
};

/*
 * setEdge(v, w, [value, [name]])
 * setEdge({ v, w, [name] }, [value])
 */
Graph.prototype.setEdge = function() {
  var v, w, name, value,
      valueSpecified = false;

  if (_.isPlainObject(arguments[0])) {
    v = arguments[0].v;
    w = arguments[0].w;
    name = arguments[0].name;
    if (arguments.length === 2) {
      value = arguments[1];
      valueSpecified = true;
    }
  } else {
    v = arguments[0];
    w = arguments[1];
    name = arguments[3];
    if (arguments.length > 2) {
      value = arguments[2];
      valueSpecified = true;
    }
  }

  v = "" + v;
  w = "" + w;
  if (!_.isUndefined(name)) {
    name = "" + name;
  }

  var e = edgeArgsToId(this._isDirected, v, w, name);
  if (_.has(this._edgeLabels, e)) {
    if (valueSpecified) {
      this._edgeLabels[e] = value;
    }
    return this;
  }

  if (!_.isUndefined(name) && !this._isMultigraph) {
    throw new Error("Cannot set a named edge when isMultigraph = false");
  }

  // It didn't exist, so we need to create it.
  // First ensure the nodes exist.
  this.setNode(v);
  this.setNode(w);

  this._edgeLabels[e] = valueSpecified ? value : this._defaultEdgeLabelFn(v, w, name);

  var edgeObj = edgeArgsToObj(this._isDirected, v, w, name);
  // Ensure we add undirected edges in a consistent way.
  v = edgeObj.v;
  w = edgeObj.w;

  Object.freeze(edgeObj);
  this._edgeObjs[e] = edgeObj;
  incrementOrInitEntry(this._preds[w], v);
  incrementOrInitEntry(this._sucs[v], w);
  this._in[w][e] = edgeObj;
  this._out[v][e] = edgeObj;
  this._edgeCount++;
  return this;
};

Graph.prototype.edge = function(v, w, name) {
  var e = (arguments.length === 1
            ? edgeObjToId(this._isDirected, arguments[0])
            : edgeArgsToId(this._isDirected, v, w, name));
  return this._edgeLabels[e];
};

Graph.prototype.hasEdge = function(v, w, name) {
  var e = (arguments.length === 1
            ? edgeObjToId(this._isDirected, arguments[0])
            : edgeArgsToId(this._isDirected, v, w, name));
  return _.has(this._edgeLabels, e);
};

Graph.prototype.removeEdge = function(v, w, name) {
  var e = (arguments.length === 1
            ? edgeObjToId(this._isDirected, arguments[0])
            : edgeArgsToId(this._isDirected, v, w, name)),
      edge = this._edgeObjs[e];
  if (edge) {
    v = edge.v;
    w = edge.w;
    delete this._edgeLabels[e];
    delete this._edgeObjs[e];
    decrementOrRemoveEntry(this._preds[w], v);
    decrementOrRemoveEntry(this._sucs[v], w);
    delete this._in[w][e];
    delete this._out[v][e];
    this._edgeCount--;
  }
  return this;
};

Graph.prototype.inEdges = function(v, u) {
  var inV = this._in[v];
  if (inV) {
    var edges = _.values(inV);
    if (!u) {
      return edges;
    }
    return _.filter(edges, function(edge) { return edge.v === u; });
  }
};

Graph.prototype.outEdges = function(v, w) {
  var outV = this._out[v];
  if (outV) {
    var edges = _.values(outV);
    if (!w) {
      return edges;
    }
    return _.filter(edges, function(edge) { return edge.w === w; });
  }
};

Graph.prototype.nodeEdges = function(v, w) {
  var inEdges = this.inEdges(v, w);
  if (inEdges) {
    return inEdges.concat(this.outEdges(v, w));
  }
};

function incrementOrInitEntry(map, k) {
  if (_.has(map, k)) {
    map[k]++;
  } else {
    map[k] = 1;
  }
}

function decrementOrRemoveEntry(map, k) {
  if (!--map[k]) { delete map[k]; }
}

function edgeArgsToId(isDirected, v, w, name) {
  if (!isDirected && v > w) {
    var tmp = v;
    v = w;
    w = tmp;
  }
  return v + EDGE_KEY_DELIM + w + EDGE_KEY_DELIM +
             (_.isUndefined(name) ? DEFAULT_EDGE_NAME : name);
}

function edgeArgsToObj(isDirected, v, w, name) {
  if (!isDirected && v > w) {
    var tmp = v;
    v = w;
    w = tmp;
  }
  var edgeObj =  { v: v, w: w };
  if (name) {
    edgeObj.name = name;
  }
  return edgeObj;
}

function edgeObjToId(isDirected, edgeObj) {
  return edgeArgsToId(isDirected, edgeObj.v, edgeObj.w, edgeObj.name);
}

},{"./lodash":49}],47:[function(require,module,exports){
// Includes only the "core" of graphlib
module.exports = {
  Graph: require("./graph"),
  version: require("./version")
};

},{"./graph":46,"./version":50}],48:[function(require,module,exports){
var _ = require("./lodash"),
    Graph = require("./graph");

module.exports = {
  write: write,
  read: read
};

function write(g) {
  var json = {
    options: {
      directed: g.isDirected(),
      multigraph: g.isMultigraph(),
      compound: g.isCompound()
    },
    nodes: writeNodes(g),
    edges: writeEdges(g)
  };
  if (!_.isUndefined(g.graph())) {
    json.value = _.clone(g.graph());
  }
  return json;
}

function writeNodes(g) {
  return _.map(g.nodes(), function(v) {
    var nodeValue = g.node(v),
        parent = g.parent(v),
        node = { v: v };
    if (!_.isUndefined(nodeValue)) {
      node.value = nodeValue;
    }
    if (!_.isUndefined(parent)) {
      node.parent = parent;
    }
    return node;
  });
}

function writeEdges(g) {
  return _.map(g.edges(), function(e) {
    var edgeValue = g.edge(e),
        edge = { v: e.v, w: e.w };
    if (!_.isUndefined(e.name)) {
      edge.name = e.name;
    }
    if (!_.isUndefined(edgeValue)) {
      edge.value = edgeValue;
    }
    return edge;
  });
}

function read(json) {
  var g = new Graph(json.options).setGraph(json.value);
  _.each(json.nodes, function(entry) {
    g.setNode(entry.v, entry.value);
    if (entry.parent) {
      g.setParent(entry.v, entry.parent);
    }
  });
  _.each(json.edges, function(entry) {
    g.setEdge({ v: entry.v, w: entry.w, name: entry.name }, entry.value);
  });
  return g;
}

},{"./graph":46,"./lodash":49}],49:[function(require,module,exports){
module.exports=require(10)
},{"/Users/cpettitt/projects/dagre/lib/lodash.js":10,"lodash":51}],50:[function(require,module,exports){
module.exports = '1.0.5';

},{}],51:[function(require,module,exports){
(function (global){
/**
 * @license
 * lodash 3.10.0 (Custom Build) 
 * Build: `lodash modern -d -o ./index.js`
 * Copyright 2012-2015 The Dojo Foundation 
 * Based on Underscore.js 1.8.3 
 * Copyright 2009-2015 Jeremy Ashkenas, DocumentCloud and Investigative Reporters & Editors
 * Available under MIT license 
 */
;(function() {

  /** Used as a safe reference for `undefined` in pre-ES5 environments. */
  var undefined;

  /** Used as the semantic version number. */
  var VERSION = '3.10.0';

  /** Used to compose bitmasks for wrapper metadata. */
  var BIND_FLAG = 1,
      BIND_KEY_FLAG = 2,
      CURRY_BOUND_FLAG = 4,
      CURRY_FLAG = 8,
      CURRY_RIGHT_FLAG = 16,
      PARTIAL_FLAG = 32,
      PARTIAL_RIGHT_FLAG = 64,
      ARY_FLAG = 128,
      REARG_FLAG = 256;

  /** Used as default options for `_.trunc`. */
  var DEFAULT_TRUNC_LENGTH = 30,
      DEFAULT_TRUNC_OMISSION = '...';

  /** Used to detect when a function becomes hot. */
  var HOT_COUNT = 150,
      HOT_SPAN = 16;

  /** Used as the size to enable large array optimizations. */
  var LARGE_ARRAY_SIZE = 200;

  /** Used to indicate the type of lazy iteratees. */
  var LAZY_FILTER_FLAG = 1,
      LAZY_MAP_FLAG = 2;

  /** Used as the `TypeError` message for "Functions" methods. */
  var FUNC_ERROR_TEXT = 'Expected a function';

  /** Used as the internal argument placeholder. */
  var PLACEHOLDER = '__lodash_placeholder__';

  /** `Object#toString` result references. */
  var argsTag = '[object Arguments]',
      arrayTag = '[object Array]',
      boolTag = '[object Boolean]',
      dateTag = '[object Date]',
      errorTag = '[object Error]',
      funcTag = '[object Function]',
      mapTag = '[object Map]',
      numberTag = '[object Number]',
      objectTag = '[object Object]',
      regexpTag = '[object RegExp]',
      setTag = '[object Set]',
      stringTag = '[object String]',
      weakMapTag = '[object WeakMap]';

  var arrayBufferTag = '[object ArrayBuffer]',
      float32Tag = '[object Float32Array]',
      float64Tag = '[object Float64Array]',
      int8Tag = '[object Int8Array]',
      int16Tag = '[object Int16Array]',
      int32Tag = '[object Int32Array]',
      uint8Tag = '[object Uint8Array]',
      uint8ClampedTag = '[object Uint8ClampedArray]',
      uint16Tag = '[object Uint16Array]',
      uint32Tag = '[object Uint32Array]';

  /** Used to match empty string literals in compiled template source. */
  var reEmptyStringLeading = /\b__p \+= '';/g,
      reEmptyStringMiddle = /\b(__p \+=) '' \+/g,
      reEmptyStringTrailing = /(__e\(.*?\)|\b__t\)) \+\n'';/g;

  /** Used to match HTML entities and HTML characters. */
  var reEscapedHtml = /&(?:amp|lt|gt|quot|#39|#96);/g,
      reUnescapedHtml = /[&<>"'`]/g,
      reHasEscapedHtml = RegExp(reEscapedHtml.source),
      reHasUnescapedHtml = RegExp(reUnescapedHtml.source);

  /** Used to match template delimiters. */
  var reEscape = /<%-([\s\S]+?)%>/g,
      reEvaluate = /<%([\s\S]+?)%>/g,
      reInterpolate = /<%=([\s\S]+?)%>/g;

  /** Used to match property names within property paths. */
  var reIsDeepProp = /\.|\[(?:[^[\]]*|(["'])(?:(?!\1)[^\n\\]|\\.)*?\1)\]/,
      reIsPlainProp = /^\w*$/,
      rePropName = /[^.[\]]+|\[(?:(-?\d+(?:\.\d+)?)|(["'])((?:(?!\2)[^\n\\]|\\.)*?)\2)\]/g;

  /**
   * Used to match `RegExp` [syntax characters](http://ecma-international.org/ecma-262/6.0/#sec-patterns)
   * and those outlined by [`EscapeRegExpPattern`](http://ecma-international.org/ecma-262/6.0/#sec-escaperegexppattern).
   */
  var reRegExpChars = /^[:!,]|[\\^$.*+?()[\]{}|\/]|(^[0-9a-fA-Fnrtuvx])|([\n\r\u2028\u2029])/g,
      reHasRegExpChars = RegExp(reRegExpChars.source);

  /** Used to match [combining diacritical marks](https://en.wikipedia.org/wiki/Combining_Diacritical_Marks). */
  var reComboMark = /[\u0300-\u036f\ufe20-\ufe23]/g;

  /** Used to match backslashes in property paths. */
  var reEscapeChar = /\\(\\)?/g;

  /** Used to match [ES template delimiters](http://ecma-international.org/ecma-262/6.0/#sec-template-literal-lexical-components). */
  var reEsTemplate = /\$\{([^\\}]*(?:\\.[^\\}]*)*)\}/g;

  /** Used to match `RegExp` flags from their coerced string values. */
  var reFlags = /\w*$/;

  /** Used to detect hexadecimal string values. */
  var reHasHexPrefix = /^0[xX]/;

  /** Used to detect host constructors (Safari > 5). */
  var reIsHostCtor = /^\[object .+?Constructor\]$/;

  /** Used to detect unsigned integer values. */
  var reIsUint = /^\d+$/;

  /** Used to match latin-1 supplementary letters (excluding mathematical operators). */
  var reLatin1 = /[\xc0-\xd6\xd8-\xde\xdf-\xf6\xf8-\xff]/g;

  /** Used to ensure capturing order of template delimiters. */
  var reNoMatch = /($^)/;

  /** Used to match unescaped characters in compiled string literals. */
  var reUnescapedString = /['\n\r\u2028\u2029\\]/g;

  /** Used to match words to create compound words. */
  var reWords = (function() {
    var upper = '[A-Z\\xc0-\\xd6\\xd8-\\xde]',
        lower = '[a-z\\xdf-\\xf6\\xf8-\\xff]+';

    return RegExp(upper + '+(?=' + upper + lower + ')|' + upper + '?' + lower + '|' + upper + '+|[0-9]+', 'g');
  }());

  /** Used to assign default `context` object properties. */
  var contextProps = [
    'Array', 'ArrayBuffer', 'Date', 'Error', 'Float32Array', 'Float64Array',
    'Function', 'Int8Array', 'Int16Array', 'Int32Array', 'Math', 'Number',
    'Object', 'RegExp', 'Set', 'String', '_', 'clearTimeout', 'isFinite',
    'parseFloat', 'parseInt', 'setTimeout', 'TypeError', 'Uint8Array',
    'Uint8ClampedArray', 'Uint16Array', 'Uint32Array', 'WeakMap'
  ];

  /** Used to make template sourceURLs easier to identify. */
  var templateCounter = -1;

  /** Used to identify `toStringTag` values of typed arrays. */
  var typedArrayTags = {};
  typedArrayTags[float32Tag] = typedArrayTags[float64Tag] =
  typedArrayTags[int8Tag] = typedArrayTags[int16Tag] =
  typedArrayTags[int32Tag] = typedArrayTags[uint8Tag] =
  typedArrayTags[uint8ClampedTag] = typedArrayTags[uint16Tag] =
  typedArrayTags[uint32Tag] = true;
  typedArrayTags[argsTag] = typedArrayTags[arrayTag] =
  typedArrayTags[arrayBufferTag] = typedArrayTags[boolTag] =
  typedArrayTags[dateTag] = typedArrayTags[errorTag] =
  typedArrayTags[funcTag] = typedArrayTags[mapTag] =
  typedArrayTags[numberTag] = typedArrayTags[objectTag] =
  typedArrayTags[regexpTag] = typedArrayTags[setTag] =
  typedArrayTags[stringTag] = typedArrayTags[weakMapTag] = false;

  /** Used to identify `toStringTag` values supported by `_.clone`. */
  var cloneableTags = {};
  cloneableTags[argsTag] = cloneableTags[arrayTag] =
  cloneableTags[arrayBufferTag] = cloneableTags[boolTag] =
  cloneableTags[dateTag] = cloneableTags[float32Tag] =
  cloneableTags[float64Tag] = cloneableTags[int8Tag] =
  cloneableTags[int16Tag] = cloneableTags[int32Tag] =
  cloneableTags[numberTag] = cloneableTags[objectTag] =
  cloneableTags[regexpTag] = cloneableTags[stringTag] =
  cloneableTags[uint8Tag] = cloneableTags[uint8ClampedTag] =
  cloneableTags[uint16Tag] = cloneableTags[uint32Tag] = true;
  cloneableTags[errorTag] = cloneableTags[funcTag] =
  cloneableTags[mapTag] = cloneableTags[setTag] =
  cloneableTags[weakMapTag] = false;

  /** Used to map latin-1 supplementary letters to basic latin letters. */
  var deburredLetters = {
    '\xc0': 'A',  '\xc1': 'A', '\xc2': 'A', '\xc3': 'A', '\xc4': 'A', '\xc5': 'A',
    '\xe0': 'a',  '\xe1': 'a', '\xe2': 'a', '\xe3': 'a', '\xe4': 'a', '\xe5': 'a',
    '\xc7': 'C',  '\xe7': 'c',
    '\xd0': 'D',  '\xf0': 'd',
    '\xc8': 'E',  '\xc9': 'E', '\xca': 'E', '\xcb': 'E',
    '\xe8': 'e',  '\xe9': 'e', '\xea': 'e', '\xeb': 'e',
    '\xcC': 'I',  '\xcd': 'I', '\xce': 'I', '\xcf': 'I',
    '\xeC': 'i',  '\xed': 'i', '\xee': 'i', '\xef': 'i',
    '\xd1': 'N',  '\xf1': 'n',
    '\xd2': 'O',  '\xd3': 'O', '\xd4': 'O', '\xd5': 'O', '\xd6': 'O', '\xd8': 'O',
    '\xf2': 'o',  '\xf3': 'o', '\xf4': 'o', '\xf5': 'o', '\xf6': 'o', '\xf8': 'o',
    '\xd9': 'U',  '\xda': 'U', '\xdb': 'U', '\xdc': 'U',
    '\xf9': 'u',  '\xfa': 'u', '\xfb': 'u', '\xfc': 'u',
    '\xdd': 'Y',  '\xfd': 'y', '\xff': 'y',
    '\xc6': 'Ae', '\xe6': 'ae',
    '\xde': 'Th', '\xfe': 'th',
    '\xdf': 'ss'
  };

  /** Used to map characters to HTML entities. */
  var htmlEscapes = {
    '&': '&',
    '<': '<',
    '>': '>',
    '"': '"',
    "'": ''',
    '`': '`'
  };

  /** Used to map HTML entities to characters. */
  var htmlUnescapes = {
    '&': '&',
    '<': '<',
    '>': '>',
    '"': '"',
    ''': "'",
    '`': '`'
  };

  /** Used to determine if values are of the language type `Object`. */
  var objectTypes = {
    'function': true,
    'object': true
  };

  /** Used to escape characters for inclusion in compiled regexes. */
  var regexpEscapes = {
    '0': 'x30', '1': 'x31', '2': 'x32', '3': 'x33', '4': 'x34',
    '5': 'x35', '6': 'x36', '7': 'x37', '8': 'x38', '9': 'x39',
    'A': 'x41', 'B': 'x42', 'C': 'x43', 'D': 'x44', 'E': 'x45', 'F': 'x46',
    'a': 'x61', 'b': 'x62', 'c': 'x63', 'd': 'x64', 'e': 'x65', 'f': 'x66',
    'n': 'x6e', 'r': 'x72', 't': 'x74', 'u': 'x75', 'v': 'x76', 'x': 'x78'
  };

  /** Used to escape characters for inclusion in compiled string literals. */
  var stringEscapes = {
    '\\': '\\',
    "'": "'",
    '\n': 'n',
    '\r': 'r',
    '\u2028': 'u2028',
    '\u2029': 'u2029'
  };

  /** Detect free variable `exports`. */
  var freeExports = objectTypes[typeof exports] && exports && !exports.nodeType && exports;

  /** Detect free variable `module`. */
  var freeModule = objectTypes[typeof module] && module && !module.nodeType && module;

  /** Detect free variable `global` from Node.js. */
  var freeGlobal = freeExports && freeModule && typeof global == 'object' && global && global.Object && global;

  /** Detect free variable `self`. */
  var freeSelf = objectTypes[typeof self] && self && self.Object && self;

  /** Detect free variable `window`. */
  var freeWindow = objectTypes[typeof window] && window && window.Object && window;

  /** Detect the popular CommonJS extension `module.exports`. */
  var moduleExports = freeModule && freeModule.exports === freeExports && freeExports;

  /**
   * Used as a reference to the global object.
   *
   * The `this` value is used if it's the global object to avoid Greasemonkey's
   * restricted `window` object, otherwise the `window` object is used.
   */
  var root = freeGlobal || ((freeWindow !== (this && this.window)) && freeWindow) || freeSelf || this;

  /*--------------------------------------------------------------------------*/

  /**
   * The base implementation of `compareAscending` which compares values and
   * sorts them in ascending order without guaranteeing a stable sort.
   *
   * @private
   * @param {*} value The value to compare.
   * @param {*} other The other value to compare.
   * @returns {number} Returns the sort order indicator for `value`.
   */
  function baseCompareAscending(value, other) {
    if (value !== other) {
      var valIsNull = value === null,
          valIsUndef = value === undefined,
          valIsReflexive = value === value;

      var othIsNull = other === null,
          othIsUndef = other === undefined,
          othIsReflexive = other === other;

      if ((value > other && !othIsNull) || !valIsReflexive ||
          (valIsNull && !othIsUndef && othIsReflexive) ||
          (valIsUndef && othIsReflexive)) {
        return 1;
      }
      if ((value < other && !valIsNull) || !othIsReflexive ||
          (othIsNull && !valIsUndef && valIsReflexive) ||
          (othIsUndef && valIsReflexive)) {
        return -1;
      }
    }
    return 0;
  }

  /**
   * The base implementation of `_.findIndex` and `_.findLastIndex` without
   * support for callback shorthands and `this` binding.
   *
   * @private
   * @param {Array} array The array to search.
   * @param {Function} predicate The function invoked per iteration.
   * @param {boolean} [fromRight] Specify iterating from right to left.
   * @returns {number} Returns the index of the matched value, else `-1`.
   */
  function baseFindIndex(array, predicate, fromRight) {
    var length = array.length,
        index = fromRight ? length : -1;

    while ((fromRight ? index-- : ++index < length)) {
      if (predicate(array[index], index, array)) {
        return index;
      }
    }
    return -1;
  }

  /**
   * The base implementation of `_.indexOf` without support for binary searches.
   *
   * @private
   * @param {Array} array The array to search.
   * @param {*} value The value to search for.
   * @param {number} fromIndex The index to search from.
   * @returns {number} Returns the index of the matched value, else `-1`.
   */
  function baseIndexOf(array, value, fromIndex) {
    if (value !== value) {
      return indexOfNaN(array, fromIndex);
    }
    var index = fromIndex - 1,
        length = array.length;

    while (++index < length) {
      if (array[index] === value) {
        return index;
      }
    }
    return -1;
  }

  /**
   * The base implementation of `_.isFunction` without support for environments
   * with incorrect `typeof` results.
   *
   * @private
   * @param {*} value The value to check.
   * @returns {boolean} Returns `true` if `value` is correctly classified, else `false`.
   */
  function baseIsFunction(value) {
    // Avoid a Chakra JIT bug in compatibility modes of IE 11.
    // See https://github.com/jashkenas/underscore/issues/1621 for more details.
    return typeof value == 'function' || false;
  }

  /**
   * Converts `value` to a string if it's not one. An empty string is returned
   * for `null` or `undefined` values.
   *
   * @private
   * @param {*} value The value to process.
   * @returns {string} Returns the string.
   */
  function baseToString(value) {
    return value == null ? '' : (value + '');
  }

  /**
   * Used by `_.trim` and `_.trimLeft` to get the index of the first character
   * of `string` that is not found in `chars`.
   *
   * @private
   * @param {string} string The string to inspect.
   * @param {string} chars The characters to find.
   * @returns {number} Returns the index of the first character not found in `chars`.
   */
  function charsLeftIndex(string, chars) {
    var index = -1,
        length = string.length;

    while (++index < length && chars.indexOf(string.charAt(index)) > -1) {}
    return index;
  }

  /**
   * Used by `_.trim` and `_.trimRight` to get the index of the last character
   * of `string` that is not found in `chars`.
   *
   * @private
   * @param {string} string The string to inspect.
   * @param {string} chars The characters to find.
   * @returns {number} Returns the index of the last character not found in `chars`.
   */
  function charsRightIndex(string, chars) {
    var index = string.length;

    while (index-- && chars.indexOf(string.charAt(index)) > -1) {}
    return index;
  }

  /**
   * Used by `_.sortBy` to compare transformed elements of a collection and stable
   * sort them in ascending order.
   *
   * @private
   * @param {Object} object The object to compare.
   * @param {Object} other The other object to compare.
   * @returns {number} Returns the sort order indicator for `object`.
   */
  function compareAscending(object, other) {
    return baseCompareAscending(object.criteria, other.criteria) || (object.index - other.index);
  }

  /**
   * Used by `_.sortByOrder` to compare multiple properties of a value to another
   * and stable sort them.
   *
   * If `orders` is unspecified, all valuess are sorted in ascending order. Otherwise,
   * a value is sorted in ascending order if its corresponding order is "asc", and
   * descending if "desc".
   *
   * @private
   * @param {Object} object The object to compare.
   * @param {Object} other The other object to compare.
   * @param {boolean[]} orders The order to sort by for each property.
   * @returns {number} Returns the sort order indicator for `object`.
   */
  function compareMultiple(object, other, orders) {
    var index = -1,
        objCriteria = object.criteria,
        othCriteria = other.criteria,
        length = objCriteria.length,
        ordersLength = orders.length;

    while (++index < length) {
      var result = baseCompareAscending(objCriteria[index], othCriteria[index]);
      if (result) {
        if (index >= ordersLength) {
          return result;
        }
        var order = orders[index];
        return result * ((order === 'asc' || order === true) ? 1 : -1);
      }
    }
    // Fixes an `Array#sort` bug in the JS engine embedded in Adobe applications
    // that causes it, under certain circumstances, to provide the same value for
    // `object` and `other`. See https://github.com/jashkenas/underscore/pull/1247
    // for more details.
    //
    // This also ensures a stable sort in V8 and other engines.
    // See https://code.google.com/p/v8/issues/detail?id=90 for more details.
    return object.index - other.index;
  }

  /**
   * Used by `_.deburr` to convert latin-1 supplementary letters to basic latin letters.
   *
   * @private
   * @param {string} letter The matched letter to deburr.
   * @returns {string} Returns the deburred letter.
   */
  function deburrLetter(letter) {
    return deburredLetters[letter];
  }

  /**
   * Used by `_.escape` to convert characters to HTML entities.
   *
   * @private
   * @param {string} chr The matched character to escape.
   * @returns {string} Returns the escaped character.
   */
  function escapeHtmlChar(chr) {
    return htmlEscapes[chr];
  }

  /**
   * Used by `_.escapeRegExp` to escape characters for inclusion in compiled regexes.
   *
   * @private
   * @param {string} chr The matched character to escape.
   * @param {string} leadingChar The capture group for a leading character.
   * @param {string} whitespaceChar The capture group for a whitespace character.
   * @returns {string} Returns the escaped character.
   */
  function escapeRegExpChar(chr, leadingChar, whitespaceChar) {
    if (leadingChar) {
      chr = regexpEscapes[chr];
    } else if (whitespaceChar) {
      chr = stringEscapes[chr];
    }
    return '\\' + chr;
  }

  /**
   * Used by `_.template` to escape characters for inclusion in compiled string literals.
   *
   * @private
   * @param {string} chr The matched character to escape.
   * @returns {string} Returns the escaped character.
   */
  function escapeStringChar(chr) {
    return '\\' + stringEscapes[chr];
  }

  /**
   * Gets the index at which the first occurrence of `NaN` is found in `array`.
   *
   * @private
   * @param {Array} array The array to search.
   * @param {number} fromIndex The index to search from.
   * @param {boolean} [fromRight] Specify iterating from right to left.
   * @returns {number} Returns the index of the matched `NaN`, else `-1`.
   */
  function indexOfNaN(array, fromIndex, fromRight) {
    var length = array.length,
        index = fromIndex + (fromRight ? 0 : -1);

    while ((fromRight ? index-- : ++index < length)) {
      var other = array[index];
      if (other !== other) {
        return index;
      }
    }
    return -1;
  }

  /**
   * Checks if `value` is object-like.
   *
   * @private
   * @param {*} value The value to check.
   * @returns {boolean} Returns `true` if `value` is object-like, else `false`.
   */
  function isObjectLike(value) {
    return !!value && typeof value == 'object';
  }

  /**
   * Used by `trimmedLeftIndex` and `trimmedRightIndex` to determine if a
   * character code is whitespace.
   *
   * @private
   * @param {number} charCode The character code to inspect.
   * @returns {boolean} Returns `true` if `charCode` is whitespace, else `false`.
   */
  function isSpace(charCode) {
    return ((charCode <= 160 && (charCode >= 9 && charCode <= 13) || charCode == 32 || charCode == 160) || charCode == 5760 || charCode == 6158 ||
      (charCode >= 8192 && (charCode <= 8202 || charCode == 8232 || charCode == 8233 || charCode == 8239 || charCode == 8287 || charCode == 12288 || charCode == 65279)));
  }

  /**
   * Replaces all `placeholder` elements in `array` with an internal placeholder
   * and returns an array of their indexes.
   *
   * @private
   * @param {Array} array The array to modify.
   * @param {*} placeholder The placeholder to replace.
   * @returns {Array} Returns the new array of placeholder indexes.
   */
  function replaceHolders(array, placeholder) {
    var index = -1,
        length = array.length,
        resIndex = -1,
        result = [];

    while (++index < length) {
      if (array[index] === placeholder) {
        array[index] = PLACEHOLDER;
        result[++resIndex] = index;
      }
    }
    return result;
  }

  /**
   * An implementation of `_.uniq` optimized for sorted arrays without support
   * for callback shorthands and `this` binding.
   *
   * @private
   * @param {Array} array The array to inspect.
   * @param {Function} [iteratee] The function invoked per iteration.
   * @returns {Array} Returns the new duplicate-value-free array.
   */
  function sortedUniq(array, iteratee) {
    var seen,
        index = -1,
        length = array.length,
        resIndex = -1,
        result = [];

    while (++index < length) {
      var value = array[index],
          computed = iteratee ? iteratee(value, index, array) : value;

      if (!index || seen !== computed) {
        seen = computed;
        result[++resIndex] = value;
      }
    }
    return result;
  }

  /**
   * Used by `_.trim` and `_.trimLeft` to get the index of the first non-whitespace
   * character of `string`.
   *
   * @private
   * @param {string} string The string to inspect.
   * @returns {number} Returns the index of the first non-whitespace character.
   */
  function trimmedLeftIndex(string) {
    var index = -1,
        length = string.length;

    while (++index < length && isSpace(string.charCodeAt(index))) {}
    return index;
  }

  /**
   * Used by `_.trim` and `_.trimRight` to get the index of the last non-whitespace
   * character of `string`.
   *
   * @private
   * @param {string} string The string to inspect.
   * @returns {number} Returns the index of the last non-whitespace character.
   */
  function trimmedRightIndex(string) {
    var index = string.length;

    while (index-- && isSpace(string.charCodeAt(index))) {}
    return index;
  }

  /**
   * Used by `_.unescape` to convert HTML entities to characters.
   *
   * @private
   * @param {string} chr The matched character to unescape.
   * @returns {string} Returns the unescaped character.
   */
  function unescapeHtmlChar(chr) {
    return htmlUnescapes[chr];
  }

  /*--------------------------------------------------------------------------*/

  /**
   * Create a new pristine `lodash` function using the given `context` object.
   *
   * @static
   * @memberOf _
   * @category Utility
   * @param {Object} [context=root] The context object.
   * @returns {Function} Returns a new `lodash` function.
   * @example
   *
   * _.mixin({ 'foo': _.constant('foo') });
   *
   * var lodash = _.runInContext();
   * lodash.mixin({ 'bar': lodash.constant('bar') });
   *
   * _.isFunction(_.foo);
   * // => true
   * _.isFunction(_.bar);
   * // => false
   *
   * lodash.isFunction(lodash.foo);
   * // => false
   * lodash.isFunction(lodash.bar);
   * // => true
   *
   * // using `context` to mock `Date#getTime` use in `_.now`
   * var mock = _.runInContext({
   *   'Date': function() {
   *     return { 'getTime': getTimeMock };
   *   }
   * });
   *
   * // or creating a suped-up `defer` in Node.js
   * var defer = _.runInContext({ 'setTimeout': setImmediate }).defer;
   */
  function runInContext(context) {
    // Avoid issues with some ES3 environments that attempt to use values, named
    // after built-in constructors like `Object`, for the creation of literals.
    // ES5 clears this up by stating that literals must use built-in constructors.
    // See https://es5.github.io/#x11.1.5 for more details.
    context = context ? _.defaults(root.Object(), context, _.pick(root, contextProps)) : root;

    /** Native constructor references. */
    var Array = context.Array,
        Date = context.Date,
        Error = context.Error,
        Function = context.Function,
        Math = context.Math,
        Number = context.Number,
        Object = context.Object,
        RegExp = context.RegExp,
        String = context.String,
        TypeError = context.TypeError;

    /** Used for native method references. */
    var arrayProto = Array.prototype,
        objectProto = Object.prototype,
        stringProto = String.prototype;

    /** Used to resolve the decompiled source of functions. */
    var fnToString = Function.prototype.toString;

    /** Used to check objects for own properties. */
    var hasOwnProperty = objectProto.hasOwnProperty;

    /** Used to generate unique IDs. */
    var idCounter = 0;

    /**
     * Used to resolve the [`toStringTag`](http://ecma-international.org/ecma-262/6.0/#sec-object.prototype.tostring)
     * of values.
     */
    var objToString = objectProto.toString;

    /** Used to restore the original `_` reference in `_.noConflict`. */
    var oldDash = root._;

    /** Used to detect if a method is native. */
    var reIsNative = RegExp('^' +
      fnToString.call(hasOwnProperty).replace(/[\\^$.*+?()[\]{}|]/g, '\\$&')
      .replace(/hasOwnProperty|(function).*?(?=\\\()| for .+?(?=\\\])/g, '$1.*?') + '$'
    );

    /** Native method references. */
    var ArrayBuffer = context.ArrayBuffer,
        clearTimeout = context.clearTimeout,
        parseFloat = context.parseFloat,
        pow = Math.pow,
        propertyIsEnumerable = objectProto.propertyIsEnumerable,
        Set = getNative(context, 'Set'),
        setTimeout = context.setTimeout,
        splice = arrayProto.splice,
        Uint8Array = context.Uint8Array,
        WeakMap = getNative(context, 'WeakMap');

    /* Native method references for those with the same name as other `lodash` methods. */
    var nativeCeil = Math.ceil,
        nativeCreate = getNative(Object, 'create'),
        nativeFloor = Math.floor,
        nativeIsArray = getNative(Array, 'isArray'),
        nativeIsFinite = context.isFinite,
        nativeKeys = getNative(Object, 'keys'),
        nativeMax = Math.max,
        nativeMin = Math.min,
        nativeNow = getNative(Date, 'now'),
        nativeParseInt = context.parseInt,
        nativeRandom = Math.random;

    /** Used as references for `-Infinity` and `Infinity`. */
    var NEGATIVE_INFINITY = Number.NEGATIVE_INFINITY,
        POSITIVE_INFINITY = Number.POSITIVE_INFINITY;

    /** Used as references for the maximum length and index of an array. */
    var MAX_ARRAY_LENGTH = 4294967295,
        MAX_ARRAY_INDEX = MAX_ARRAY_LENGTH - 1,
        HALF_MAX_ARRAY_LENGTH = MAX_ARRAY_LENGTH >>> 1;

    /**
     * Used as the [maximum length](http://ecma-international.org/ecma-262/6.0/#sec-number.max_safe_integer)
     * of an array-like value.
     */
    var MAX_SAFE_INTEGER = 9007199254740991;

    /** Used to store function metadata. */
    var metaMap = WeakMap && new WeakMap;

    /** Used to lookup unminified function names. */
    var realNames = {};

    /*------------------------------------------------------------------------*/

    /**
     * Creates a `lodash` object which wraps `value` to enable implicit chaining.
     * Methods that operate on and return arrays, collections, and functions can
     * be chained together. Methods that retrieve a single value or may return a
     * primitive value will automatically end the chain returning the unwrapped
     * value. Explicit chaining may be enabled using `_.chain`. The execution of
     * chained methods is lazy, that is, execution is deferred until `_#value`
     * is implicitly or explicitly called.
     *
     * Lazy evaluation allows several methods to support shortcut fusion. Shortcut
     * fusion is an optimization strategy which merge iteratee calls; this can help
     * to avoid the creation of intermediate data structures and greatly reduce the
     * number of iteratee executions.
     *
     * Chaining is supported in custom builds as long as the `_#value` method is
     * directly or indirectly included in the build.
     *
     * In addition to lodash methods, wrappers have `Array` and `String` methods.
     *
     * The wrapper `Array` methods are:
     * `concat`, `join`, `pop`, `push`, `reverse`, `shift`, `slice`, `sort`,
     * `splice`, and `unshift`
     *
     * The wrapper `String` methods are:
     * `replace` and `split`
     *
     * The wrapper methods that support shortcut fusion are:
     * `compact`, `drop`, `dropRight`, `dropRightWhile`, `dropWhile`, `filter`,
     * `first`, `initial`, `last`, `map`, `pluck`, `reject`, `rest`, `reverse`,
     * `slice`, `take`, `takeRight`, `takeRightWhile`, `takeWhile`, `toArray`,
     * and `where`
     *
     * The chainable wrapper methods are:
     * `after`, `ary`, `assign`, `at`, `before`, `bind`, `bindAll`, `bindKey`,
     * `callback`, `chain`, `chunk`, `commit`, `compact`, `concat`, `constant`,
     * `countBy`, `create`, `curry`, `debounce`, `defaults`, `defaultsDeep`,
     * `defer`, `delay`, `difference`, `drop`, `dropRight`, `dropRightWhile`,
     * `dropWhile`, `fill`, `filter`, `flatten`, `flattenDeep`, `flow`, `flowRight`,
     * `forEach`, `forEachRight`, `forIn`, `forInRight`, `forOwn`, `forOwnRight`,
     * `functions`, `groupBy`, `indexBy`, `initial`, `intersection`, `invert`,
     * `invoke`, `keys`, `keysIn`, `map`, `mapKeys`, `mapValues`, `matches`,
     * `matchesProperty`, `memoize`, `merge`, `method`, `methodOf`, `mixin`,
     * `modArgs`, `negate`, `omit`, `once`, `pairs`, `partial`, `partialRight`,
     * `partition`, `pick`, `plant`, `pluck`, `property`, `propertyOf`, `pull`,
     * `pullAt`, `push`, `range`, `rearg`, `reject`, `remove`, `rest`, `restParam`,
     * `reverse`, `set`, `shuffle`, `slice`, `sort`, `sortBy`, `sortByAll`,
     * `sortByOrder`, `splice`, `spread`, `take`, `takeRight`, `takeRightWhile`,
     * `takeWhile`, `tap`, `throttle`, `thru`, `times`, `toArray`, `toPlainObject`,
     * `transform`, `union`, `uniq`, `unshift`, `unzip`, `unzipWith`, `values`,
     * `valuesIn`, `where`, `without`, `wrap`, `xor`, `zip`, `zipObject`, `zipWith`
     *
     * The wrapper methods that are **not** chainable by default are:
     * `add`, `attempt`, `camelCase`, `capitalize`, `ceil`, `clone`, `cloneDeep`,
     * `deburr`, `endsWith`, `escape`, `escapeRegExp`, `every`, `find`, `findIndex`,
     * `findKey`, `findLast`, `findLastIndex`, `findLastKey`, `findWhere`, `first`,
     * `floor`, `get`, `gt`, `gte`, `has`, `identity`, `includes`, `indexOf`,
     * `inRange`, `isArguments`, `isArray`, `isBoolean`, `isDate`, `isElement`,
     * `isEmpty`, `isEqual`, `isError`, `isFinite` `isFunction`, `isMatch`,
     * `isNative`, `isNaN`, `isNull`, `isNumber`, `isObject`, `isPlainObject`,
     * `isRegExp`, `isString`, `isUndefined`, `isTypedArray`, `join`, `kebabCase`,
     * `last`, `lastIndexOf`, `lt`, `lte`, `max`, `min`, `noConflict`, `noop`,
     * `now`, `pad`, `padLeft`, `padRight`, `parseInt`, `pop`, `random`, `reduce`,
     * `reduceRight`, `repeat`, `result`, `round`, `runInContext`, `shift`, `size`,
     * `snakeCase`, `some`, `sortedIndex`, `sortedLastIndex`, `startCase`,
     * `startsWith`, `sum`, `template`, `trim`, `trimLeft`, `trimRight`, `trunc`,
     * `unescape`, `uniqueId`, `value`, and `words`
     *
     * The wrapper method `sample` will return a wrapped value when `n` is provided,
     * otherwise an unwrapped value is returned.
     *
     * @name _
     * @constructor
     * @category Chain
     * @param {*} value The value to wrap in a `lodash` instance.
     * @returns {Object} Returns the new `lodash` wrapper instance.
     * @example
     *
     * var wrapped = _([1, 2, 3]);
     *
     * // returns an unwrapped value
     * wrapped.reduce(function(total, n) {
     *   return total + n;
     * });
     * // => 6
     *
     * // returns a wrapped value
     * var squares = wrapped.map(function(n) {
     *   return n * n;
     * });
     *
     * _.isArray(squares);
     * // => false
     *
     * _.isArray(squares.value());
     * // => true
     */
    function lodash(value) {
      if (isObjectLike(value) && !isArray(value) && !(value instanceof LazyWrapper)) {
        if (value instanceof LodashWrapper) {
          return value;
        }
        if (hasOwnProperty.call(value, '__chain__') && hasOwnProperty.call(value, '__wrapped__')) {
          return wrapperClone(value);
        }
      }
      return new LodashWrapper(value);
    }

    /**
     * The function whose prototype all chaining wrappers inherit from.
     *
     * @private
     */
    function baseLodash() {
      // No operation performed.
    }

    /**
     * The base constructor for creating `lodash` wrapper objects.
     *
     * @private
     * @param {*} value The value to wrap.
     * @param {boolean} [chainAll] Enable chaining for all wrapper methods.
     * @param {Array} [actions=[]] Actions to peform to resolve the unwrapped value.
     */
    function LodashWrapper(value, chainAll, actions) {
      this.__wrapped__ = value;
      this.__actions__ = actions || [];
      this.__chain__ = !!chainAll;
    }

    /**
     * An object environment feature flags.
     *
     * @static
     * @memberOf _
     * @type Object
     */
    var support = lodash.support = {};

    /**
     * By default, the template delimiters used by lodash are like those in
     * embedded Ruby (ERB). Change the following template settings to use
     * alternative delimiters.
     *
     * @static
     * @memberOf _
     * @type Object
     */
    lodash.templateSettings = {

      /**
       * Used to detect `data` property values to be HTML-escaped.
       *
       * @memberOf _.templateSettings
       * @type RegExp
       */
      'escape': reEscape,

      /**
       * Used to detect code to be evaluated.
       *
       * @memberOf _.templateSettings
       * @type RegExp
       */
      'evaluate': reEvaluate,

      /**
       * Used to detect `data` property values to inject.
       *
       * @memberOf _.templateSettings
       * @type RegExp
       */
      'interpolate': reInterpolate,

      /**
       * Used to reference the data object in the template text.
       *
       * @memberOf _.templateSettings
       * @type string
       */
      'variable': '',

      /**
       * Used to import variables into the compiled template.
       *
       * @memberOf _.templateSettings
       * @type Object
       */
      'imports': {

        /**
         * A reference to the `lodash` function.
         *
         * @memberOf _.templateSettings.imports
         * @type Function
         */
        '_': lodash
      }
    };

    /*------------------------------------------------------------------------*/

    /**
     * Creates a lazy wrapper object which wraps `value` to enable lazy evaluation.
     *
     * @private
     * @param {*} value The value to wrap.
     */
    function LazyWrapper(value) {
      this.__wrapped__ = value;
      this.__actions__ = [];
      this.__dir__ = 1;
      this.__filtered__ = false;
      this.__iteratees__ = [];
      this.__takeCount__ = POSITIVE_INFINITY;
      this.__views__ = [];
    }

    /**
     * Creates a clone of the lazy wrapper object.
     *
     * @private
     * @name clone
     * @memberOf LazyWrapper
     * @returns {Object} Returns the cloned `LazyWrapper` object.
     */
    function lazyClone() {
      var result = new LazyWrapper(this.__wrapped__);
      result.__actions__ = arrayCopy(this.__actions__);
      result.__dir__ = this.__dir__;
      result.__filtered__ = this.__filtered__;
      result.__iteratees__ = arrayCopy(this.__iteratees__);
      result.__takeCount__ = this.__takeCount__;
      result.__views__ = arrayCopy(this.__views__);
      return result;
    }

    /**
     * Reverses the direction of lazy iteration.
     *
     * @private
     * @name reverse
     * @memberOf LazyWrapper
     * @returns {Object} Returns the new reversed `LazyWrapper` object.
     */
    function lazyReverse() {
      if (this.__filtered__) {
        var result = new LazyWrapper(this);
        result.__dir__ = -1;
        result.__filtered__ = true;
      } else {
        result = this.clone();
        result.__dir__ *= -1;
      }
      return result;
    }

    /**
     * Extracts the unwrapped value from its lazy wrapper.
     *
     * @private
     * @name value
     * @memberOf LazyWrapper
     * @returns {*} Returns the unwrapped value.
     */
    function lazyValue() {
      var array = this.__wrapped__.value(),
          dir = this.__dir__,
          isArr = isArray(array),
          isRight = dir < 0,
          arrLength = isArr ? array.length : 0,
          view = getView(0, arrLength, this.__views__),
          start = view.start,
          end = view.end,
          length = end - start,
          index = isRight ? end : (start - 1),
          iteratees = this.__iteratees__,
          iterLength = iteratees.length,
          resIndex = 0,
          takeCount = nativeMin(length, this.__takeCount__);

      if (!isArr || arrLength < LARGE_ARRAY_SIZE || (arrLength == length && takeCount == length)) {
        return baseWrapperValue((isRight && isArr) ? array.reverse() : array, this.__actions__);
      }
      var result = [];

      outer:
      while (length-- && resIndex < takeCount) {
        index += dir;

        var iterIndex = -1,
            value = array[index];

        while (++iterIndex < iterLength) {
          var data = iteratees[iterIndex],
              iteratee = data.iteratee,
              type = data.type,
              computed = iteratee(value);

          if (type == LAZY_MAP_FLAG) {
            value = computed;
          } else if (!computed) {
            if (type == LAZY_FILTER_FLAG) {
              continue outer;
            } else {
              break outer;
            }
          }
        }
        result[resIndex++] = value;
      }
      return result;
    }

    /*------------------------------------------------------------------------*/

    /**
     * Creates a cache object to store key/value pairs.
     *
     * @private
     * @static
     * @name Cache
     * @memberOf _.memoize
     */
    function MapCache() {
      this.__data__ = {};
    }

    /**
     * Removes `key` and its value from the cache.
     *
     * @private
     * @name delete
     * @memberOf _.memoize.Cache
     * @param {string} key The key of the value to remove.
     * @returns {boolean} Returns `true` if the entry was removed successfully, else `false`.
     */
    function mapDelete(key) {
      return this.has(key) && delete this.__data__[key];
    }

    /**
     * Gets the cached value for `key`.
     *
     * @private
     * @name get
     * @memberOf _.memoize.Cache
     * @param {string} key The key of the value to get.
     * @returns {*} Returns the cached value.
     */
    function mapGet(key) {
      return key == '__proto__' ? undefined : this.__data__[key];
    }

    /**
     * Checks if a cached value for `key` exists.
     *
     * @private
     * @name has
     * @memberOf _.memoize.Cache
     * @param {string} key The key of the entry to check.
     * @returns {boolean} Returns `true` if an entry for `key` exists, else `false`.
     */
    function mapHas(key) {
      return key != '__proto__' && hasOwnProperty.call(this.__data__, key);
    }

    /**
     * Sets `value` to `key` of the cache.
     *
     * @private
     * @name set
     * @memberOf _.memoize.Cache
     * @param {string} key The key of the value to cache.
     * @param {*} value The value to cache.
     * @returns {Object} Returns the cache object.
     */
    function mapSet(key, value) {
      if (key != '__proto__') {
        this.__data__[key] = value;
      }
      return this;
    }

    /*------------------------------------------------------------------------*/

    /**
     *
     * Creates a cache object to store unique values.
     *
     * @private
     * @param {Array} [values] The values to cache.
     */
    function SetCache(values) {
      var length = values ? values.length : 0;

      this.data = { 'hash': nativeCreate(null), 'set': new Set };
      while (length--) {
        this.push(values[length]);
      }
    }

    /**
     * Checks if `value` is in `cache` mimicking the return signature of
     * `_.indexOf` by returning `0` if the value is found, else `-1`.
     *
     * @private
     * @param {Object} cache The cache to search.
     * @param {*} value The value to search for.
     * @returns {number} Returns `0` if `value` is found, else `-1`.
     */
    function cacheIndexOf(cache, value) {
      var data = cache.data,
          result = (typeof value == 'string' || isObject(value)) ? data.set.has(value) : data.hash[value];

      return result ? 0 : -1;
    }

    /**
     * Adds `value` to the cache.
     *
     * @private
     * @name push
     * @memberOf SetCache
     * @param {*} value The value to cache.
     */
    function cachePush(value) {
      var data = this.data;
      if (typeof value == 'string' || isObject(value)) {
        data.set.add(value);
      } else {
        data.hash[value] = true;
      }
    }

    /*------------------------------------------------------------------------*/

    /**
     * Creates a new array joining `array` with `other`.
     *
     * @private
     * @param {Array} array The array to join.
     * @param {Array} other The other array to join.
     * @returns {Array} Returns the new concatenated array.
     */
    function arrayConcat(array, other) {
      var index = -1,
          length = array.length,
          othIndex = -1,
          othLength = other.length,
          result = Array(length + othLength);

      while (++index < length) {
        result[index] = array[index];
      }
      while (++othIndex < othLength) {
        result[index++] = other[othIndex];
      }
      return result;
    }

    /**
     * Copies the values of `source` to `array`.
     *
     * @private
     * @param {Array} source The array to copy values from.
     * @param {Array} [array=[]] The array to copy values to.
     * @returns {Array} Returns `array`.
     */
    function arrayCopy(source, array) {
      var index = -1,
          length = source.length;

      array || (array = Array(length));
      while (++index < length) {
        array[index] = source[index];
      }
      return array;
    }

    /**
     * A specialized version of `_.forEach` for arrays without support for callback
     * shorthands and `this` binding.
     *
     * @private
     * @param {Array} array The array to iterate over.
     * @param {Function} iteratee The function invoked per iteration.
     * @returns {Array} Returns `array`.
     */
    function arrayEach(array, iteratee) {
      var index = -1,
          length = array.length;

      while (++index < length) {
        if (iteratee(array[index], index, array) === false) {
          break;
        }
      }
      return array;
    }

    /**
     * A specialized version of `_.forEachRight` for arrays without support for
     * callback shorthands and `this` binding.
     *
     * @private
     * @param {Array} array The array to iterate over.
     * @param {Function} iteratee The function invoked per iteration.
     * @returns {Array} Returns `array`.
     */
    function arrayEachRight(array, iteratee) {
      var length = array.length;

      while (length--) {
        if (iteratee(array[length], length, array) === false) {
          break;
        }
      }
      return array;
    }

    /**
     * A specialized version of `_.every` for arrays without support for callback
     * shorthands and `this` binding.
     *
     * @private
     * @param {Array} array The array to iterate over.
     * @param {Function} predicate The function invoked per iteration.
     * @returns {boolean} Returns `true` if all elements pass the predicate check,
     *  else `false`.
     */
    function arrayEvery(array, predicate) {
      var index = -1,
          length = array.length;

      while (++index < length) {
        if (!predicate(array[index], index, array)) {
          return false;
        }
      }
      return true;
    }

    /**
     * A specialized version of `baseExtremum` for arrays which invokes `iteratee`
     * with one argument: (value).
     *
     * @private
     * @param {Array} array The array to iterate over.
     * @param {Function} iteratee The function invoked per iteration.
     * @param {Function} comparator The function used to compare values.
     * @param {*} exValue The initial extremum value.
     * @returns {*} Returns the extremum value.
     */
    function arrayExtremum(array, iteratee, comparator, exValue) {
      var index = -1,
          length = array.length,
          computed = exValue,
          result = computed;

      while (++index < length) {
        var value = array[index],
            current = +iteratee(value);

        if (comparator(current, computed)) {
          computed = current;
          result = value;
        }
      }
      return result;
    }

    /**
     * A specialized version of `_.filter` for arrays without support for callback
     * shorthands and `this` binding.
     *
     * @private
     * @param {Array} array The array to iterate over.
     * @param {Function} predicate The function invoked per iteration.
     * @returns {Array} Returns the new filtered array.
     */
    function arrayFilter(array, predicate) {
      var index = -1,
          length = array.length,
          resIndex = -1,
          result = [];

      while (++index < length) {
        var value = array[index];
        if (predicate(value, index, array)) {
          result[++resIndex] = value;
        }
      }
      return result;
    }

    /**
     * A specialized version of `_.map` for arrays without support for callback
     * shorthands and `this` binding.
     *
     * @private
     * @param {Array} array The array to iterate over.
     * @param {Function} iteratee The function invoked per iteration.
     * @returns {Array} Returns the new mapped array.
     */
    function arrayMap(array, iteratee) {
      var index = -1,
          length = array.length,
          result = Array(length);

      while (++index < length) {
        result[index] = iteratee(array[index], index, array);
      }
      return result;
    }

    /**
     * Appends the elements of `values` to `array`.
     *
     * @private
     * @param {Array} array The array to modify.
     * @param {Array} values The values to append.
     * @returns {Array} Returns `array`.
     */
    function arrayPush(array, values) {
      var index = -1,
          length = values.length,
          offset = array.length;

      while (++index < length) {
        array[offset + index] = values[index];
      }
      return array;
    }

    /**
     * A specialized version of `_.reduce` for arrays without support for callback
     * shorthands and `this` binding.
     *
     * @private
     * @param {Array} array The array to iterate over.
     * @param {Function} iteratee The function invoked per iteration.
     * @param {*} [accumulator] The initial value.
     * @param {boolean} [initFromArray] Specify using the first element of `array`
     *  as the initial value.
     * @returns {*} Returns the accumulated value.
     */
    function arrayReduce(array, iteratee, accumulator, initFromArray) {
      var index = -1,
          length = array.length;

      if (initFromArray && length) {
        accumulator = array[++index];
      }
      while (++index < length) {
        accumulator = iteratee(accumulator, array[index], index, array);
      }
      return accumulator;
    }

    /**
     * A specialized version of `_.reduceRight` for arrays without support for
     * callback shorthands and `this` binding.
     *
     * @private
     * @param {Array} array The array to iterate over.
     * @param {Function} iteratee The function invoked per iteration.
     * @param {*} [accumulator] The initial value.
     * @param {boolean} [initFromArray] Specify using the last element of `array`
     *  as the initial value.
     * @returns {*} Returns the accumulated value.
     */
    function arrayReduceRight(array, iteratee, accumulator, initFromArray) {
      var length = array.length;
      if (initFromArray && length) {
        accumulator = array[--length];
      }
      while (length--) {
        accumulator = iteratee(accumulator, array[length], length, array);
      }
      return accumulator;
    }

    /**
     * A specialized version of `_.some` for arrays without support for callback
     * shorthands and `this` binding.
     *
     * @private
     * @param {Array} array The array to iterate over.
     * @param {Function} predicate The function invoked per iteration.
     * @returns {boolean} Returns `true` if any element passes the predicate check,
     *  else `false`.
     */
    function arraySome(array, predicate) {
      var index = -1,
          length = array.length;

      while (++index < length) {
        if (predicate(array[index], index, array)) {
          return true;
        }
      }
      return false;
    }

    /**
     * A specialized version of `_.sum` for arrays without support for callback
     * shorthands and `this` binding..
     *
     * @private
     * @param {Array} array The array to iterate over.
     * @param {Function} iteratee The function invoked per iteration.
     * @returns {number} Returns the sum.
     */
    function arraySum(array, iteratee) {
      var length = array.length,
          result = 0;

      while (length--) {
        result += +iteratee(array[length]) || 0;
      }
      return result;
    }

    /**
     * Used by `_.defaults` to customize its `_.assign` use.
     *
     * @private
     * @param {*} objectValue The destination object property value.
     * @param {*} sourceValue The source object property value.
     * @returns {*} Returns the value to assign to the destination object.
     */
    function assignDefaults(objectValue, sourceValue) {
      return objectValue === undefined ? sourceValue : objectValue;
    }

    /**
     * Used by `_.template` to customize its `_.assign` use.
     *
     * **Note:** This function is like `assignDefaults` except that it ignores
     * inherited property values when checking if a property is `undefined`.
     *
     * @private
     * @param {*} objectValue The destination object property value.
     * @param {*} sourceValue The source object property value.
     * @param {string} key The key associated with the object and source values.
     * @param {Object} object The destination object.
     * @returns {*} Returns the value to assign to the destination object.
     */
    function assignOwnDefaults(objectValue, sourceValue, key, object) {
      return (objectValue === undefined || !hasOwnProperty.call(object, key))
        ? sourceValue
        : objectValue;
    }

    /**
     * A specialized version of `_.assign` for customizing assigned values without
     * support for argument juggling, multiple sources, and `this` binding `customizer`
     * functions.
     *
     * @private
     * @param {Object} object The destination object.
     * @param {Object} source The source object.
     * @param {Function} customizer The function to customize assigned values.
     * @returns {Object} Returns `object`.
     */
    function assignWith(object, source, customizer) {
      var index = -1,
          props = keys(source),
          length = props.length;

      while (++index < length) {
        var key = props[index],
            value = object[key],
            result = customizer(value, source[key], key, object, source);

        if ((result === result ? (result !== value) : (value === value)) ||
            (value === undefined && !(key in object))) {
          object[key] = result;
        }
      }
      return object;
    }

    /**
     * The base implementation of `_.assign` without support for argument juggling,
     * multiple sources, and `customizer` functions.
     *
     * @private
     * @param {Object} object The destination object.
     * @param {Object} source The source object.
     * @returns {Object} Returns `object`.
     */
    function baseAssign(object, source) {
      return source == null
        ? object
        : baseCopy(source, keys(source), object);
    }

    /**
     * The base implementation of `_.at` without support for string collections
     * and individual key arguments.
     *
     * @private
     * @param {Array|Object} collection The collection to iterate over.
     * @param {number[]|string[]} props The property names or indexes of elements to pick.
     * @returns {Array} Returns the new array of picked elements.
     */
    function baseAt(collection, props) {
      var index = -1,
          isNil = collection == null,
          isArr = !isNil && isArrayLike(collection),
          length = isArr ? collection.length : 0,
          propsLength = props.length,
          result = Array(propsLength);

      while(++index < propsLength) {
        var key = props[index];
        if (isArr) {
          result[index] = isIndex(key, length) ? collection[key] : undefined;
        } else {
          result[index] = isNil ? undefined : collection[key];
        }
      }
      return result;
    }

    /**
     * Copies properties of `source` to `object`.
     *
     * @private
     * @param {Object} source The object to copy properties from.
     * @param {Array} props The property names to copy.
     * @param {Object} [object={}] The object to copy properties to.
     * @returns {Object} Returns `object`.
     */
    function baseCopy(source, props, object) {
      object || (object = {});

      var index = -1,
          length = props.length;

      while (++index < length) {
        var key = props[index];
        object[key] = source[key];
      }
      return object;
    }

    /**
     * The base implementation of `_.callback` which supports specifying the
     * number of arguments to provide to `func`.
     *
     * @private
     * @param {*} [func=_.identity] The value to convert to a callback.
     * @param {*} [thisArg] The `this` binding of `func`.
     * @param {number} [argCount] The number of arguments to provide to `func`.
     * @returns {Function} Returns the callback.
     */
    function baseCallback(func, thisArg, argCount) {
      var type = typeof func;
      if (type == 'function') {
        return thisArg === undefined
          ? func
          : bindCallback(func, thisArg, argCount);
      }
      if (func == null) {
        return identity;
      }
      if (type == 'object') {
        return baseMatches(func);
      }
      return thisArg === undefined
        ? property(func)
        : baseMatchesProperty(func, thisArg);
    }

    /**
     * The base implementation of `_.clone` without support for argument juggling
     * and `this` binding `customizer` functions.
     *
     * @private
     * @param {*} value The value to clone.
     * @param {boolean} [isDeep] Specify a deep clone.
     * @param {Function} [customizer] The function to customize cloning values.
     * @param {string} [key] The key of `value`.
     * @param {Object} [object] The object `value` belongs to.
     * @param {Array} [stackA=[]] Tracks traversed source objects.
     * @param {Array} [stackB=[]] Associates clones with source counterparts.
     * @returns {*} Returns the cloned value.
     */
    function baseClone(value, isDeep, customizer, key, object, stackA, stackB) {
      var result;
      if (customizer) {
        result = object ? customizer(value, key, object) : customizer(value);
      }
      if (result !== undefined) {
        return result;
      }
      if (!isObject(value)) {
        return value;
      }
      var isArr = isArray(value);
      if (isArr) {
        result = initCloneArray(value);
        if (!isDeep) {
          return arrayCopy(value, result);
        }
      } else {
        var tag = objToString.call(value),
            isFunc = tag == funcTag;

        if (tag == objectTag || tag == argsTag || (isFunc && !object)) {
          result = initCloneObject(isFunc ? {} : value);
          if (!isDeep) {
            return baseAssign(result, value);
          }
        } else {
          return cloneableTags[tag]
            ? initCloneByTag(value, tag, isDeep)
            : (object ? value : {});
        }
      }
      // Check for circular references and return its corresponding clone.
      stackA || (stackA = []);
      stackB || (stackB = []);

      var length = stackA.length;
      while (length--) {
        if (stackA[length] == value) {
          return stackB[length];
        }
      }
      // Add the source value to the stack of traversed objects and associate it with its clone.
      stackA.push(value);
      stackB.push(result);

      // Recursively populate clone (susceptible to call stack limits).
      (isArr ? arrayEach : baseForOwn)(value, function(subValue, key) {
        result[key] = baseClone(subValue, isDeep, customizer, key, value, stackA, stackB);
      });
      return result;
    }

    /**
     * The base implementation of `_.create` without support for assigning
     * properties to the created object.
     *
     * @private
     * @param {Object} prototype The object to inherit from.
     * @returns {Object} Returns the new object.
     */
    var baseCreate = (function() {
      function object() {}
      return function(prototype) {
        if (isObject(prototype)) {
          object.prototype = prototype;
          var result = new object;
          object.prototype = undefined;
        }
        return result || {};
      };
    }());

    /**
     * The base implementation of `_.delay` and `_.defer` which accepts an index
     * of where to slice the arguments to provide to `func`.
     *
     * @private
     * @param {Function} func The function to delay.
     * @param {number} wait The number of milliseconds to delay invocation.
     * @param {Object} args The arguments provide to `func`.
     * @returns {number} Returns the timer id.
     */
    function baseDelay(func, wait, args) {
      if (typeof func != 'function') {
        throw new TypeError(FUNC_ERROR_TEXT);
      }
      return setTimeout(function() { func.apply(undefined, args); }, wait);
    }

    /**
     * The base implementation of `_.difference` which accepts a single array
     * of values to exclude.
     *
     * @private
     * @param {Array} array The array to inspect.
     * @param {Array} values The values to exclude.
     * @returns {Array} Returns the new array of filtered values.
     */
    function baseDifference(array, values) {
      var length = array ? array.length : 0,
          result = [];

      if (!length) {
        return result;
      }
      var index = -1,
          indexOf = getIndexOf(),
          isCommon = indexOf == baseIndexOf,
          cache = (isCommon && values.length >= LARGE_ARRAY_SIZE) ? createCache(values) : null,
          valuesLength = values.length;

      if (cache) {
        indexOf = cacheIndexOf;
        isCommon = false;
        values = cache;
      }
      outer:
      while (++index < length) {
        var value = array[index];

        if (isCommon && value === value) {
          var valuesIndex = valuesLength;
          while (valuesIndex--) {
            if (values[valuesIndex] === value) {
              continue outer;
            }
          }
          result.push(value);
        }
        else if (indexOf(values, value, 0) < 0) {
          result.push(value);
        }
      }
      return result;
    }

    /**
     * The base implementation of `_.forEach` without support for callback
     * shorthands and `this` binding.
     *
     * @private
     * @param {Array|Object|string} collection The collection to iterate over.
     * @param {Function} iteratee The function invoked per iteration.
     * @returns {Array|Object|string} Returns `collection`.
     */
    var baseEach = createBaseEach(baseForOwn);

    /**
     * The base implementation of `_.forEachRight` without support for callback
     * shorthands and `this` binding.
     *
     * @private
     * @param {Array|Object|string} collection The collection to iterate over.
     * @param {Function} iteratee The function invoked per iteration.
     * @returns {Array|Object|string} Returns `collection`.
     */
    var baseEachRight = createBaseEach(baseForOwnRight, true);

    /**
     * The base implementation of `_.every` without support for callback
     * shorthands and `this` binding.
     *
     * @private
     * @param {Array|Object|string} collection The collection to iterate over.
     * @param {Function} predicate The function invoked per iteration.
     * @returns {boolean} Returns `true` if all elements pass the predicate check,
     *  else `false`
     */
    function baseEvery(collection, predicate) {
      var result = true;
      baseEach(collection, function(value, index, collection) {
        result = !!predicate(value, index, collection);
        return result;
      });
      return result;
    }

    /**
     * Gets the extremum value of `collection` invoking `iteratee` for each value
     * in `collection` to generate the criterion by which the value is ranked.
     * The `iteratee` is invoked with three arguments: (value, index|key, collection).
     *
     * @private
     * @param {Array|Object|string} collection The collection to iterate over.
     * @param {Function} iteratee The function invoked per iteration.
     * @param {Function} comparator The function used to compare values.
     * @param {*} exValue The initial extremum value.
     * @returns {*} Returns the extremum value.
     */
    function baseExtremum(collection, iteratee, comparator, exValue) {
      var computed = exValue,
          result = computed;

      baseEach(collection, function(value, index, collection) {
        var current = +iteratee(value, index, collection);
        if (comparator(current, computed) || (current === exValue && current === result)) {
          computed = current;
          result = value;
        }
      });
      return result;
    }

    /**
     * The base implementation of `_.fill` without an iteratee call guard.
     *
     * @private
     * @param {Array} array The array to fill.
     * @param {*} value The value to fill `array` with.
     * @param {number} [start=0] The start position.
     * @param {number} [end=array.length] The end position.
     * @returns {Array} Returns `array`.
     */
    function baseFill(array, value, start, end) {
      var length = array.length;

      start = start == null ? 0 : (+start || 0);
      if (start < 0) {
        start = -start > length ? 0 : (length + start);
      }
      end = (end === undefined || end > length) ? length : (+end || 0);
      if (end < 0) {
        end += length;
      }
      length = start > end ? 0 : (end >>> 0);
      start >>>= 0;

      while (start < length) {
        array[start++] = value;
      }
      return array;
    }

    /**
     * The base implementation of `_.filter` without support for callback
     * shorthands and `this` binding.
     *
     * @private
     * @param {Array|Object|string} collection The collection to iterate over.
     * @param {Function} predicate The function invoked per iteration.
     * @returns {Array} Returns the new filtered array.
     */
    function baseFilter(collection, predicate) {
      var result = [];
      baseEach(collection, function(value, index, collection) {
        if (predicate(value, index, collection)) {
          result.push(value);
        }
      });
      return result;
    }

    /**
     * The base implementation of `_.find`, `_.findLast`, `_.findKey`, and `_.findLastKey`,
     * without support for callback shorthands and `this` binding, which iterates
     * over `collection` using the provided `eachFunc`.
     *
     * @private
     * @param {Array|Object|string} collection The collection to search.
     * @param {Function} predicate The function invoked per iteration.
     * @param {Function} eachFunc The function to iterate over `collection`.
     * @param {boolean} [retKey] Specify returning the key of the found element
     *  instead of the element itself.
     * @returns {*} Returns the found element or its key, else `undefined`.
     */
    function baseFind(collection, predicate, eachFunc, retKey) {
      var result;
      eachFunc(collection, function(value, key, collection) {
        if (predicate(value, key, collection)) {
          result = retKey ? key : value;
          return false;
        }
      });
      return result;
    }

    /**
     * The base implementation of `_.flatten` with added support for restricting
     * flattening and specifying the start index.
     *
     * @private
     * @param {Array} array The array to flatten.
     * @param {boolean} [isDeep] Specify a deep flatten.
     * @param {boolean} [isStrict] Restrict flattening to arrays-like objects.
     * @param {Array} [result=[]] The initial result value.
     * @returns {Array} Returns the new flattened array.
     */
    function baseFlatten(array, isDeep, isStrict, result) {
      result || (result = []);

      var index = -1,
          length = array.length;

      while (++index < length) {
        var value = array[index];
        if (isObjectLike(value) && isArrayLike(value) &&
            (isStrict || isArray(value) || isArguments(value))) {
          if (isDeep) {
            // Recursively flatten arrays (susceptible to call stack limits).
            baseFlatten(value, isDeep, isStrict, result);
          } else {
            arrayPush(result, value);
          }
        } else if (!isStrict) {
          result[result.length] = value;
        }
      }
      return result;
    }

    /**
     * The base implementation of `baseForIn` and `baseForOwn` which iterates
     * over `object` properties returned by `keysFunc` invoking `iteratee` for
     * each property. Iteratee functions may exit iteration early by explicitly
     * returning `false`.
     *
     * @private
     * @param {Object} object The object to iterate over.
     * @param {Function} iteratee The function invoked per iteration.
     * @param {Function} keysFunc The function to get the keys of `object`.
     * @returns {Object} Returns `object`.
     */
    var baseFor = createBaseFor();

    /**
     * This function is like `baseFor` except that it iterates over properties
     * in the opposite order.
     *
     * @private
     * @param {Object} object The object to iterate over.
     * @param {Function} iteratee The function invoked per iteration.
     * @param {Function} keysFunc The function to get the keys of `object`.
     * @returns {Object} Returns `object`.
     */
    var baseForRight = createBaseFor(true);

    /**
     * The base implementation of `_.forIn` without support for callback
     * shorthands and `this` binding.
     *
     * @private
     * @param {Object} object The object to iterate over.
     * @param {Function} iteratee The function invoked per iteration.
     * @returns {Object} Returns `object`.
     */
    function baseForIn(object, iteratee) {
      return baseFor(object, iteratee, keysIn);
    }

    /**
     * The base implementation of `_.forOwn` without support for callback
     * shorthands and `this` binding.
     *
     * @private
     * @param {Object} object The object to iterate over.
     * @param {Function} iteratee The function invoked per iteration.
     * @returns {Object} Returns `object`.
     */
    function baseForOwn(object, iteratee) {
      return baseFor(object, iteratee, keys);
    }

    /**
     * The base implementation of `_.forOwnRight` without support for callback
     * shorthands and `this` binding.
     *
     * @private
     * @param {Object} object The object to iterate over.
     * @param {Function} iteratee The function invoked per iteration.
     * @returns {Object} Returns `object`.
     */
    function baseForOwnRight(object, iteratee) {
      return baseForRight(object, iteratee, keys);
    }

    /**
     * The base implementation of `_.functions` which creates an array of
     * `object` function property names filtered from those provided.
     *
     * @private
     * @param {Object} object The object to inspect.
     * @param {Array} props The property names to filter.
     * @returns {Array} Returns the new array of filtered property names.
     */
    function baseFunctions(object, props) {
      var index = -1,
          length = props.length,
          resIndex = -1,
          result = [];

      while (++index < length) {
        var key = props[index];
        if (isFunction(object[key])) {
          result[++resIndex] = key;
        }
      }
      return result;
    }

    /**
     * The base implementation of `get` without support for string paths
     * and default values.
     *
     * @private
     * @param {Object} object The object to query.
     * @param {Array} path The path of the property to get.
     * @param {string} [pathKey] The key representation of path.
     * @returns {*} Returns the resolved value.
     */
    function baseGet(object, path, pathKey) {
      if (object == null) {
        return;
      }
      if (pathKey !== undefined && pathKey in toObject(object)) {
        path = [pathKey];
      }
      var index = 0,
          length = path.length;

      while (object != null && index < length) {
        object = object[path[index++]];
      }
      return (index && index == length) ? object : undefined;
    }

    /**
     * The base implementation of `_.isEqual` without support for `this` binding
     * `customizer` functions.
     *
     * @private
     * @param {*} value The value to compare.
     * @param {*} other The other value to compare.
     * @param {Function} [customizer] The function to customize comparing values.
     * @param {boolean} [isLoose] Specify performing partial comparisons.
     * @param {Array} [stackA] Tracks traversed `value` objects.
     * @param {Array} [stackB] Tracks traversed `other` objects.
     * @returns {boolean} Returns `true` if the values are equivalent, else `false`.
     */
    function baseIsEqual(value, other, customizer, isLoose, stackA, stackB) {
      if (value === other) {
        return true;
      }
      if (value == null || other == null || (!isObject(value) && !isObjectLike(other))) {
        return value !== value && other !== other;
      }
      return baseIsEqualDeep(value, other, baseIsEqual, customizer, isLoose, stackA, stackB);
    }

    /**
     * A specialized version of `baseIsEqual` for arrays and objects which performs
     * deep comparisons and tracks traversed objects enabling objects with circular
     * references to be compared.
     *
     * @private
     * @param {Object} object The object to compare.
     * @param {Object} other The other object to compare.
     * @param {Function} equalFunc The function to determine equivalents of values.
     * @param {Function} [customizer] The function to customize comparing objects.
     * @param {boolean} [isLoose] Specify performing partial comparisons.
     * @param {Array} [stackA=[]] Tracks traversed `value` objects.
     * @param {Array} [stackB=[]] Tracks traversed `other` objects.
     * @returns {boolean} Returns `true` if the objects are equivalent, else `false`.
     */
    function baseIsEqualDeep(object, other, equalFunc, customizer, isLoose, stackA, stackB) {
      var objIsArr = isArray(object),
          othIsArr = isArray(other),
          objTag = arrayTag,
          othTag = arrayTag;

      if (!objIsArr) {
        objTag = objToString.call(object);
        if (objTag == argsTag) {
          objTag = objectTag;
        } else if (objTag != objectTag) {
          objIsArr = isTypedArray(object);
        }
      }
      if (!othIsArr) {
        othTag = objToString.call(other);
        if (othTag == argsTag) {
          othTag = objectTag;
        } else if (othTag != objectTag) {
          othIsArr = isTypedArray(other);
        }
      }
      var objIsObj = objTag == objectTag,
          othIsObj = othTag == objectTag,
          isSameTag = objTag == othTag;

      if (isSameTag && !(objIsArr || objIsObj)) {
        return equalByTag(object, other, objTag);
      }
      if (!isLoose) {
        var objIsWrapped = objIsObj && hasOwnProperty.call(object, '__wrapped__'),
            othIsWrapped = othIsObj && hasOwnProperty.call(other, '__wrapped__');

        if (objIsWrapped || othIsWrapped) {
          return equalFunc(objIsWrapped ? object.value() : object, othIsWrapped ? other.value() : other, customizer, isLoose, stackA, stackB);
        }
      }
      if (!isSameTag) {
        return false;
      }
      // Assume cyclic values are equal.
      // For more information on detecting circular references see https://es5.github.io/#JO.
      stackA || (stackA = []);
      stackB || (stackB = []);

      var length = stackA.length;
      while (length--) {
        if (stackA[length] == object) {
          return stackB[length] == other;
        }
      }
      // Add `object` and `other` to the stack of traversed objects.
      stackA.push(object);
      stackB.push(other);

      var result = (objIsArr ? equalArrays : equalObjects)(object, other, equalFunc, customizer, isLoose, stackA, stackB);

      stackA.pop();
      stackB.pop();

      return result;
    }

    /**
     * The base implementation of `_.isMatch` without support for callback
     * shorthands and `this` binding.
     *
     * @private
     * @param {Object} object The object to inspect.
     * @param {Array} matchData The propery names, values, and compare flags to match.
     * @param {Function} [customizer] The function to customize comparing objects.
     * @returns {boolean} Returns `true` if `object` is a match, else `false`.
     */
    function baseIsMatch(object, matchData, customizer) {
      var index = matchData.length,
          length = index,
          noCustomizer = !customizer;

      if (object == null) {
        return !length;
      }
      object = toObject(object);
      while (index--) {
        var data = matchData[index];
        if ((noCustomizer && data[2])
              ? data[1] !== object[data[0]]
              : !(data[0] in object)
            ) {
          return false;
        }
      }
      while (++index < length) {
        data = matchData[index];
        var key = data[0],
            objValue = object[key],
            srcValue = data[1];

        if (noCustomizer && data[2]) {
          if (objValue === undefined && !(key in object)) {
            return false;
          }
        } else {
          var result = customizer ? customizer(objValue, srcValue, key) : undefined;
          if (!(result === undefined ? baseIsEqual(srcValue, objValue, customizer, true) : result)) {
            return false;
          }
        }
      }
      return true;
    }

    /**
     * The base implementation of `_.map` without support for callback shorthands
     * and `this` binding.
     *
     * @private
     * @param {Array|Object|string} collection The collection to iterate over.
     * @param {Function} iteratee The function invoked per iteration.
     * @returns {Array} Returns the new mapped array.
     */
    function baseMap(collection, iteratee) {
      var index = -1,
          result = isArrayLike(collection) ? Array(collection.length) : [];

      baseEach(collection, function(value, key, collection) {
        result[++index] = iteratee(value, key, collection);
      });
      return result;
    }

    /**
     * The base implementation of `_.matches` which does not clone `source`.
     *
     * @private
     * @param {Object} source The object of property values to match.
     * @returns {Function} Returns the new function.
     */
    function baseMatches(source) {
      var matchData = getMatchData(source);
      if (matchData.length == 1 && matchData[0][2]) {
        var key = matchData[0][0],
            value = matchData[0][1];

        return function(object) {
          if (object == null) {
            return false;
          }
          return object[key] === value && (value !== undefined || (key in toObject(object)));
        };
      }
      return function(object) {
        return baseIsMatch(object, matchData);
      };
    }

    /**
     * The base implementation of `_.matchesProperty` which does not clone `srcValue`.
     *
     * @private
     * @param {string} path The path of the property to get.
     * @param {*} srcValue The value to compare.
     * @returns {Function} Returns the new function.
     */
    function baseMatchesProperty(path, srcValue) {
      var isArr = isArray(path),
          isCommon = isKey(path) && isStrictComparable(srcValue),
          pathKey = (path + '');

      path = toPath(path);
      return function(object) {
        if (object == null) {
          return false;
        }
        var key = pathKey;
        object = toObject(object);
        if ((isArr || !isCommon) && !(key in object)) {
          object = path.length == 1 ? object : baseGet(object, baseSlice(path, 0, -1));
          if (object == null) {
            return false;
          }
          key = last(path);
          object = toObject(object);
        }
        return object[key] === srcValue
          ? (srcValue !== undefined || (key in object))
          : baseIsEqual(srcValue, object[key], undefined, true);
      };
    }

    /**
     * The base implementation of `_.merge` without support for argument juggling,
     * multiple sources, and `this` binding `customizer` functions.
     *
     * @private
     * @param {Object} object The destination object.
     * @param {Object} source The source object.
     * @param {Function} [customizer] The function to customize merged values.
     * @param {Array} [stackA=[]] Tracks traversed source objects.
     * @param {Array} [stackB=[]] Associates values with source counterparts.
     * @returns {Object} Returns `object`.
     */
    function baseMerge(object, source, customizer, stackA, stackB) {
      if (!isObject(object)) {
        return object;
      }
      var isSrcArr = isArrayLike(source) && (isArray(source) || isTypedArray(source)),
          props = isSrcArr ? undefined : keys(source);

      arrayEach(props || source, function(srcValue, key) {
        if (props) {
          key = srcValue;
          srcValue = source[key];
        }
        if (isObjectLike(srcValue)) {
          stackA || (stackA = []);
          stackB || (stackB = []);
          baseMergeDeep(object, source, key, baseMerge, customizer, stackA, stackB);
        }
        else {
          var value = object[key],
              result = customizer ? customizer(value, srcValue, key, object, source) : undefined,
              isCommon = result === undefined;

          if (isCommon) {
            result = srcValue;
          }
          if ((result !== undefined || (isSrcArr && !(key in object))) &&
              (isCommon || (result === result ? (result !== value) : (value === value)))) {
            object[key] = result;
          }
        }
      });
      return object;
    }

    /**
     * A specialized version of `baseMerge` for arrays and objects which performs
     * deep merges and tracks traversed objects enabling objects with circular
     * references to be merged.
     *
     * @private
     * @param {Object} object The destination object.
     * @param {Object} source The source object.
     * @param {string} key The key of the value to merge.
     * @param {Function} mergeFunc The function to merge values.
     * @param {Function} [customizer] The function to customize merged values.
     * @param {Array} [stackA=[]] Tracks traversed source objects.
     * @param {Array} [stackB=[]] Associates values with source counterparts.
     * @returns {boolean} Returns `true` if the objects are equivalent, else `false`.
     */
    function baseMergeDeep(object, source, key, mergeFunc, customizer, stackA, stackB) {
      var length = stackA.length,
          srcValue = source[key];

      while (length--) {
        if (stackA[length] == srcValue) {
          object[key] = stackB[length];
          return;
        }
      }
      var value = object[key],
          result = customizer ? customizer(value, srcValue, key, object, source) : undefined,
          isCommon = result === undefined;

      if (isCommon) {
        result = srcValue;
        if (isArrayLike(srcValue) && (isArray(srcValue) || isTypedArray(srcValue))) {
          result = isArray(value)
            ? value
            : (isArrayLike(value) ? arrayCopy(value) : []);
        }
        else if (isPlainObject(srcValue) || isArguments(srcValue)) {
          result = isArguments(value)
            ? toPlainObject(value)
            : (isPlainObject(value) ? value : {});
        }
        else {
          isCommon = false;
        }
      }
      // Add the source value to the stack of traversed objects and associate
      // it with its merged value.
      stackA.push(srcValue);
      stackB.push(result);

      if (isCommon) {
        // Recursively merge objects and arrays (susceptible to call stack limits).
        object[key] = mergeFunc(result, srcValue, customizer, stackA, stackB);
      } else if (result === result ? (result !== value) : (value === value)) {
        object[key] = result;
      }
    }

    /**
     * The base implementation of `_.property` without support for deep paths.
     *
     * @private
     * @param {string} key The key of the property to get.
     * @returns {Function} Returns the new function.
     */
    function baseProperty(key) {
      return function(object) {
        return object == null ? undefined : object[key];
      };
    }

    /**
     * A specialized version of `baseProperty` which supports deep paths.
     *
     * @private
     * @param {Array|string} path The path of the property to get.
     * @returns {Function} Returns the new function.
     */
    function basePropertyDeep(path) {
      var pathKey = (path + '');
      path = toPath(path);
      return function(object) {
        return baseGet(object, path, pathKey);
      };
    }

    /**
     * The base implementation of `_.pullAt` without support for individual
     * index arguments and capturing the removed elements.
     *
     * @private
     * @param {Array} array The array to modify.
     * @param {number[]} indexes The indexes of elements to remove.
     * @returns {Array} Returns `array`.
     */
    function basePullAt(array, indexes) {
      var length = array ? indexes.length : 0;
      while (length--) {
        var index = indexes[length];
        if (index != previous && isIndex(index)) {
          var previous = index;
          splice.call(array, index, 1);
        }
      }
      return array;
    }

    /**
     * The base implementation of `_.random` without support for argument juggling
     * and returning floating-point numbers.
     *
     * @private
     * @param {number} min The minimum possible value.
     * @param {number} max The maximum possible value.
     * @returns {number} Returns the random number.
     */
    function baseRandom(min, max) {
      return min + nativeFloor(nativeRandom() * (max - min + 1));
    }

    /**
     * The base implementation of `_.reduce` and `_.reduceRight` without support
     * for callback shorthands and `this` binding, which iterates over `collection`
     * using the provided `eachFunc`.
     *
     * @private
     * @param {Array|Object|string} collection The collection to iterate over.
     * @param {Function} iteratee The function invoked per iteration.
     * @param {*} accumulator The initial value.
     * @param {boolean} initFromCollection Specify using the first or last element
     *  of `collection` as the initial value.
     * @param {Function} eachFunc The function to iterate over `collection`.
     * @returns {*} Returns the accumulated value.
     */
    function baseReduce(collection, iteratee, accumulator, initFromCollection, eachFunc) {
      eachFunc(collection, function(value, index, collection) {
        accumulator = initFromCollection
          ? (initFromCollection = false, value)
          : iteratee(accumulator, value, index, collection);
      });
      return accumulator;
    }

    /**
     * The base implementation of `setData` without support for hot loop detection.
     *
     * @private
     * @param {Function} func The function to associate metadata with.
     * @param {*} data The metadata.
     * @returns {Function} Returns `func`.
     */
    var baseSetData = !metaMap ? identity : function(func, data) {
      metaMap.set(func, data);
      return func;
    };

    /**
     * The base implementation of `_.slice` without an iteratee call guard.
     *
     * @private
     * @param {Array} array The array to slice.
     * @param {number} [start=0] The start position.
     * @param {number} [end=array.length] The end position.
     * @returns {Array} Returns the slice of `array`.
     */
    function baseSlice(array, start, end) {
      var index = -1,
          length = array.length;

      start = start == null ? 0 : (+start || 0);
      if (start < 0) {
        start = -start > length ? 0 : (length + start);
      }
      end = (end === undefined || end > length) ? length : (+end || 0);
      if (end < 0) {
        end += length;
      }
      length = start > end ? 0 : ((end - start) >>> 0);
      start >>>= 0;

      var result = Array(length);
      while (++index < length) {
        result[index] = array[index + start];
      }
      return result;
    }

    /**
     * The base implementation of `_.some` without support for callback shorthands
     * and `this` binding.
     *
     * @private
     * @param {Array|Object|string} collection The collection to iterate over.
     * @param {Function} predicate The function invoked per iteration.
     * @returns {boolean} Returns `true` if any element passes the predicate check,
     *  else `false`.
     */
    function baseSome(collection, predicate) {
      var result;

      baseEach(collection, function(value, index, collection) {
        result = predicate(value, index, collection);
        return !result;
      });
      return !!result;
    }

    /**
     * The base implementation of `_.sortBy` which uses `comparer` to define
     * the sort order of `array` and replaces criteria objects with their
     * corresponding values.
     *
     * @private
     * @param {Array} array The array to sort.
     * @param {Function} comparer The function to define sort order.
     * @returns {Array} Returns `array`.
     */
    function baseSortBy(array, comparer) {
      var length = array.length;

      array.sort(comparer);
      while (length--) {
        array[length] = array[length].value;
      }
      return array;
    }

    /**
     * The base implementation of `_.sortByOrder` without param guards.
     *
     * @private
     * @param {Array|Object|string} collection The collection to iterate over.
     * @param {Function[]|Object[]|string[]} iteratees The iteratees to sort by.
     * @param {boolean[]} orders The sort orders of `iteratees`.
     * @returns {Array} Returns the new sorted array.
     */
    function baseSortByOrder(collection, iteratees, orders) {
      var callback = getCallback(),
          index = -1;

      iteratees = arrayMap(iteratees, function(iteratee) { return callback(iteratee); });

      var result = baseMap(collection, function(value) {
        var criteria = arrayMap(iteratees, function(iteratee) { return iteratee(value); });
        return { 'criteria': criteria, 'index': ++index, 'value': value };
      });

      return baseSortBy(result, function(object, other) {
        return compareMultiple(object, other, orders);
      });
    }

    /**
     * The base implementation of `_.sum` without support for callback shorthands
     * and `this` binding.
     *
     * @private
     * @param {Array|Object|string} collection The collection to iterate over.
     * @param {Function} iteratee The function invoked per iteration.
     * @returns {number} Returns the sum.
     */
    function baseSum(collection, iteratee) {
      var result = 0;
      baseEach(collection, function(value, index, collection) {
        result += +iteratee(value, index, collection) || 0;
      });
      return result;
    }

    /**
     * The base implementation of `_.uniq` without support for callback shorthands
     * and `this` binding.
     *
     * @private
     * @param {Array} array The array to inspect.
     * @param {Function} [iteratee] The function invoked per iteration.
     * @returns {Array} Returns the new duplicate-value-free array.
     */
    function baseUniq(array, iteratee) {
      var index = -1,
          indexOf = getIndexOf(),
          length = array.length,
          isCommon = indexOf == baseIndexOf,
          isLarge = isCommon && length >= LARGE_ARRAY_SIZE,
          seen = isLarge ? createCache() : null,
          result = [];

      if (seen) {
        indexOf = cacheIndexOf;
        isCommon = false;
      } else {
        isLarge = false;
        seen = iteratee ? [] : result;
      }
      outer:
      while (++index < length) {
        var value = array[index],
            computed = iteratee ? iteratee(value, index, array) : value;

        if (isCommon && value === value) {
          var seenIndex = seen.length;
          while (seenIndex--) {
            if (seen[seenIndex] === computed) {
              continue outer;
            }
          }
          if (iteratee) {
            seen.push(computed);
          }
          result.push(value);
        }
        else if (indexOf(seen, computed, 0) < 0) {
          if (iteratee || isLarge) {
            seen.push(computed);
          }
          result.push(value);
        }
      }
      return result;
    }

    /**
     * The base implementation of `_.values` and `_.valuesIn` which creates an
     * array of `object` property values corresponding to the property names
     * of `props`.
     *
     * @private
     * @param {Object} object The object to query.
     * @param {Array} props The property names to get values for.
     * @returns {Object} Returns the array of property values.
     */
    function baseValues(object, props) {
      var index = -1,
          length = props.length,
          result = Array(length);

      while (++index < length) {
        result[index] = object[props[index]];
      }
      return result;
    }

    /**
     * The base implementation of `_.dropRightWhile`, `_.dropWhile`, `_.takeRightWhile`,
     * and `_.takeWhile` without support for callback shorthands and `this` binding.
     *
     * @private
     * @param {Array} array The array to query.
     * @param {Function} predicate The function invoked per iteration.
     * @param {boolean} [isDrop] Specify dropping elements instead of taking them.
     * @param {boolean} [fromRight] Specify iterating from right to left.
     * @returns {Array} Returns the slice of `array`.
     */
    function baseWhile(array, predicate, isDrop, fromRight) {
      var length = array.length,
          index = fromRight ? length : -1;

      while ((fromRight ? index-- : ++index < length) && predicate(array[index], index, array)) {}
      return isDrop
        ? baseSlice(array, (fromRight ? 0 : index), (fromRight ? index + 1 : length))
        : baseSlice(array, (fromRight ? index + 1 : 0), (fromRight ? length : index));
    }

    /**
     * The base implementation of `wrapperValue` which returns the result of
     * performing a sequence of actions on the unwrapped `value`, where each
     * successive action is supplied the return value of the previous.
     *
     * @private
     * @param {*} value The unwrapped value.
     * @param {Array} actions Actions to peform to resolve the unwrapped value.
     * @returns {*} Returns the resolved value.
     */
    function baseWrapperValue(value, actions) {
      var result = value;
      if (result instanceof LazyWrapper) {
        result = result.value();
      }
      var index = -1,
          length = actions.length;

      while (++index < length) {
        var action = actions[index];
        result = action.func.apply(action.thisArg, arrayPush([result], action.args));
      }
      return result;
    }

    /**
     * Performs a binary search of `array` to determine the index at which `value`
     * should be inserted into `array` in order to maintain its sort order.
     *
     * @private
     * @param {Array} array The sorted array to inspect.
     * @param {*} value The value to evaluate.
     * @param {boolean} [retHighest] Specify returning the highest qualified index.
     * @returns {number} Returns the index at which `value` should be inserted
     *  into `array`.
     */
    function binaryIndex(array, value, retHighest) {
      var low = 0,
          high = array ? array.length : low;

      if (typeof value == 'number' && value === value && high <= HALF_MAX_ARRAY_LENGTH) {
        while (low < high) {
          var mid = (low + high) >>> 1,
              computed = array[mid];

          if ((retHighest ? (computed <= value) : (computed < value)) && computed !== null) {
            low = mid + 1;
          } else {
            high = mid;
          }
        }
        return high;
      }
      return binaryIndexBy(array, value, identity, retHighest);
    }

    /**
     * This function is like `binaryIndex` except that it invokes `iteratee` for
     * `value` and each element of `array` to compute their sort ranking. The
     * iteratee is invoked with one argument; (value).
     *
     * @private
     * @param {Array} array The sorted array to inspect.
     * @param {*} value The value to evaluate.
     * @param {Function} iteratee The function invoked per iteration.
     * @param {boolean} [retHighest] Specify returning the highest qualified index.
     * @returns {number} Returns the index at which `value` should be inserted
     *  into `array`.
     */
    function binaryIndexBy(array, value, iteratee, retHighest) {
      value = iteratee(value);

      var low = 0,
          high = array ? array.length : 0,
          valIsNaN = value !== value,
          valIsNull = value === null,
          valIsUndef = value === undefined;

      while (low < high) {
        var mid = nativeFloor((low + high) / 2),
            computed = iteratee(array[mid]),
            isDef = computed !== undefined,
            isReflexive = computed === computed;

        if (valIsNaN) {
          var setLow = isReflexive || retHighest;
        } else if (valIsNull) {
          setLow = isReflexive && isDef && (retHighest || computed != null);
        } else if (valIsUndef) {
          setLow = isReflexive && (retHighest || isDef);
        } else if (computed == null) {
          setLow = false;
        } else {
          setLow = retHighest ? (computed <= value) : (computed < value);
        }
        if (setLow) {
          low = mid + 1;
        } else {
          high = mid;
        }
      }
      return nativeMin(high, MAX_ARRAY_INDEX);
    }

    /**
     * A specialized version of `baseCallback` which only supports `this` binding
     * and specifying the number of arguments to provide to `func`.
     *
     * @private
     * @param {Function} func The function to bind.
     * @param {*} thisArg The `this` binding of `func`.
     * @param {number} [argCount] The number of arguments to provide to `func`.
     * @returns {Function} Returns the callback.
     */
    function bindCallback(func, thisArg, argCount) {
      if (typeof func != 'function') {
        return identity;
      }
      if (thisArg === undefined) {
        return func;
      }
      switch (argCount) {
        case 1: return function(value) {
          return func.call(thisArg, value);
        };
        case 3: return function(value, index, collection) {
          return func.call(thisArg, value, index, collection);
        };
        case 4: return function(accumulator, value, index, collection) {
          return func.call(thisArg, accumulator, value, index, collection);
        };
        case 5: return function(value, other, key, object, source) {
          return func.call(thisArg, value, other, key, object, source);
        };
      }
      return function() {
        return func.apply(thisArg, arguments);
      };
    }

    /**
     * Creates a clone of the given array buffer.
     *
     * @private
     * @param {ArrayBuffer} buffer The array buffer to clone.
     * @returns {ArrayBuffer} Returns the cloned array buffer.
     */
    function bufferClone(buffer) {
      var result = new ArrayBuffer(buffer.byteLength),
          view = new Uint8Array(result);

      view.set(new Uint8Array(buffer));
      return result;
    }

    /**
     * Creates an array that is the composition of partially applied arguments,
     * placeholders, and provided arguments into a single array of arguments.
     *
     * @private
     * @param {Array|Object} args The provided arguments.
     * @param {Array} partials The arguments to prepend to those provided.
     * @param {Array} holders The `partials` placeholder indexes.
     * @returns {Array} Returns the new array of composed arguments.
     */
    function composeArgs(args, partials, holders) {
      var holdersLength = holders.length,
          argsIndex = -1,
          argsLength = nativeMax(args.length - holdersLength, 0),
          leftIndex = -1,
          leftLength = partials.length,
          result = Array(leftLength + argsLength);

      while (++leftIndex < leftLength) {
        result[leftIndex] = partials[leftIndex];
      }
      while (++argsIndex < holdersLength) {
        result[holders[argsIndex]] = args[argsIndex];
      }
      while (argsLength--) {
        result[leftIndex++] = args[argsIndex++];
      }
      return result;
    }

    /**
     * This function is like `composeArgs` except that the arguments composition
     * is tailored for `_.partialRight`.
     *
     * @private
     * @param {Array|Object} args The provided arguments.
     * @param {Array} partials The arguments to append to those provided.
     * @param {Array} holders The `partials` placeholder indexes.
     * @returns {Array} Returns the new array of composed arguments.
     */
    function composeArgsRight(args, partials, holders) {
      var holdersIndex = -1,
          holdersLength = holders.length,
          argsIndex = -1,
          argsLength = nativeMax(args.length - holdersLength, 0),
          rightIndex = -1,
          rightLength = partials.length,
          result = Array(argsLength + rightLength);

      while (++argsIndex < argsLength) {
        result[argsIndex] = args[argsIndex];
      }
      var offset = argsIndex;
      while (++rightIndex < rightLength) {
        result[offset + rightIndex] = partials[rightIndex];
      }
      while (++holdersIndex < holdersLength) {
        result[offset + holders[holdersIndex]] = args[argsIndex++];
      }
      return result;
    }

    /**
     * Creates a `_.countBy`, `_.groupBy`, `_.indexBy`, or `_.partition` function.
     *
     * @private
     * @param {Function} setter The function to set keys and values of the accumulator object.
     * @param {Function} [initializer] The function to initialize the accumulator object.
     * @returns {Function} Returns the new aggregator function.
     */
    function createAggregator(setter, initializer) {
      return function(collection, iteratee, thisArg) {
        var result = initializer ? initializer() : {};
        iteratee = getCallback(iteratee, thisArg, 3);

        if (isArray(collection)) {
          var index = -1,
              length = collection.length;

          while (++index < length) {
            var value = collection[index];
            setter(result, value, iteratee(value, index, collection), collection);
          }
        } else {
          baseEach(collection, function(value, key, collection) {
            setter(result, value, iteratee(value, key, collection), collection);
          });
        }
        return result;
      };
    }

    /**
     * Creates a `_.assign`, `_.defaults`, or `_.merge` function.
     *
     * @private
     * @param {Function} assigner The function to assign values.
     * @returns {Function} Returns the new assigner function.
     */
    function createAssigner(assigner) {
      return restParam(function(object, sources) {
        var index = -1,
            length = object == null ? 0 : sources.length,
            customizer = length > 2 ? sources[length - 2] : undefined,
            guard = length > 2 ? sources[2] : undefined,
            thisArg = length > 1 ? sources[length - 1] : undefined;

        if (typeof customizer == 'function') {
          customizer = bindCallback(customizer, thisArg, 5);
          length -= 2;
        } else {
          customizer = typeof thisArg == 'function' ? thisArg : undefined;
          length -= (customizer ? 1 : 0);
        }
        if (guard && isIterateeCall(sources[0], sources[1], guard)) {
          customizer = length < 3 ? undefined : customizer;
          length = 1;
        }
        while (++index < length) {
          var source = sources[index];
          if (source) {
            assigner(object, source, customizer);
          }
        }
        return object;
      });
    }

    /**
     * Creates a `baseEach` or `baseEachRight` function.
     *
     * @private
     * @param {Function} eachFunc The function to iterate over a collection.
     * @param {boolean} [fromRight] Specify iterating from right to left.
     * @returns {Function} Returns the new base function.
     */
    function createBaseEach(eachFunc, fromRight) {
      return function(collection, iteratee) {
        var length = collection ? getLength(collection) : 0;
        if (!isLength(length)) {
          return eachFunc(collection, iteratee);
        }
        var index = fromRight ? length : -1,
            iterable = toObject(collection);

        while ((fromRight ? index-- : ++index < length)) {
          if (iteratee(iterable[index], index, iterable) === false) {
            break;
          }
        }
        return collection;
      };
    }

    /**
     * Creates a base function for `_.forIn` or `_.forInRight`.
     *
     * @private
     * @param {boolean} [fromRight] Specify iterating from right to left.
     * @returns {Function} Returns the new base function.
     */
    function createBaseFor(fromRight) {
      return function(object, iteratee, keysFunc) {
        var iterable = toObject(object),
            props = keysFunc(object),
            length = props.length,
            index = fromRight ? length : -1;

        while ((fromRight ? index-- : ++index < length)) {
          var key = props[index];
          if (iteratee(iterable[key], key, iterable) === false) {
            break;
          }
        }
        return object;
      };
    }

    /**
     * Creates a function that wraps `func` and invokes it with the `this`
     * binding of `thisArg`.
     *
     * @private
     * @param {Function} func The function to bind.
     * @param {*} [thisArg] The `this` binding of `func`.
     * @returns {Function} Returns the new bound function.
     */
    function createBindWrapper(func, thisArg) {
      var Ctor = createCtorWrapper(func);

      function wrapper() {
        var fn = (this && this !== root && this instanceof wrapper) ? Ctor : func;
        return fn.apply(thisArg, arguments);
      }
      return wrapper;
    }

    /**
     * Creates a `Set` cache object to optimize linear searches of large arrays.
     *
     * @private
     * @param {Array} [values] The values to cache.
     * @returns {null|Object} Returns the new cache object if `Set` is supported, else `null`.
     */
    function createCache(values) {
      return (nativeCreate && Set) ? new SetCache(values) : null;
    }

    /**
     * Creates a function that produces compound words out of the words in a
     * given string.
     *
     * @private
     * @param {Function} callback The function to combine each word.
     * @returns {Function} Returns the new compounder function.
     */
    function createCompounder(callback) {
      return function(string) {
        var index = -1,
            array = words(deburr(string)),
            length = array.length,
            result = '';

        while (++index < length) {
          result = callback(result, array[index], index);
        }
        return result;
      };
    }

    /**
     * Creates a function that produces an instance of `Ctor` regardless of
     * whether it was invoked as part of a `new` expression or by `call` or `apply`.
     *
     * @private
     * @param {Function} Ctor The constructor to wrap.
     * @returns {Function} Returns the new wrapped function.
     */
    function createCtorWrapper(Ctor) {
      return function() {
        // Use a `switch` statement to work with class constructors.
        // See http://ecma-international.org/ecma-262/6.0/#sec-ecmascript-function-objects-call-thisargument-argumentslist
        // for more details.
        var args = arguments;
        switch (args.length) {
          case 0: return new Ctor;
          case 1: return new Ctor(args[0]);
          case 2: return new Ctor(args[0], args[1]);
          case 3: return new Ctor(args[0], args[1], args[2]);
          case 4: return new Ctor(args[0], args[1], args[2], args[3]);
          case 5: return new Ctor(args[0], args[1], args[2], args[3], args[4]);
          case 6: return new Ctor(args[0], args[1], args[2], args[3], args[4], args[5]);
          case 7: return new Ctor(args[0], args[1], args[2], args[3], args[4], args[5], args[6]);
        }
        var thisBinding = baseCreate(Ctor.prototype),
            result = Ctor.apply(thisBinding, args);

        // Mimic the constructor's `return` behavior.
        // See https://es5.github.io/#x13.2.2 for more details.
        return isObject(result) ? result : thisBinding;
      };
    }

    /**
     * Creates a `_.curry` or `_.curryRight` function.
     *
     * @private
     * @param {boolean} flag The curry bit flag.
     * @returns {Function} Returns the new curry function.
     */
    function createCurry(flag) {
      function curryFunc(func, arity, guard) {
        if (guard && isIterateeCall(func, arity, guard)) {
          arity = undefined;
        }
        var result = createWrapper(func, flag, undefined, undefined, undefined, undefined, undefined, arity);
        result.placeholder = curryFunc.placeholder;
        return result;
      }
      return curryFunc;
    }

    /**
     * Creates a `_.defaults` or `_.defaultsDeep` function.
     *
     * @private
     * @param {Function} assigner The function to assign values.
     * @param {Function} customizer The function to customize assigned values.
     * @returns {Function} Returns the new defaults function.
     */
    function createDefaults(assigner, customizer) {
      return restParam(function(args) {
        var object = args[0];
        if (object == null) {
          return object;
        }
        args.push(customizer);
        return assigner.apply(undefined, args);
      });
    }

    /**
     * Creates a `_.max` or `_.min` function.
     *
     * @private
     * @param {Function} comparator The function used to compare values.
     * @param {*} exValue The initial extremum value.
     * @returns {Function} Returns the new extremum function.
     */
    function createExtremum(comparator, exValue) {
      return function(collection, iteratee, thisArg) {
        if (thisArg && isIterateeCall(collection, iteratee, thisArg)) {
          iteratee = undefined;
        }
        iteratee = getCallback(iteratee, thisArg, 3);
        if (iteratee.length == 1) {
          collection = isArray(collection) ? collection : toIterable(collection);
          var result = arrayExtremum(collection, iteratee, comparator, exValue);
          if (!(collection.length && result === exValue)) {
            return result;
          }
        }
        return baseExtremum(collection, iteratee, comparator, exValue);
      };
    }

    /**
     * Creates a `_.find` or `_.findLast` function.
     *
     * @private
     * @param {Function} eachFunc The function to iterate over a collection.
     * @param {boolean} [fromRight] Specify iterating from right to left.
     * @returns {Function} Returns the new find function.
     */
    function createFind(eachFunc, fromRight) {
      return function(collection, predicate, thisArg) {
        predicate = getCallback(predicate, thisArg, 3);
        if (isArray(collection)) {
          var index = baseFindIndex(collection, predicate, fromRight);
          return index > -1 ? collection[index] : undefined;
        }
        return baseFind(collection, predicate, eachFunc);
      };
    }

    /**
     * Creates a `_.findIndex` or `_.findLastIndex` function.
     *
     * @private
     * @param {boolean} [fromRight] Specify iterating from right to left.
     * @returns {Function} Returns the new find function.
     */
    function createFindIndex(fromRight) {
      return function(array, predicate, thisArg) {
        if (!(array && array.length)) {
          return -1;
        }
        predicate = getCallback(predicate, thisArg, 3);
        return baseFindIndex(array, predicate, fromRight);
      };
    }

    /**
     * Creates a `_.findKey` or `_.findLastKey` function.
     *
     * @private
     * @param {Function} objectFunc The function to iterate over an object.
     * @returns {Function} Returns the new find function.
     */
    function createFindKey(objectFunc) {
      return function(object, predicate, thisArg) {
        predicate = getCallback(predicate, thisArg, 3);
        return baseFind(object, predicate, objectFunc, true);
      };
    }

    /**
     * Creates a `_.flow` or `_.flowRight` function.
     *
     * @private
     * @param {boolean} [fromRight] Specify iterating from right to left.
     * @returns {Function} Returns the new flow function.
     */
    function createFlow(fromRight) {
      return function() {
        var wrapper,
            length = arguments.length,
            index = fromRight ? length : -1,
            leftIndex = 0,
            funcs = Array(length);

        while ((fromRight ? index-- : ++index < length)) {
          var func = funcs[leftIndex++] = arguments[index];
          if (typeof func != 'function') {
            throw new TypeError(FUNC_ERROR_TEXT);
          }
          if (!wrapper && LodashWrapper.prototype.thru && getFuncName(func) == 'wrapper') {
            wrapper = new LodashWrapper([], true);
          }
        }
        index = wrapper ? -1 : length;
        while (++index < length) {
          func = funcs[index];

          var funcName = getFuncName(func),
              data = funcName == 'wrapper' ? getData(func) : undefined;

          if (data && isLaziable(data[0]) && data[1] == (ARY_FLAG | CURRY_FLAG | PARTIAL_FLAG | REARG_FLAG) && !data[4].length && data[9] == 1) {
            wrapper = wrapper[getFuncName(data[0])].apply(wrapper, data[3]);
          } else {
            wrapper = (func.length == 1 && isLaziable(func)) ? wrapper[funcName]() : wrapper.thru(func);
          }
        }
        return function() {
          var args = arguments,
              value = args[0];

          if (wrapper && args.length == 1 && isArray(value) && value.length >= LARGE_ARRAY_SIZE) {
            return wrapper.plant(value).value();
          }
          var index = 0,
              result = length ? funcs[index].apply(this, args) : value;

          while (++index < length) {
            result = funcs[index].call(this, result);
          }
          return result;
        };
      };
    }

    /**
     * Creates a function for `_.forEach` or `_.forEachRight`.
     *
     * @private
     * @param {Function} arrayFunc The function to iterate over an array.
     * @param {Function} eachFunc The function to iterate over a collection.
     * @returns {Function} Returns the new each function.
     */
    function createForEach(arrayFunc, eachFunc) {
      return function(collection, iteratee, thisArg) {
        return (typeof iteratee == 'function' && thisArg === undefined && isArray(collection))
          ? arrayFunc(collection, iteratee)
          : eachFunc(collection, bindCallback(iteratee, thisArg, 3));
      };
    }

    /**
     * Creates a function for `_.forIn` or `_.forInRight`.
     *
     * @private
     * @param {Function} objectFunc The function to iterate over an object.
     * @returns {Function} Returns the new each function.
     */
    function createForIn(objectFunc) {
      return function(object, iteratee, thisArg) {
        if (typeof iteratee != 'function' || thisArg !== undefined) {
          iteratee = bindCallback(iteratee, thisArg, 3);
        }
        return objectFunc(object, iteratee, keysIn);
      };
    }

    /**
     * Creates a function for `_.forOwn` or `_.forOwnRight`.
     *
     * @private
     * @param {Function} objectFunc The function to iterate over an object.
     * @returns {Function} Returns the new each function.
     */
    function createForOwn(objectFunc) {
      return function(object, iteratee, thisArg) {
        if (typeof iteratee != 'function' || thisArg !== undefined) {
          iteratee = bindCallback(iteratee, thisArg, 3);
        }
        return objectFunc(object, iteratee);
      };
    }

    /**
     * Creates a function for `_.mapKeys` or `_.mapValues`.
     *
     * @private
     * @param {boolean} [isMapKeys] Specify mapping keys instead of values.
     * @returns {Function} Returns the new map function.
     */
    function createObjectMapper(isMapKeys) {
      return function(object, iteratee, thisArg) {
        var result = {};
        iteratee = getCallback(iteratee, thisArg, 3);

        baseForOwn(object, function(value, key, object) {
          var mapped = iteratee(value, key, object);
          key = isMapKeys ? mapped : key;
          value = isMapKeys ? value : mapped;
          result[key] = value;
        });
        return result;
      };
    }

    /**
     * Creates a function for `_.padLeft` or `_.padRight`.
     *
     * @private
     * @param {boolean} [fromRight] Specify padding from the right.
     * @returns {Function} Returns the new pad function.
     */
    function createPadDir(fromRight) {
      return function(string, length, chars) {
        string = baseToString(string);
        return (fromRight ? string : '') + createPadding(string, length, chars) + (fromRight ? '' : string);
      };
    }

    /**
     * Creates a `_.partial` or `_.partialRight` function.
     *
     * @private
     * @param {boolean} flag The partial bit flag.
     * @returns {Function} Returns the new partial function.
     */
    function createPartial(flag) {
      var partialFunc = restParam(function(func, partials) {
        var holders = replaceHolders(partials, partialFunc.placeholder);
        return createWrapper(func, flag, undefined, partials, holders);
      });
      return partialFunc;
    }

    /**
     * Creates a function for `_.reduce` or `_.reduceRight`.
     *
     * @private
     * @param {Function} arrayFunc The function to iterate over an array.
     * @param {Function} eachFunc The function to iterate over a collection.
     * @returns {Function} Returns the new each function.
     */
    function createReduce(arrayFunc, eachFunc) {
      return function(collection, iteratee, accumulator, thisArg) {
        var initFromArray = arguments.length < 3;
        return (typeof iteratee == 'function' && thisArg === undefined && isArray(collection))
          ? arrayFunc(collection, iteratee, accumulator, initFromArray)
          : baseReduce(collection, getCallback(iteratee, thisArg, 4), accumulator, initFromArray, eachFunc);
      };
    }

    /**
     * Creates a function that wraps `func` and invokes it with optional `this`
     * binding of, partial application, and currying.
     *
     * @private
     * @param {Function|string} func The function or method name to reference.
     * @param {number} bitmask The bitmask of flags. See `createWrapper` for more details.
     * @param {*} [thisArg] The `this` binding of `func`.
     * @param {Array} [partials] The arguments to prepend to those provided to the new function.
     * @param {Array} [holders] The `partials` placeholder indexes.
     * @param {Array} [partialsRight] The arguments to append to those provided to the new function.
     * @param {Array} [holdersRight] The `partialsRight` placeholder indexes.
     * @param {Array} [argPos] The argument positions of the new function.
     * @param {number} [ary] The arity cap of `func`.
     * @param {number} [arity] The arity of `func`.
     * @returns {Function} Returns the new wrapped function.
     */
    function createHybridWrapper(func, bitmask, thisArg, partials, holders, partialsRight, holdersRight, argPos, ary, arity) {
      var isAry = bitmask & ARY_FLAG,
          isBind = bitmask & BIND_FLAG,
          isBindKey = bitmask & BIND_KEY_FLAG,
          isCurry = bitmask & CURRY_FLAG,
          isCurryBound = bitmask & CURRY_BOUND_FLAG,
          isCurryRight = bitmask & CURRY_RIGHT_FLAG,
          Ctor = isBindKey ? undefined : createCtorWrapper(func);

      function wrapper() {
        // Avoid `arguments` object use disqualifying optimizations by
        // converting it to an array before providing it to other functions.
        var length = arguments.length,
            index = length,
            args = Array(length);

        while (index--) {
          args[index] = arguments[index];
        }
        if (partials) {
          args = composeArgs(args, partials, holders);
        }
        if (partialsRight) {
          args = composeArgsRight(args, partialsRight, holdersRight);
        }
        if (isCurry || isCurryRight) {
          var placeholder = wrapper.placeholder,
              argsHolders = replaceHolders(args, placeholder);

          length -= argsHolders.length;
          if (length < arity) {
            var newArgPos = argPos ? arrayCopy(argPos) : undefined,
                newArity = nativeMax(arity - length, 0),
                newsHolders = isCurry ? argsHolders : undefined,
                newHoldersRight = isCurry ? undefined : argsHolders,
                newPartials = isCurry ? args : undefined,
                newPartialsRight = isCurry ? undefined : args;

            bitmask |= (isCurry ? PARTIAL_FLAG : PARTIAL_RIGHT_FLAG);
            bitmask &= ~(isCurry ? PARTIAL_RIGHT_FLAG : PARTIAL_FLAG);

            if (!isCurryBound) {
              bitmask &= ~(BIND_FLAG | BIND_KEY_FLAG);
            }
            var newData = [func, bitmask, thisArg, newPartials, newsHolders, newPartialsRight, newHoldersRight, newArgPos, ary, newArity],
                result = createHybridWrapper.apply(undefined, newData);

            if (isLaziable(func)) {
              setData(result, newData);
            }
            result.placeholder = placeholder;
            return result;
          }
        }
        var thisBinding = isBind ? thisArg : this,
            fn = isBindKey ? thisBinding[func] : func;

        if (argPos) {
          args = reorder(args, argPos);
        }
        if (isAry && ary < args.length) {
          args.length = ary;
        }
        if (this && this !== root && this instanceof wrapper) {
          fn = Ctor || createCtorWrapper(func);
        }
        return fn.apply(thisBinding, args);
      }
      return wrapper;
    }

    /**
     * Creates the padding required for `string` based on the given `length`.
     * The `chars` string is truncated if the number of characters exceeds `length`.
     *
     * @private
     * @param {string} string The string to create padding for.
     * @param {number} [length=0] The padding length.
     * @param {string} [chars=' '] The string used as padding.
     * @returns {string} Returns the pad for `string`.
     */
    function createPadding(string, length, chars) {
      var strLength = string.length;
      length = +length;

      if (strLength >= length || !nativeIsFinite(length)) {
        return '';
      }
      var padLength = length - strLength;
      chars = chars == null ? ' ' : (chars + '');
      return repeat(chars, nativeCeil(padLength / chars.length)).slice(0, padLength);
    }

    /**
     * Creates a function that wraps `func` and invokes it with the optional `this`
     * binding of `thisArg` and the `partials` prepended to those provided to
     * the wrapper.
     *
     * @private
     * @param {Function} func The function to partially apply arguments to.
     * @param {number} bitmask The bitmask of flags. See `createWrapper` for more details.
     * @param {*} thisArg The `this` binding of `func`.
     * @param {Array} partials The arguments to prepend to those provided to the new function.
     * @returns {Function} Returns the new bound function.
     */
    function createPartialWrapper(func, bitmask, thisArg, partials) {
      var isBind = bitmask & BIND_FLAG,
          Ctor = createCtorWrapper(func);

      function wrapper() {
        // Avoid `arguments` object use disqualifying optimizations by
        // converting it to an array before providing it `func`.
        var argsIndex = -1,
            argsLength = arguments.length,
            leftIndex = -1,
            leftLength = partials.length,
            args = Array(leftLength + argsLength);

        while (++leftIndex < leftLength) {
          args[leftIndex] = partials[leftIndex];
        }
        while (argsLength--) {
          args[leftIndex++] = arguments[++argsIndex];
        }
        var fn = (this && this !== root && this instanceof wrapper) ? Ctor : func;
        return fn.apply(isBind ? thisArg : this, args);
      }
      return wrapper;
    }

    /**
     * Creates a `_.ceil`, `_.floor`, or `_.round` function.
     *
     * @private
     * @param {string} methodName The name of the `Math` method to use when rounding.
     * @returns {Function} Returns the new round function.
     */
    function createRound(methodName) {
      var func = Math[methodName];
      return function(number, precision) {
        precision = precision === undefined ? 0 : (+precision || 0);
        if (precision) {
          precision = pow(10, precision);
          return func(number * precision) / precision;
        }
        return func(number);
      };
    }

    /**
     * Creates a `_.sortedIndex` or `_.sortedLastIndex` function.
     *
     * @private
     * @param {boolean} [retHighest] Specify returning the highest qualified index.
     * @returns {Function} Returns the new index function.
     */
    function createSortedIndex(retHighest) {
      return function(array, value, iteratee, thisArg) {
        var callback = getCallback(iteratee);
        return (iteratee == null && callback === baseCallback)
          ? binaryIndex(array, value, retHighest)
          : binaryIndexBy(array, value, callback(iteratee, thisArg, 1), retHighest);
      };
    }

    /**
     * Creates a function that either curries or invokes `func` with optional
     * `this` binding and partially applied arguments.
     *
     * @private
     * @param {Function|string} func The function or method name to reference.
     * @param {number} bitmask The bitmask of flags.
     *  The bitmask may be composed of the following flags:
     *     1 - `_.bind`
     *     2 - `_.bindKey`
     *     4 - `_.curry` or `_.curryRight` of a bound function
     *     8 - `_.curry`
     *    16 - `_.curryRight`
     *    32 - `_.partial`
     *    64 - `_.partialRight`
     *   128 - `_.rearg`
     *   256 - `_.ary`
     * @param {*} [thisArg] The `this` binding of `func`.
     * @param {Array} [partials] The arguments to be partially applied.
     * @param {Array} [holders] The `partials` placeholder indexes.
     * @param {Array} [argPos] The argument positions of the new function.
     * @param {number} [ary] The arity cap of `func`.
     * @param {number} [arity] The arity of `func`.
     * @returns {Function} Returns the new wrapped function.
     */
    function createWrapper(func, bitmask, thisArg, partials, holders, argPos, ary, arity) {
      var isBindKey = bitmask & BIND_KEY_FLAG;
      if (!isBindKey && typeof func != 'function') {
        throw new TypeError(FUNC_ERROR_TEXT);
      }
      var length = partials ? partials.length : 0;
      if (!length) {
        bitmask &= ~(PARTIAL_FLAG | PARTIAL_RIGHT_FLAG);
        partials = holders = undefined;
      }
      length -= (holders ? holders.length : 0);
      if (bitmask & PARTIAL_RIGHT_FLAG) {
        var partialsRight = partials,
            holdersRight = holders;

        partials = holders = undefined;
      }
      var data = isBindKey ? undefined : getData(func),
          newData = [func, bitmask, thisArg, partials, holders, partialsRight, holdersRight, argPos, ary, arity];

      if (data) {
        mergeData(newData, data);
        bitmask = newData[1];
        arity = newData[9];
      }
      newData[9] = arity == null
        ? (isBindKey ? 0 : func.length)
        : (nativeMax(arity - length, 0) || 0);

      if (bitmask == BIND_FLAG) {
        var result = createBindWrapper(newData[0], newData[2]);
      } else if ((bitmask == PARTIAL_FLAG || bitmask == (BIND_FLAG | PARTIAL_FLAG)) && !newData[4].length) {
        result = createPartialWrapper.apply(undefined, newData);
      } else {
        result = createHybridWrapper.apply(undefined, newData);
      }
      var setter = data ? baseSetData : setData;
      return setter(result, newData);
    }

    /**
     * A specialized version of `baseIsEqualDeep` for arrays with support for
     * partial deep comparisons.
     *
     * @private
     * @param {Array} array The array to compare.
     * @param {Array} other The other array to compare.
     * @param {Function} equalFunc The function to determine equivalents of values.
     * @param {Function} [customizer] The function to customize comparing arrays.
     * @param {boolean} [isLoose] Specify performing partial comparisons.
     * @param {Array} [stackA] Tracks traversed `value` objects.
     * @param {Array} [stackB] Tracks traversed `other` objects.
     * @returns {boolean} Returns `true` if the arrays are equivalent, else `false`.
     */
    function equalArrays(array, other, equalFunc, customizer, isLoose, stackA, stackB) {
      var index = -1,
          arrLength = array.length,
          othLength = other.length;

      if (arrLength != othLength && !(isLoose && othLength > arrLength)) {
        return false;
      }
      // Ignore non-index properties.
      while (++index < arrLength) {
        var arrValue = array[index],
            othValue = other[index],
            result = customizer ? customizer(isLoose ? othValue : arrValue, isLoose ? arrValue : othValue, index) : undefined;

        if (result !== undefined) {
          if (result) {
            continue;
          }
          return false;
        }
        // Recursively compare arrays (susceptible to call stack limits).
        if (isLoose) {
          if (!arraySome(other, function(othValue) {
                return arrValue === othValue || equalFunc(arrValue, othValue, customizer, isLoose, stackA, stackB);
              })) {
            return false;
          }
        } else if (!(arrValue === othValue || equalFunc(arrValue, othValue, customizer, isLoose, stackA, stackB))) {
          return false;
        }
      }
      return true;
    }

    /**
     * A specialized version of `baseIsEqualDeep` for comparing objects of
     * the same `toStringTag`.
     *
     * **Note:** This function only supports comparing values with tags of
     * `Boolean`, `Date`, `Error`, `Number`, `RegExp`, or `String`.
     *
     * @private
     * @param {Object} object The object to compare.
     * @param {Object} other The other object to compare.
     * @param {string} tag The `toStringTag` of the objects to compare.
     * @returns {boolean} Returns `true` if the objects are equivalent, else `false`.
     */
    function equalByTag(object, other, tag) {
      switch (tag) {
        case boolTag:
        case dateTag:
          // Coerce dates and booleans to numbers, dates to milliseconds and booleans
          // to `1` or `0` treating invalid dates coerced to `NaN` as not equal.
          return +object == +other;

        case errorTag:
          return object.name == other.name && object.message == other.message;

        case numberTag:
          // Treat `NaN` vs. `NaN` as equal.
          return (object != +object)
            ? other != +other
            : object == +other;

        case regexpTag:
        case stringTag:
          // Coerce regexes to strings and treat strings primitives and string
          // objects as equal. See https://es5.github.io/#x15.10.6.4 for more details.
          return object == (other + '');
      }
      return false;
    }

    /**
     * A specialized version of `baseIsEqualDeep` for objects with support for
     * partial deep comparisons.
     *
     * @private
     * @param {Object} object The object to compare.
     * @param {Object} other The other object to compare.
     * @param {Function} equalFunc The function to determine equivalents of values.
     * @param {Function} [customizer] The function to customize comparing values.
     * @param {boolean} [isLoose] Specify performing partial comparisons.
     * @param {Array} [stackA] Tracks traversed `value` objects.
     * @param {Array} [stackB] Tracks traversed `other` objects.
     * @returns {boolean} Returns `true` if the objects are equivalent, else `false`.
     */
    function equalObjects(object, other, equalFunc, customizer, isLoose, stackA, stackB) {
      var objProps = keys(object),
          objLength = objProps.length,
          othProps = keys(other),
          othLength = othProps.length;

      if (objLength != othLength && !isLoose) {
        return false;
      }
      var index = objLength;
      while (index--) {
        var key = objProps[index];
        if (!(isLoose ? key in other : hasOwnProperty.call(other, key))) {
          return false;
        }
      }
      var skipCtor = isLoose;
      while (++index < objLength) {
        key = objProps[index];
        var objValue = object[key],
            othValue = other[key],
            result = customizer ? customizer(isLoose ? othValue : objValue, isLoose? objValue : othValue, key) : undefined;

        // Recursively compare objects (susceptible to call stack limits).
        if (!(result === undefined ? equalFunc(objValue, othValue, customizer, isLoose, stackA, stackB) : result)) {
          return false;
        }
        skipCtor || (skipCtor = key == 'constructor');
      }
      if (!skipCtor) {
        var objCtor = object.constructor,
            othCtor = other.constructor;

        // Non `Object` object instances with different constructors are not equal.
        if (objCtor != othCtor &&
            ('constructor' in object && 'constructor' in other) &&
            !(typeof objCtor == 'function' && objCtor instanceof objCtor &&
              typeof othCtor == 'function' && othCtor instanceof othCtor)) {
          return false;
        }
      }
      return true;
    }

    /**
     * Gets the appropriate "callback" function. If the `_.callback` method is
     * customized this function returns the custom method, otherwise it returns
     * the `baseCallback` function. If arguments are provided the chosen function
     * is invoked with them and its result is returned.
     *
     * @private
     * @returns {Function} Returns the chosen function or its result.
     */
    function getCallback(func, thisArg, argCount) {
      var result = lodash.callback || callback;
      result = result === callback ? baseCallback : result;
      return argCount ? result(func, thisArg, argCount) : result;
    }

    /**
     * Gets metadata for `func`.
     *
     * @private
     * @param {Function} func The function to query.
     * @returns {*} Returns the metadata for `func`.
     */
    var getData = !metaMap ? noop : function(func) {
      return metaMap.get(func);
    };

    /**
     * Gets the name of `func`.
     *
     * @private
     * @param {Function} func The function to query.
     * @returns {string} Returns the function name.
     */
    function getFuncName(func) {
      var result = func.name,
          array = realNames[result],
          length = array ? array.length : 0;

      while (length--) {
        var data = array[length],
            otherFunc = data.func;
        if (otherFunc == null || otherFunc == func) {
          return data.name;
        }
      }
      return result;
    }

    /**
     * Gets the appropriate "indexOf" function. If the `_.indexOf` method is
     * customized this function returns the custom method, otherwise it returns
     * the `baseIndexOf` function. If arguments are provided the chosen function
     * is invoked with them and its result is returned.
     *
     * @private
     * @returns {Function|number} Returns the chosen function or its result.
     */
    function getIndexOf(collection, target, fromIndex) {
      var result = lodash.indexOf || indexOf;
      result = result === indexOf ? baseIndexOf : result;
      return collection ? result(collection, target, fromIndex) : result;
    }

    /**
     * Gets the "length" property value of `object`.
     *
     * **Note:** This function is used to avoid a [JIT bug](https://bugs.webkit.org/show_bug.cgi?id=142792)
     * that affects Safari on at least iOS 8.1-8.3 ARM64.
     *
     * @private
     * @param {Object} object The object to query.
     * @returns {*} Returns the "length" value.
     */
    var getLength = baseProperty('length');

    /**
     * Gets the propery names, values, and compare flags of `object`.
     *
     * @private
     * @param {Object} object The object to query.
     * @returns {Array} Returns the match data of `object`.
     */
    function getMatchData(object) {
      var result = pairs(object),
          length = result.length;

      while (length--) {
        result[length][2] = isStrictComparable(result[length][1]);
      }
      return result;
    }

    /**
     * Gets the native function at `key` of `object`.
     *
     * @private
     * @param {Object} object The object to query.
     * @param {string} key The key of the method to get.
     * @returns {*} Returns the function if it's native, else `undefined`.
     */
    function getNative(object, key) {
      var value = object == null ? undefined : object[key];
      return isNative(value) ? value : undefined;
    }

    /**
     * Gets the view, applying any `transforms` to the `start` and `end` positions.
     *
     * @private
     * @param {number} start The start of the view.
     * @param {number} end The end of the view.
     * @param {Array} transforms The transformations to apply to the view.
     * @returns {Object} Returns an object containing the `start` and `end`
     *  positions of the view.
     */
    function getView(start, end, transforms) {
      var index = -1,
          length = transforms.length;

      while (++index < length) {
        var data = transforms[index],
            size = data.size;

        switch (data.type) {
          case 'drop':      start += size; break;
          case 'dropRight': end -= size; break;
          case 'take':      end = nativeMin(end, start + size); break;
          case 'takeRight': start = nativeMax(start, end - size); break;
        }
      }
      return { 'start': start, 'end': end };
    }

    /**
     * Initializes an array clone.
     *
     * @private
     * @param {Array} array The array to clone.
     * @returns {Array} Returns the initialized clone.
     */
    function initCloneArray(array) {
      var length = array.length,
          result = new array.constructor(length);

      // Add array properties assigned by `RegExp#exec`.
      if (length && typeof array[0] == 'string' && hasOwnProperty.call(array, 'index')) {
        result.index = array.index;
        result.input = array.input;
      }
      return result;
    }

    /**
     * Initializes an object clone.
     *
     * @private
     * @param {Object} object The object to clone.
     * @returns {Object} Returns the initialized clone.
     */
    function initCloneObject(object) {
      var Ctor = object.constructor;
      if (!(typeof Ctor == 'function' && Ctor instanceof Ctor)) {
        Ctor = Object;
      }
      return new Ctor;
    }

    /**
     * Initializes an object clone based on its `toStringTag`.
     *
     * **Note:** This function only supports cloning values with tags of
     * `Boolean`, `Date`, `Error`, `Number`, `RegExp`, or `String`.
     *
     * @private
     * @param {Object} object The object to clone.
     * @param {string} tag The `toStringTag` of the object to clone.
     * @param {boolean} [isDeep] Specify a deep clone.
     * @returns {Object} Returns the initialized clone.
     */
    function initCloneByTag(object, tag, isDeep) {
      var Ctor = object.constructor;
      switch (tag) {
        case arrayBufferTag:
          return bufferClone(object);

        case boolTag:
        case dateTag:
          return new Ctor(+object);

        case float32Tag: case float64Tag:
        case int8Tag: case int16Tag: case int32Tag:
        case uint8Tag: case uint8ClampedTag: case uint16Tag: case uint32Tag:
          var buffer = object.buffer;
          return new Ctor(isDeep ? bufferClone(buffer) : buffer, object.byteOffset, object.length);

        case numberTag:
        case stringTag:
          return new Ctor(object);

        case regexpTag:
          var result = new Ctor(object.source, reFlags.exec(object));
          result.lastIndex = object.lastIndex;
      }
      return result;
    }

    /**
     * Invokes the method at `path` on `object`.
     *
     * @private
     * @param {Object} object The object to query.
     * @param {Array|string} path The path of the method to invoke.
     * @param {Array} args The arguments to invoke the method with.
     * @returns {*} Returns the result of the invoked method.
     */
    function invokePath(object, path, args) {
      if (object != null && !isKey(path, object)) {
        path = toPath(path);
        object = path.length == 1 ? object : baseGet(object, baseSlice(path, 0, -1));
        path = last(path);
      }
      var func = object == null ? object : object[path];
      return func == null ? undefined : func.apply(object, args);
    }

    /**
     * Checks if `value` is array-like.
     *
     * @private
     * @param {*} value The value to check.
     * @returns {boolean} Returns `true` if `value` is array-like, else `false`.
     */
    function isArrayLike(value) {
      return value != null && isLength(getLength(value));
    }

    /**
     * Checks if `value` is a valid array-like index.
     *
     * @private
     * @param {*} value The value to check.
     * @param {number} [length=MAX_SAFE_INTEGER] The upper bounds of a valid index.
     * @returns {boolean} Returns `true` if `value` is a valid index, else `false`.
     */
    function isIndex(value, length) {
      value = (typeof value == 'number' || reIsUint.test(value)) ? +value : -1;
      length = length == null ? MAX_SAFE_INTEGER : length;
      return value > -1 && value % 1 == 0 && value < length;
    }

    /**
     * Checks if the provided arguments are from an iteratee call.
     *
     * @private
     * @param {*} value The potential iteratee value argument.
     * @param {*} index The potential iteratee index or key argument.
     * @param {*} object The potential iteratee object argument.
     * @returns {boolean} Returns `true` if the arguments are from an iteratee call, else `false`.
     */
    function isIterateeCall(value, index, object) {
      if (!isObject(object)) {
        return false;
      }
      var type = typeof index;
      if (type == 'number'
          ? (isArrayLike(object) && isIndex(index, object.length))
          : (type == 'string' && index in object)) {
        var other = object[index];
        return value === value ? (value === other) : (other !== other);
      }
      return false;
    }

    /**
     * Checks if `value` is a property name and not a property path.
     *
     * @private
     * @param {*} value The value to check.
     * @param {Object} [object] The object to query keys on.
     * @returns {boolean} Returns `true` if `value` is a property name, else `false`.
     */
    function isKey(value, object) {
      var type = typeof value;
      if ((type == 'string' && reIsPlainProp.test(value)) || type == 'number') {
        return true;
      }
      if (isArray(value)) {
        return false;
      }
      var result = !reIsDeepProp.test(value);
      return result || (object != null && value in toObject(object));
    }

    /**
     * Checks if `func` has a lazy counterpart.
     *
     * @private
     * @param {Function} func The function to check.
     * @returns {boolean} Returns `true` if `func` has a lazy counterpart, else `false`.
     */
    function isLaziable(func) {
      var funcName = getFuncName(func);
      if (!(funcName in LazyWrapper.prototype)) {
        return false;
      }
      var other = lodash[funcName];
      if (func === other) {
        return true;
      }
      var data = getData(other);
      return !!data && func === data[0];
    }

    /**
     * Checks if `value` is a valid array-like length.
     *
     * **Note:** This function is based on [`ToLength`](http://ecma-international.org/ecma-262/6.0/#sec-tolength).
     *
     * @private
     * @param {*} value The value to check.
     * @returns {boolean} Returns `true` if `value` is a valid length, else `false`.
     */
    function isLength(value) {
      return typeof value == 'number' && value > -1 && value % 1 == 0 && value <= MAX_SAFE_INTEGER;
    }

    /**
     * Checks if `value` is suitable for strict equality comparisons, i.e. `===`.
     *
     * @private
     * @param {*} value The value to check.
     * @returns {boolean} Returns `true` if `value` if suitable for strict
     *  equality comparisons, else `false`.
     */
    function isStrictComparable(value) {
      return value === value && !isObject(value);
    }

    /**
     * Merges the function metadata of `source` into `data`.
     *
     * Merging metadata reduces the number of wrappers required to invoke a function.
     * This is possible because methods like `_.bind`, `_.curry`, and `_.partial`
     * may be applied regardless of execution order. Methods like `_.ary` and `_.rearg`
     * augment function arguments, making the order in which they are executed important,
     * preventing the merging of metadata. However, we make an exception for a safe
     * common case where curried functions have `_.ary` and or `_.rearg` applied.
     *
     * @private
     * @param {Array} data The destination metadata.
     * @param {Array} source The source metadata.
     * @returns {Array} Returns `data`.
     */
    function mergeData(data, source) {
      var bitmask = data[1],
          srcBitmask = source[1],
          newBitmask = bitmask | srcBitmask,
          isCommon = newBitmask < ARY_FLAG;

      var isCombo =
        (srcBitmask == ARY_FLAG && bitmask == CURRY_FLAG) ||
        (srcBitmask == ARY_FLAG && bitmask == REARG_FLAG && data[7].length <= source[8]) ||
        (srcBitmask == (ARY_FLAG | REARG_FLAG) && bitmask == CURRY_FLAG);

      // Exit early if metadata can't be merged.
      if (!(isCommon || isCombo)) {
        return data;
      }
      // Use source `thisArg` if available.
      if (srcBitmask & BIND_FLAG) {
        data[2] = source[2];
        // Set when currying a bound function.
        newBitmask |= (bitmask & BIND_FLAG) ? 0 : CURRY_BOUND_FLAG;
      }
      // Compose partial arguments.
      var value = source[3];
      if (value) {
        var partials = data[3];
        data[3] = partials ? composeArgs(partials, value, source[4]) : arrayCopy(value);
        data[4] = partials ? replaceHolders(data[3], PLACEHOLDER) : arrayCopy(source[4]);
      }
      // Compose partial right arguments.
      value = source[5];
      if (value) {
        partials = data[5];
        data[5] = partials ? composeArgsRight(partials, value, source[6]) : arrayCopy(value);
        data[6] = partials ? replaceHolders(data[5], PLACEHOLDER) : arrayCopy(source[6]);
      }
      // Use source `argPos` if available.
      value = source[7];
      if (value) {
        data[7] = arrayCopy(value);
      }
      // Use source `ary` if it's smaller.
      if (srcBitmask & ARY_FLAG) {
        data[8] = data[8] == null ? source[8] : nativeMin(data[8], source[8]);
      }
      // Use source `arity` if one is not provided.
      if (data[9] == null) {
        data[9] = source[9];
      }
      // Use source `func` and merge bitmasks.
      data[0] = source[0];
      data[1] = newBitmask;

      return data;
    }

    /**
     * Used by `_.defaultsDeep` to customize its `_.merge` use.
     *
     * @private
     * @param {*} objectValue The destination object property value.
     * @param {*} sourceValue The source object property value.
     * @returns {*} Returns the value to assign to the destination object.
     */
    function mergeDefaults(objectValue, sourceValue) {
      return objectValue === undefined ? sourceValue : merge(objectValue, sourceValue, mergeDefaults);
    }

    /**
     * A specialized version of `_.pick` which picks `object` properties specified
     * by `props`.
     *
     * @private
     * @param {Object} object The source object.
     * @param {string[]} props The property names to pick.
     * @returns {Object} Returns the new object.
     */
    function pickByArray(object, props) {
      object = toObject(object);

      var index = -1,
          length = props.length,
          result = {};

      while (++index < length) {
        var key = props[index];
        if (key in object) {
          result[key] = object[key];
        }
      }
      return result;
    }

    /**
     * A specialized version of `_.pick` which picks `object` properties `predicate`
     * returns truthy for.
     *
     * @private
     * @param {Object} object The source object.
     * @param {Function} predicate The function invoked per iteration.
     * @returns {Object} Returns the new object.
     */
    function pickByCallback(object, predicate) {
      var result = {};
      baseForIn(object, function(value, key, object) {
        if (predicate(value, key, object)) {
          result[key] = value;
        }
      });
      return result;
    }

    /**
     * Reorder `array` according to the specified indexes where the element at
     * the first index is assigned as the first element, the element at
     * the second index is assigned as the second element, and so on.
     *
     * @private
     * @param {Array} array The array to reorder.
     * @param {Array} indexes The arranged array indexes.
     * @returns {Array} Returns `array`.
     */
    function reorder(array, indexes) {
      var arrLength = array.length,
          length = nativeMin(indexes.length, arrLength),
          oldArray = arrayCopy(array);

      while (length--) {
        var index = indexes[length];
        array[length] = isIndex(index, arrLength) ? oldArray[index] : undefined;
      }
      return array;
    }

    /**
     * Sets metadata for `func`.
     *
     * **Note:** If this function becomes hot, i.e. is invoked a lot in a short
     * period of time, it will trip its breaker and transition to an identity function
     * to avoid garbage collection pauses in V8. See [V8 issue 2070](https://code.google.com/p/v8/issues/detail?id=2070)
     * for more details.
     *
     * @private
     * @param {Function} func The function to associate metadata with.
     * @param {*} data The metadata.
     * @returns {Function} Returns `func`.
     */
    var setData = (function() {
      var count = 0,
          lastCalled = 0;

      return function(key, value) {
        var stamp = now(),
            remaining = HOT_SPAN - (stamp - lastCalled);

        lastCalled = stamp;
        if (remaining > 0) {
          if (++count >= HOT_COUNT) {
            return key;
          }
        } else {
          count = 0;
        }
        return baseSetData(key, value);
      };
    }());

    /**
     * A fallback implementation of `Object.keys` which creates an array of the
     * own enumerable property names of `object`.
     *
     * @private
     * @param {Object} object The object to query.
     * @returns {Array} Returns the array of property names.
     */
    function shimKeys(object) {
      var props = keysIn(object),
          propsLength = props.length,
          length = propsLength && object.length;

      var allowIndexes = !!length && isLength(length) &&
        (isArray(object) || isArguments(object));

      var index = -1,
          result = [];

      while (++index < propsLength) {
        var key = props[index];
        if ((allowIndexes && isIndex(key, length)) || hasOwnProperty.call(object, key)) {
          result.push(key);
        }
      }
      return result;
    }

    /**
     * Converts `value` to an array-like object if it's not one.
     *
     * @private
     * @param {*} value The value to process.
     * @returns {Array|Object} Returns the array-like object.
     */
    function toIterable(value) {
      if (value == null) {
        return [];
      }
      if (!isArrayLike(value)) {
        return values(value);
      }
      return isObject(value) ? value : Object(value);
    }

    /**
     * Converts `value` to an object if it's not one.
     *
     * @private
     * @param {*} value The value to process.
     * @returns {Object} Returns the object.
     */
    function toObject(value) {
      return isObject(value) ? value : Object(value);
    }

    /**
     * Converts `value` to property path array if it's not one.
     *
     * @private
     * @param {*} value The value to process.
     * @returns {Array} Returns the property path array.
     */
    function toPath(value) {
      if (isArray(value)) {
        return value;
      }
      var result = [];
      baseToString(value).replace(rePropName, function(match, number, quote, string) {
        result.push(quote ? string.replace(reEscapeChar, '$1') : (number || match));
      });
      return result;
    }

    /**
     * Creates a clone of `wrapper`.
     *
     * @private
     * @param {Object} wrapper The wrapper to clone.
     * @returns {Object} Returns the cloned wrapper.
     */
    function wrapperClone(wrapper) {
      return wrapper instanceof LazyWrapper
        ? wrapper.clone()
        : new LodashWrapper(wrapper.__wrapped__, wrapper.__chain__, arrayCopy(wrapper.__actions__));
    }

    /*------------------------------------------------------------------------*/

    /**
     * Creates an array of elements split into groups the length of `size`.
     * If `collection` can't be split evenly, the final chunk will be the remaining
     * elements.
     *
     * @static
     * @memberOf _
     * @category Array
     * @param {Array} array The array to process.
     * @param {number} [size=1] The length of each chunk.
     * @param- {Object} [guard] Enables use as a callback for functions like `_.map`.
     * @returns {Array} Returns the new array containing chunks.
     * @example
     *
     * _.chunk(['a', 'b', 'c', 'd'], 2);
     * // => [['a', 'b'], ['c', 'd']]
     *
     * _.chunk(['a', 'b', 'c', 'd'], 3);
     * // => [['a', 'b', 'c'], ['d']]
     */
    function chunk(array, size, guard) {
      if (guard ? isIterateeCall(array, size, guard) : size == null) {
        size = 1;
      } else {
        size = nativeMax(nativeFloor(size) || 1, 1);
      }
      var index = 0,
          length = array ? array.length : 0,
          resIndex = -1,
          result = Array(nativeCeil(length / size));

      while (index < length) {
        result[++resIndex] = baseSlice(array, index, (index += size));
      }
      return result;
    }

    /**
     * Creates an array with all falsey values removed. The values `false`, `null`,
     * `0`, `""`, `undefined`, and `NaN` are falsey.
     *
     * @static
     * @memberOf _
     * @category Array
     * @param {Array} array The array to compact.
     * @returns {Array} Returns the new array of filtered values.
     * @example
     *
     * _.compact([0, 1, false, 2, '', 3]);
     * // => [1, 2, 3]
     */
    function compact(array) {
      var index = -1,
          length = array ? array.length : 0,
          resIndex = -1,
          result = [];

      while (++index < length) {
        var value = array[index];
        if (value) {
          result[++resIndex] = value;
        }
      }
      return result;
    }

    /**
     * Creates an array of unique `array` values not included in the other
     * provided arrays using [`SameValueZero`](http://ecma-international.org/ecma-262/6.0/#sec-samevaluezero)
     * for equality comparisons.
     *
     * @static
     * @memberOf _
     * @category Array
     * @param {Array} array The array to inspect.
     * @param {...Array} [values] The arrays of values to exclude.
     * @returns {Array} Returns the new array of filtered values.
     * @example
     *
     * _.difference([1, 2, 3], [4, 2]);
     * // => [1, 3]
     */
    var difference = restParam(function(array, values) {
      return (isObjectLike(array) && isArrayLike(array))
        ? baseDifference(array, baseFlatten(values, false, true))
        : [];
    });

    /**
     * Creates a slice of `array` with `n` elements dropped from the beginning.
     *
     * @static
     * @memberOf _
     * @category Array
     * @param {Array} array The array to query.
     * @param {number} [n=1] The number of elements to drop.
     * @param- {Object} [guard] Enables use as a callback for functions like `_.map`.
     * @returns {Array} Returns the slice of `array`.
     * @example
     *
     * _.drop([1, 2, 3]);
     * // => [2, 3]
     *
     * _.drop([1, 2, 3], 2);
     * // => [3]
     *
     * _.drop([1, 2, 3], 5);
     * // => []
     *
     * _.drop([1, 2, 3], 0);
     * // => [1, 2, 3]
     */
    function drop(array, n, guard) {
      var length = array ? array.length : 0;
      if (!length) {
        return [];
      }
      if (guard ? isIterateeCall(array, n, guard) : n == null) {
        n = 1;
      }
      return baseSlice(array, n < 0 ? 0 : n);
    }

    /**
     * Creates a slice of `array` with `n` elements dropped from the end.
     *
     * @static
     * @memberOf _
     * @category Array
     * @param {Array} array The array to query.
     * @param {number} [n=1] The number of elements to drop.
     * @param- {Object} [guard] Enables use as a callback for functions like `_.map`.
     * @returns {Array} Returns the slice of `array`.
     * @example
     *
     * _.dropRight([1, 2, 3]);
     * // => [1, 2]
     *
     * _.dropRight([1, 2, 3], 2);
     * // => [1]
     *
     * _.dropRight([1, 2, 3], 5);
     * // => []
     *
     * _.dropRight([1, 2, 3], 0);
     * // => [1, 2, 3]
     */
    function dropRight(array, n, guard) {
      var length = array ? array.length : 0;
      if (!length) {
        return [];
      }
      if (guard ? isIterateeCall(array, n, guard) : n == null) {
        n = 1;
      }
      n = length - (+n || 0);
      return baseSlice(array, 0, n < 0 ? 0 : n);
    }

    /**
     * Creates a slice of `array` excluding elements dropped from the end.
     * Elements are dropped until `predicate` returns falsey. The predicate is
     * bound to `thisArg` and invoked with three arguments: (value, index, array).
     *
     * If a property name is provided for `predicate` the created `_.property`
     * style callback returns the property value of the given element.
     *
     * If a value is also provided for `thisArg` the created `_.matchesProperty`
     * style callback returns `true` for elements that have a matching property
     * value, else `false`.
     *
     * If an object is provided for `predicate` the created `_.matches` style
     * callback returns `true` for elements that match the properties of the given
     * object, else `false`.
     *
     * @static
     * @memberOf _
     * @category Array
     * @param {Array} array The array to query.
     * @param {Function|Object|string} [predicate=_.identity] The function invoked
     *  per iteration.
     * @param {*} [thisArg] The `this` binding of `predicate`.
     * @returns {Array} Returns the slice of `array`.
     * @example
     *
     * _.dropRightWhile([1, 2, 3], function(n) {
     *   return n > 1;
     * });
     * // => [1]
     *
     * var users = [
     *   { 'user': 'barney',  'active': true },
     *   { 'user': 'fred',    'active': false },
     *   { 'user': 'pebbles', 'active': false }
     * ];
     *
     * // using the `_.matches` callback shorthand
     * _.pluck(_.dropRightWhile(users, { 'user': 'pebbles', 'active': false }), 'user');
     * // => ['barney', 'fred']
     *
     * // using the `_.matchesProperty` callback shorthand
     * _.pluck(_.dropRightWhile(users, 'active', false), 'user');
     * // => ['barney']
     *
     * // using the `_.property` callback shorthand
     * _.pluck(_.dropRightWhile(users, 'active'), 'user');
     * // => ['barney', 'fred', 'pebbles']
     */
    function dropRightWhile(array, predicate, thisArg) {
      return (array && array.length)
        ? baseWhile(array, getCallback(predicate, thisArg, 3), true, true)
        : [];
    }

    /**
     * Creates a slice of `array` excluding elements dropped from the beginning.
     * Elements are dropped until `predicate` returns falsey. The predicate is
     * bound to `thisArg` and invoked with three arguments: (value, index, array).
     *
     * If a property name is provided for `predicate` the created `_.property`
     * style callback returns the property value of the given element.
     *
     * If a value is also provided for `thisArg` the created `_.matchesProperty`
     * style callback returns `true` for elements that have a matching property
     * value, else `false`.
     *
     * If an object is provided for `predicate` the created `_.matches` style
     * callback returns `true` for elements that have the properties of the given
     * object, else `false`.
     *
     * @static
     * @memberOf _
     * @category Array
     * @param {Array} array The array to query.
     * @param {Function|Object|string} [predicate=_.identity] The function invoked
     *  per iteration.
     * @param {*} [thisArg] The `this` binding of `predicate`.
     * @returns {Array} Returns the slice of `array`.
     * @example
     *
     * _.dropWhile([1, 2, 3], function(n) {
     *   return n < 3;
     * });
     * // => [3]
     *
     * var users = [
     *   { 'user': 'barney',  'active': false },
     *   { 'user': 'fred',    'active': false },
     *   { 'user': 'pebbles', 'active': true }
     * ];
     *
     * // using the `_.matches` callback shorthand
     * _.pluck(_.dropWhile(users, { 'user': 'barney', 'active': false }), 'user');
     * // => ['fred', 'pebbles']
     *
     * // using the `_.matchesProperty` callback shorthand
     * _.pluck(_.dropWhile(users, 'active', false), 'user');
     * // => ['pebbles']
     *
     * // using the `_.property` callback shorthand
     * _.pluck(_.dropWhile(users, 'active'), 'user');
     * // => ['barney', 'fred', 'pebbles']
     */
    function dropWhile(array, predicate, thisArg) {
      return (array && array.length)
        ? baseWhile(array, getCallback(predicate, thisArg, 3), true)
        : [];
    }

    /**
     * Fills elements of `array` with `value` from `start` up to, but not
     * including, `end`.
     *
     * **Note:** This method mutates `array`.
     *
     * @static
     * @memberOf _
     * @category Array
     * @param {Array} array The array to fill.
     * @param {*} value The value to fill `array` with.
     * @param {number} [start=0] The start position.
     * @param {number} [end=array.length] The end position.
     * @returns {Array} Returns `array`.
     * @example
     *
     * var array = [1, 2, 3];
     *
     * _.fill(array, 'a');
     * console.log(array);
     * // => ['a', 'a', 'a']
     *
     * _.fill(Array(3), 2);
     * // => [2, 2, 2]
     *
     * _.fill([4, 6, 8], '*', 1, 2);
     * // => [4, '*', 8]
     */
    function fill(array, value, start, end) {
      var length = array ? array.length : 0;
      if (!length) {
        return [];
      }
      if (start && typeof start != 'number' && isIterateeCall(array, value, start)) {
        start = 0;
        end = length;
      }
      return baseFill(array, value, start, end);
    }

    /**
     * This method is like `_.find` except that it returns the index of the first
     * element `predicate` returns truthy for instead of the element itself.
     *
     * If a property name is provided for `predicate` the created `_.property`
     * style callback returns the property value of the given element.
     *
     * If a value is also provided for `thisArg` the created `_.matchesProperty`
     * style callback returns `true` for elements that have a matching property
     * value, else `false`.
     *
     * If an object is provided for `predicate` the created `_.matches` style
     * callback returns `true` for elements that have the properties of the given
     * object, else `false`.
     *
     * @static
     * @memberOf _
     * @category Array
     * @param {Array} array The array to search.
     * @param {Function|Object|string} [predicate=_.identity] The function invoked
     *  per iteration.
     * @param {*} [thisArg] The `this` binding of `predicate`.
     * @returns {number} Returns the index of the found element, else `-1`.
     * @example
     *
     * var users = [
     *   { 'user': 'barney',  'active': false },
     *   { 'user': 'fred',    'active': false },
     *   { 'user': 'pebbles', 'active': true }
     * ];
     *
     * _.findIndex(users, function(chr) {
     *   return chr.user == 'barney';
     * });
     * // => 0
     *
     * // using the `_.matches` callback shorthand
     * _.findIndex(users, { 'user': 'fred', 'active': false });
     * // => 1
     *
     * // using the `_.matchesProperty` callback shorthand
     * _.findIndex(users, 'active', false);
     * // => 0
     *
     * // using the `_.property` callback shorthand
     * _.findIndex(users, 'active');
     * // => 2
     */
    var findIndex = createFindIndex();

    /**
     * This method is like `_.findIndex` except that it iterates over elements
     * of `collection` from right to left.
     *
     * If a property name is provided for `predicate` the created `_.property`
     * style callback returns the property value of the given element.
     *
     * If a value is also provided for `thisArg` the created `_.matchesProperty`
     * style callback returns `true` for elements that have a matching property
     * value, else `false`.
     *
     * If an object is provided for `predicate` the created `_.matches` style
     * callback returns `true` for elements that have the properties of the given
     * object, else `false`.
     *
     * @static
     * @memberOf _
     * @category Array
     * @param {Array} array The array to search.
     * @param {Function|Object|string} [predicate=_.identity] The function invoked
     *  per iteration.
     * @param {*} [thisArg] The `this` binding of `predicate`.
     * @returns {number} Returns the index of the found element, else `-1`.
     * @example
     *
     * var users = [
     *   { 'user': 'barney',  'active': true },
     *   { 'user': 'fred',    'active': false },
     *   { 'user': 'pebbles', 'active': false }
     * ];
     *
     * _.findLastIndex(users, function(chr) {
     *   return chr.user == 'pebbles';
     * });
     * // => 2
     *
     * // using the `_.matches` callback shorthand
     * _.findLastIndex(users, { 'user': 'barney', 'active': true });
     * // => 0
     *
     * // using the `_.matchesProperty` callback shorthand
     * _.findLastIndex(users, 'active', false);
     * // => 2
     *
     * // using the `_.property` callback shorthand
     * _.findLastIndex(users, 'active');
     * // => 0
     */
    var findLastIndex = createFindIndex(true);

    /**
     * Gets the first element of `array`.
     *
     * @static
     * @memberOf _
     * @alias head
     * @category Array
     * @param {Array} array The array to query.
     * @returns {*} Returns the first element of `array`.
     * @example
     *
     * _.first([1, 2, 3]);
     * // => 1
     *
     * _.first([]);
     * // => undefined
     */
    function first(array) {
      return array ? array[0] : undefined;
    }

    /**
     * Flattens a nested array. If `isDeep` is `true` the array is recursively
     * flattened, otherwise it is only flattened a single level.
     *
     * @static
     * @memberOf _
     * @category Array
     * @param {Array} array The array to flatten.
     * @param {boolean} [isDeep] Specify a deep flatten.
     * @param- {Object} [guard] Enables use as a callback for functions like `_.map`.
     * @returns {Array} Returns the new flattened array.
     * @example
     *
     * _.flatten([1, [2, 3, [4]]]);
     * // => [1, 2, 3, [4]]
     *
     * // using `isDeep`
     * _.flatten([1, [2, 3, [4]]], true);
     * // => [1, 2, 3, 4]
     */
    function flatten(array, isDeep, guard) {
      var length = array ? array.length : 0;
      if (guard && isIterateeCall(array, isDeep, guard)) {
        isDeep = false;
      }
      return length ? baseFlatten(array, isDeep) : [];
    }

    /**
     * Recursively flattens a nested array.
     *
     * @static
     * @memberOf _
     * @category Array
     * @param {Array} array The array to recursively flatten.
     * @returns {Array} Returns the new flattened array.
     * @example
     *
     * _.flattenDeep([1, [2, 3, [4]]]);
     * // => [1, 2, 3, 4]
     */
    function flattenDeep(array) {
      var length = array ? array.length : 0;
      return length ? baseFlatten(array, true) : [];
    }

    /**
     * Gets the index at which the first occurrence of `value` is found in `array`
     * using [`SameValueZero`](http://ecma-international.org/ecma-262/6.0/#sec-samevaluezero)
     * for equality comparisons. If `fromIndex` is negative, it is used as the offset
     * from the end of `array`. If `array` is sorted providing `true` for `fromIndex`
     * performs a faster binary search.
     *
     * @static
     * @memberOf _
     * @category Array
     * @param {Array} array The array to search.
     * @param {*} value The value to search for.
     * @param {boolean|number} [fromIndex=0] The index to search from or `true`
     *  to perform a binary search on a sorted array.
     * @returns {number} Returns the index of the matched value, else `-1`.
     * @example
     *
     * _.indexOf([1, 2, 1, 2], 2);
     * // => 1
     *
     * // using `fromIndex`
     * _.indexOf([1, 2, 1, 2], 2, 2);
     * // => 3
     *
     * // performing a binary search
     * _.indexOf([1, 1, 2, 2], 2, true);
     * // => 2
     */
    function indexOf(array, value, fromIndex) {
      var length = array ? array.length : 0;
      if (!length) {
        return -1;
      }
      if (typeof fromIndex == 'number') {
        fromIndex = fromIndex < 0 ? nativeMax(length + fromIndex, 0) : fromIndex;
      } else if (fromIndex) {
        var index = binaryIndex(array, value);
        if (index < length &&
            (value === value ? (value === array[index]) : (array[index] !== array[index]))) {
          return index;
        }
        return -1;
      }
      return baseIndexOf(array, value, fromIndex || 0);
    }

    /**
     * Gets all but the last element of `array`.
     *
     * @static
     * @memberOf _
     * @category Array
     * @param {Array} array The array to query.
     * @returns {Array} Returns the slice of `array`.
     * @example
     *
     * _.initial([1, 2, 3]);
     * // => [1, 2]
     */
    function initial(array) {
      return dropRight(array, 1);
    }

    /**
     * Creates an array of unique values that are included in all of the provided
     * arrays using [`SameValueZero`](http://ecma-international.org/ecma-262/6.0/#sec-samevaluezero)
     * for equality comparisons.
     *
     * @static
     * @memberOf _
     * @category Array
     * @param {...Array} [arrays] The arrays to inspect.
     * @returns {Array} Returns the new array of shared values.
     * @example
     * _.intersection([1, 2], [4, 2], [2, 1]);
     * // => [2]
     */
    var intersection = restParam(function(arrays) {
      var othLength = arrays.length,
          othIndex = othLength,
          caches = Array(length),
          indexOf = getIndexOf(),
          isCommon = indexOf == baseIndexOf,
          result = [];

      while (othIndex--) {
        var value = arrays[othIndex] = isArrayLike(value = arrays[othIndex]) ? value : [];
        caches[othIndex] = (isCommon && value.length >= 120) ? createCache(othIndex && value) : null;
      }
      var array = arrays[0],
          index = -1,
          length = array ? array.length : 0,
          seen = caches[0];

      outer:
      while (++index < length) {
        value = array[index];
        if ((seen ? cacheIndexOf(seen, value) : indexOf(result, value, 0)) < 0) {
          var othIndex = othLength;
          while (--othIndex) {
            var cache = caches[othIndex];
            if ((cache ? cacheIndexOf(cache, value) : indexOf(arrays[othIndex], value, 0)) < 0) {
              continue outer;
            }
          }
          if (seen) {
            seen.push(value);
          }
          result.push(value);
        }
      }
      return result;
    });

    /**
     * Gets the last element of `array`.
     *
     * @static
     * @memberOf _
     * @category Array
     * @param {Array} array The array to query.
     * @returns {*} Returns the last element of `array`.
     * @example
     *
     * _.last([1, 2, 3]);
     * // => 3
     */
    function last(array) {
      var length = array ? array.length : 0;
      return length ? array[length - 1] : undefined;
    }

    /**
     * This method is like `_.indexOf` except that it iterates over elements of
     * `array` from right to left.
     *
     * @static
     * @memberOf _
     * @category Array
     * @param {Array} array The array to search.
     * @param {*} value The value to search for.
     * @param {boolean|number} [fromIndex=array.length-1] The index to search from
     *  or `true` to perform a binary search on a sorted array.
     * @returns {number} Returns the index of the matched value, else `-1`.
     * @example
     *
     * _.lastIndexOf([1, 2, 1, 2], 2);
     * // => 3
     *
     * // using `fromIndex`
     * _.lastIndexOf([1, 2, 1, 2], 2, 2);
     * // => 1
     *
     * // performing a binary search
     * _.lastIndexOf([1, 1, 2, 2], 2, true);
     * // => 3
     */
    function lastIndexOf(array, value, fromIndex) {
      var length = array ? array.length : 0;
      if (!length) {
        return -1;
      }
      var index = length;
      if (typeof fromIndex == 'number') {
        index = (fromIndex < 0 ? nativeMax(length + fromIndex, 0) : nativeMin(fromIndex || 0, length - 1)) + 1;
      } else if (fromIndex) {
        index = binaryIndex(array, value, true) - 1;
        var other = array[index];
        if (value === value ? (value === other) : (other !== other)) {
          return index;
        }
        return -1;
      }
      if (value !== value) {
        return indexOfNaN(array, index, true);
      }
      while (index--) {
        if (array[index] === value) {
          return index;
        }
      }
      return -1;
    }

    /**
     * Removes all provided values from `array` using
     * [`SameValueZero`](http://ecma-international.org/ecma-262/6.0/#sec-samevaluezero)
     * for equality comparisons.
     *
     * **Note:** Unlike `_.without`, this method mutates `array`.
     *
     * @static
     * @memberOf _
     * @category Array
     * @param {Array} array The array to modify.
     * @param {...*} [values] The values to remove.
     * @returns {Array} Returns `array`.
     * @example
     *
     * var array = [1, 2, 3, 1, 2, 3];
     *
     * _.pull(array, 2, 3);
     * console.log(array);
     * // => [1, 1]
     */
    function pull() {
      var args = arguments,
          array = args[0];

      if (!(array && array.length)) {
        return array;
      }
      var index = 0,
          indexOf = getIndexOf(),
          length = args.length;

      while (++index < length) {
        var fromIndex = 0,
            value = args[index];

        while ((fromIndex = indexOf(array, value, fromIndex)) > -1) {
          splice.call(array, fromIndex, 1);
        }
      }
      return array;
    }

    /**
     * Removes elements from `array` corresponding to the given indexes and returns
     * an array of the removed elements. Indexes may be specified as an array of
     * indexes or as individual arguments.
     *
     * **Note:** Unlike `_.at`, this method mutates `array`.
     *
     * @static
     * @memberOf _
     * @category Array
     * @param {Array} array The array to modify.
     * @param {...(number|number[])} [indexes] The indexes of elements to remove,
     *  specified as individual indexes or arrays of indexes.
     * @returns {Array} Returns the new array of removed elements.
     * @example
     *
     * var array = [5, 10, 15, 20];
     * var evens = _.pullAt(array, 1, 3);
     *
     * console.log(array);
     * // => [5, 15]
     *
     * console.log(evens);
     * // => [10, 20]
     */
    var pullAt = restParam(function(array, indexes) {
      indexes = baseFlatten(indexes);

      var result = baseAt(array, indexes);
      basePullAt(array, indexes.sort(baseCompareAscending));
      return result;
    });

    /**
     * Removes all elements from `array` that `predicate` returns truthy for
     * and returns an array of the removed elements. The predicate is bound to
     * `thisArg` and invoked with three arguments: (value, index, array).
     *
     * If a property name is provided for `predicate` the created `_.property`
     * style callback returns the property value of the given element.
     *
     * If a value is also provided for `thisArg` the created `_.matchesProperty`
     * style callback returns `true` for elements that have a matching property
     * value, else `false`.
     *
     * If an object is provided for `predicate` the created `_.matches` style
     * callback returns `true` for elements that have the properties of the given
     * object, else `false`.
     *
     * **Note:** Unlike `_.filter`, this method mutates `array`.
     *
     * @static
     * @memberOf _
     * @category Array
     * @param {Array} array The array to modify.
     * @param {Function|Object|string} [predicate=_.identity] The function invoked
     *  per iteration.
     * @param {*} [thisArg] The `this` binding of `predicate`.
     * @returns {Array} Returns the new array of removed elements.
     * @example
     *
     * var array = [1, 2, 3, 4];
     * var evens = _.remove(array, function(n) {
     *   return n % 2 == 0;
     * });
     *
     * console.log(array);
     * // => [1, 3]
     *
     * console.log(evens);
     * // => [2, 4]
     */
    function remove(array, predicate, thisArg) {
      var result = [];
      if (!(array && array.length)) {
        return result;
      }
      var index = -1,
          indexes = [],
          length = array.length;

      predicate = getCallback(predicate, thisArg, 3);
      while (++index < length) {
        var value = array[index];
        if (predicate(value, index, array)) {
          result.push(value);
          indexes.push(index);
        }
      }
      basePullAt(array, indexes);
      return result;
    }

    /**
     * Gets all but the first element of `array`.
     *
     * @static
     * @memberOf _
     * @alias tail
     * @category Array
     * @param {Array} array The array to query.
     * @returns {Array} Returns the slice of `array`.
     * @example
     *
     * _.rest([1, 2, 3]);
     * // => [2, 3]
     */
    function rest(array) {
      return drop(array, 1);
    }

    /**
     * Creates a slice of `array` from `start` up to, but not including, `end`.
     *
     * **Note:** This method is used instead of `Array#slice` to support node
     * lists in IE < 9 and to ensure dense arrays are returned.
     *
     * @static
     * @memberOf _
     * @category Array
     * @param {Array} array The array to slice.
     * @param {number} [start=0] The start position.
     * @param {number} [end=array.length] The end position.
     * @returns {Array} Returns the slice of `array`.
     */
    function slice(array, start, end) {
      var length = array ? array.length : 0;
      if (!length) {
        return [];
      }
      if (end && typeof end != 'number' && isIterateeCall(array, start, end)) {
        start = 0;
        end = length;
      }
      return baseSlice(array, start, end);
    }

    /**
     * Uses a binary search to determine the lowest index at which `value` should
     * be inserted into `array` in order to maintain its sort order. If an iteratee
     * function is provided it is invoked for `value` and each element of `array`
     * to compute their sort ranking. The iteratee is bound to `thisArg` and
     * invoked with one argument; (value).
     *
     * If a property name is provided for `iteratee` the created `_.property`
     * style callback returns the property value of the given element.
     *
     * If a value is also provided for `thisArg` the created `_.matchesProperty`
     * style callback returns `true` for elements that have a matching property
     * value, else `false`.
     *
     * If an object is provided for `iteratee` the created `_.matches` style
     * callback returns `true` for elements that have the properties of the given
     * object, else `false`.
     *
     * @static
     * @memberOf _
     * @category Array
     * @param {Array} array The sorted array to inspect.
     * @param {*} value The value to evaluate.
     * @param {Function|Object|string} [iteratee=_.identity] The function invoked
     *  per iteration.
     * @param {*} [thisArg] The `this` binding of `iteratee`.
     * @returns {number} Returns the index at which `value` should be inserted
     *  into `array`.
     * @example
     *
     * _.sortedIndex([30, 50], 40);
     * // => 1
     *
     * _.sortedIndex([4, 4, 5, 5], 5);
     * // => 2
     *
     * var dict = { 'data': { 'thirty': 30, 'forty': 40, 'fifty': 50 } };
     *
     * // using an iteratee function
     * _.sortedIndex(['thirty', 'fifty'], 'forty', function(word) {
     *   return this.data[word];
     * }, dict);
     * // => 1
     *
     * // using the `_.property` callback shorthand
     * _.sortedIndex([{ 'x': 30 }, { 'x': 50 }], { 'x': 40 }, 'x');
     * // => 1
     */
    var sortedIndex = createSortedIndex();

    /**
     * This method is like `_.sortedIndex` except that it returns the highest
     * index at which `value` should be inserted into `array` in order to
     * maintain its sort order.
     *
     * @static
     * @memberOf _
     * @category Array
     * @param {Array} array The sorted array to inspect.
     * @param {*} value The value to evaluate.
     * @param {Function|Object|string} [iteratee=_.identity] The function invoked
     *  per iteration.
     * @param {*} [thisArg] The `this` binding of `iteratee`.
     * @returns {number} Returns the index at which `value` should be inserted
     *  into `array`.
     * @example
     *
     * _.sortedLastIndex([4, 4, 5, 5], 5);
     * // => 4
     */
    var sortedLastIndex = createSortedIndex(true);

    /**
     * Creates a slice of `array` with `n` elements taken from the beginning.
     *
     * @static
     * @memberOf _
     * @category Array
     * @param {Array} array The array to query.
     * @param {number} [n=1] The number of elements to take.
     * @param- {Object} [guard] Enables use as a callback for functions like `_.map`.
     * @returns {Array} Returns the slice of `array`.
     * @example
     *
     * _.take([1, 2, 3]);
     * // => [1]
     *
     * _.take([1, 2, 3], 2);
     * // => [1, 2]
     *
     * _.take([1, 2, 3], 5);
     * // => [1, 2, 3]
     *
     * _.take([1, 2, 3], 0);
     * // => []
     */
    function take(array, n, guard) {
      var length = array ? array.length : 0;
      if (!length) {
        return [];
      }
      if (guard ? isIterateeCall(array, n, guard) : n == null) {
        n = 1;
      }
      return baseSlice(array, 0, n < 0 ? 0 : n);
    }

    /**
     * Creates a slice of `array` with `n` elements taken from the end.
     *
     * @static
     * @memberOf _
     * @category Array
     * @param {Array} array The array to query.
     * @param {number} [n=1] The number of elements to take.
     * @param- {Object} [guard] Enables use as a callback for functions like `_.map`.
     * @returns {Array} Returns the slice of `array`.
     * @example
     *
     * _.takeRight([1, 2, 3]);
     * // => [3]
     *
     * _.takeRight([1, 2, 3], 2);
     * // => [2, 3]
     *
     * _.takeRight([1, 2, 3], 5);
     * // => [1, 2, 3]
     *
     * _.takeRight([1, 2, 3], 0);
     * // => []
     */
    function takeRight(array, n, guard) {
      var length = array ? array.length : 0;
      if (!length) {
        return [];
      }
      if (guard ? isIterateeCall(array, n, guard) : n == null) {
        n = 1;
      }
      n = length - (+n || 0);
      return baseSlice(array, n < 0 ? 0 : n);
    }

    /**
     * Creates a slice of `array` with elements taken from the end. Elements are
     * taken until `predicate` returns falsey. The predicate is bound to `thisArg`
     * and invoked with three arguments: (value, index, array).
     *
     * If a property name is provided for `predicate` the created `_.property`
     * style callback returns the property value of the given element.
     *
     * If a value is also provided for `thisArg` the created `_.matchesProperty`
     * style callback returns `true` for elements that have a matching property
     * value, else `false`.
     *
     * If an object is provided for `predicate` the created `_.matches` style
     * callback returns `true` for elements that have the properties of the given
     * object, else `false`.
     *
     * @static
     * @memberOf _
     * @category Array
     * @param {Array} array The array to query.
     * @param {Function|Object|string} [predicate=_.identity] The function invoked
     *  per iteration.
     * @param {*} [thisArg] The `this` binding of `predicate`.
     * @returns {Array} Returns the slice of `array`.
     * @example
     *
     * _.takeRightWhile([1, 2, 3], function(n) {
     *   return n > 1;
     * });
     * // => [2, 3]
     *
     * var users = [
     *   { 'user': 'barney',  'active': true },
     *   { 'user': 'fred',    'active': false },
     *   { 'user': 'pebbles', 'active': false }
     * ];
     *
     * // using the `_.matches` callback shorthand
     * _.pluck(_.takeRightWhile(users, { 'user': 'pebbles', 'active': false }), 'user');
     * // => ['pebbles']
     *
     * // using the `_.matchesProperty` callback shorthand
     * _.pluck(_.takeRightWhile(users, 'active', false), 'user');
     * // => ['fred', 'pebbles']
     *
     * // using the `_.property` callback shorthand
     * _.pluck(_.takeRightWhile(users, 'active'), 'user');
     * // => []
     */
    function takeRightWhile(array, predicate, thisArg) {
      return (array && array.length)
        ? baseWhile(array, getCallback(predicate, thisArg, 3), false, true)
        : [];
    }

    /**
     * Creates a slice of `array` with elements taken from the beginning. Elements
     * are taken until `predicate` returns falsey. The predicate is bound to
     * `thisArg` and invoked with three arguments: (value, index, array).
     *
     * If a property name is provided for `predicate` the created `_.property`
     * style callback returns the property value of the given element.
     *
     * If a value is also provided for `thisArg` the created `_.matchesProperty`
     * style callback returns `true` for elements that have a matching property
     * value, else `false`.
     *
     * If an object is provided for `predicate` the created `_.matches` style
     * callback returns `true` for elements that have the properties of the given
     * object, else `false`.
     *
     * @static
     * @memberOf _
     * @category Array
     * @param {Array} array The array to query.
     * @param {Function|Object|string} [predicate=_.identity] The function invoked
     *  per iteration.
     * @param {*} [thisArg] The `this` binding of `predicate`.
     * @returns {Array} Returns the slice of `array`.
     * @example
     *
     * _.takeWhile([1, 2, 3], function(n) {
     *   return n < 3;
     * });
     * // => [1, 2]
     *
     * var users = [
     *   { 'user': 'barney',  'active': false },
     *   { 'user': 'fred',    'active': false},
     *   { 'user': 'pebbles', 'active': true }
     * ];
     *
     * // using the `_.matches` callback shorthand
     * _.pluck(_.takeWhile(users, { 'user': 'barney', 'active': false }), 'user');
     * // => ['barney']
     *
     * // using the `_.matchesProperty` callback shorthand
     * _.pluck(_.takeWhile(users, 'active', false), 'user');
     * // => ['barney', 'fred']
     *
     * // using the `_.property` callback shorthand
     * _.pluck(_.takeWhile(users, 'active'), 'user');
     * // => []
     */
    function takeWhile(array, predicate, thisArg) {
      return (array && array.length)
        ? baseWhile(array, getCallback(predicate, thisArg, 3))
        : [];
    }

    /**
     * Creates an array of unique values, in order, from all of the provided arrays
     * using [`SameValueZero`](http://ecma-international.org/ecma-262/6.0/#sec-samevaluezero)
     * for equality comparisons.
     *
     * @static
     * @memberOf _
     * @category Array
     * @param {...Array} [arrays] The arrays to inspect.
     * @returns {Array} Returns the new array of combined values.
     * @example
     *
     * _.union([1, 2], [4, 2], [2, 1]);
     * // => [1, 2, 4]
     */
    var union = restParam(function(arrays) {
      return baseUniq(baseFlatten(arrays, false, true));
    });

    /**
     * Creates a duplicate-free version of an array, using
     * [`SameValueZero`](http://ecma-international.org/ecma-262/6.0/#sec-samevaluezero)
     * for equality comparisons, in which only the first occurence of each element
     * is kept. Providing `true` for `isSorted` performs a faster search algorithm
     * for sorted arrays. If an iteratee function is provided it is invoked for
     * each element in the array to generate the criterion by which uniqueness
     * is computed. The `iteratee` is bound to `thisArg` and invoked with three
     * arguments: (value, index, array).
     *
     * If a property name is provided for `iteratee` the created `_.property`
     * style callback returns the property value of the given element.
     *
     * If a value is also provided for `thisArg` the created `_.matchesProperty`
     * style callback returns `true` for elements that have a matching property
     * value, else `false`.
     *
     * If an object is provided for `iteratee` the created `_.matches` style
     * callback returns `true` for elements that have the properties of the given
     * object, else `false`.
     *
     * @static
     * @memberOf _
     * @alias unique
     * @category Array
     * @param {Array} array The array to inspect.
     * @param {boolean} [isSorted] Specify the array is sorted.
     * @param {Function|Object|string} [iteratee] The function invoked per iteration.
     * @param {*} [thisArg] The `this` binding of `iteratee`.
     * @returns {Array} Returns the new duplicate-value-free array.
     * @example
     *
     * _.uniq([2, 1, 2]);
     * // => [2, 1]
     *
     * // using `isSorted`
     * _.uniq([1, 1, 2], true);
     * // => [1, 2]
     *
     * // using an iteratee function
     * _.uniq([1, 2.5, 1.5, 2], function(n) {
     *   return this.floor(n);
     * }, Math);
     * // => [1, 2.5]
     *
     * // using the `_.property` callback shorthand
     * _.uniq([{ 'x': 1 }, { 'x': 2 }, { 'x': 1 }], 'x');
     * // => [{ 'x': 1 }, { 'x': 2 }]
     */
    function uniq(array, isSorted, iteratee, thisArg) {
      var length = array ? array.length : 0;
      if (!length) {
        return [];
      }
      if (isSorted != null && typeof isSorted != 'boolean') {
        thisArg = iteratee;
        iteratee = isIterateeCall(array, isSorted, thisArg) ? undefined : isSorted;
        isSorted = false;
      }
      var callback = getCallback();
      if (!(iteratee == null && callback === baseCallback)) {
        iteratee = callback(iteratee, thisArg, 3);
      }
      return (isSorted && getIndexOf() == baseIndexOf)
        ? sortedUniq(array, iteratee)
        : baseUniq(array, iteratee);
    }

    /**
     * This method is like `_.zip` except that it accepts an array of grouped
     * elements and creates an array regrouping the elements to their pre-zip
     * configuration.
     *
     * @static
     * @memberOf _
     * @category Array
     * @param {Array} array The array of grouped elements to process.
     * @returns {Array} Returns the new array of regrouped elements.
     * @example
     *
     * var zipped = _.zip(['fred', 'barney'], [30, 40], [true, false]);
     * // => [['fred', 30, true], ['barney', 40, false]]
     *
     * _.unzip(zipped);
     * // => [['fred', 'barney'], [30, 40], [true, false]]
     */
    function unzip(array) {
      if (!(array && array.length)) {
        return [];
      }
      var index = -1,
          length = 0;

      array = arrayFilter(array, function(group) {
        if (isArrayLike(group)) {
          length = nativeMax(group.length, length);
          return true;
        }
      });
      var result = Array(length);
      while (++index < length) {
        result[index] = arrayMap(array, baseProperty(index));
      }
      return result;
    }

    /**
     * This method is like `_.unzip` except that it accepts an iteratee to specify
     * how regrouped values should be combined. The `iteratee` is bound to `thisArg`
     * and invoked with four arguments: (accumulator, value, index, group).
     *
     * @static
     * @memberOf _
     * @category Array
     * @param {Array} array The array of grouped elements to process.
     * @param {Function} [iteratee] The function to combine regrouped values.
     * @param {*} [thisArg] The `this` binding of `iteratee`.
     * @returns {Array} Returns the new array of regrouped elements.
     * @example
     *
     * var zipped = _.zip([1, 2], [10, 20], [100, 200]);
     * // => [[1, 10, 100], [2, 20, 200]]
     *
     * _.unzipWith(zipped, _.add);
     * // => [3, 30, 300]
     */
    function unzipWith(array, iteratee, thisArg) {
      var length = array ? array.length : 0;
      if (!length) {
        return [];
      }
      var result = unzip(array);
      if (iteratee == null) {
        return result;
      }
      iteratee = bindCallback(iteratee, thisArg, 4);
      return arrayMap(result, function(group) {
        return arrayReduce(group, iteratee, undefined, true);
      });
    }

    /**
     * Creates an array excluding all provided values using
     * [`SameValueZero`](http://ecma-international.org/ecma-262/6.0/#sec-samevaluezero)
     * for equality comparisons.
     *
     * @static
     * @memberOf _
     * @category Array
     * @param {Array} array The array to filter.
     * @param {...*} [values] The values to exclude.
     * @returns {Array} Returns the new array of filtered values.
     * @example
     *
     * _.without([1, 2, 1, 3], 1, 2);
     * // => [3]
     */
    var without = restParam(function(array, values) {
      return isArrayLike(array)
        ? baseDifference(array, values)
        : [];
    });

    /**
     * Creates an array of unique values that is the [symmetric difference](https://en.wikipedia.org/wiki/Symmetric_difference)
     * of the provided arrays.
     *
     * @static
     * @memberOf _
     * @category Array
     * @param {...Array} [arrays] The arrays to inspect.
     * @returns {Array} Returns the new array of values.
     * @example
     *
     * _.xor([1, 2], [4, 2]);
     * // => [1, 4]
     */
    function xor() {
      var index = -1,
          length = arguments.length;

      while (++index < length) {
        var array = arguments[index];
        if (isArrayLike(array)) {
          var result = result
            ? arrayPush(baseDifference(result, array), baseDifference(array, result))
            : array;
        }
      }
      return result ? baseUniq(result) : [];
    }

    /**
     * Creates an array of grouped elements, the first of which contains the first
     * elements of the given arrays, the second of which contains the second elements
     * of the given arrays, and so on.
     *
     * @static
     * @memberOf _
     * @category Array
     * @param {...Array} [arrays] The arrays to process.
     * @returns {Array} Returns the new array of grouped elements.
     * @example
     *
     * _.zip(['fred', 'barney'], [30, 40], [true, false]);
     * // => [['fred', 30, true], ['barney', 40, false]]
     */
    var zip = restParam(unzip);

    /**
     * The inverse of `_.pairs`; this method returns an object composed from arrays
     * of property names and values. Provide either a single two dimensional array,
     * e.g. `[[key1, value1], [key2, value2]]` or two arrays, one of property names
     * and one of corresponding values.
     *
     * @static
     * @memberOf _
     * @alias object
     * @category Array
     * @param {Array} props The property names.
     * @param {Array} [values=[]] The property values.
     * @returns {Object} Returns the new object.
     * @example
     *
     * _.zipObject([['fred', 30], ['barney', 40]]);
     * // => { 'fred': 30, 'barney': 40 }
     *
     * _.zipObject(['fred', 'barney'], [30, 40]);
     * // => { 'fred': 30, 'barney': 40 }
     */
    function zipObject(props, values) {
      var index = -1,
          length = props ? props.length : 0,
          result = {};

      if (length && !values && !isArray(props[0])) {
        values = [];
      }
      while (++index < length) {
        var key = props[index];
        if (values) {
          result[key] = values[index];
        } else if (key) {
          result[key[0]] = key[1];
        }
      }
      return result;
    }

    /**
     * This method is like `_.zip` except that it accepts an iteratee to specify
     * how grouped values should be combined. The `iteratee` is bound to `thisArg`
     * and invoked with four arguments: (accumulator, value, index, group).
     *
     * @static
     * @memberOf _
     * @category Array
     * @param {...Array} [arrays] The arrays to process.
     * @param {Function} [iteratee] The function to combine grouped values.
     * @param {*} [thisArg] The `this` binding of `iteratee`.
     * @returns {Array} Returns the new array of grouped elements.
     * @example
     *
     * _.zipWith([1, 2], [10, 20], [100, 200], _.add);
     * // => [111, 222]
     */
    var zipWith = restParam(function(arrays) {
      var length = arrays.length,
          iteratee = length > 2 ? arrays[length - 2] : undefined,
          thisArg = length > 1 ? arrays[length - 1] : undefined;

      if (length > 2 && typeof iteratee == 'function') {
        length -= 2;
      } else {
        iteratee = (length > 1 && typeof thisArg == 'function') ? (--length, thisArg) : undefined;
        thisArg = undefined;
      }
      arrays.length = length;
      return unzipWith(arrays, iteratee, thisArg);
    });

    /*------------------------------------------------------------------------*/

    /**
     * Creates a `lodash` object that wraps `value` with explicit method
     * chaining enabled.
     *
     * @static
     * @memberOf _
     * @category Chain
     * @param {*} value The value to wrap.
     * @returns {Object} Returns the new `lodash` wrapper instance.
     * @example
     *
     * var users = [
     *   { 'user': 'barney',  'age': 36 },
     *   { 'user': 'fred',    'age': 40 },
     *   { 'user': 'pebbles', 'age': 1 }
     * ];
     *
     * var youngest = _.chain(users)
     *   .sortBy('age')
     *   .map(function(chr) {
     *     return chr.user + ' is ' + chr.age;
     *   })
     *   .first()
     *   .value();
     * // => 'pebbles is 1'
     */
    function chain(value) {
      var result = lodash(value);
      result.__chain__ = true;
      return result;
    }

    /**
     * This method invokes `interceptor` and returns `value`. The interceptor is
     * bound to `thisArg` and invoked with one argument; (value). The purpose of
     * this method is to "tap into" a method chain in order to perform operations
     * on intermediate results within the chain.
     *
     * @static
     * @memberOf _
     * @category Chain
     * @param {*} value The value to provide to `interceptor`.
     * @param {Function} interceptor The function to invoke.
     * @param {*} [thisArg] The `this` binding of `interceptor`.
     * @returns {*} Returns `value`.
     * @example
     *
     * _([1, 2, 3])
     *  .tap(function(array) {
     *    array.pop();
     *  })
     *  .reverse()
     *  .value();
     * // => [2, 1]
     */
    function tap(value, interceptor, thisArg) {
      interceptor.call(thisArg, value);
      return value;
    }

    /**
     * This method is like `_.tap` except that it returns the result of `interceptor`.
     *
     * @static
     * @memberOf _
     * @category Chain
     * @param {*} value The value to provide to `interceptor`.
     * @param {Function} interceptor The function to invoke.
     * @param {*} [thisArg] The `this` binding of `interceptor`.
     * @returns {*} Returns the result of `interceptor`.
     * @example
     *
     * _('  abc  ')
     *  .chain()
     *  .trim()
     *  .thru(function(value) {
     *    return [value];
     *  })
     *  .value();
     * // => ['abc']
     */
    function thru(value, interceptor, thisArg) {
      return interceptor.call(thisArg, value);
    }

    /**
     * Enables explicit method chaining on the wrapper object.
     *
     * @name chain
     * @memberOf _
     * @category Chain
     * @returns {Object} Returns the new `lodash` wrapper instance.
     * @example
     *
     * var users = [
     *   { 'user': 'barney', 'age': 36 },
     *   { 'user': 'fred',   'age': 40 }
     * ];
     *
     * // without explicit chaining
     * _(users).first();
     * // => { 'user': 'barney', 'age': 36 }
     *
     * // with explicit chaining
     * _(users).chain()
     *   .first()
     *   .pick('user')
     *   .value();
     * // => { 'user': 'barney' }
     */
    function wrapperChain() {
      return chain(this);
    }

    /**
     * Executes the chained sequence and returns the wrapped result.
     *
     * @name commit
     * @memberOf _
     * @category Chain
     * @returns {Object} Returns the new `lodash` wrapper instance.
     * @example
     *
     * var array = [1, 2];
     * var wrapped = _(array).push(3);
     *
     * console.log(array);
     * // => [1, 2]
     *
     * wrapped = wrapped.commit();
     * console.log(array);
     * // => [1, 2, 3]
     *
     * wrapped.last();
     * // => 3
     *
     * console.log(array);
     * // => [1, 2, 3]
     */
    function wrapperCommit() {
      return new LodashWrapper(this.value(), this.__chain__);
    }

    /**
     * Creates a new array joining a wrapped array with any additional arrays
     * and/or values.
     *
     * @name concat
     * @memberOf _
     * @category Chain
     * @param {...*} [values] The values to concatenate.
     * @returns {Array} Returns the new concatenated array.
     * @example
     *
     * var array = [1];
     * var wrapped = _(array).concat(2, [3], [[4]]);
     *
     * console.log(wrapped.value());
     * // => [1, 2, 3, [4]]
     *
     * console.log(array);
     * // => [1]
     */
    var wrapperConcat = restParam(function(values) {
      values = baseFlatten(values);
      return this.thru(function(array) {
        return arrayConcat(isArray(array) ? array : [toObject(array)], values);
      });
    });

    /**
     * Creates a clone of the chained sequence planting `value` as the wrapped value.
     *
     * @name plant
     * @memberOf _
     * @category Chain
     * @returns {Object} Returns the new `lodash` wrapper instance.
     * @example
     *
     * var array = [1, 2];
     * var wrapped = _(array).map(function(value) {
     *   return Math.pow(value, 2);
     * });
     *
     * var other = [3, 4];
     * var otherWrapped = wrapped.plant(other);
     *
     * otherWrapped.value();
     * // => [9, 16]
     *
     * wrapped.value();
     * // => [1, 4]
     */
    function wrapperPlant(value) {
      var result,
          parent = this;

      while (parent instanceof baseLodash) {
        var clone = wrapperClone(parent);
        if (result) {
          previous.__wrapped__ = clone;
        } else {
          result = clone;
        }
        var previous = clone;
        parent = parent.__wrapped__;
      }
      previous.__wrapped__ = value;
      return result;
    }

    /**
     * Reverses the wrapped array so the first element becomes the last, the
     * second element becomes the second to last, and so on.
     *
     * **Note:** This method mutates the wrapped array.
     *
     * @name reverse
     * @memberOf _
     * @category Chain
     * @returns {Object} Returns the new reversed `lodash` wrapper instance.
     * @example
     *
     * var array = [1, 2, 3];
     *
     * _(array).reverse().value()
     * // => [3, 2, 1]
     *
     * console.log(array);
     * // => [3, 2, 1]
     */
    function wrapperReverse() {
      var value = this.__wrapped__;

      var interceptor = function(value) {
        return (wrapped && wrapped.__dir__ < 0) ? value : value.reverse();
      };
      if (value instanceof LazyWrapper) {
        var wrapped = value;
        if (this.__actions__.length) {
          wrapped = new LazyWrapper(this);
        }
        wrapped = wrapped.reverse();
        wrapped.__actions__.push({ 'func': thru, 'args': [interceptor], 'thisArg': undefined });
        return new LodashWrapper(wrapped, this.__chain__);
      }
      return this.thru(interceptor);
    }

    /**
     * Produces the result of coercing the unwrapped value to a string.
     *
     * @name toString
     * @memberOf _
     * @category Chain
     * @returns {string} Returns the coerced string value.
     * @example
     *
     * _([1, 2, 3]).toString();
     * // => '1,2,3'
     */
    function wrapperToString() {
      return (this.value() + '');
    }

    /**
     * Executes the chained sequence to extract the unwrapped value.
     *
     * @name value
     * @memberOf _
     * @alias run, toJSON, valueOf
     * @category Chain
     * @returns {*} Returns the resolved unwrapped value.
     * @example
     *
     * _([1, 2, 3]).value();
     * // => [1, 2, 3]
     */
    function wrapperValue() {
      return baseWrapperValue(this.__wrapped__, this.__actions__);
    }

    /*------------------------------------------------------------------------*/

    /**
     * Creates an array of elements corresponding to the given keys, or indexes,
     * of `collection`. Keys may be specified as individual arguments or as arrays
     * of keys.
     *
     * @static
     * @memberOf _
     * @category Collection
     * @param {Array|Object|string} collection The collection to iterate over.
     * @param {...(number|number[]|string|string[])} [props] The property names
     *  or indexes of elements to pick, specified individually or in arrays.
     * @returns {Array} Returns the new array of picked elements.
     * @example
     *
     * _.at(['a', 'b', 'c'], [0, 2]);
     * // => ['a', 'c']
     *
     * _.at(['barney', 'fred', 'pebbles'], 0, 2);
     * // => ['barney', 'pebbles']
     */
    var at = restParam(function(collection, props) {
      return baseAt(collection, baseFlatten(props));
    });

    /**
     * Creates an object composed of keys generated from the results of running
     * each element of `collection` through `iteratee`. The corresponding value
     * of each key is the number of times the key was returned by `iteratee`.
     * The `iteratee` is bound to `thisArg` and invoked with three arguments:
     * (value, index|key, collection).
     *
     * If a property name is provided for `iteratee` the created `_.property`
     * style callback returns the property value of the given element.
     *
     * If a value is also provided for `thisArg` the created `_.matchesProperty`
     * style callback returns `true` for elements that have a matching property
     * value, else `false`.
     *
     * If an object is provided for `iteratee` the created `_.matches` style
     * callback returns `true` for elements that have the properties of the given
     * object, else `false`.
     *
     * @static
     * @memberOf _
     * @category Collection
     * @param {Array|Object|string} collection The collection to iterate over.
     * @param {Function|Object|string} [iteratee=_.identity] The function invoked
     *  per iteration.
     * @param {*} [thisArg] The `this` binding of `iteratee`.
     * @returns {Object} Returns the composed aggregate object.
     * @example
     *
     * _.countBy([4.3, 6.1, 6.4], function(n) {
     *   return Math.floor(n);
     * });
     * // => { '4': 1, '6': 2 }
     *
     * _.countBy([4.3, 6.1, 6.4], function(n) {
     *   return this.floor(n);
     * }, Math);
     * // => { '4': 1, '6': 2 }
     *
     * _.countBy(['one', 'two', 'three'], 'length');
     * // => { '3': 2, '5': 1 }
     */
    var countBy = createAggregator(function(result, value, key) {
      hasOwnProperty.call(result, key) ? ++result[key] : (result[key] = 1);
    });

    /**
     * Checks if `predicate` returns truthy for **all** elements of `collection`.
     * The predicate is bound to `thisArg` and invoked with three arguments:
     * (value, index|key, collection).
     *
     * If a property name is provided for `predicate` the created `_.property`
     * style callback returns the property value of the given element.
     *
     * If a value is also provided for `thisArg` the created `_.matchesProperty`
     * style callback returns `true` for elements that have a matching property
     * value, else `false`.
     *
     * If an object is provided for `predicate` the created `_.matches` style
     * callback returns `true` for elements that have the properties of the given
     * object, else `false`.
     *
     * @static
     * @memberOf _
     * @alias all
     * @category Collection
     * @param {Array|Object|string} collection The collection to iterate over.
     * @param {Function|Object|string} [predicate=_.identity] The function invoked
     *  per iteration.
     * @param {*} [thisArg] The `this` binding of `predicate`.
     * @returns {boolean} Returns `true` if all elements pass the predicate check,
     *  else `false`.
     * @example
     *
     * _.every([true, 1, null, 'yes'], Boolean);
     * // => false
     *
     * var users = [
     *   { 'user': 'barney', 'active': false },
     *   { 'user': 'fred',   'active': false }
     * ];
     *
     * // using the `_.matches` callback shorthand
     * _.every(users, { 'user': 'barney', 'active': false });
     * // => false
     *
     * // using the `_.matchesProperty` callback shorthand
     * _.every(users, 'active', false);
     * // => true
     *
     * // using the `_.property` callback shorthand
     * _.every(users, 'active');
     * // => false
     */
    function every(collection, predicate, thisArg) {
      var func = isArray(collection) ? arrayEvery : baseEvery;
      if (thisArg && isIterateeCall(collection, predicate, thisArg)) {
        predicate = undefined;
      }
      if (typeof predicate != 'function' || thisArg !== undefined) {
        predicate = getCallback(predicate, thisArg, 3);
      }
      return func(collection, predicate);
    }

    /**
     * Iterates over elements of `collection`, returning an array of all elements
     * `predicate` returns truthy for. The predicate is bound to `thisArg` and
     * invoked with three arguments: (value, index|key, collection).
     *
     * If a property name is provided for `predicate` the created `_.property`
     * style callback returns the property value of the given element.
     *
     * If a value is also provided for `thisArg` the created `_.matchesProperty`
     * style callback returns `true` for elements that have a matching property
     * value, else `false`.
     *
     * If an object is provided for `predicate` the created `_.matches` style
     * callback returns `true` for elements that have the properties of the given
     * object, else `false`.
     *
     * @static
     * @memberOf _
     * @alias select
     * @category Collection
     * @param {Array|Object|string} collection The collection to iterate over.
     * @param {Function|Object|string} [predicate=_.identity] The function invoked
     *  per iteration.
     * @param {*} [thisArg] The `this` binding of `predicate`.
     * @returns {Array} Returns the new filtered array.
     * @example
     *
     * _.filter([4, 5, 6], function(n) {
     *   return n % 2 == 0;
     * });
     * // => [4, 6]
     *
     * var users = [
     *   { 'user': 'barney', 'age': 36, 'active': true },
     *   { 'user': 'fred',   'age': 40, 'active': false }
     * ];
     *
     * // using the `_.matches` callback shorthand
     * _.pluck(_.filter(users, { 'age': 36, 'active': true }), 'user');
     * // => ['barney']
     *
     * // using the `_.matchesProperty` callback shorthand
     * _.pluck(_.filter(users, 'active', false), 'user');
     * // => ['fred']
     *
     * // using the `_.property` callback shorthand
     * _.pluck(_.filter(users, 'active'), 'user');
     * // => ['barney']
     */
    function filter(collection, predicate, thisArg) {
      var func = isArray(collection) ? arrayFilter : baseFilter;
      predicate = getCallback(predicate, thisArg, 3);
      return func(collection, predicate);
    }

    /**
     * Iterates over elements of `collection`, returning the first element
     * `predicate` returns truthy for. The predicate is bound to `thisArg` and
     * invoked with three arguments: (value, index|key, collection).
     *
     * If a property name is provided for `predicate` the created `_.property`
     * style callback returns the property value of the given element.
     *
     * If a value is also provided for `thisArg` the created `_.matchesProperty`
     * style callback returns `true` for elements that have a matching property
     * value, else `false`.
     *
     * If an object is provided for `predicate` the created `_.matches` style
     * callback returns `true` for elements that have the properties of the given
     * object, else `false`.
     *
     * @static
     * @memberOf _
     * @alias detect
     * @category Collection
     * @param {Array|Object|string} collection The collection to search.
     * @param {Function|Object|string} [predicate=_.identity] The function invoked
     *  per iteration.
     * @param {*} [thisArg] The `this` binding of `predicate`.
     * @returns {*} Returns the matched element, else `undefined`.
     * @example
     *
     * var users = [
     *   { 'user': 'barney',  'age': 36, 'active': true },
     *   { 'user': 'fred',    'age': 40, 'active': false },
     *   { 'user': 'pebbles', 'age': 1,  'active': true }
     * ];
     *
     * _.result(_.find(users, function(chr) {
     *   return chr.age < 40;
     * }), 'user');
     * // => 'barney'
     *
     * // using the `_.matches` callback shorthand
     * _.result(_.find(users, { 'age': 1, 'active': true }), 'user');
     * // => 'pebbles'
     *
     * // using the `_.matchesProperty` callback shorthand
     * _.result(_.find(users, 'active', false), 'user');
     * // => 'fred'
     *
     * // using the `_.property` callback shorthand
     * _.result(_.find(users, 'active'), 'user');
     * // => 'barney'
     */
    var find = createFind(baseEach);

    /**
     * This method is like `_.find` except that it iterates over elements of
     * `collection` from right to left.
     *
     * @static
     * @memberOf _
     * @category Collection
     * @param {Array|Object|string} collection The collection to search.
     * @param {Function|Object|string} [predicate=_.identity] The function invoked
     *  per iteration.
     * @param {*} [thisArg] The `this` binding of `predicate`.
     * @returns {*} Returns the matched element, else `undefined`.
     * @example
     *
     * _.findLast([1, 2, 3, 4], function(n) {
     *   return n % 2 == 1;
     * });
     * // => 3
     */
    var findLast = createFind(baseEachRight, true);

    /**
     * Performs a deep comparison between each element in `collection` and the
     * source object, returning the first element that has equivalent property
     * values.
     *
     * **Note:** This method supports comparing arrays, booleans, `Date` objects,
     * numbers, `Object` objects, regexes, and strings. Objects are compared by
     * their own, not inherited, enumerable properties. For comparing a single
     * own or inherited property value see `_.matchesProperty`.
     *
     * @static
     * @memberOf _
     * @category Collection
     * @param {Array|Object|string} collection The collection to search.
     * @param {Object} source The object of property values to match.
     * @returns {*} Returns the matched element, else `undefined`.
     * @example
     *
     * var users = [
     *   { 'user': 'barney', 'age': 36, 'active': true },
     *   { 'user': 'fred',   'age': 40, 'active': false }
     * ];
     *
     * _.result(_.findWhere(users, { 'age': 36, 'active': true }), 'user');
     * // => 'barney'
     *
     * _.result(_.findWhere(users, { 'age': 40, 'active': false }), 'user');
     * // => 'fred'
     */
    function findWhere(collection, source) {
      return find(collection, baseMatches(source));
    }

    /**
     * Iterates over elements of `collection` invoking `iteratee` for each element.
     * The `iteratee` is bound to `thisArg` and invoked with three arguments:
     * (value, index|key, collection). Iteratee functions may exit iteration early
     * by explicitly returning `false`.
     *
     * **Note:** As with other "Collections" methods, objects with a "length" property
     * are iterated like arrays. To avoid this behavior `_.forIn` or `_.forOwn`
     * may be used for object iteration.
     *
     * @static
     * @memberOf _
     * @alias each
     * @category Collection
     * @param {Array|Object|string} collection The collection to iterate over.
     * @param {Function} [iteratee=_.identity] The function invoked per iteration.
     * @param {*} [thisArg] The `this` binding of `iteratee`.
     * @returns {Array|Object|string} Returns `collection`.
     * @example
     *
     * _([1, 2]).forEach(function(n) {
     *   console.log(n);
     * }).value();
     * // => logs each value from left to right and returns the array
     *
     * _.forEach({ 'a': 1, 'b': 2 }, function(n, key) {
     *   console.log(n, key);
     * });
     * // => logs each value-key pair and returns the object (iteration order is not guaranteed)
     */
    var forEach = createForEach(arrayEach, baseEach);

    /**
     * This method is like `_.forEach` except that it iterates over elements of
     * `collection` from right to left.
     *
     * @static
     * @memberOf _
     * @alias eachRight
     * @category Collection
     * @param {Array|Object|string} collection The collection to iterate over.
     * @param {Function} [iteratee=_.identity] The function invoked per iteration.
     * @param {*} [thisArg] The `this` binding of `iteratee`.
     * @returns {Array|Object|string} Returns `collection`.
     * @example
     *
     * _([1, 2]).forEachRight(function(n) {
     *   console.log(n);
     * }).value();
     * // => logs each value from right to left and returns the array
     */
    var forEachRight = createForEach(arrayEachRight, baseEachRight);

    /**
     * Creates an object composed of keys generated from the results of running
     * each element of `collection` through `iteratee`. The corresponding value
     * of each key is an array of the elements responsible for generating the key.
     * The `iteratee` is bound to `thisArg` and invoked with three arguments:
     * (value, index|key, collection).
     *
     * If a property name is provided for `iteratee` the created `_.property`
     * style callback returns the property value of the given element.
     *
     * If a value is also provided for `thisArg` the created `_.matchesProperty`
     * style callback returns `true` for elements that have a matching property
     * value, else `false`.
     *
     * If an object is provided for `iteratee` the created `_.matches` style
     * callback returns `true` for elements that have the properties of the given
     * object, else `false`.
     *
     * @static
     * @memberOf _
     * @category Collection
     * @param {Array|Object|string} collection The collection to iterate over.
     * @param {Function|Object|string} [iteratee=_.identity] The function invoked
     *  per iteration.
     * @param {*} [thisArg] The `this` binding of `iteratee`.
     * @returns {Object} Returns the composed aggregate object.
     * @example
     *
     * _.groupBy([4.2, 6.1, 6.4], function(n) {
     *   return Math.floor(n);
     * });
     * // => { '4': [4.2], '6': [6.1, 6.4] }
     *
     * _.groupBy([4.2, 6.1, 6.4], function(n) {
     *   return this.floor(n);
     * }, Math);
     * // => { '4': [4.2], '6': [6.1, 6.4] }
     *
     * // using the `_.property` callback shorthand
     * _.groupBy(['one', 'two', 'three'], 'length');
     * // => { '3': ['one', 'two'], '5': ['three'] }
     */
    var groupBy = createAggregator(function(result, value, key) {
      if (hasOwnProperty.call(result, key)) {
        result[key].push(value);
      } else {
        result[key] = [value];
      }
    });

    /**
     * Checks if `value` is in `collection` using
     * [`SameValueZero`](http://ecma-international.org/ecma-262/6.0/#sec-samevaluezero)
     * for equality comparisons. If `fromIndex` is negative, it is used as the offset
     * from the end of `collection`.
     *
     * @static
     * @memberOf _
     * @alias contains, include
     * @category Collection
     * @param {Array|Object|string} collection The collection to search.
     * @param {*} target The value to search for.
     * @param {number} [fromIndex=0] The index to search from.
     * @param- {Object} [guard] Enables use as a callback for functions like `_.reduce`.
     * @returns {boolean} Returns `true` if a matching element is found, else `false`.
     * @example
     *
     * _.includes([1, 2, 3], 1);
     * // => true
     *
     * _.includes([1, 2, 3], 1, 2);
     * // => false
     *
     * _.includes({ 'user': 'fred', 'age': 40 }, 'fred');
     * // => true
     *
     * _.includes('pebbles', 'eb');
     * // => true
     */
    function includes(collection, target, fromIndex, guard) {
      var length = collection ? getLength(collection) : 0;
      if (!isLength(length)) {
        collection = values(collection);
        length = collection.length;
      }
      if (typeof fromIndex != 'number' || (guard && isIterateeCall(target, fromIndex, guard))) {
        fromIndex = 0;
      } else {
        fromIndex = fromIndex < 0 ? nativeMax(length + fromIndex, 0) : (fromIndex || 0);
      }
      return (typeof collection == 'string' || !isArray(collection) && isString(collection))
        ? (fromIndex <= length && collection.indexOf(target, fromIndex) > -1)
        : (!!length && getIndexOf(collection, target, fromIndex) > -1);
    }

    /**
     * Creates an object composed of keys generated from the results of running
     * each element of `collection` through `iteratee`. The corresponding value
     * of each key is the last element responsible for generating the key. The
     * iteratee function is bound to `thisArg` and invoked with three arguments:
     * (value, index|key, collection).
     *
     * If a property name is provided for `iteratee` the created `_.property`
     * style callback returns the property value of the given element.
     *
     * If a value is also provided for `thisArg` the created `_.matchesProperty`
     * style callback returns `true` for elements that have a matching property
     * value, else `false`.
     *
     * If an object is provided for `iteratee` the created `_.matches` style
     * callback returns `true` for elements that have the properties of the given
     * object, else `false`.
     *
     * @static
     * @memberOf _
     * @category Collection
     * @param {Array|Object|string} collection The collection to iterate over.
     * @param {Function|Object|string} [iteratee=_.identity] The function invoked
     *  per iteration.
     * @param {*} [thisArg] The `this` binding of `iteratee`.
     * @returns {Object} Returns the composed aggregate object.
     * @example
     *
     * var keyData = [
     *   { 'dir': 'left', 'code': 97 },
     *   { 'dir': 'right', 'code': 100 }
     * ];
     *
     * _.indexBy(keyData, 'dir');
     * // => { 'left': { 'dir': 'left', 'code': 97 }, 'right': { 'dir': 'right', 'code': 100 } }
     *
     * _.indexBy(keyData, function(object) {
     *   return String.fromCharCode(object.code);
     * });
     * // => { 'a': { 'dir': 'left', 'code': 97 }, 'd': { 'dir': 'right', 'code': 100 } }
     *
     * _.indexBy(keyData, function(object) {
     *   return this.fromCharCode(object.code);
     * }, String);
     * // => { 'a': { 'dir': 'left', 'code': 97 }, 'd': { 'dir': 'right', 'code': 100 } }
     */
    var indexBy = createAggregator(function(result, value, key) {
      result[key] = value;
    });

    /**
     * Invokes the method at `path` of each element in `collection`, returning
     * an array of the results of each invoked method. Any additional arguments
     * are provided to each invoked method. If `methodName` is a function it is
     * invoked for, and `this` bound to, each element in `collection`.
     *
     * @static
     * @memberOf _
     * @category Collection
     * @param {Array|Object|string} collection The collection to iterate over.
     * @param {Array|Function|string} path The path of the method to invoke or
     *  the function invoked per iteration.
     * @param {...*} [args] The arguments to invoke the method with.
     * @returns {Array} Returns the array of results.
     * @example
     *
     * _.invoke([[5, 1, 7], [3, 2, 1]], 'sort');
     * // => [[1, 5, 7], [1, 2, 3]]
     *
     * _.invoke([123, 456], String.prototype.split, '');
     * // => [['1', '2', '3'], ['4', '5', '6']]
     */
    var invoke = restParam(function(collection, path, args) {
      var index = -1,
          isFunc = typeof path == 'function',
          isProp = isKey(path),
          result = isArrayLike(collection) ? Array(collection.length) : [];

      baseEach(collection, function(value) {
        var func = isFunc ? path : ((isProp && value != null) ? value[path] : undefined);
        result[++index] = func ? func.apply(value, args) : invokePath(value, path, args);
      });
      return result;
    });

    /**
     * Creates an array of values by running each element in `collection` through
     * `iteratee`. The `iteratee` is bound to `thisArg` and invoked with three
     * arguments: (value, index|key, collection).
     *
     * If a property name is provided for `iteratee` the created `_.property`
     * style callback returns the property value of the given element.
     *
     * If a value is also provided for `thisArg` the created `_.matchesProperty`
     * style callback returns `true` for elements that have a matching property
     * value, else `false`.
     *
     * If an object is provided for `iteratee` the created `_.matches` style
     * callback returns `true` for elements that have the properties of the given
     * object, else `false`.
     *
     * Many lodash methods are guarded to work as iteratees for methods like
     * `_.every`, `_.filter`, `_.map`, `_.mapValues`, `_.reject`, and `_.some`.
     *
     * The guarded methods are:
     * `ary`, `callback`, `chunk`, `clone`, `create`, `curry`, `curryRight`,
     * `drop`, `dropRight`, `every`, `fill`, `flatten`, `invert`, `max`, `min`,
     * `parseInt`, `slice`, `sortBy`, `take`, `takeRight`, `template`, `trim`,
     * `trimLeft`, `trimRight`, `trunc`, `random`, `range`, `sample`, `some`,
     * `sum`, `uniq`, and `words`
     *
     * @static
     * @memberOf _
     * @alias collect
     * @category Collection
     * @param {Array|Object|string} collection The collection to iterate over.
     * @param {Function|Object|string} [iteratee=_.identity] The function invoked
     *  per iteration.
     * @param {*} [thisArg] The `this` binding of `iteratee`.
     * @returns {Array} Returns the new mapped array.
     * @example
     *
     * function timesThree(n) {
     *   return n * 3;
     * }
     *
     * _.map([1, 2], timesThree);
     * // => [3, 6]
     *
     * _.map({ 'a': 1, 'b': 2 }, timesThree);
     * // => [3, 6] (iteration order is not guaranteed)
     *
     * var users = [
     *   { 'user': 'barney' },
     *   { 'user': 'fred' }
     * ];
     *
     * // using the `_.property` callback shorthand
     * _.map(users, 'user');
     * // => ['barney', 'fred']
     */
    function map(collection, iteratee, thisArg) {
      var func = isArray(collection) ? arrayMap : baseMap;
      iteratee = getCallback(iteratee, thisArg, 3);
      return func(collection, iteratee);
    }

    /**
     * Creates an array of elements split into two groups, the first of which
     * contains elements `predicate` returns truthy for, while the second of which
     * contains elements `predicate` returns falsey for. The predicate is bound
     * to `thisArg` and invoked with three arguments: (value, index|key, collection).
     *
     * If a property name is provided for `predicate` the created `_.property`
     * style callback returns the property value of the given element.
     *
     * If a value is also provided for `thisArg` the created `_.matchesProperty`
     * style callback returns `true` for elements that have a matching property
     * value, else `false`.
     *
     * If an object is provided for `predicate` the created `_.matches` style
     * callback returns `true` for elements that have the properties of the given
     * object, else `false`.
     *
     * @static
     * @memberOf _
     * @category Collection
     * @param {Array|Object|string} collection The collection to iterate over.
     * @param {Function|Object|string} [predicate=_.identity] The function invoked
     *  per iteration.
     * @param {*} [thisArg] The `this` binding of `predicate`.
     * @returns {Array} Returns the array of grouped elements.
     * @example
     *
     * _.partition([1, 2, 3], function(n) {
     *   return n % 2;
     * });
     * // => [[1, 3], [2]]
     *
     * _.partition([1.2, 2.3, 3.4], function(n) {
     *   return this.floor(n) % 2;
     * }, Math);
     * // => [[1.2, 3.4], [2.3]]
     *
     * var users = [
     *   { 'user': 'barney',  'age': 36, 'active': false },
     *   { 'user': 'fred',    'age': 40, 'active': true },
     *   { 'user': 'pebbles', 'age': 1,  'active': false }
     * ];
     *
     * var mapper = function(array) {
     *   return _.pluck(array, 'user');
     * };
     *
     * // using the `_.matches` callback shorthand
     * _.map(_.partition(users, { 'age': 1, 'active': false }), mapper);
     * // => [['pebbles'], ['barney', 'fred']]
     *
     * // using the `_.matchesProperty` callback shorthand
     * _.map(_.partition(users, 'active', false), mapper);
     * // => [['barney', 'pebbles'], ['fred']]
     *
     * // using the `_.property` callback shorthand
     * _.map(_.partition(users, 'active'), mapper);
     * // => [['fred'], ['barney', 'pebbles']]
     */
    var partition = createAggregator(function(result, value, key) {
      result[key ? 0 : 1].push(value);
    }, function() { return [[], []]; });

    /**
     * Gets the property value of `path` from all elements in `collection`.
     *
     * @static
     * @memberOf _
     * @category Collection
     * @param {Array|Object|string} collection The collection to iterate over.
     * @param {Array|string} path The path of the property to pluck.
     * @returns {Array} Returns the property values.
     * @example
     *
     * var users = [
     *   { 'user': 'barney', 'age': 36 },
     *   { 'user': 'fred',   'age': 40 }
     * ];
     *
     * _.pluck(users, 'user');
     * // => ['barney', 'fred']
     *
     * var userIndex = _.indexBy(users, 'user');
     * _.pluck(userIndex, 'age');
     * // => [36, 40] (iteration order is not guaranteed)
     */
    function pluck(collection, path) {
      return map(collection, property(path));
    }

    /**
     * Reduces `collection` to a value which is the accumulated result of running
     * each element in `collection` through `iteratee`, where each successive
     * invocation is supplied the return value of the previous. If `accumulator`
     * is not provided the first element of `collection` is used as the initial
     * value. The `iteratee` is bound to `thisArg` and invoked with four arguments:
     * (accumulator, value, index|key, collection).
     *
     * Many lodash methods are guarded to work as iteratees for methods like
     * `_.reduce`, `_.reduceRight`, and `_.transform`.
     *
     * The guarded methods are:
     * `assign`, `defaults`, `defaultsDeep`, `includes`, `merge`, `sortByAll`,
     * and `sortByOrder`
     *
     * @static
     * @memberOf _
     * @alias foldl, inject
     * @category Collection
     * @param {Array|Object|string} collection The collection to iterate over.
     * @param {Function} [iteratee=_.identity] The function invoked per iteration.
     * @param {*} [accumulator] The initial value.
     * @param {*} [thisArg] The `this` binding of `iteratee`.
     * @returns {*} Returns the accumulated value.
     * @example
     *
     * _.reduce([1, 2], function(total, n) {
     *   return total + n;
     * });
     * // => 3
     *
     * _.reduce({ 'a': 1, 'b': 2 }, function(result, n, key) {
     *   result[key] = n * 3;
     *   return result;
     * }, {});
     * // => { 'a': 3, 'b': 6 } (iteration order is not guaranteed)
     */
    var reduce = createReduce(arrayReduce, baseEach);

    /**
     * This method is like `_.reduce` except that it iterates over elements of
     * `collection` from right to left.
     *
     * @static
     * @memberOf _
     * @alias foldr
     * @category Collection
     * @param {Array|Object|string} collection The collection to iterate over.
     * @param {Function} [iteratee=_.identity] The function invoked per iteration.
     * @param {*} [accumulator] The initial value.
     * @param {*} [thisArg] The `this` binding of `iteratee`.
     * @returns {*} Returns the accumulated value.
     * @example
     *
     * var array = [[0, 1], [2, 3], [4, 5]];
     *
     * _.reduceRight(array, function(flattened, other) {
     *   return flattened.concat(other);
     * }, []);
     * // => [4, 5, 2, 3, 0, 1]
     */
    var reduceRight = createReduce(arrayReduceRight, baseEachRight);

    /**
     * The opposite of `_.filter`; this method returns the elements of `collection`
     * that `predicate` does **not** return truthy for.
     *
     * @static
     * @memberOf _
     * @category Collection
     * @param {Array|Object|string} collection The collection to iterate over.
     * @param {Function|Object|string} [predicate=_.identity] The function invoked
     *  per iteration.
     * @param {*} [thisArg] The `this` binding of `predicate`.
     * @returns {Array} Returns the new filtered array.
     * @example
     *
     * _.reject([1, 2, 3, 4], function(n) {
     *   return n % 2 == 0;
     * });
     * // => [1, 3]
     *
     * var users = [
     *   { 'user': 'barney', 'age': 36, 'active': false },
     *   { 'user': 'fred',   'age': 40, 'active': true }
     * ];
     *
     * // using the `_.matches` callback shorthand
     * _.pluck(_.reject(users, { 'age': 40, 'active': true }), 'user');
     * // => ['barney']
     *
     * // using the `_.matchesProperty` callback shorthand
     * _.pluck(_.reject(users, 'active', false), 'user');
     * // => ['fred']
     *
     * // using the `_.property` callback shorthand
     * _.pluck(_.reject(users, 'active'), 'user');
     * // => ['barney']
     */
    function reject(collection, predicate, thisArg) {
      var func = isArray(collection) ? arrayFilter : baseFilter;
      predicate = getCallback(predicate, thisArg, 3);
      return func(collection, function(value, index, collection) {
        return !predicate(value, index, collection);
      });
    }

    /**
     * Gets a random element or `n` random elements from a collection.
     *
     * @static
     * @memberOf _
     * @category Collection
     * @param {Array|Object|string} collection The collection to sample.
     * @param {number} [n] The number of elements to sample.
     * @param- {Object} [guard] Enables use as a callback for functions like `_.map`.
     * @returns {*} Returns the random sample(s).
     * @example
     *
     * _.sample([1, 2, 3, 4]);
     * // => 2
     *
     * _.sample([1, 2, 3, 4], 2);
     * // => [3, 1]
     */
    function sample(collection, n, guard) {
      if (guard ? isIterateeCall(collection, n, guard) : n == null) {
        collection = toIterable(collection);
        var length = collection.length;
        return length > 0 ? collection[baseRandom(0, length - 1)] : undefined;
      }
      var index = -1,
          result = toArray(collection),
          length = result.length,
          lastIndex = length - 1;

      n = nativeMin(n < 0 ? 0 : (+n || 0), length);
      while (++index < n) {
        var rand = baseRandom(index, lastIndex),
            value = result[rand];

        result[rand] = result[index];
        result[index] = value;
      }
      result.length = n;
      return result;
    }

    /**
     * Creates an array of shuffled values, using a version of the
     * [Fisher-Yates shuffle](https://en.wikipedia.org/wiki/Fisher-Yates_shuffle).
     *
     * @static
     * @memberOf _
     * @category Collection
     * @param {Array|Object|string} collection The collection to shuffle.
     * @returns {Array} Returns the new shuffled array.
     * @example
     *
     * _.shuffle([1, 2, 3, 4]);
     * // => [4, 1, 3, 2]
     */
    function shuffle(collection) {
      return sample(collection, POSITIVE_INFINITY);
    }

    /**
     * Gets the size of `collection` by returning its length for array-like
     * values or the number of own enumerable properties for objects.
     *
     * @static
     * @memberOf _
     * @category Collection
     * @param {Array|Object|string} collection The collection to inspect.
     * @returns {number} Returns the size of `collection`.
     * @example
     *
     * _.size([1, 2, 3]);
     * // => 3
     *
     * _.size({ 'a': 1, 'b': 2 });
     * // => 2
     *
     * _.size('pebbles');
     * // => 7
     */
    function size(collection) {
      var length = collection ? getLength(collection) : 0;
      return isLength(length) ? length : keys(collection).length;
    }

    /**
     * Checks if `predicate` returns truthy for **any** element of `collection`.
     * The function returns as soon as it finds a passing value and does not iterate
     * over the entire collection. The predicate is bound to `thisArg` and invoked
     * with three arguments: (value, index|key, collection).
     *
     * If a property name is provided for `predicate` the created `_.property`
     * style callback returns the property value of the given element.
     *
     * If a value is also provided for `thisArg` the created `_.matchesProperty`
     * style callback returns `true` for elements that have a matching property
     * value, else `false`.
     *
     * If an object is provided for `predicate` the created `_.matches` style
     * callback returns `true` for elements that have the properties of the given
     * object, else `false`.
     *
     * @static
     * @memberOf _
     * @alias any
     * @category Collection
     * @param {Array|Object|string} collection The collection to iterate over.
     * @param {Function|Object|string} [predicate=_.identity] The function invoked
     *  per iteration.
     * @param {*} [thisArg] The `this` binding of `predicate`.
     * @returns {boolean} Returns `true` if any element passes the predicate check,
     *  else `false`.
     * @example
     *
     * _.some([null, 0, 'yes', false], Boolean);
     * // => true
     *
     * var users = [
     *   { 'user': 'barney', 'active': true },
     *   { 'user': 'fred',   'active': false }
     * ];
     *
     * // using the `_.matches` callback shorthand
     * _.some(users, { 'user': 'barney', 'active': false });
     * // => false
     *
     * // using the `_.matchesProperty` callback shorthand
     * _.some(users, 'active', false);
     * // => true
     *
     * // using the `_.property` callback shorthand
     * _.some(users, 'active');
     * // => true
     */
    function some(collection, predicate, thisArg) {
      var func = isArray(collection) ? arraySome : baseSome;
      if (thisArg && isIterateeCall(collection, predicate, thisArg)) {
        predicate = undefined;
      }
      if (typeof predicate != 'function' || thisArg !== undefined) {
        predicate = getCallback(predicate, thisArg, 3);
      }
      return func(collection, predicate);
    }

    /**
     * Creates an array of elements, sorted in ascending order by the results of
     * running each element in a collection through `iteratee`. This method performs
     * a stable sort, that is, it preserves the original sort order of equal elements.
     * The `iteratee` is bound to `thisArg` and invoked with three arguments:
     * (value, index|key, collection).
     *
     * If a property name is provided for `iteratee` the created `_.property`
     * style callback returns the property value of the given element.
     *
     * If a value is also provided for `thisArg` the created `_.matchesProperty`
     * style callback returns `true` for elements that have a matching property
     * value, else `false`.
     *
     * If an object is provided for `iteratee` the created `_.matches` style
     * callback returns `true` for elements that have the properties of the given
     * object, else `false`.
     *
     * @static
     * @memberOf _
     * @category Collection
     * @param {Array|Object|string} collection The collection to iterate over.
     * @param {Function|Object|string} [iteratee=_.identity] The function invoked
     *  per iteration.
     * @param {*} [thisArg] The `this` binding of `iteratee`.
     * @returns {Array} Returns the new sorted array.
     * @example
     *
     * _.sortBy([1, 2, 3], function(n) {
     *   return Math.sin(n);
     * });
     * // => [3, 1, 2]
     *
     * _.sortBy([1, 2, 3], function(n) {
     *   return this.sin(n);
     * }, Math);
     * // => [3, 1, 2]
     *
     * var users = [
     *   { 'user': 'fred' },
     *   { 'user': 'pebbles' },
     *   { 'user': 'barney' }
     * ];
     *
     * // using the `_.property` callback shorthand
     * _.pluck(_.sortBy(users, 'user'), 'user');
     * // => ['barney', 'fred', 'pebbles']
     */
    function sortBy(collection, iteratee, thisArg) {
      if (collection == null) {
        return [];
      }
      if (thisArg && isIterateeCall(collection, iteratee, thisArg)) {
        iteratee = undefined;
      }
      var index = -1;
      iteratee = getCallback(iteratee, thisArg, 3);

      var result = baseMap(collection, function(value, key, collection) {
        return { 'criteria': iteratee(value, key, collection), 'index': ++index, 'value': value };
      });
      return baseSortBy(result, compareAscending);
    }

    /**
     * This method is like `_.sortBy` except that it can sort by multiple iteratees
     * or property names.
     *
     * If a property name is provided for an iteratee the created `_.property`
     * style callback returns the property value of the given element.
     *
     * If an object is provided for an iteratee the created `_.matches` style
     * callback returns `true` for elements that have the properties of the given
     * object, else `false`.
     *
     * @static
     * @memberOf _
     * @category Collection
     * @param {Array|Object|string} collection The collection to iterate over.
     * @param {...(Function|Function[]|Object|Object[]|string|string[])} iteratees
     *  The iteratees to sort by, specified as individual values or arrays of values.
     * @returns {Array} Returns the new sorted array.
     * @example
     *
     * var users = [
     *   { 'user': 'fred',   'age': 48 },
     *   { 'user': 'barney', 'age': 36 },
     *   { 'user': 'fred',   'age': 42 },
     *   { 'user': 'barney', 'age': 34 }
     * ];
     *
     * _.map(_.sortByAll(users, ['user', 'age']), _.values);
     * // => [['barney', 34], ['barney', 36], ['fred', 42], ['fred', 48]]
     *
     * _.map(_.sortByAll(users, 'user', function(chr) {
     *   return Math.floor(chr.age / 10);
     * }), _.values);
     * // => [['barney', 36], ['barney', 34], ['fred', 48], ['fred', 42]]
     */
    var sortByAll = restParam(function(collection, iteratees) {
      if (collection == null) {
        return [];
      }
      var guard = iteratees[2];
      if (guard && isIterateeCall(iteratees[0], iteratees[1], guard)) {
        iteratees.length = 1;
      }
      return baseSortByOrder(collection, baseFlatten(iteratees), []);
    });

    /**
     * This method is like `_.sortByAll` except that it allows specifying the
     * sort orders of the iteratees to sort by. If `orders` is unspecified, all
     * values are sorted in ascending order. Otherwise, a value is sorted in
     * ascending order if its corresponding order is "asc", and descending if "desc".
     *
     * If a property name is provided for an iteratee the created `_.property`
     * style callback returns the property value of the given element.
     *
     * If an object is provided for an iteratee the created `_.matches` style
     * callback returns `true` for elements that have the properties of the given
     * object, else `false`.
     *
     * @static
     * @memberOf _
     * @category Collection
     * @param {Array|Object|string} collection The collection to iterate over.
     * @param {Function[]|Object[]|string[]} iteratees The iteratees to sort by.
     * @param {boolean[]} [orders] The sort orders of `iteratees`.
     * @param- {Object} [guard] Enables use as a callback for functions like `_.reduce`.
     * @returns {Array} Returns the new sorted array.
     * @example
     *
     * var users = [
     *   { 'user': 'fred',   'age': 48 },
     *   { 'user': 'barney', 'age': 34 },
     *   { 'user': 'fred',   'age': 42 },
     *   { 'user': 'barney', 'age': 36 }
     * ];
     *
     * // sort by `user` in ascending order and by `age` in descending order
     * _.map(_.sortByOrder(users, ['user', 'age'], ['asc', 'desc']), _.values);
     * // => [['barney', 36], ['barney', 34], ['fred', 48], ['fred', 42]]
     */
    function sortByOrder(collection, iteratees, orders, guard) {
      if (collection == null) {
        return [];
      }
      if (guard && isIterateeCall(iteratees, orders, guard)) {
        orders = undefined;
      }
      if (!isArray(iteratees)) {
        iteratees = iteratees == null ? [] : [iteratees];
      }
      if (!isArray(orders)) {
        orders = orders == null ? [] : [orders];
      }
      return baseSortByOrder(collection, iteratees, orders);
    }

    /**
     * Performs a deep comparison between each element in `collection` and the
     * source object, returning an array of all elements that have equivalent
     * property values.
     *
     * **Note:** This method supports comparing arrays, booleans, `Date` objects,
     * numbers, `Object` objects, regexes, and strings. Objects are compared by
     * their own, not inherited, enumerable properties. For comparing a single
     * own or inherited property value see `_.matchesProperty`.
     *
     * @static
     * @memberOf _
     * @category Collection
     * @param {Array|Object|string} collection The collection to search.
     * @param {Object} source The object of property values to match.
     * @returns {Array} Returns the new filtered array.
     * @example
     *
     * var users = [
     *   { 'user': 'barney', 'age': 36, 'active': false, 'pets': ['hoppy'] },
     *   { 'user': 'fred',   'age': 40, 'active': true, 'pets': ['baby puss', 'dino'] }
     * ];
     *
     * _.pluck(_.where(users, { 'age': 36, 'active': false }), 'user');
     * // => ['barney']
     *
     * _.pluck(_.where(users, { 'pets': ['dino'] }), 'user');
     * // => ['fred']
     */
    function where(collection, source) {
      return filter(collection, baseMatches(source));
    }

    /*------------------------------------------------------------------------*/

    /**
     * Gets the number of milliseconds that have elapsed since the Unix epoch
     * (1 January 1970 00:00:00 UTC).
     *
     * @static
     * @memberOf _
     * @category Date
     * @example
     *
     * _.defer(function(stamp) {
     *   console.log(_.now() - stamp);
     * }, _.now());
     * // => logs the number of milliseconds it took for the deferred function to be invoked
     */
    var now = nativeNow || function() {
      return new Date().getTime();
    };

    /*------------------------------------------------------------------------*/

    /**
     * The opposite of `_.before`; this method creates a function that invokes
     * `func` once it is called `n` or more times.
     *
     * @static
     * @memberOf _
     * @category Function
     * @param {number} n The number of calls before `func` is invoked.
     * @param {Function} func The function to restrict.
     * @returns {Function} Returns the new restricted function.
     * @example
     *
     * var saves = ['profile', 'settings'];
     *
     * var done = _.after(saves.length, function() {
     *   console.log('done saving!');
     * });
     *
     * _.forEach(saves, function(type) {
     *   asyncSave({ 'type': type, 'complete': done });
     * });
     * // => logs 'done saving!' after the two async saves have completed
     */
    function after(n, func) {
      if (typeof func != 'function') {
        if (typeof n == 'function') {
          var temp = n;
          n = func;
          func = temp;
        } else {
          throw new TypeError(FUNC_ERROR_TEXT);
        }
      }
      n = nativeIsFinite(n = +n) ? n : 0;
      return function() {
        if (--n < 1) {
          return func.apply(this, arguments);
        }
      };
    }

    /**
     * Creates a function that accepts up to `n` arguments ignoring any
     * additional arguments.
     *
     * @static
     * @memberOf _
     * @category Function
     * @param {Function} func The function to cap arguments for.
     * @param {number} [n=func.length] The arity cap.
     * @param- {Object} [guard] Enables use as a callback for functions like `_.map`.
     * @returns {Function} Returns the new function.
     * @example
     *
     * _.map(['6', '8', '10'], _.ary(parseInt, 1));
     * // => [6, 8, 10]
     */
    function ary(func, n, guard) {
      if (guard && isIterateeCall(func, n, guard)) {
        n = undefined;
      }
      n = (func && n == null) ? func.length : nativeMax(+n || 0, 0);
      return createWrapper(func, ARY_FLAG, undefined, undefined, undefined, undefined, n);
    }

    /**
     * Creates a function that invokes `func`, with the `this` binding and arguments
     * of the created function, while it is called less than `n` times. Subsequent
     * calls to the created function return the result of the last `func` invocation.
     *
     * @static
     * @memberOf _
     * @category Function
     * @param {number} n The number of calls at which `func` is no longer invoked.
     * @param {Function} func The function to restrict.
     * @returns {Function} Returns the new restricted function.
     * @example
     *
     * jQuery('#add').on('click', _.before(5, addContactToList));
     * // => allows adding up to 4 contacts to the list
     */
    function before(n, func) {
      var result;
      if (typeof func != 'function') {
        if (typeof n == 'function') {
          var temp = n;
          n = func;
          func = temp;
        } else {
          throw new TypeError(FUNC_ERROR_TEXT);
        }
      }
      return function() {
        if (--n > 0) {
          result = func.apply(this, arguments);
        }
        if (n <= 1) {
          func = undefined;
        }
        return result;
      };
    }

    /**
     * Creates a function that invokes `func` with the `this` binding of `thisArg`
     * and prepends any additional `_.bind` arguments to those provided to the
     * bound function.
     *
     * The `_.bind.placeholder` value, which defaults to `_` in monolithic builds,
     * may be used as a placeholder for partially applied arguments.
     *
     * **Note:** Unlike native `Function#bind` this method does not set the "length"
     * property of bound functions.
     *
     * @static
     * @memberOf _
     * @category Function
     * @param {Function} func The function to bind.
     * @param {*} thisArg The `this` binding of `func`.
     * @param {...*} [partials] The arguments to be partially applied.
     * @returns {Function} Returns the new bound function.
     * @example
     *
     * var greet = function(greeting, punctuation) {
     *   return greeting + ' ' + this.user + punctuation;
     * };
     *
     * var object = { 'user': 'fred' };
     *
     * var bound = _.bind(greet, object, 'hi');
     * bound('!');
     * // => 'hi fred!'
     *
     * // using placeholders
     * var bound = _.bind(greet, object, _, '!');
     * bound('hi');
     * // => 'hi fred!'
     */
    var bind = restParam(function(func, thisArg, partials) {
      var bitmask = BIND_FLAG;
      if (partials.length) {
        var holders = replaceHolders(partials, bind.placeholder);
        bitmask |= PARTIAL_FLAG;
      }
      return createWrapper(func, bitmask, thisArg, partials, holders);
    });

    /**
     * Binds methods of an object to the object itself, overwriting the existing
     * method. Method names may be specified as individual arguments or as arrays
     * of method names. If no method names are provided all enumerable function
     * properties, own and inherited, of `object` are bound.
     *
     * **Note:** This method does not set the "length" property of bound functions.
     *
     * @static
     * @memberOf _
     * @category Function
     * @param {Object} object The object to bind and assign the bound methods to.
     * @param {...(string|string[])} [methodNames] The object method names to bind,
     *  specified as individual method names or arrays of method names.
     * @returns {Object} Returns `object`.
     * @example
     *
     * var view = {
     *   'label': 'docs',
     *   'onClick': function() {
     *     console.log('clicked ' + this.label);
     *   }
     * };
     *
     * _.bindAll(view);
     * jQuery('#docs').on('click', view.onClick);
     * // => logs 'clicked docs' when the element is clicked
     */
    var bindAll = restParam(function(object, methodNames) {
      methodNames = methodNames.length ? baseFlatten(methodNames) : functions(object);

      var index = -1,
          length = methodNames.length;

      while (++index < length) {
        var key = methodNames[index];
        object[key] = createWrapper(object[key], BIND_FLAG, object);
      }
      return object;
    });

    /**
     * Creates a function that invokes the method at `object[key]` and prepends
     * any additional `_.bindKey` arguments to those provided to the bound function.
     *
     * This method differs from `_.bind` by allowing bound functions to reference
     * methods that may be redefined or don't yet exist.
     * See [Peter Michaux's article](http://peter.michaux.ca/articles/lazy-function-definition-pattern)
     * for more details.
     *
     * The `_.bindKey.placeholder` value, which defaults to `_` in monolithic
     * builds, may be used as a placeholder for partially applied arguments.
     *
     * @static
     * @memberOf _
     * @category Function
     * @param {Object} object The object the method belongs to.
     * @param {string} key The key of the method.
     * @param {...*} [partials] The arguments to be partially applied.
     * @returns {Function} Returns the new bound function.
     * @example
     *
     * var object = {
     *   'user': 'fred',
     *   'greet': function(greeting, punctuation) {
     *     return greeting + ' ' + this.user + punctuation;
     *   }
     * };
     *
     * var bound = _.bindKey(object, 'greet', 'hi');
     * bound('!');
     * // => 'hi fred!'
     *
     * object.greet = function(greeting, punctuation) {
     *   return greeting + 'ya ' + this.user + punctuation;
     * };
     *
     * bound('!');
     * // => 'hiya fred!'
     *
     * // using placeholders
     * var bound = _.bindKey(object, 'greet', _, '!');
     * bound('hi');
     * // => 'hiya fred!'
     */
    var bindKey = restParam(function(object, key, partials) {
      var bitmask = BIND_FLAG | BIND_KEY_FLAG;
      if (partials.length) {
        var holders = replaceHolders(partials, bindKey.placeholder);
        bitmask |= PARTIAL_FLAG;
      }
      return createWrapper(key, bitmask, object, partials, holders);
    });

    /**
     * Creates a function that accepts one or more arguments of `func` that when
     * called either invokes `func` returning its result, if all `func` arguments
     * have been provided, or returns a function that accepts one or more of the
     * remaining `func` arguments, and so on. The arity of `func` may be specified
     * if `func.length` is not sufficient.
     *
     * The `_.curry.placeholder` value, which defaults to `_` in monolithic builds,
     * may be used as a placeholder for provided arguments.
     *
     * **Note:** This method does not set the "length" property of curried functions.
     *
     * @static
     * @memberOf _
     * @category Function
     * @param {Function} func The function to curry.
     * @param {number} [arity=func.length] The arity of `func`.
     * @param- {Object} [guard] Enables use as a callback for functions like `_.map`.
     * @returns {Function} Returns the new curried function.
     * @example
     *
     * var abc = function(a, b, c) {
     *   return [a, b, c];
     * };
     *
     * var curried = _.curry(abc);
     *
     * curried(1)(2)(3);
     * // => [1, 2, 3]
     *
     * curried(1, 2)(3);
     * // => [1, 2, 3]
     *
     * curried(1, 2, 3);
     * // => [1, 2, 3]
     *
     * // using placeholders
     * curried(1)(_, 3)(2);
     * // => [1, 2, 3]
     */
    var curry = createCurry(CURRY_FLAG);

    /**
     * This method is like `_.curry` except that arguments are applied to `func`
     * in the manner of `_.partialRight` instead of `_.partial`.
     *
     * The `_.curryRight.placeholder` value, which defaults to `_` in monolithic
     * builds, may be used as a placeholder for provided arguments.
     *
     * **Note:** This method does not set the "length" property of curried functions.
     *
     * @static
     * @memberOf _
     * @category Function
     * @param {Function} func The function to curry.
     * @param {number} [arity=func.length] The arity of `func`.
     * @param- {Object} [guard] Enables use as a callback for functions like `_.map`.
     * @returns {Function} Returns the new curried function.
     * @example
     *
     * var abc = function(a, b, c) {
     *   return [a, b, c];
     * };
     *
     * var curried = _.curryRight(abc);
     *
     * curried(3)(2)(1);
     * // => [1, 2, 3]
     *
     * curried(2, 3)(1);
     * // => [1, 2, 3]
     *
     * curried(1, 2, 3);
     * // => [1, 2, 3]
     *
     * // using placeholders
     * curried(3)(1, _)(2);
     * // => [1, 2, 3]
     */
    var curryRight = createCurry(CURRY_RIGHT_FLAG);

    /**
     * Creates a debounced function that delays invoking `func` until after `wait`
     * milliseconds have elapsed since the last time the debounced function was
     * invoked. The debounced function comes with a `cancel` method to cancel
     * delayed invocations. Provide an options object to indicate that `func`
     * should be invoked on the leading and/or trailing edge of the `wait` timeout.
     * Subsequent calls to the debounced function return the result of the last
     * `func` invocation.
     *
     * **Note:** If `leading` and `trailing` options are `true`, `func` is invoked
     * on the trailing edge of the timeout only if the the debounced function is
     * invoked more than once during the `wait` timeout.
     *
     * See [David Corbacho's article](http://drupalmotion.com/article/debounce-and-throttle-visual-explanation)
     * for details over the differences between `_.debounce` and `_.throttle`.
     *
     * @static
     * @memberOf _
     * @category Function
     * @param {Function} func The function to debounce.
     * @param {number} [wait=0] The number of milliseconds to delay.
     * @param {Object} [options] The options object.
     * @param {boolean} [options.leading=false] Specify invoking on the leading
     *  edge of the timeout.
     * @param {number} [options.maxWait] The maximum time `func` is allowed to be
     *  delayed before it is invoked.
     * @param {boolean} [options.trailing=true] Specify invoking on the trailing
     *  edge of the timeout.
     * @returns {Function} Returns the new debounced function.
     * @example
     *
     * // avoid costly calculations while the window size is in flux
     * jQuery(window).on('resize', _.debounce(calculateLayout, 150));
     *
     * // invoke `sendMail` when the click event is fired, debouncing subsequent calls
     * jQuery('#postbox').on('click', _.debounce(sendMail, 300, {
     *   'leading': true,
     *   'trailing': false
     * }));
     *
     * // ensure `batchLog` is invoked once after 1 second of debounced calls
     * var source = new EventSource('/stream');
     * jQuery(source).on('message', _.debounce(batchLog, 250, {
     *   'maxWait': 1000
     * }));
     *
     * // cancel a debounced call
     * var todoChanges = _.debounce(batchLog, 1000);
     * Object.observe(models.todo, todoChanges);
     *
     * Object.observe(models, function(changes) {
     *   if (_.find(changes, { 'user': 'todo', 'type': 'delete'})) {
     *     todoChanges.cancel();
     *   }
     * }, ['delete']);
     *
     * // ...at some point `models.todo` is changed
     * models.todo.completed = true;
     *
     * // ...before 1 second has passed `models.todo` is deleted
     * // which cancels the debounced `todoChanges` call
     * delete models.todo;
     */
    function debounce(func, wait, options) {
      var args,
          maxTimeoutId,
          result,
          stamp,
          thisArg,
          timeoutId,
          trailingCall,
          lastCalled = 0,
          maxWait = false,
          trailing = true;

      if (typeof func != 'function') {
        throw new TypeError(FUNC_ERROR_TEXT);
      }
      wait = wait < 0 ? 0 : (+wait || 0);
      if (options === true) {
        var leading = true;
        trailing = false;
      } else if (isObject(options)) {
        leading = !!options.leading;
        maxWait = 'maxWait' in options && nativeMax(+options.maxWait || 0, wait);
        trailing = 'trailing' in options ? !!options.trailing : trailing;
      }

      function cancel() {
        if (timeoutId) {
          clearTimeout(timeoutId);
        }
        if (maxTimeoutId) {
          clearTimeout(maxTimeoutId);
        }
        lastCalled = 0;
        maxTimeoutId = timeoutId = trailingCall = undefined;
      }

      function complete(isCalled, id) {
        if (id) {
          clearTimeout(id);
        }
        maxTimeoutId = timeoutId = trailingCall = undefined;
        if (isCalled) {
          lastCalled = now();
          result = func.apply(thisArg, args);
          if (!timeoutId && !maxTimeoutId) {
            args = thisArg = undefined;
          }
        }
      }

      function delayed() {
        var remaining = wait - (now() - stamp);
        if (remaining <= 0 || remaining > wait) {
          complete(trailingCall, maxTimeoutId);
        } else {
          timeoutId = setTimeout(delayed, remaining);
        }
      }

      function maxDelayed() {
        complete(trailing, timeoutId);
      }

      function debounced() {
        args = arguments;
        stamp = now();
        thisArg = this;
        trailingCall = trailing && (timeoutId || !leading);

        if (maxWait === false) {
          var leadingCall = leading && !timeoutId;
        } else {
          if (!maxTimeoutId && !leading) {
            lastCalled = stamp;
          }
          var remaining = maxWait - (stamp - lastCalled),
              isCalled = remaining <= 0 || remaining > maxWait;

          if (isCalled) {
            if (maxTimeoutId) {
              maxTimeoutId = clearTimeout(maxTimeoutId);
            }
            lastCalled = stamp;
            result = func.apply(thisArg, args);
          }
          else if (!maxTimeoutId) {
            maxTimeoutId = setTimeout(maxDelayed, remaining);
          }
        }
        if (isCalled && timeoutId) {
          timeoutId = clearTimeout(timeoutId);
        }
        else if (!timeoutId && wait !== maxWait) {
          timeoutId = setTimeout(delayed, wait);
        }
        if (leadingCall) {
          isCalled = true;
          result = func.apply(thisArg, args);
        }
        if (isCalled && !timeoutId && !maxTimeoutId) {
          args = thisArg = undefined;
        }
        return result;
      }
      debounced.cancel = cancel;
      return debounced;
    }

    /**
     * Defers invoking the `func` until the current call stack has cleared. Any
     * additional arguments are provided to `func` when it is invoked.
     *
     * @static
     * @memberOf _
     * @category Function
     * @param {Function} func The function to defer.
     * @param {...*} [args] The arguments to invoke the function with.
     * @returns {number} Returns the timer id.
     * @example
     *
     * _.defer(function(text) {
     *   console.log(text);
     * }, 'deferred');
     * // logs 'deferred' after one or more milliseconds
     */
    var defer = restParam(function(func, args) {
      return baseDelay(func, 1, args);
    });

    /**
     * Invokes `func` after `wait` milliseconds. Any additional arguments are
     * provided to `func` when it is invoked.
     *
     * @static
     * @memberOf _
     * @category Function
     * @param {Function} func The function to delay.
     * @param {number} wait The number of milliseconds to delay invocation.
     * @param {...*} [args] The arguments to invoke the function with.
     * @returns {number} Returns the timer id.
     * @example
     *
     * _.delay(function(text) {
     *   console.log(text);
     * }, 1000, 'later');
     * // => logs 'later' after one second
     */
    var delay = restParam(function(func, wait, args) {
      return baseDelay(func, wait, args);
    });

    /**
     * Creates a function that returns the result of invoking the provided
     * functions with the `this` binding of the created function, where each
     * successive invocation is supplied the return value of the previous.
     *
     * @static
     * @memberOf _
     * @category Function
     * @param {...Function} [funcs] Functions to invoke.
     * @returns {Function} Returns the new function.
     * @example
     *
     * function square(n) {
     *   return n * n;
     * }
     *
     * var addSquare = _.flow(_.add, square);
     * addSquare(1, 2);
     * // => 9
     */
    var flow = createFlow();

    /**
     * This method is like `_.flow` except that it creates a function that
     * invokes the provided functions from right to left.
     *
     * @static
     * @memberOf _
     * @alias backflow, compose
     * @category Function
     * @param {...Function} [funcs] Functions to invoke.
     * @returns {Function} Returns the new function.
     * @example
     *
     * function square(n) {
     *   return n * n;
     * }
     *
     * var addSquare = _.flowRight(square, _.add);
     * addSquare(1, 2);
     * // => 9
     */
    var flowRight = createFlow(true);

    /**
     * Creates a function that memoizes the result of `func`. If `resolver` is
     * provided it determines the cache key for storing the result based on the
     * arguments provided to the memoized function. By default, the first argument
     * provided to the memoized function is coerced to a string and used as the
     * cache key. The `func` is invoked with the `this` binding of the memoized
     * function.
     *
     * **Note:** The cache is exposed as the `cache` property on the memoized
     * function. Its creation may be customized by replacing the `_.memoize.Cache`
     * constructor with one whose instances implement the [`Map`](http://ecma-international.org/ecma-262/6.0/#sec-properties-of-the-map-prototype-object)
     * method interface of `get`, `has`, and `set`.
     *
     * @static
     * @memberOf _
     * @category Function
     * @param {Function} func The function to have its output memoized.
     * @param {Function} [resolver] The function to resolve the cache key.
     * @returns {Function} Returns the new memoizing function.
     * @example
     *
     * var upperCase = _.memoize(function(string) {
     *   return string.toUpperCase();
     * });
     *
     * upperCase('fred');
     * // => 'FRED'
     *
     * // modifying the result cache
     * upperCase.cache.set('fred', 'BARNEY');
     * upperCase('fred');
     * // => 'BARNEY'
     *
     * // replacing `_.memoize.Cache`
     * var object = { 'user': 'fred' };
     * var other = { 'user': 'barney' };
     * var identity = _.memoize(_.identity);
     *
     * identity(object);
     * // => { 'user': 'fred' }
     * identity(other);
     * // => { 'user': 'fred' }
     *
     * _.memoize.Cache = WeakMap;
     * var identity = _.memoize(_.identity);
     *
     * identity(object);
     * // => { 'user': 'fred' }
     * identity(other);
     * // => { 'user': 'barney' }
     */
    function memoize(func, resolver) {
      if (typeof func != 'function' || (resolver && typeof resolver != 'function')) {
        throw new TypeError(FUNC_ERROR_TEXT);
      }
      var memoized = function() {
        var args = arguments,
            key = resolver ? resolver.apply(this, args) : args[0],
            cache = memoized.cache;

        if (cache.has(key)) {
          return cache.get(key);
        }
        var result = func.apply(this, args);
        memoized.cache = cache.set(key, result);
        return result;
      };
      memoized.cache = new memoize.Cache;
      return memoized;
    }

    /**
     * Creates a function that runs each argument through a corresponding
     * transform function.
     *
     * @static
     * @memberOf _
     * @category Function
     * @param {Function} func The function to wrap.
     * @param {...(Function|Function[])} [transforms] The functions to transform
     * arguments, specified as individual functions or arrays of functions.
     * @returns {Function} Returns the new function.
     * @example
     *
     * function doubled(n) {
     *   return n * 2;
     * }
     *
     * function square(n) {
     *   return n * n;
     * }
     *
     * var modded = _.modArgs(function(x, y) {
     *   return [x, y];
     * }, square, doubled);
     *
     * modded(1, 2);
     * // => [1, 4]
     *
     * modded(5, 10);
     * // => [25, 20]
     */
    var modArgs = restParam(function(func, transforms) {
      transforms = baseFlatten(transforms);
      if (typeof func != 'function' || !arrayEvery(transforms, baseIsFunction)) {
        throw new TypeError(FUNC_ERROR_TEXT);
      }
      var length = transforms.length;
      return restParam(function(args) {
        var index = nativeMin(args.length, length);
        while (index--) {
          args[index] = transforms[index](args[index]);
        }
        return func.apply(this, args);
      });
    });

    /**
     * Creates a function that negates the result of the predicate `func`. The
     * `func` predicate is invoked with the `this` binding and arguments of the
     * created function.
     *
     * @static
     * @memberOf _
     * @category Function
     * @param {Function} predicate The predicate to negate.
     * @returns {Function} Returns the new function.
     * @example
     *
     * function isEven(n) {
     *   return n % 2 == 0;
     * }
     *
     * _.filter([1, 2, 3, 4, 5, 6], _.negate(isEven));
     * // => [1, 3, 5]
     */
    function negate(predicate) {
      if (typeof predicate != 'function') {
        throw new TypeError(FUNC_ERROR_TEXT);
      }
      return function() {
        return !predicate.apply(this, arguments);
      };
    }

    /**
     * Creates a function that is restricted to invoking `func` once. Repeat calls
     * to the function return the value of the first call. The `func` is invoked
     * with the `this` binding and arguments of the created function.
     *
     * @static
     * @memberOf _
     * @category Function
     * @param {Function} func The function to restrict.
     * @returns {Function} Returns the new restricted function.
     * @example
     *
     * var initialize = _.once(createApplication);
     * initialize();
     * initialize();
     * // `initialize` invokes `createApplication` once
     */
    function once(func) {
      return before(2, func);
    }

    /**
     * Creates a function that invokes `func` with `partial` arguments prepended
     * to those provided to the new function. This method is like `_.bind` except
     * it does **not** alter the `this` binding.
     *
     * The `_.partial.placeholder` value, which defaults to `_` in monolithic
     * builds, may be used as a placeholder for partially applied arguments.
     *
     * **Note:** This method does not set the "length" property of partially
     * applied functions.
     *
     * @static
     * @memberOf _
     * @category Function
     * @param {Function} func The function to partially apply arguments to.
     * @param {...*} [partials] The arguments to be partially applied.
     * @returns {Function} Returns the new partially applied function.
     * @example
     *
     * var greet = function(greeting, name) {
     *   return greeting + ' ' + name;
     * };
     *
     * var sayHelloTo = _.partial(greet, 'hello');
     * sayHelloTo('fred');
     * // => 'hello fred'
     *
     * // using placeholders
     * var greetFred = _.partial(greet, _, 'fred');
     * greetFred('hi');
     * // => 'hi fred'
     */
    var partial = createPartial(PARTIAL_FLAG);

    /**
     * This method is like `_.partial` except that partially applied arguments
     * are appended to those provided to the new function.
     *
     * The `_.partialRight.placeholder` value, which defaults to `_` in monolithic
     * builds, may be used as a placeholder for partially applied arguments.
     *
     * **Note:** This method does not set the "length" property of partially
     * applied functions.
     *
     * @static
     * @memberOf _
     * @category Function
     * @param {Function} func The function to partially apply arguments to.
     * @param {...*} [partials] The arguments to be partially applied.
     * @returns {Function} Returns the new partially applied function.
     * @example
     *
     * var greet = function(greeting, name) {
     *   return greeting + ' ' + name;
     * };
     *
     * var greetFred = _.partialRight(greet, 'fred');
     * greetFred('hi');
     * // => 'hi fred'
     *
     * // using placeholders
     * var sayHelloTo = _.partialRight(greet, 'hello', _);
     * sayHelloTo('fred');
     * // => 'hello fred'
     */
    var partialRight = createPartial(PARTIAL_RIGHT_FLAG);

    /**
     * Creates a function that invokes `func` with arguments arranged according
     * to the specified indexes where the argument value at the first index is
     * provided as the first argument, the argument value at the second index is
     * provided as the second argument, and so on.
     *
     * @static
     * @memberOf _
     * @category Function
     * @param {Function} func The function to rearrange arguments for.
     * @param {...(number|number[])} indexes The arranged argument indexes,
     *  specified as individual indexes or arrays of indexes.
     * @returns {Function} Returns the new function.
     * @example
     *
     * var rearged = _.rearg(function(a, b, c) {
     *   return [a, b, c];
     * }, 2, 0, 1);
     *
     * rearged('b', 'c', 'a')
     * // => ['a', 'b', 'c']
     *
     * var map = _.rearg(_.map, [1, 0]);
     * map(function(n) {
     *   return n * 3;
     * }, [1, 2, 3]);
     * // => [3, 6, 9]
     */
    var rearg = restParam(function(func, indexes) {
      return createWrapper(func, REARG_FLAG, undefined, undefined, undefined, baseFlatten(indexes));
    });

    /**
     * Creates a function that invokes `func` with the `this` binding of the
     * created function and arguments from `start` and beyond provided as an array.
     *
     * **Note:** This method is based on the [rest parameter](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Functions/rest_parameters).
     *
     * @static
     * @memberOf _
     * @category Function
     * @param {Function} func The function to apply a rest parameter to.
     * @param {number} [start=func.length-1] The start position of the rest parameter.
     * @returns {Function} Returns the new function.
     * @example
     *
     * var say = _.restParam(function(what, names) {
     *   return what + ' ' + _.initial(names).join(', ') +
     *     (_.size(names) > 1 ? ', & ' : '') + _.last(names);
     * });
     *
     * say('hello', 'fred', 'barney', 'pebbles');
     * // => 'hello fred, barney, & pebbles'
     */
    function restParam(func, start) {
      if (typeof func != 'function') {
        throw new TypeError(FUNC_ERROR_TEXT);
      }
      start = nativeMax(start === undefined ? (func.length - 1) : (+start || 0), 0);
      return function() {
        var args = arguments,
            index = -1,
            length = nativeMax(args.length - start, 0),
            rest = Array(length);

        while (++index < length) {
          rest[index] = args[start + index];
        }
        switch (start) {
          case 0: return func.call(this, rest);
          case 1: return func.call(this, args[0], rest);
          case 2: return func.call(this, args[0], args[1], rest);
        }
        var otherArgs = Array(start + 1);
        index = -1;
        while (++index < start) {
          otherArgs[index] = args[index];
        }
        otherArgs[start] = rest;
        return func.apply(this, otherArgs);
      };
    }

    /**
     * Creates a function that invokes `func` with the `this` binding of the created
     * function and an array of arguments much like [`Function#apply`](https://es5.github.io/#x15.3.4.3).
     *
     * **Note:** This method is based on the [spread operator](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Operators/Spread_operator).
     *
     * @static
     * @memberOf _
     * @category Function
     * @param {Function} func The function to spread arguments over.
     * @returns {Function} Returns the new function.
     * @example
     *
     * var say = _.spread(function(who, what) {
     *   return who + ' says ' + what;
     * });
     *
     * say(['fred', 'hello']);
     * // => 'fred says hello'
     *
     * // with a Promise
     * var numbers = Promise.all([
     *   Promise.resolve(40),
     *   Promise.resolve(36)
     * ]);
     *
     * numbers.then(_.spread(function(x, y) {
     *   return x + y;
     * }));
     * // => a Promise of 76
     */
    function spread(func) {
      if (typeof func != 'function') {
        throw new TypeError(FUNC_ERROR_TEXT);
      }
      return function(array) {
        return func.apply(this, array);
      };
    }

    /**
     * Creates a throttled function that only invokes `func` at most once per
     * every `wait` milliseconds. The throttled function comes with a `cancel`
     * method to cancel delayed invocations. Provide an options object to indicate
     * that `func` should be invoked on the leading and/or trailing edge of the
     * `wait` timeout. Subsequent calls to the throttled function return the
     * result of the last `func` call.
     *
     * **Note:** If `leading` and `trailing` options are `true`, `func` is invoked
     * on the trailing edge of the timeout only if the the throttled function is
     * invoked more than once during the `wait` timeout.
     *
     * See [David Corbacho's article](http://drupalmotion.com/article/debounce-and-throttle-visual-explanation)
     * for details over the differences between `_.throttle` and `_.debounce`.
     *
     * @static
     * @memberOf _
     * @category Function
     * @param {Function} func The function to throttle.
     * @param {number} [wait=0] The number of milliseconds to throttle invocations to.
     * @param {Object} [options] The options object.
     * @param {boolean} [options.leading=true] Specify invoking on the leading
     *  edge of the timeout.
     * @param {boolean} [options.trailing=true] Specify invoking on the trailing
     *  edge of the timeout.
     * @returns {Function} Returns the new throttled function.
     * @example
     *
     * // avoid excessively updating the position while scrolling
     * jQuery(window).on('scroll', _.throttle(updatePosition, 100));
     *
     * // invoke `renewToken` when the click event is fired, but not more than once every 5 minutes
     * jQuery('.interactive').on('click', _.throttle(renewToken, 300000, {
     *   'trailing': false
     * }));
     *
     * // cancel a trailing throttled call
     * jQuery(window).on('popstate', throttled.cancel);
     */
    function throttle(func, wait, options) {
      var leading = true,
          trailing = true;

      if (typeof func != 'function') {
        throw new TypeError(FUNC_ERROR_TEXT);
      }
      if (options === false) {
        leading = false;
      } else if (isObject(options)) {
        leading = 'leading' in options ? !!options.leading : leading;
        trailing = 'trailing' in options ? !!options.trailing : trailing;
      }
      return debounce(func, wait, { 'leading': leading, 'maxWait': +wait, 'trailing': trailing });
    }

    /**
     * Creates a function that provides `value` to the wrapper function as its
     * first argument. Any additional arguments provided to the function are
     * appended to those provided to the wrapper function. The wrapper is invoked
     * with the `this` binding of the created function.
     *
     * @static
     * @memberOf _
     * @category Function
     * @param {*} value The value to wrap.
     * @param {Function} wrapper The wrapper function.
     * @returns {Function} Returns the new function.
     * @example
     *
     * var p = _.wrap(_.escape, function(func, text) {
     *   return '

' + func(text) + '

'; * }); * * p('fred, barney, & pebbles'); * // => '

fred, barney, & pebbles

' */ function wrap(value, wrapper) { wrapper = wrapper == null ? identity : wrapper; return createWrapper(wrapper, PARTIAL_FLAG, undefined, [value], []); } /*------------------------------------------------------------------------*/ /** * Creates a clone of `value`. If `isDeep` is `true` nested objects are cloned, * otherwise they are assigned by reference. If `customizer` is provided it is * invoked to produce the cloned values. If `customizer` returns `undefined` * cloning is handled by the method instead. The `customizer` is bound to * `thisArg` and invoked with two argument; (value [, index|key, object]). * * **Note:** This method is loosely based on the * [structured clone algorithm](http://www.w3.org/TR/html5/infrastructure.html#internal-structured-cloning-algorithm). * The enumerable properties of `arguments` objects and objects created by * constructors other than `Object` are cloned to plain `Object` objects. An * empty object is returned for uncloneable values such as functions, DOM nodes, * Maps, Sets, and WeakMaps. * * @static * @memberOf _ * @category Lang * @param {*} value The value to clone. * @param {boolean} [isDeep] Specify a deep clone. * @param {Function} [customizer] The function to customize cloning values. * @param {*} [thisArg] The `this` binding of `customizer`. * @returns {*} Returns the cloned value. * @example * * var users = [ * { 'user': 'barney' }, * { 'user': 'fred' } * ]; * * var shallow = _.clone(users); * shallow[0] === users[0]; * // => true * * var deep = _.clone(users, true); * deep[0] === users[0]; * // => false * * // using a customizer callback * var el = _.clone(document.body, function(value) { * if (_.isElement(value)) { * return value.cloneNode(false); * } * }); * * el === document.body * // => false * el.nodeName * // => BODY * el.childNodes.length; * // => 0 */ function clone(value, isDeep, customizer, thisArg) { if (isDeep && typeof isDeep != 'boolean' && isIterateeCall(value, isDeep, customizer)) { isDeep = false; } else if (typeof isDeep == 'function') { thisArg = customizer; customizer = isDeep; isDeep = false; } return typeof customizer == 'function' ? baseClone(value, isDeep, bindCallback(customizer, thisArg, 1)) : baseClone(value, isDeep); } /** * Creates a deep clone of `value`. If `customizer` is provided it is invoked * to produce the cloned values. If `customizer` returns `undefined` cloning * is handled by the method instead. The `customizer` is bound to `thisArg` * and invoked with two argument; (value [, index|key, object]). * * **Note:** This method is loosely based on the * [structured clone algorithm](http://www.w3.org/TR/html5/infrastructure.html#internal-structured-cloning-algorithm). * The enumerable properties of `arguments` objects and objects created by * constructors other than `Object` are cloned to plain `Object` objects. An * empty object is returned for uncloneable values such as functions, DOM nodes, * Maps, Sets, and WeakMaps. * * @static * @memberOf _ * @category Lang * @param {*} value The value to deep clone. * @param {Function} [customizer] The function to customize cloning values. * @param {*} [thisArg] The `this` binding of `customizer`. * @returns {*} Returns the deep cloned value. * @example * * var users = [ * { 'user': 'barney' }, * { 'user': 'fred' } * ]; * * var deep = _.cloneDeep(users); * deep[0] === users[0]; * // => false * * // using a customizer callback * var el = _.cloneDeep(document.body, function(value) { * if (_.isElement(value)) { * return value.cloneNode(true); * } * }); * * el === document.body * // => false * el.nodeName * // => BODY * el.childNodes.length; * // => 20 */ function cloneDeep(value, customizer, thisArg) { return typeof customizer == 'function' ? baseClone(value, true, bindCallback(customizer, thisArg, 1)) : baseClone(value, true); } /** * Checks if `value` is greater than `other`. * * @static * @memberOf _ * @category Lang * @param {*} value The value to compare. * @param {*} other The other value to compare. * @returns {boolean} Returns `true` if `value` is greater than `other`, else `false`. * @example * * _.gt(3, 1); * // => true * * _.gt(3, 3); * // => false * * _.gt(1, 3); * // => false */ function gt(value, other) { return value > other; } /** * Checks if `value` is greater than or equal to `other`. * * @static * @memberOf _ * @category Lang * @param {*} value The value to compare. * @param {*} other The other value to compare. * @returns {boolean} Returns `true` if `value` is greater than or equal to `other`, else `false`. * @example * * _.gte(3, 1); * // => true * * _.gte(3, 3); * // => true * * _.gte(1, 3); * // => false */ function gte(value, other) { return value >= other; } /** * Checks if `value` is classified as an `arguments` object. * * @static * @memberOf _ * @category Lang * @param {*} value The value to check. * @returns {boolean} Returns `true` if `value` is correctly classified, else `false`. * @example * * _.isArguments(function() { return arguments; }()); * // => true * * _.isArguments([1, 2, 3]); * // => false */ function isArguments(value) { return isObjectLike(value) && isArrayLike(value) && hasOwnProperty.call(value, 'callee') && !propertyIsEnumerable.call(value, 'callee'); } /** * Checks if `value` is classified as an `Array` object. * * @static * @memberOf _ * @category Lang * @param {*} value The value to check. * @returns {boolean} Returns `true` if `value` is correctly classified, else `false`. * @example * * _.isArray([1, 2, 3]); * // => true * * _.isArray(function() { return arguments; }()); * // => false */ var isArray = nativeIsArray || function(value) { return isObjectLike(value) && isLength(value.length) && objToString.call(value) == arrayTag; }; /** * Checks if `value` is classified as a boolean primitive or object. * * @static * @memberOf _ * @category Lang * @param {*} value The value to check. * @returns {boolean} Returns `true` if `value` is correctly classified, else `false`. * @example * * _.isBoolean(false); * // => true * * _.isBoolean(null); * // => false */ function isBoolean(value) { return value === true || value === false || (isObjectLike(value) && objToString.call(value) == boolTag); } /** * Checks if `value` is classified as a `Date` object. * * @static * @memberOf _ * @category Lang * @param {*} value The value to check. * @returns {boolean} Returns `true` if `value` is correctly classified, else `false`. * @example * * _.isDate(new Date); * // => true * * _.isDate('Mon April 23 2012'); * // => false */ function isDate(value) { return isObjectLike(value) && objToString.call(value) == dateTag; } /** * Checks if `value` is a DOM element. * * @static * @memberOf _ * @category Lang * @param {*} value The value to check. * @returns {boolean} Returns `true` if `value` is a DOM element, else `false`. * @example * * _.isElement(document.body); * // => true * * _.isElement(''); * // => false */ function isElement(value) { return !!value && value.nodeType === 1 && isObjectLike(value) && !isPlainObject(value); } /** * Checks if `value` is empty. A value is considered empty unless it is an * `arguments` object, array, string, or jQuery-like collection with a length * greater than `0` or an object with own enumerable properties. * * @static * @memberOf _ * @category Lang * @param {Array|Object|string} value The value to inspect. * @returns {boolean} Returns `true` if `value` is empty, else `false`. * @example * * _.isEmpty(null); * // => true * * _.isEmpty(true); * // => true * * _.isEmpty(1); * // => true * * _.isEmpty([1, 2, 3]); * // => false * * _.isEmpty({ 'a': 1 }); * // => false */ function isEmpty(value) { if (value == null) { return true; } if (isArrayLike(value) && (isArray(value) || isString(value) || isArguments(value) || (isObjectLike(value) && isFunction(value.splice)))) { return !value.length; } return !keys(value).length; } /** * Performs a deep comparison between two values to determine if they are * equivalent. If `customizer` is provided it is invoked to compare values. * If `customizer` returns `undefined` comparisons are handled by the method * instead. The `customizer` is bound to `thisArg` and invoked with three * arguments: (value, other [, index|key]). * * **Note:** This method supports comparing arrays, booleans, `Date` objects, * numbers, `Object` objects, regexes, and strings. Objects are compared by * their own, not inherited, enumerable properties. Functions and DOM nodes * are **not** supported. Provide a customizer function to extend support * for comparing other values. * * @static * @memberOf _ * @alias eq * @category Lang * @param {*} value The value to compare. * @param {*} other The other value to compare. * @param {Function} [customizer] The function to customize value comparisons. * @param {*} [thisArg] The `this` binding of `customizer`. * @returns {boolean} Returns `true` if the values are equivalent, else `false`. * @example * * var object = { 'user': 'fred' }; * var other = { 'user': 'fred' }; * * object == other; * // => false * * _.isEqual(object, other); * // => true * * // using a customizer callback * var array = ['hello', 'goodbye']; * var other = ['hi', 'goodbye']; * * _.isEqual(array, other, function(value, other) { * if (_.every([value, other], RegExp.prototype.test, /^h(?:i|ello)$/)) { * return true; * } * }); * // => true */ function isEqual(value, other, customizer, thisArg) { customizer = typeof customizer == 'function' ? bindCallback(customizer, thisArg, 3) : undefined; var result = customizer ? customizer(value, other) : undefined; return result === undefined ? baseIsEqual(value, other, customizer) : !!result; } /** * Checks if `value` is an `Error`, `EvalError`, `RangeError`, `ReferenceError`, * `SyntaxError`, `TypeError`, or `URIError` object. * * @static * @memberOf _ * @category Lang * @param {*} value The value to check. * @returns {boolean} Returns `true` if `value` is an error object, else `false`. * @example * * _.isError(new Error); * // => true * * _.isError(Error); * // => false */ function isError(value) { return isObjectLike(value) && typeof value.message == 'string' && objToString.call(value) == errorTag; } /** * Checks if `value` is a finite primitive number. * * **Note:** This method is based on [`Number.isFinite`](http://ecma-international.org/ecma-262/6.0/#sec-number.isfinite). * * @static * @memberOf _ * @category Lang * @param {*} value The value to check. * @returns {boolean} Returns `true` if `value` is a finite number, else `false`. * @example * * _.isFinite(10); * // => true * * _.isFinite('10'); * // => false * * _.isFinite(true); * // => false * * _.isFinite(Object(10)); * // => false * * _.isFinite(Infinity); * // => false */ function isFinite(value) { return typeof value == 'number' && nativeIsFinite(value); } /** * Checks if `value` is classified as a `Function` object. * * @static * @memberOf _ * @category Lang * @param {*} value The value to check. * @returns {boolean} Returns `true` if `value` is correctly classified, else `false`. * @example * * _.isFunction(_); * // => true * * _.isFunction(/abc/); * // => false */ function isFunction(value) { // The use of `Object#toString` avoids issues with the `typeof` operator // in older versions of Chrome and Safari which return 'function' for regexes // and Safari 8 equivalents which return 'object' for typed array constructors. return isObject(value) && objToString.call(value) == funcTag; } /** * Checks if `value` is the [language type](https://es5.github.io/#x8) of `Object`. * (e.g. arrays, functions, objects, regexes, `new Number(0)`, and `new String('')`) * * @static * @memberOf _ * @category Lang * @param {*} value The value to check. * @returns {boolean} Returns `true` if `value` is an object, else `false`. * @example * * _.isObject({}); * // => true * * _.isObject([1, 2, 3]); * // => true * * _.isObject(1); * // => false */ function isObject(value) { // Avoid a V8 JIT bug in Chrome 19-20. // See https://code.google.com/p/v8/issues/detail?id=2291 for more details. var type = typeof value; return !!value && (type == 'object' || type == 'function'); } /** * Performs a deep comparison between `object` and `source` to determine if * `object` contains equivalent property values. If `customizer` is provided * it is invoked to compare values. If `customizer` returns `undefined` * comparisons are handled by the method instead. The `customizer` is bound * to `thisArg` and invoked with three arguments: (value, other, index|key). * * **Note:** This method supports comparing properties of arrays, booleans, * `Date` objects, numbers, `Object` objects, regexes, and strings. Functions * and DOM nodes are **not** supported. Provide a customizer function to extend * support for comparing other values. * * @static * @memberOf _ * @category Lang * @param {Object} object The object to inspect. * @param {Object} source The object of property values to match. * @param {Function} [customizer] The function to customize value comparisons. * @param {*} [thisArg] The `this` binding of `customizer`. * @returns {boolean} Returns `true` if `object` is a match, else `false`. * @example * * var object = { 'user': 'fred', 'age': 40 }; * * _.isMatch(object, { 'age': 40 }); * // => true * * _.isMatch(object, { 'age': 36 }); * // => false * * // using a customizer callback * var object = { 'greeting': 'hello' }; * var source = { 'greeting': 'hi' }; * * _.isMatch(object, source, function(value, other) { * return _.every([value, other], RegExp.prototype.test, /^h(?:i|ello)$/) || undefined; * }); * // => true */ function isMatch(object, source, customizer, thisArg) { customizer = typeof customizer == 'function' ? bindCallback(customizer, thisArg, 3) : undefined; return baseIsMatch(object, getMatchData(source), customizer); } /** * Checks if `value` is `NaN`. * * **Note:** This method is not the same as [`isNaN`](https://es5.github.io/#x15.1.2.4) * which returns `true` for `undefined` and other non-numeric values. * * @static * @memberOf _ * @category Lang * @param {*} value The value to check. * @returns {boolean} Returns `true` if `value` is `NaN`, else `false`. * @example * * _.isNaN(NaN); * // => true * * _.isNaN(new Number(NaN)); * // => true * * isNaN(undefined); * // => true * * _.isNaN(undefined); * // => false */ function isNaN(value) { // An `NaN` primitive is the only value that is not equal to itself. // Perform the `toStringTag` check first to avoid errors with some host objects in IE. return isNumber(value) && value != +value; } /** * Checks if `value` is a native function. * * @static * @memberOf _ * @category Lang * @param {*} value The value to check. * @returns {boolean} Returns `true` if `value` is a native function, else `false`. * @example * * _.isNative(Array.prototype.push); * // => true * * _.isNative(_); * // => false */ function isNative(value) { if (value == null) { return false; } if (isFunction(value)) { return reIsNative.test(fnToString.call(value)); } return isObjectLike(value) && reIsHostCtor.test(value); } /** * Checks if `value` is `null`. * * @static * @memberOf _ * @category Lang * @param {*} value The value to check. * @returns {boolean} Returns `true` if `value` is `null`, else `false`. * @example * * _.isNull(null); * // => true * * _.isNull(void 0); * // => false */ function isNull(value) { return value === null; } /** * Checks if `value` is classified as a `Number` primitive or object. * * **Note:** To exclude `Infinity`, `-Infinity`, and `NaN`, which are classified * as numbers, use the `_.isFinite` method. * * @static * @memberOf _ * @category Lang * @param {*} value The value to check. * @returns {boolean} Returns `true` if `value` is correctly classified, else `false`. * @example * * _.isNumber(8.4); * // => true * * _.isNumber(NaN); * // => true * * _.isNumber('8.4'); * // => false */ function isNumber(value) { return typeof value == 'number' || (isObjectLike(value) && objToString.call(value) == numberTag); } /** * Checks if `value` is a plain object, that is, an object created by the * `Object` constructor or one with a `[[Prototype]]` of `null`. * * **Note:** This method assumes objects created by the `Object` constructor * have no inherited enumerable properties. * * @static * @memberOf _ * @category Lang * @param {*} value The value to check. * @returns {boolean} Returns `true` if `value` is a plain object, else `false`. * @example * * function Foo() { * this.a = 1; * } * * _.isPlainObject(new Foo); * // => false * * _.isPlainObject([1, 2, 3]); * // => false * * _.isPlainObject({ 'x': 0, 'y': 0 }); * // => true * * _.isPlainObject(Object.create(null)); * // => true */ function isPlainObject(value) { var Ctor; // Exit early for non `Object` objects. if (!(isObjectLike(value) && objToString.call(value) == objectTag && !isArguments(value)) || (!hasOwnProperty.call(value, 'constructor') && (Ctor = value.constructor, typeof Ctor == 'function' && !(Ctor instanceof Ctor)))) { return false; } // IE < 9 iterates inherited properties before own properties. If the first // iterated property is an object's own property then there are no inherited // enumerable properties. var result; // In most environments an object's own properties are iterated before // its inherited properties. If the last iterated property is an object's // own property then there are no inherited enumerable properties. baseForIn(value, function(subValue, key) { result = key; }); return result === undefined || hasOwnProperty.call(value, result); } /** * Checks if `value` is classified as a `RegExp` object. * * @static * @memberOf _ * @category Lang * @param {*} value The value to check. * @returns {boolean} Returns `true` if `value` is correctly classified, else `false`. * @example * * _.isRegExp(/abc/); * // => true * * _.isRegExp('/abc/'); * // => false */ function isRegExp(value) { return isObject(value) && objToString.call(value) == regexpTag; } /** * Checks if `value` is classified as a `String` primitive or object. * * @static * @memberOf _ * @category Lang * @param {*} value The value to check. * @returns {boolean} Returns `true` if `value` is correctly classified, else `false`. * @example * * _.isString('abc'); * // => true * * _.isString(1); * // => false */ function isString(value) { return typeof value == 'string' || (isObjectLike(value) && objToString.call(value) == stringTag); } /** * Checks if `value` is classified as a typed array. * * @static * @memberOf _ * @category Lang * @param {*} value The value to check. * @returns {boolean} Returns `true` if `value` is correctly classified, else `false`. * @example * * _.isTypedArray(new Uint8Array); * // => true * * _.isTypedArray([]); * // => false */ function isTypedArray(value) { return isObjectLike(value) && isLength(value.length) && !!typedArrayTags[objToString.call(value)]; } /** * Checks if `value` is `undefined`. * * @static * @memberOf _ * @category Lang * @param {*} value The value to check. * @returns {boolean} Returns `true` if `value` is `undefined`, else `false`. * @example * * _.isUndefined(void 0); * // => true * * _.isUndefined(null); * // => false */ function isUndefined(value) { return value === undefined; } /** * Checks if `value` is less than `other`. * * @static * @memberOf _ * @category Lang * @param {*} value The value to compare. * @param {*} other The other value to compare. * @returns {boolean} Returns `true` if `value` is less than `other`, else `false`. * @example * * _.lt(1, 3); * // => true * * _.lt(3, 3); * // => false * * _.lt(3, 1); * // => false */ function lt(value, other) { return value < other; } /** * Checks if `value` is less than or equal to `other`. * * @static * @memberOf _ * @category Lang * @param {*} value The value to compare. * @param {*} other The other value to compare. * @returns {boolean} Returns `true` if `value` is less than or equal to `other`, else `false`. * @example * * _.lte(1, 3); * // => true * * _.lte(3, 3); * // => true * * _.lte(3, 1); * // => false */ function lte(value, other) { return value <= other; } /** * Converts `value` to an array. * * @static * @memberOf _ * @category Lang * @param {*} value The value to convert. * @returns {Array} Returns the converted array. * @example * * (function() { * return _.toArray(arguments).slice(1); * }(1, 2, 3)); * // => [2, 3] */ function toArray(value) { var length = value ? getLength(value) : 0; if (!isLength(length)) { return values(value); } if (!length) { return []; } return arrayCopy(value); } /** * Converts `value` to a plain object flattening inherited enumerable * properties of `value` to own properties of the plain object. * * @static * @memberOf _ * @category Lang * @param {*} value The value to convert. * @returns {Object} Returns the converted plain object. * @example * * function Foo() { * this.b = 2; * } * * Foo.prototype.c = 3; * * _.assign({ 'a': 1 }, new Foo); * // => { 'a': 1, 'b': 2 } * * _.assign({ 'a': 1 }, _.toPlainObject(new Foo)); * // => { 'a': 1, 'b': 2, 'c': 3 } */ function toPlainObject(value) { return baseCopy(value, keysIn(value)); } /*------------------------------------------------------------------------*/ /** * Recursively merges own enumerable properties of the source object(s), that * don't resolve to `undefined` into the destination object. Subsequent sources * overwrite property assignments of previous sources. If `customizer` is * provided it is invoked to produce the merged values of the destination and * source properties. If `customizer` returns `undefined` merging is handled * by the method instead. The `customizer` is bound to `thisArg` and invoked * with five arguments: (objectValue, sourceValue, key, object, source). * * @static * @memberOf _ * @category Object * @param {Object} object The destination object. * @param {...Object} [sources] The source objects. * @param {Function} [customizer] The function to customize assigned values. * @param {*} [thisArg] The `this` binding of `customizer`. * @returns {Object} Returns `object`. * @example * * var users = { * 'data': [{ 'user': 'barney' }, { 'user': 'fred' }] * }; * * var ages = { * 'data': [{ 'age': 36 }, { 'age': 40 }] * }; * * _.merge(users, ages); * // => { 'data': [{ 'user': 'barney', 'age': 36 }, { 'user': 'fred', 'age': 40 }] } * * // using a customizer callback * var object = { * 'fruits': ['apple'], * 'vegetables': ['beet'] * }; * * var other = { * 'fruits': ['banana'], * 'vegetables': ['carrot'] * }; * * _.merge(object, other, function(a, b) { * if (_.isArray(a)) { * return a.concat(b); * } * }); * // => { 'fruits': ['apple', 'banana'], 'vegetables': ['beet', 'carrot'] } */ var merge = createAssigner(baseMerge); /** * Assigns own enumerable properties of source object(s) to the destination * object. Subsequent sources overwrite property assignments of previous sources. * If `customizer` is provided it is invoked to produce the assigned values. * The `customizer` is bound to `thisArg` and invoked with five arguments: * (objectValue, sourceValue, key, object, source). * * **Note:** This method mutates `object` and is based on * [`Object.assign`](http://ecma-international.org/ecma-262/6.0/#sec-object.assign). * * @static * @memberOf _ * @alias extend * @category Object * @param {Object} object The destination object. * @param {...Object} [sources] The source objects. * @param {Function} [customizer] The function to customize assigned values. * @param {*} [thisArg] The `this` binding of `customizer`. * @returns {Object} Returns `object`. * @example * * _.assign({ 'user': 'barney' }, { 'age': 40 }, { 'user': 'fred' }); * // => { 'user': 'fred', 'age': 40 } * * // using a customizer callback * var defaults = _.partialRight(_.assign, function(value, other) { * return _.isUndefined(value) ? other : value; * }); * * defaults({ 'user': 'barney' }, { 'age': 36 }, { 'user': 'fred' }); * // => { 'user': 'barney', 'age': 36 } */ var assign = createAssigner(function(object, source, customizer) { return customizer ? assignWith(object, source, customizer) : baseAssign(object, source); }); /** * Creates an object that inherits from the given `prototype` object. If a * `properties` object is provided its own enumerable properties are assigned * to the created object. * * @static * @memberOf _ * @category Object * @param {Object} prototype The object to inherit from. * @param {Object} [properties] The properties to assign to the object. * @param- {Object} [guard] Enables use as a callback for functions like `_.map`. * @returns {Object} Returns the new object. * @example * * function Shape() { * this.x = 0; * this.y = 0; * } * * function Circle() { * Shape.call(this); * } * * Circle.prototype = _.create(Shape.prototype, { * 'constructor': Circle * }); * * var circle = new Circle; * circle instanceof Circle; * // => true * * circle instanceof Shape; * // => true */ function create(prototype, properties, guard) { var result = baseCreate(prototype); if (guard && isIterateeCall(prototype, properties, guard)) { properties = undefined; } return properties ? baseAssign(result, properties) : result; } /** * Assigns own enumerable properties of source object(s) to the destination * object for all destination properties that resolve to `undefined`. Once a * property is set, additional values of the same property are ignored. * * **Note:** This method mutates `object`. * * @static * @memberOf _ * @category Object * @param {Object} object The destination object. * @param {...Object} [sources] The source objects. * @returns {Object} Returns `object`. * @example * * _.defaults({ 'user': 'barney' }, { 'age': 36 }, { 'user': 'fred' }); * // => { 'user': 'barney', 'age': 36 } */ var defaults = createDefaults(assign, assignDefaults); /** * This method is like `_.defaults` except that it recursively assigns * default properties. * * **Note:** This method mutates `object`. * * @static * @memberOf _ * @category Object * @param {Object} object The destination object. * @param {...Object} [sources] The source objects. * @returns {Object} Returns `object`. * @example * * _.defaultsDeep({ 'user': { 'name': 'barney' } }, { 'user': { 'name': 'fred', 'age': 36 } }); * // => { 'user': { 'name': 'barney', 'age': 36 } } * */ var defaultsDeep = createDefaults(merge, mergeDefaults); /** * This method is like `_.find` except that it returns the key of the first * element `predicate` returns truthy for instead of the element itself. * * If a property name is provided for `predicate` the created `_.property` * style callback returns the property value of the given element. * * If a value is also provided for `thisArg` the created `_.matchesProperty` * style callback returns `true` for elements that have a matching property * value, else `false`. * * If an object is provided for `predicate` the created `_.matches` style * callback returns `true` for elements that have the properties of the given * object, else `false`. * * @static * @memberOf _ * @category Object * @param {Object} object The object to search. * @param {Function|Object|string} [predicate=_.identity] The function invoked * per iteration. * @param {*} [thisArg] The `this` binding of `predicate`. * @returns {string|undefined} Returns the key of the matched element, else `undefined`. * @example * * var users = { * 'barney': { 'age': 36, 'active': true }, * 'fred': { 'age': 40, 'active': false }, * 'pebbles': { 'age': 1, 'active': true } * }; * * _.findKey(users, function(chr) { * return chr.age < 40; * }); * // => 'barney' (iteration order is not guaranteed) * * // using the `_.matches` callback shorthand * _.findKey(users, { 'age': 1, 'active': true }); * // => 'pebbles' * * // using the `_.matchesProperty` callback shorthand * _.findKey(users, 'active', false); * // => 'fred' * * // using the `_.property` callback shorthand * _.findKey(users, 'active'); * // => 'barney' */ var findKey = createFindKey(baseForOwn); /** * This method is like `_.findKey` except that it iterates over elements of * a collection in the opposite order. * * If a property name is provided for `predicate` the created `_.property` * style callback returns the property value of the given element. * * If a value is also provided for `thisArg` the created `_.matchesProperty` * style callback returns `true` for elements that have a matching property * value, else `false`. * * If an object is provided for `predicate` the created `_.matches` style * callback returns `true` for elements that have the properties of the given * object, else `false`. * * @static * @memberOf _ * @category Object * @param {Object} object The object to search. * @param {Function|Object|string} [predicate=_.identity] The function invoked * per iteration. * @param {*} [thisArg] The `this` binding of `predicate`. * @returns {string|undefined} Returns the key of the matched element, else `undefined`. * @example * * var users = { * 'barney': { 'age': 36, 'active': true }, * 'fred': { 'age': 40, 'active': false }, * 'pebbles': { 'age': 1, 'active': true } * }; * * _.findLastKey(users, function(chr) { * return chr.age < 40; * }); * // => returns `pebbles` assuming `_.findKey` returns `barney` * * // using the `_.matches` callback shorthand * _.findLastKey(users, { 'age': 36, 'active': true }); * // => 'barney' * * // using the `_.matchesProperty` callback shorthand * _.findLastKey(users, 'active', false); * // => 'fred' * * // using the `_.property` callback shorthand * _.findLastKey(users, 'active'); * // => 'pebbles' */ var findLastKey = createFindKey(baseForOwnRight); /** * Iterates over own and inherited enumerable properties of an object invoking * `iteratee` for each property. The `iteratee` is bound to `thisArg` and invoked * with three arguments: (value, key, object). Iteratee functions may exit * iteration early by explicitly returning `false`. * * @static * @memberOf _ * @category Object * @param {Object} object The object to iterate over. * @param {Function} [iteratee=_.identity] The function invoked per iteration. * @param {*} [thisArg] The `this` binding of `iteratee`. * @returns {Object} Returns `object`. * @example * * function Foo() { * this.a = 1; * this.b = 2; * } * * Foo.prototype.c = 3; * * _.forIn(new Foo, function(value, key) { * console.log(key); * }); * // => logs 'a', 'b', and 'c' (iteration order is not guaranteed) */ var forIn = createForIn(baseFor); /** * This method is like `_.forIn` except that it iterates over properties of * `object` in the opposite order. * * @static * @memberOf _ * @category Object * @param {Object} object The object to iterate over. * @param {Function} [iteratee=_.identity] The function invoked per iteration. * @param {*} [thisArg] The `this` binding of `iteratee`. * @returns {Object} Returns `object`. * @example * * function Foo() { * this.a = 1; * this.b = 2; * } * * Foo.prototype.c = 3; * * _.forInRight(new Foo, function(value, key) { * console.log(key); * }); * // => logs 'c', 'b', and 'a' assuming `_.forIn ` logs 'a', 'b', and 'c' */ var forInRight = createForIn(baseForRight); /** * Iterates over own enumerable properties of an object invoking `iteratee` * for each property. The `iteratee` is bound to `thisArg` and invoked with * three arguments: (value, key, object). Iteratee functions may exit iteration * early by explicitly returning `false`. * * @static * @memberOf _ * @category Object * @param {Object} object The object to iterate over. * @param {Function} [iteratee=_.identity] The function invoked per iteration. * @param {*} [thisArg] The `this` binding of `iteratee`. * @returns {Object} Returns `object`. * @example * * function Foo() { * this.a = 1; * this.b = 2; * } * * Foo.prototype.c = 3; * * _.forOwn(new Foo, function(value, key) { * console.log(key); * }); * // => logs 'a' and 'b' (iteration order is not guaranteed) */ var forOwn = createForOwn(baseForOwn); /** * This method is like `_.forOwn` except that it iterates over properties of * `object` in the opposite order. * * @static * @memberOf _ * @category Object * @param {Object} object The object to iterate over. * @param {Function} [iteratee=_.identity] The function invoked per iteration. * @param {*} [thisArg] The `this` binding of `iteratee`. * @returns {Object} Returns `object`. * @example * * function Foo() { * this.a = 1; * this.b = 2; * } * * Foo.prototype.c = 3; * * _.forOwnRight(new Foo, function(value, key) { * console.log(key); * }); * // => logs 'b' and 'a' assuming `_.forOwn` logs 'a' and 'b' */ var forOwnRight = createForOwn(baseForOwnRight); /** * Creates an array of function property names from all enumerable properties, * own and inherited, of `object`. * * @static * @memberOf _ * @alias methods * @category Object * @param {Object} object The object to inspect. * @returns {Array} Returns the new array of property names. * @example * * _.functions(_); * // => ['after', 'ary', 'assign', ...] */ function functions(object) { return baseFunctions(object, keysIn(object)); } /** * Gets the property value at `path` of `object`. If the resolved value is * `undefined` the `defaultValue` is used in its place. * * @static * @memberOf _ * @category Object * @param {Object} object The object to query. * @param {Array|string} path The path of the property to get. * @param {*} [defaultValue] The value returned if the resolved value is `undefined`. * @returns {*} Returns the resolved value. * @example * * var object = { 'a': [{ 'b': { 'c': 3 } }] }; * * _.get(object, 'a[0].b.c'); * // => 3 * * _.get(object, ['a', '0', 'b', 'c']); * // => 3 * * _.get(object, 'a.b.c', 'default'); * // => 'default' */ function get(object, path, defaultValue) { var result = object == null ? undefined : baseGet(object, toPath(path), path + ''); return result === undefined ? defaultValue : result; } /** * Checks if `path` is a direct property. * * @static * @memberOf _ * @category Object * @param {Object} object The object to query. * @param {Array|string} path The path to check. * @returns {boolean} Returns `true` if `path` is a direct property, else `false`. * @example * * var object = { 'a': { 'b': { 'c': 3 } } }; * * _.has(object, 'a'); * // => true * * _.has(object, 'a.b.c'); * // => true * * _.has(object, ['a', 'b', 'c']); * // => true */ function has(object, path) { if (object == null) { return false; } var result = hasOwnProperty.call(object, path); if (!result && !isKey(path)) { path = toPath(path); object = path.length == 1 ? object : baseGet(object, baseSlice(path, 0, -1)); if (object == null) { return false; } path = last(path); result = hasOwnProperty.call(object, path); } return result || (isLength(object.length) && isIndex(path, object.length) && (isArray(object) || isArguments(object))); } /** * Creates an object composed of the inverted keys and values of `object`. * If `object` contains duplicate values, subsequent values overwrite property * assignments of previous values unless `multiValue` is `true`. * * @static * @memberOf _ * @category Object * @param {Object} object The object to invert. * @param {boolean} [multiValue] Allow multiple values per key. * @param- {Object} [guard] Enables use as a callback for functions like `_.map`. * @returns {Object} Returns the new inverted object. * @example * * var object = { 'a': 1, 'b': 2, 'c': 1 }; * * _.invert(object); * // => { '1': 'c', '2': 'b' } * * // with `multiValue` * _.invert(object, true); * // => { '1': ['a', 'c'], '2': ['b'] } */ function invert(object, multiValue, guard) { if (guard && isIterateeCall(object, multiValue, guard)) { multiValue = undefined; } var index = -1, props = keys(object), length = props.length, result = {}; while (++index < length) { var key = props[index], value = object[key]; if (multiValue) { if (hasOwnProperty.call(result, value)) { result[value].push(key); } else { result[value] = [key]; } } else { result[value] = key; } } return result; } /** * Creates an array of the own enumerable property names of `object`. * * **Note:** Non-object values are coerced to objects. See the * [ES spec](http://ecma-international.org/ecma-262/6.0/#sec-object.keys) * for more details. * * @static * @memberOf _ * @category Object * @param {Object} object The object to query. * @returns {Array} Returns the array of property names. * @example * * function Foo() { * this.a = 1; * this.b = 2; * } * * Foo.prototype.c = 3; * * _.keys(new Foo); * // => ['a', 'b'] (iteration order is not guaranteed) * * _.keys('hi'); * // => ['0', '1'] */ var keys = !nativeKeys ? shimKeys : function(object) { var Ctor = object == null ? undefined : object.constructor; if ((typeof Ctor == 'function' && Ctor.prototype === object) || (typeof object != 'function' && isArrayLike(object))) { return shimKeys(object); } return isObject(object) ? nativeKeys(object) : []; }; /** * Creates an array of the own and inherited enumerable property names of `object`. * * **Note:** Non-object values are coerced to objects. * * @static * @memberOf _ * @category Object * @param {Object} object The object to query. * @returns {Array} Returns the array of property names. * @example * * function Foo() { * this.a = 1; * this.b = 2; * } * * Foo.prototype.c = 3; * * _.keysIn(new Foo); * // => ['a', 'b', 'c'] (iteration order is not guaranteed) */ function keysIn(object) { if (object == null) { return []; } if (!isObject(object)) { object = Object(object); } var length = object.length; length = (length && isLength(length) && (isArray(object) || isArguments(object)) && length) || 0; var Ctor = object.constructor, index = -1, isProto = typeof Ctor == 'function' && Ctor.prototype === object, result = Array(length), skipIndexes = length > 0; while (++index < length) { result[index] = (index + ''); } for (var key in object) { if (!(skipIndexes && isIndex(key, length)) && !(key == 'constructor' && (isProto || !hasOwnProperty.call(object, key)))) { result.push(key); } } return result; } /** * The opposite of `_.mapValues`; this method creates an object with the * same values as `object` and keys generated by running each own enumerable * property of `object` through `iteratee`. * * @static * @memberOf _ * @category Object * @param {Object} object The object to iterate over. * @param {Function|Object|string} [iteratee=_.identity] The function invoked * per iteration. * @param {*} [thisArg] The `this` binding of `iteratee`. * @returns {Object} Returns the new mapped object. * @example * * _.mapKeys({ 'a': 1, 'b': 2 }, function(value, key) { * return key + value; * }); * // => { 'a1': 1, 'b2': 2 } */ var mapKeys = createObjectMapper(true); /** * Creates an object with the same keys as `object` and values generated by * running each own enumerable property of `object` through `iteratee`. The * iteratee function is bound to `thisArg` and invoked with three arguments: * (value, key, object). * * If a property name is provided for `iteratee` the created `_.property` * style callback returns the property value of the given element. * * If a value is also provided for `thisArg` the created `_.matchesProperty` * style callback returns `true` for elements that have a matching property * value, else `false`. * * If an object is provided for `iteratee` the created `_.matches` style * callback returns `true` for elements that have the properties of the given * object, else `false`. * * @static * @memberOf _ * @category Object * @param {Object} object The object to iterate over. * @param {Function|Object|string} [iteratee=_.identity] The function invoked * per iteration. * @param {*} [thisArg] The `this` binding of `iteratee`. * @returns {Object} Returns the new mapped object. * @example * * _.mapValues({ 'a': 1, 'b': 2 }, function(n) { * return n * 3; * }); * // => { 'a': 3, 'b': 6 } * * var users = { * 'fred': { 'user': 'fred', 'age': 40 }, * 'pebbles': { 'user': 'pebbles', 'age': 1 } * }; * * // using the `_.property` callback shorthand * _.mapValues(users, 'age'); * // => { 'fred': 40, 'pebbles': 1 } (iteration order is not guaranteed) */ var mapValues = createObjectMapper(); /** * The opposite of `_.pick`; this method creates an object composed of the * own and inherited enumerable properties of `object` that are not omitted. * * @static * @memberOf _ * @category Object * @param {Object} object The source object. * @param {Function|...(string|string[])} [predicate] The function invoked per * iteration or property names to omit, specified as individual property * names or arrays of property names. * @param {*} [thisArg] The `this` binding of `predicate`. * @returns {Object} Returns the new object. * @example * * var object = { 'user': 'fred', 'age': 40 }; * * _.omit(object, 'age'); * // => { 'user': 'fred' } * * _.omit(object, _.isNumber); * // => { 'user': 'fred' } */ var omit = restParam(function(object, props) { if (object == null) { return {}; } if (typeof props[0] != 'function') { var props = arrayMap(baseFlatten(props), String); return pickByArray(object, baseDifference(keysIn(object), props)); } var predicate = bindCallback(props[0], props[1], 3); return pickByCallback(object, function(value, key, object) { return !predicate(value, key, object); }); }); /** * Creates a two dimensional array of the key-value pairs for `object`, * e.g. `[[key1, value1], [key2, value2]]`. * * @static * @memberOf _ * @category Object * @param {Object} object The object to query. * @returns {Array} Returns the new array of key-value pairs. * @example * * _.pairs({ 'barney': 36, 'fred': 40 }); * // => [['barney', 36], ['fred', 40]] (iteration order is not guaranteed) */ function pairs(object) { object = toObject(object); var index = -1, props = keys(object), length = props.length, result = Array(length); while (++index < length) { var key = props[index]; result[index] = [key, object[key]]; } return result; } /** * Creates an object composed of the picked `object` properties. Property * names may be specified as individual arguments or as arrays of property * names. If `predicate` is provided it is invoked for each property of `object` * picking the properties `predicate` returns truthy for. The predicate is * bound to `thisArg` and invoked with three arguments: (value, key, object). * * @static * @memberOf _ * @category Object * @param {Object} object The source object. * @param {Function|...(string|string[])} [predicate] The function invoked per * iteration or property names to pick, specified as individual property * names or arrays of property names. * @param {*} [thisArg] The `this` binding of `predicate`. * @returns {Object} Returns the new object. * @example * * var object = { 'user': 'fred', 'age': 40 }; * * _.pick(object, 'user'); * // => { 'user': 'fred' } * * _.pick(object, _.isString); * // => { 'user': 'fred' } */ var pick = restParam(function(object, props) { if (object == null) { return {}; } return typeof props[0] == 'function' ? pickByCallback(object, bindCallback(props[0], props[1], 3)) : pickByArray(object, baseFlatten(props)); }); /** * This method is like `_.get` except that if the resolved value is a function * it is invoked with the `this` binding of its parent object and its result * is returned. * * @static * @memberOf _ * @category Object * @param {Object} object The object to query. * @param {Array|string} path The path of the property to resolve. * @param {*} [defaultValue] The value returned if the resolved value is `undefined`. * @returns {*} Returns the resolved value. * @example * * var object = { 'a': [{ 'b': { 'c1': 3, 'c2': _.constant(4) } }] }; * * _.result(object, 'a[0].b.c1'); * // => 3 * * _.result(object, 'a[0].b.c2'); * // => 4 * * _.result(object, 'a.b.c', 'default'); * // => 'default' * * _.result(object, 'a.b.c', _.constant('default')); * // => 'default' */ function result(object, path, defaultValue) { var result = object == null ? undefined : object[path]; if (result === undefined) { if (object != null && !isKey(path, object)) { path = toPath(path); object = path.length == 1 ? object : baseGet(object, baseSlice(path, 0, -1)); result = object == null ? undefined : object[last(path)]; } result = result === undefined ? defaultValue : result; } return isFunction(result) ? result.call(object) : result; } /** * Sets the property value of `path` on `object`. If a portion of `path` * does not exist it is created. * * @static * @memberOf _ * @category Object * @param {Object} object The object to augment. * @param {Array|string} path The path of the property to set. * @param {*} value The value to set. * @returns {Object} Returns `object`. * @example * * var object = { 'a': [{ 'b': { 'c': 3 } }] }; * * _.set(object, 'a[0].b.c', 4); * console.log(object.a[0].b.c); * // => 4 * * _.set(object, 'x[0].y.z', 5); * console.log(object.x[0].y.z); * // => 5 */ function set(object, path, value) { if (object == null) { return object; } var pathKey = (path + ''); path = (object[pathKey] != null || isKey(path, object)) ? [pathKey] : toPath(path); var index = -1, length = path.length, lastIndex = length - 1, nested = object; while (nested != null && ++index < length) { var key = path[index]; if (isObject(nested)) { if (index == lastIndex) { nested[key] = value; } else if (nested[key] == null) { nested[key] = isIndex(path[index + 1]) ? [] : {}; } } nested = nested[key]; } return object; } /** * An alternative to `_.reduce`; this method transforms `object` to a new * `accumulator` object which is the result of running each of its own enumerable * properties through `iteratee`, with each invocation potentially mutating * the `accumulator` object. The `iteratee` is bound to `thisArg` and invoked * with four arguments: (accumulator, value, key, object). Iteratee functions * may exit iteration early by explicitly returning `false`. * * @static * @memberOf _ * @category Object * @param {Array|Object} object The object to iterate over. * @param {Function} [iteratee=_.identity] The function invoked per iteration. * @param {*} [accumulator] The custom accumulator value. * @param {*} [thisArg] The `this` binding of `iteratee`. * @returns {*} Returns the accumulated value. * @example * * _.transform([2, 3, 4], function(result, n) { * result.push(n *= n); * return n % 2 == 0; * }); * // => [4, 9] * * _.transform({ 'a': 1, 'b': 2 }, function(result, n, key) { * result[key] = n * 3; * }); * // => { 'a': 3, 'b': 6 } */ function transform(object, iteratee, accumulator, thisArg) { var isArr = isArray(object) || isTypedArray(object); iteratee = getCallback(iteratee, thisArg, 4); if (accumulator == null) { if (isArr || isObject(object)) { var Ctor = object.constructor; if (isArr) { accumulator = isArray(object) ? new Ctor : []; } else { accumulator = baseCreate(isFunction(Ctor) ? Ctor.prototype : undefined); } } else { accumulator = {}; } } (isArr ? arrayEach : baseForOwn)(object, function(value, index, object) { return iteratee(accumulator, value, index, object); }); return accumulator; } /** * Creates an array of the own enumerable property values of `object`. * * **Note:** Non-object values are coerced to objects. * * @static * @memberOf _ * @category Object * @param {Object} object The object to query. * @returns {Array} Returns the array of property values. * @example * * function Foo() { * this.a = 1; * this.b = 2; * } * * Foo.prototype.c = 3; * * _.values(new Foo); * // => [1, 2] (iteration order is not guaranteed) * * _.values('hi'); * // => ['h', 'i'] */ function values(object) { return baseValues(object, keys(object)); } /** * Creates an array of the own and inherited enumerable property values * of `object`. * * **Note:** Non-object values are coerced to objects. * * @static * @memberOf _ * @category Object * @param {Object} object The object to query. * @returns {Array} Returns the array of property values. * @example * * function Foo() { * this.a = 1; * this.b = 2; * } * * Foo.prototype.c = 3; * * _.valuesIn(new Foo); * // => [1, 2, 3] (iteration order is not guaranteed) */ function valuesIn(object) { return baseValues(object, keysIn(object)); } /*------------------------------------------------------------------------*/ /** * Checks if `n` is between `start` and up to but not including, `end`. If * `end` is not specified it is set to `start` with `start` then set to `0`. * * @static * @memberOf _ * @category Number * @param {number} n The number to check. * @param {number} [start=0] The start of the range. * @param {number} end The end of the range. * @returns {boolean} Returns `true` if `n` is in the range, else `false`. * @example * * _.inRange(3, 2, 4); * // => true * * _.inRange(4, 8); * // => true * * _.inRange(4, 2); * // => false * * _.inRange(2, 2); * // => false * * _.inRange(1.2, 2); * // => true * * _.inRange(5.2, 4); * // => false */ function inRange(value, start, end) { start = +start || 0; if (end === undefined) { end = start; start = 0; } else { end = +end || 0; } return value >= nativeMin(start, end) && value < nativeMax(start, end); } /** * Produces a random number between `min` and `max` (inclusive). If only one * argument is provided a number between `0` and the given number is returned. * If `floating` is `true`, or either `min` or `max` are floats, a floating-point * number is returned instead of an integer. * * @static * @memberOf _ * @category Number * @param {number} [min=0] The minimum possible value. * @param {number} [max=1] The maximum possible value. * @param {boolean} [floating] Specify returning a floating-point number. * @returns {number} Returns the random number. * @example * * _.random(0, 5); * // => an integer between 0 and 5 * * _.random(5); * // => also an integer between 0 and 5 * * _.random(5, true); * // => a floating-point number between 0 and 5 * * _.random(1.2, 5.2); * // => a floating-point number between 1.2 and 5.2 */ function random(min, max, floating) { if (floating && isIterateeCall(min, max, floating)) { max = floating = undefined; } var noMin = min == null, noMax = max == null; if (floating == null) { if (noMax && typeof min == 'boolean') { floating = min; min = 1; } else if (typeof max == 'boolean') { floating = max; noMax = true; } } if (noMin && noMax) { max = 1; noMax = false; } min = +min || 0; if (noMax) { max = min; min = 0; } else { max = +max || 0; } if (floating || min % 1 || max % 1) { var rand = nativeRandom(); return nativeMin(min + (rand * (max - min + parseFloat('1e-' + ((rand + '').length - 1)))), max); } return baseRandom(min, max); } /*------------------------------------------------------------------------*/ /** * Converts `string` to [camel case](https://en.wikipedia.org/wiki/CamelCase). * * @static * @memberOf _ * @category String * @param {string} [string=''] The string to convert. * @returns {string} Returns the camel cased string. * @example * * _.camelCase('Foo Bar'); * // => 'fooBar' * * _.camelCase('--foo-bar'); * // => 'fooBar' * * _.camelCase('__foo_bar__'); * // => 'fooBar' */ var camelCase = createCompounder(function(result, word, index) { word = word.toLowerCase(); return result + (index ? (word.charAt(0).toUpperCase() + word.slice(1)) : word); }); /** * Capitalizes the first character of `string`. * * @static * @memberOf _ * @category String * @param {string} [string=''] The string to capitalize. * @returns {string} Returns the capitalized string. * @example * * _.capitalize('fred'); * // => 'Fred' */ function capitalize(string) { string = baseToString(string); return string && (string.charAt(0).toUpperCase() + string.slice(1)); } /** * Deburrs `string` by converting [latin-1 supplementary letters](https://en.wikipedia.org/wiki/Latin-1_Supplement_(Unicode_block)#Character_table) * to basic latin letters and removing [combining diacritical marks](https://en.wikipedia.org/wiki/Combining_Diacritical_Marks). * * @static * @memberOf _ * @category String * @param {string} [string=''] The string to deburr. * @returns {string} Returns the deburred string. * @example * * _.deburr('déjà vu'); * // => 'deja vu' */ function deburr(string) { string = baseToString(string); return string && string.replace(reLatin1, deburrLetter).replace(reComboMark, ''); } /** * Checks if `string` ends with the given target string. * * @static * @memberOf _ * @category String * @param {string} [string=''] The string to search. * @param {string} [target] The string to search for. * @param {number} [position=string.length] The position to search from. * @returns {boolean} Returns `true` if `string` ends with `target`, else `false`. * @example * * _.endsWith('abc', 'c'); * // => true * * _.endsWith('abc', 'b'); * // => false * * _.endsWith('abc', 'b', 2); * // => true */ function endsWith(string, target, position) { string = baseToString(string); target = (target + ''); var length = string.length; position = position === undefined ? length : nativeMin(position < 0 ? 0 : (+position || 0), length); position -= target.length; return position >= 0 && string.indexOf(target, position) == position; } /** * Converts the characters "&", "<", ">", '"', "'", and "\`", in `string` to * their corresponding HTML entities. * * **Note:** No other characters are escaped. To escape additional characters * use a third-party library like [_he_](https://mths.be/he). * * Though the ">" character is escaped for symmetry, characters like * ">" and "/" don't need escaping in HTML and have no special meaning * unless they're part of a tag or unquoted attribute value. * See [Mathias Bynens's article](https://mathiasbynens.be/notes/ambiguous-ampersands) * (under "semi-related fun fact") for more details. * * Backticks are escaped because in Internet Explorer < 9, they can break out * of attribute values or HTML comments. See [#59](https://html5sec.org/#59), * [#102](https://html5sec.org/#102), [#108](https://html5sec.org/#108), and * [#133](https://html5sec.org/#133) of the [HTML5 Security Cheatsheet](https://html5sec.org/) * for more details. * * When working with HTML you should always [quote attribute values](http://wonko.com/post/html-escaping) * to reduce XSS vectors. * * @static * @memberOf _ * @category String * @param {string} [string=''] The string to escape. * @returns {string} Returns the escaped string. * @example * * _.escape('fred, barney, & pebbles'); * // => 'fred, barney, & pebbles' */ function escape(string) { // Reset `lastIndex` because in IE < 9 `String#replace` does not. string = baseToString(string); return (string && reHasUnescapedHtml.test(string)) ? string.replace(reUnescapedHtml, escapeHtmlChar) : string; } /** * Escapes the `RegExp` special characters "\", "/", "^", "$", ".", "|", "?", * "*", "+", "(", ")", "[", "]", "{" and "}" in `string`. * * @static * @memberOf _ * @category String * @param {string} [string=''] The string to escape. * @returns {string} Returns the escaped string. * @example * * _.escapeRegExp('[lodash](https://lodash.com/)'); * // => '\[lodash\]\(https:\/\/lodash\.com\/\)' */ function escapeRegExp(string) { string = baseToString(string); return (string && reHasRegExpChars.test(string)) ? string.replace(reRegExpChars, escapeRegExpChar) : (string || '(?:)'); } /** * Converts `string` to [kebab case](https://en.wikipedia.org/wiki/Letter_case#Special_case_styles). * * @static * @memberOf _ * @category String * @param {string} [string=''] The string to convert. * @returns {string} Returns the kebab cased string. * @example * * _.kebabCase('Foo Bar'); * // => 'foo-bar' * * _.kebabCase('fooBar'); * // => 'foo-bar' * * _.kebabCase('__foo_bar__'); * // => 'foo-bar' */ var kebabCase = createCompounder(function(result, word, index) { return result + (index ? '-' : '') + word.toLowerCase(); }); /** * Pads `string` on the left and right sides if it's shorter than `length`. * Padding characters are truncated if they can't be evenly divided by `length`. * * @static * @memberOf _ * @category String * @param {string} [string=''] The string to pad. * @param {number} [length=0] The padding length. * @param {string} [chars=' '] The string used as padding. * @returns {string} Returns the padded string. * @example * * _.pad('abc', 8); * // => ' abc ' * * _.pad('abc', 8, '_-'); * // => '_-abc_-_' * * _.pad('abc', 3); * // => 'abc' */ function pad(string, length, chars) { string = baseToString(string); length = +length; var strLength = string.length; if (strLength >= length || !nativeIsFinite(length)) { return string; } var mid = (length - strLength) / 2, leftLength = nativeFloor(mid), rightLength = nativeCeil(mid); chars = createPadding('', rightLength, chars); return chars.slice(0, leftLength) + string + chars; } /** * Pads `string` on the left side if it's shorter than `length`. Padding * characters are truncated if they exceed `length`. * * @static * @memberOf _ * @category String * @param {string} [string=''] The string to pad. * @param {number} [length=0] The padding length. * @param {string} [chars=' '] The string used as padding. * @returns {string} Returns the padded string. * @example * * _.padLeft('abc', 6); * // => ' abc' * * _.padLeft('abc', 6, '_-'); * // => '_-_abc' * * _.padLeft('abc', 3); * // => 'abc' */ var padLeft = createPadDir(); /** * Pads `string` on the right side if it's shorter than `length`. Padding * characters are truncated if they exceed `length`. * * @static * @memberOf _ * @category String * @param {string} [string=''] The string to pad. * @param {number} [length=0] The padding length. * @param {string} [chars=' '] The string used as padding. * @returns {string} Returns the padded string. * @example * * _.padRight('abc', 6); * // => 'abc ' * * _.padRight('abc', 6, '_-'); * // => 'abc_-_' * * _.padRight('abc', 3); * // => 'abc' */ var padRight = createPadDir(true); /** * Converts `string` to an integer of the specified radix. If `radix` is * `undefined` or `0`, a `radix` of `10` is used unless `value` is a hexadecimal, * in which case a `radix` of `16` is used. * * **Note:** This method aligns with the [ES5 implementation](https://es5.github.io/#E) * of `parseInt`. * * @static * @memberOf _ * @category String * @param {string} string The string to convert. * @param {number} [radix] The radix to interpret `value` by. * @param- {Object} [guard] Enables use as a callback for functions like `_.map`. * @returns {number} Returns the converted integer. * @example * * _.parseInt('08'); * // => 8 * * _.map(['6', '08', '10'], _.parseInt); * // => [6, 8, 10] */ function parseInt(string, radix, guard) { // Firefox < 21 and Opera < 15 follow ES3 for `parseInt`. // Chrome fails to trim leading whitespace characters. // See https://code.google.com/p/v8/issues/detail?id=3109 for more details. if (guard ? isIterateeCall(string, radix, guard) : radix == null) { radix = 0; } else if (radix) { radix = +radix; } string = trim(string); return nativeParseInt(string, radix || (reHasHexPrefix.test(string) ? 16 : 10)); } /** * Repeats the given string `n` times. * * @static * @memberOf _ * @category String * @param {string} [string=''] The string to repeat. * @param {number} [n=0] The number of times to repeat the string. * @returns {string} Returns the repeated string. * @example * * _.repeat('*', 3); * // => '***' * * _.repeat('abc', 2); * // => 'abcabc' * * _.repeat('abc', 0); * // => '' */ function repeat(string, n) { var result = ''; string = baseToString(string); n = +n; if (n < 1 || !string || !nativeIsFinite(n)) { return result; } // Leverage the exponentiation by squaring algorithm for a faster repeat. // See https://en.wikipedia.org/wiki/Exponentiation_by_squaring for more details. do { if (n % 2) { result += string; } n = nativeFloor(n / 2); string += string; } while (n); return result; } /** * Converts `string` to [snake case](https://en.wikipedia.org/wiki/Snake_case). * * @static * @memberOf _ * @category String * @param {string} [string=''] The string to convert. * @returns {string} Returns the snake cased string. * @example * * _.snakeCase('Foo Bar'); * // => 'foo_bar' * * _.snakeCase('fooBar'); * // => 'foo_bar' * * _.snakeCase('--foo-bar'); * // => 'foo_bar' */ var snakeCase = createCompounder(function(result, word, index) { return result + (index ? '_' : '') + word.toLowerCase(); }); /** * Converts `string` to [start case](https://en.wikipedia.org/wiki/Letter_case#Stylistic_or_specialised_usage). * * @static * @memberOf _ * @category String * @param {string} [string=''] The string to convert. * @returns {string} Returns the start cased string. * @example * * _.startCase('--foo-bar'); * // => 'Foo Bar' * * _.startCase('fooBar'); * // => 'Foo Bar' * * _.startCase('__foo_bar__'); * // => 'Foo Bar' */ var startCase = createCompounder(function(result, word, index) { return result + (index ? ' ' : '') + (word.charAt(0).toUpperCase() + word.slice(1)); }); /** * Checks if `string` starts with the given target string. * * @static * @memberOf _ * @category String * @param {string} [string=''] The string to search. * @param {string} [target] The string to search for. * @param {number} [position=0] The position to search from. * @returns {boolean} Returns `true` if `string` starts with `target`, else `false`. * @example * * _.startsWith('abc', 'a'); * // => true * * _.startsWith('abc', 'b'); * // => false * * _.startsWith('abc', 'b', 1); * // => true */ function startsWith(string, target, position) { string = baseToString(string); position = position == null ? 0 : nativeMin(position < 0 ? 0 : (+position || 0), string.length); return string.lastIndexOf(target, position) == position; } /** * Creates a compiled template function that can interpolate data properties * in "interpolate" delimiters, HTML-escape interpolated data properties in * "escape" delimiters, and execute JavaScript in "evaluate" delimiters. Data * properties may be accessed as free variables in the template. If a setting * object is provided it takes precedence over `_.templateSettings` values. * * **Note:** In the development build `_.template` utilizes * [sourceURLs](http://www.html5rocks.com/en/tutorials/developertools/sourcemaps/#toc-sourceurl) * for easier debugging. * * For more information on precompiling templates see * [lodash's custom builds documentation](https://lodash.com/custom-builds). * * For more information on Chrome extension sandboxes see * [Chrome's extensions documentation](https://developer.chrome.com/extensions/sandboxingEval). * * @static * @memberOf _ * @category String * @param {string} [string=''] The template string. * @param {Object} [options] The options object. * @param {RegExp} [options.escape] The HTML "escape" delimiter. * @param {RegExp} [options.evaluate] The "evaluate" delimiter. * @param {Object} [options.imports] An object to import into the template as free variables. * @param {RegExp} [options.interpolate] The "interpolate" delimiter. * @param {string} [options.sourceURL] The sourceURL of the template's compiled source. * @param {string} [options.variable] The data object variable name. * @param- {Object} [otherOptions] Enables the legacy `options` param signature. * @returns {Function} Returns the compiled template function. * @example * * // using the "interpolate" delimiter to create a compiled template * var compiled = _.template('hello <%= user %>!'); * compiled({ 'user': 'fred' }); * // => 'hello fred!' * * // using the HTML "escape" delimiter to escape data property values * var compiled = _.template('<%- value %>'); * compiled({ 'value': '