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/*
 * #%L
 * The AIBench Shell Plugin
 * %%
 * Copyright (C) 2006 - 2017 Daniel Glez-Peña and Florentino Fdez-Riverola
 * %%
 * This program is free software: you can redistribute it and/or modify
 * it under the terms of the GNU Lesser General Public License as
 * published by the Free Software Foundation, either version 3 of the
 * License, or (at your option) any later version.
 * 
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Lesser Public License for more details.
 * 
 * You should have received a copy of the GNU General Lesser Public
 * License along with this program.  If not, see
 * .
 * #L%
 */
/* Generated By:JJTree: Do not edit this line. src/bsh/JJTParserState.java */

package bsh;

class JJTParserState {
        private java.util.Stack nodes;

        private java.util.Stack marks;

        private int sp; // number of nodes on stack

        private int mk; // current mark

        private boolean node_created;

        JJTParserState() {
                nodes = new java.util.Stack();
                marks = new java.util.Stack();
                sp = 0;
                mk = 0;
        }

        /*
         * Determines whether the current node was actually closed and pushed.
         * This should only be called in the final user action of a node scope.
         */
        boolean nodeCreated() {
                return node_created;
        }

        /*
         * Call this to reinitialize the node stack. It is called automatically
         * by the parser's ReInit() method.
         */
        void reset() {
                nodes.removeAllElements();
                marks.removeAllElements();
                sp = 0;
                mk = 0;
        }

        /*
         * Returns the root node of the AST. It only makes sense to call this
         * after a successful parse.
         */
        Node rootNode() {
                return (Node) nodes.elementAt(0);
        }

        /* Pushes a node on to the stack. */
        void pushNode(Node n) {
                nodes.push(n);
                ++sp;
        }

        /*
         * Returns the node on the top of the stack, and remove it from the
         * stack.
         */
        Node popNode() {
                if (--sp < mk) {
                        mk = ((Integer) marks.pop()).intValue();
                }
                return (Node) nodes.pop();
        }

        /* Returns the node currently on the top of the stack. */
        Node peekNode() {
                return (Node) nodes.peek();
        }

        /*
         * Returns the number of children on the stack in the current node
         * scope.
         */
        int nodeArity() {
                return sp - mk;
        }

        void clearNodeScope(Node n) {
                while (sp > mk) {
                        popNode();
                }
                mk = ((Integer) marks.pop()).intValue();
        }

        void openNodeScope(Node n) {
                marks.push(new Integer(mk));
                mk = sp;
                n.jjtOpen();
        }

        /*
         * A definite node is constructed from a specified number of children.
         * That number of nodes are popped from the stack and made the children
         * of the definite node. Then the definite node is pushed on to the
         * stack.
         */
        void closeNodeScope(Node n, int num) {
                mk = ((Integer) marks.pop()).intValue();
                while (num-- > 0) {
                        Node c = popNode();
                        c.jjtSetParent(n);
                        n.jjtAddChild(c, num);
                }
                n.jjtClose();
                pushNode(n);
                node_created = true;
        }

        /*
         * A conditional node is constructed if its condition is true. All the
         * nodes that have been pushed since the node was opened are made
         * children of the the conditional node, which is then pushed on to the
         * stack. If the condition is false the node is not constructed and they
         * are left on the stack.
         */
        void closeNodeScope(Node n, boolean condition) {
                if (condition) {
                        int a = nodeArity();
                        mk = ((Integer) marks.pop()).intValue();
                        while (a-- > 0) {
                                Node c = popNode();
                                c.jjtSetParent(n);
                                n.jjtAddChild(c, a);
                        }
                        n.jjtClose();
                        pushNode(n);
                        node_created = true;
                } else {
                        mk = ((Integer) marks.pop()).intValue();
                        node_created = false;
                }
        }
}