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// Stanford Parser -- a probabilistic lexicalized NL CFG parser
// Copyright (c) 2002 - 2011 The Board of Trustees of
// The Leland Stanford Junior University. All Rights Reserved.
//
// This program is free software; you can redistribute it and/or
// modify it under the terms of the GNU General Public License
// as published by the Free Software Foundation; either version 2
// 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 Public License for more details.
//
// You should have received a copy of the GNU General Public License
// along with this program; if not, write to the Free Software
// Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA  02111-1307, USA.
//
// For more information, bug reports, fixes, contact:
//    Christopher Manning
//    Dept of Computer Science, Gates 1A
//    Stanford CA 94305-9010
//    USA
//    [email protected]
//    http://nlp.stanford.edu/software/lex-parser.shtml

package edu.stanford.nlp.parser.lexparser;

import java.io.PrintWriter;
import java.util.ArrayList;
import java.util.Iterator;
import java.util.List;

import edu.stanford.nlp.ling.CoreLabel;
import edu.stanford.nlp.ling.HasTag;
import edu.stanford.nlp.ling.HasWord;
import edu.stanford.nlp.ling.Label;
import edu.stanford.nlp.ling.Sentence;
import edu.stanford.nlp.ling.TaggedWord;
import edu.stanford.nlp.ling.Word;
import edu.stanford.nlp.parser.KBestViterbiParser;
import edu.stanford.nlp.parser.common.NoSuchParseException;
import edu.stanford.nlp.parser.common.ParserConstraint;
import edu.stanford.nlp.parser.common.ParserQuery;
import edu.stanford.nlp.parser.common.ParserUtils;
import edu.stanford.nlp.trees.Tree;
import edu.stanford.nlp.trees.TreePrint;
import edu.stanford.nlp.trees.TreeTransformer;
import edu.stanford.nlp.trees.TreebankLanguagePack;
import edu.stanford.nlp.util.Generics;
import edu.stanford.nlp.util.Index;
import edu.stanford.nlp.util.ScoredObject;
import edu.stanford.nlp.util.DeltaIndex;
import edu.stanford.nlp.util.RuntimeInterruptedException;


public class LexicalizedParserQuery implements ParserQuery {

  private final Options op;
  private final TreeTransformer debinarizer;
  private final TreeTransformer boundaryRemover;

  /** The PCFG parser. */
  private final ExhaustivePCFGParser pparser;
  /** The dependency parser. */
  private final ExhaustiveDependencyParser dparser;
  /** The factored parser that combines the dependency and PCFG parsers. */
  private final KBestViterbiParser bparser;

  private final boolean fallbackToPCFG = true;

  private final TreeTransformer subcategoryStripper;

  // Whether or not the most complicated model available successfully
  // parsed the input sentence.
  private boolean parseSucceeded = false;
  // parseSkipped means that not only did we not succeed at parsing,
  // but for some reason we didn't even try.  Most likely this happens
  // when the sentence is too long or is of length 0.
  private boolean parseSkipped = false;
  // In some sense we succeeded, but only because we used a fallback grammar
  private boolean parseFallback = false;
  // Not enough memory to parse
  private boolean parseNoMemory = false;
  // Horrible error
  private boolean parseUnparsable = false;
  // If something ran out of memory, where the error occurred
  private String whatFailed = null;

  public boolean parseSucceeded() { return parseSucceeded; }
  public boolean parseSkipped() { return parseSkipped; }
  public boolean parseFallback() { return parseFallback; }
  public boolean parseNoMemory() { return parseNoMemory; }
  public boolean parseUnparsable() { return parseUnparsable; }

  private List originalSentence;

  @Override
  public List originalSentence() { return originalSentence; }

  /** Keeps track of whether the sentence had punctuation added, which affects the expected length of the sentence */
  private boolean addedPunct = false;

  private boolean saidMemMessage = false;

  public boolean saidMemMessage() {
    return saidMemMessage;
  }


  LexicalizedParserQuery(LexicalizedParser parser) {
    this.op = parser.getOp();

    BinaryGrammar bg = parser.bg;
    UnaryGrammar ug = parser.ug;
    Lexicon lex = parser.lex;
    DependencyGrammar dg = parser.dg;

    Index stateIndex = parser.stateIndex;
    Index wordIndex = new DeltaIndex<>(parser.wordIndex);
    Index tagIndex = parser.tagIndex;

    this.debinarizer = new Debinarizer(op.forceCNF);
    this.boundaryRemover = new BoundaryRemover();

    if (op.doPCFG) {
      if (op.testOptions.iterativeCKY) {
        pparser = new IterativeCKYPCFGParser(bg, ug, lex, op, stateIndex, wordIndex, tagIndex);
      } else {
        pparser = new ExhaustivePCFGParser(bg, ug, lex, op, stateIndex, wordIndex, tagIndex);
      }
    } else {
      pparser = null;
    }

    if (op.doDep) {
      dg.setLexicon(lex);
      if (!op.testOptions.useFastFactored) {
        dparser = new ExhaustiveDependencyParser(dg, lex, op, wordIndex, tagIndex);
      } else {
        dparser = null;
      }
    } else {
      dparser = null;
    }

    if (op.doDep && op.doPCFG) {
      if (op.testOptions.useFastFactored) {
        MLEDependencyGrammar mledg = (MLEDependencyGrammar) dg;
        int numToFind = 1;
        if (op.testOptions.printFactoredKGood > 0) {
          numToFind = op.testOptions.printFactoredKGood;
        }
        bparser = new FastFactoredParser(pparser, mledg, op, numToFind, wordIndex, tagIndex);
      } else {
        Scorer scorer = new TwinScorer(pparser, dparser);
        //Scorer scorer = parser;
        if (op.testOptions.useN5) {
          bparser = new BiLexPCFGParser.N5BiLexPCFGParser(scorer, pparser, dparser, bg, ug, dg, lex, op, stateIndex, wordIndex, tagIndex);
        } else {
          bparser = new BiLexPCFGParser(scorer, pparser, dparser, bg, ug, dg, lex, op, stateIndex, wordIndex, tagIndex);
        }
      }
    } else {
      bparser = null;
    }

    subcategoryStripper = op.tlpParams.subcategoryStripper();
  }

  @Override
  public void setConstraints(List constraints) {
    if (pparser != null) {
      pparser.setConstraints(constraints);
    }
  }

  /**
   * Parse a sentence represented as a List of tokens.
   * The text must already have been tokenized and
   * normalized into tokens that are appropriate to the treebank
   * which was used to train the parser.  The tokens can be of
   * multiple types, and the list items need not be homogeneous as to type
   * (in particular, only some words might be given tags):
   * 
    *
  • If a token implements HasWord, then the word to be parsed is * given by its word() value.
  • *
  • If a token implements HasTag and the tag() value is not * null or the empty String, then the parser is strongly advised to assign * a part of speech tag that begins with this String.
  • *
* * @param sentence The sentence to parse * @return true Iff the sentence was accepted by the grammar * @throws UnsupportedOperationException If the Sentence is too long or * of zero length or the parse * otherwise fails for resource reasons */ private boolean parseInternal(List sentence) { parseSucceeded = false; parseNoMemory = false; parseUnparsable = false; parseSkipped = false; parseFallback = false; whatFailed = null; addedPunct = false; originalSentence = sentence; int length = sentence.size(); if (length == 0) { parseSkipped = true; throw new UnsupportedOperationException("Can't parse a zero-length sentence!"); } List sentenceB; if (op.wordFunction != null) { sentenceB = Generics.newArrayList(); for (HasWord word : originalSentence) { if (word instanceof Label) { Label label = (Label) word; Label newLabel = label.labelFactory().newLabel(label); if (newLabel instanceof HasWord) { sentenceB.add((HasWord) newLabel); } else { throw new AssertionError("This should have been a HasWord"); } } else if (word instanceof HasTag) { TaggedWord tw = new TaggedWord(word.word(), ((HasTag) word).tag()); sentenceB.add(tw); } else { sentenceB.add(new Word(word.word())); } } for (HasWord word : sentenceB) { word.setWord(op.wordFunction.apply(word.word())); } } else { sentenceB = new ArrayList<>(sentence); } if (op.testOptions.addMissingFinalPunctuation) { addedPunct = addSentenceFinalPunctIfNeeded(sentenceB, length); } if (length > op.testOptions.maxLength) { parseSkipped = true; throw new UnsupportedOperationException("Sentence too long: length " + length); } TreePrint treePrint = getTreePrint(); PrintWriter pwOut = op.tlpParams.pw(); //Insert the boundary symbol if(sentence.get(0) instanceof CoreLabel) { CoreLabel boundary = new CoreLabel(); boundary.setWord(Lexicon.BOUNDARY); boundary.setValue(Lexicon.BOUNDARY); boundary.setTag(Lexicon.BOUNDARY_TAG); boundary.setIndex(sentence.size()+1);//1-based indexing used in the parser sentenceB.add(boundary); } else { sentenceB.add(new TaggedWord(Lexicon.BOUNDARY, Lexicon.BOUNDARY_TAG)); } if (Thread.interrupted()) { throw new RuntimeInterruptedException(); } if (op.doPCFG) { if (!pparser.parse(sentenceB)) { return parseSucceeded; } if (op.testOptions.verbose) { pwOut.println("PParser output"); // getBestPCFGParse(false).pennPrint(pwOut); // with scores on nodes treePrint.printTree(getBestPCFGParse(false), pwOut); // without scores on nodes } } if (Thread.interrupted()) { throw new RuntimeInterruptedException(); } if (op.doDep && ! op.testOptions.useFastFactored) { if ( ! dparser.parse(sentenceB)) { return parseSucceeded; } // cdm nov 2006: should move these printing bits to the main printing section, // so don't calculate the best parse twice! if (op.testOptions.verbose) { pwOut.println("DParser output"); treePrint.printTree(dparser.getBestParse(), pwOut); } } if (Thread.interrupted()) { throw new RuntimeInterruptedException(); } if (op.doPCFG && op.doDep) { if ( ! bparser.parse(sentenceB)) { return parseSucceeded; } else { parseSucceeded = true; } } return true; } @Override public void restoreOriginalWords(Tree tree) { if (originalSentence == null || tree == null) { return; } List leaves = tree.getLeaves(); int expectedSize = addedPunct ? originalSentence.size() + 1 : originalSentence.size(); if (leaves.size() != expectedSize) { throw new IllegalStateException("originalWords and sentence of different sizes: " + expectedSize + " vs. " + leaves.size() + "\n Orig: " + Sentence.listToString(originalSentence) + "\n Pars: " + Sentence.listToString(leaves)); } Iterator leafIterator = leaves.iterator(); for (HasWord word : originalSentence) { Tree leaf = leafIterator.next(); if (!(word instanceof Label)) { continue; } leaf.setLabel((Label) word); } } /** * Parse a (speech) lattice with the PCFG parser. * * @param lr a lattice to parse * @return Whether the lattice could be parsed by the grammar */ boolean parse(HTKLatticeReader lr) { TreePrint treePrint = getTreePrint(); PrintWriter pwOut = op.tlpParams.pw(); parseSucceeded = false; parseNoMemory = false; parseUnparsable = false; parseSkipped = false; parseFallback = false; whatFailed = null; originalSentence = null; if (lr.getNumStates() > op.testOptions.maxLength + 1) { // + 1 for boundary symbol parseSkipped = true; throw new UnsupportedOperationException("Lattice too big: " + lr.getNumStates()); } if (op.doPCFG) { if (!pparser.parse(lr)) { return parseSucceeded; } if (op.testOptions.verbose) { pwOut.println("PParser output"); treePrint.printTree(getBestPCFGParse(false), pwOut); } } parseSucceeded = true; return true; } /** * Return the best parse of the sentence most recently parsed. * This will be from the factored parser, if it was used and it succeeded * else from the PCFG if it was used and succeed, else from the dependency * parser. * * @return The best tree * @throws NoSuchParseException If no previously successfully parsed * sentence */ public Tree getBestParse() { return getBestParse(true); } Tree getBestParse(boolean stripSubcat) { if (parseSkipped) { return null; } if (bparser != null && parseSucceeded) { Tree binaryTree = bparser.getBestParse(); Tree tree = debinarizer.transformTree(binaryTree); if (op.nodePrune) { NodePruner np = new NodePruner(pparser, debinarizer); tree = np.prune(tree); } if (stripSubcat) { tree = subcategoryStripper.transformTree(tree); } restoreOriginalWords(tree); return tree; } else if (pparser != null && pparser.hasParse() && fallbackToPCFG) { return getBestPCFGParse(); } else if (dparser != null && dparser.hasParse()) { // && fallbackToDG // Should we strip subcategories like this? Traditionally haven't... // return subcategoryStripper.transformTree(getBestDependencyParse(true)); return getBestDependencyParse(true); } else { throw new NoSuchParseException(); } } public List> getBestPCFGParses() { return pparser.getBestParses(); } public boolean hasFactoredParse() { if (bparser == null) { return false; } return !parseSkipped && parseSucceeded && bparser.hasParse(); } public Tree getBestFactoredParse() { return bparser.getBestParse(); } public List> getKGoodFactoredParses(int k) { if (bparser == null || parseSkipped) { return null; } List> binaryTrees = bparser.getKGoodParses(k); if (binaryTrees == null) { return null; } List> trees = new ArrayList<>(k); for (ScoredObject tp : binaryTrees) { Tree t = debinarizer.transformTree(tp.object()); t = subcategoryStripper.transformTree(t); restoreOriginalWords(t); trees.add(new ScoredObject<>(t, tp.score())); } return trees; } /** * Returns the trees (and scores) corresponding to the * k-best derivations of the sentence. This cannot be * a Counter because frequently there will be multiple * derivations which lead to the same parse tree. * * @param k The number of best parses to return * @return The list of trees with their scores (log prob). */ public List> getKBestPCFGParses(int k) { if (pparser == null) { return null; } List> binaryTrees = pparser.getKBestParses(k); if (binaryTrees == null) { return null; } List> trees = new ArrayList<>(k); for (ScoredObject p : binaryTrees) { Tree t = debinarizer.transformTree(p.object()); t = subcategoryStripper.transformTree(t); restoreOriginalWords(t); trees.add(new ScoredObject<>(t, p.score())); } return trees; } public Tree getBestPCFGParse() { return getBestPCFGParse(true); } public Tree getBestPCFGParse(boolean stripSubcategories) { if (pparser == null || parseSkipped || parseUnparsable) { return null; } Tree binaryTree = pparser.getBestParse(); if (binaryTree == null) { return null; } Tree t = debinarizer.transformTree(binaryTree); if (stripSubcategories) { t = subcategoryStripper.transformTree(t); } restoreOriginalWords(t); return t; } @Override public double getPCFGScore() { return pparser.getBestScore(); } double getPCFGScore(String goalStr) { return pparser.getBestScore(goalStr); } void parsePCFG(List sentence) { parseSucceeded = false; parseNoMemory = false; parseUnparsable = false; parseSkipped = false; parseFallback = false; whatFailed = null; originalSentence = sentence; pparser.parse(sentence); } public Tree getBestDependencyParse() { return getBestDependencyParse(false); } @Override public Tree getBestDependencyParse(boolean debinarize) { if (dparser == null || parseSkipped || parseUnparsable) { return null; } Tree t = dparser.getBestParse(); if (t != null) { if (debinarize) { t = debinarizer.transformTree(t); } t = boundaryRemover.transformTree(t); // remove boundary .$$. which is otherwise still there from dparser. restoreOriginalWords(t); } return t; } /** * Parse a sentence represented as a List of tokens. * The text must already have been tokenized and * normalized into tokens that are appropriate to the treebank * which was used to train the parser. The tokens can be of * multiple types, and the list items need not be homogeneous as to type * (in particular, only some words might be given tags): *
    *
  • If a token implements HasWord, then the word to be parsed is * given by its word() value.
  • *
  • If a token implements HasTag and the tag() value is not * null or the empty String, then the parser is strongly advised to assign * a part of speech tag that begins with this String.
  • *
* * @param sentence The sentence to parse * @return true Iff the sentence was accepted by the grammar. If * the main grammar fails, but the PCFG succeeds, then * this still returns true, but parseFallback() will * also return true. getBestParse() will have a valid * result iff this returns true. */ @Override public boolean parse(List sentence) { try { if (!parseInternal(sentence)) { if (pparser != null && pparser.hasParse() && fallbackToPCFG) { parseFallback = true; return true; } else { parseUnparsable = true; return false; } } else { return true; } } catch (OutOfMemoryError e) { if (op.testOptions.maxLength != -0xDEADBEEF) { // this means they explicitly asked for a length they cannot handle. // Throw exception. Avoid string concatenation before throw it. System.err.print("NOT ENOUGH MEMORY TO PARSE SENTENCES OF LENGTH "); System.err.println(op.testOptions.maxLength); throw e; } if (pparser.hasParse() && fallbackToPCFG) { try { whatFailed = "dependency"; if (dparser.hasParse()) { whatFailed = "factored"; } parseFallback = true; return true; } catch (OutOfMemoryError oome) { oome.printStackTrace(); parseNoMemory = true; pparser.nudgeDownArraySize(); return false; } } else { parseNoMemory = true; return false; } } catch (UnsupportedOperationException uoe) { parseSkipped = true; return false; } } /** * Implements the same parsing with fallback that parse() does, but * also outputs status messages for failed parses to pwErr. */ @Override public boolean parseAndReport(List sentence, PrintWriter pwErr) { boolean result = parse(sentence); if (result) { if (whatFailed != null) { // Something failed, probably because of memory problems. // However, we still got a PCFG parse, at least. if ( ! saidMemMessage) { ParserUtils.printOutOfMemory(pwErr); saidMemMessage = true; } pwErr.println("Sentence too long for " + whatFailed + " parser. Falling back to PCFG parse..."); } else if (parseFallback) { // We had to fall back for some other reason. pwErr.println("Sentence couldn't be parsed by grammar.... falling back to PCFG parse."); } } else if (parseUnparsable) { // No parse at all, completely failed. pwErr.println("Sentence couldn't be parsed by grammar."); } else if (parseNoMemory) { // Ran out of memory, either with or without a possible PCFG parse. if (!saidMemMessage) { ParserUtils.printOutOfMemory(pwErr); saidMemMessage = true; } if (pparser.hasParse() && fallbackToPCFG) { pwErr.println("No memory to gather PCFG parse. Skipping..."); } else { pwErr.println("Sentence has no parse using PCFG grammar (or no PCFG fallback). Skipping..."); } } else if (parseSkipped) { pwErr.println("Sentence too long (or zero words)."); } return result; } /** Return a TreePrint for formatting parsed output trees. * @return A TreePrint for formatting parsed output trees. */ public TreePrint getTreePrint() { return op.testOptions.treePrint(op.tlpParams); } @Override public KBestViterbiParser getPCFGParser() { return pparser; } @Override public KBestViterbiParser getDependencyParser() { return dparser; } @Override public KBestViterbiParser getFactoredParser() { return bparser; } /** Adds a sentence final punctuation mark to sentences that lack one. * This method adds a period (the first sentence final punctuation word * in a parser language pack) to sentences that don't have one within * the last 3 words (to allow for close parentheses, etc.). It checks * tags for punctuation, if available, otherwise words. * * @param sentence The sentence to check * @param length The length of the sentence (just to avoid recomputation) */ private boolean addSentenceFinalPunctIfNeeded(List sentence, int length) { int start = length - 3; if (start < 0) start = 0; TreebankLanguagePack tlp = op.tlpParams.treebankLanguagePack(); for (int i = length - 1; i >= start; i--) { HasWord item = sentence.get(i); // An object (e.g., CoreLabel) can implement HasTag but not actually store // a tag so we need to check that there is something there for this case. // If there is, use only it, since word tokens can be ambiguous. String tag = null; if (item instanceof HasTag) { tag = ((HasTag) item).tag(); } if (tag != null && ! tag.isEmpty()) { if (tlp.isSentenceFinalPunctuationTag(tag)) { return false; } } else { String str = item.word(); if (tlp.isPunctuationWord(str)) { return false; } } } // none found so add one. if (op.testOptions.verbose) { System.err.println("Adding missing final punctuation to sentence."); } String[] sfpWords = tlp.sentenceFinalPunctuationWords(); if (sfpWords.length > 0) { sentence.add(new Word(sfpWords[0])); } return true; } }




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