    001    package org.maltparser.parser.algorithm.planar;
    002
    003    import org.maltparser.core.exception.MaltChainedException;
    004    import org.maltparser.core.syntaxgraph.DependencyStructure;
    005    import org.maltparser.core.syntaxgraph.node.DependencyNode;
    006    import org.maltparser.parser.DependencyParserConfig;
    007    import org.maltparser.parser.Oracle;
    008    import org.maltparser.parser.ParserConfiguration;
    009    import org.maltparser.parser.history.GuideUserHistory;
    010    import org.maltparser.parser.history.action.GuideUserAction;
    011    /**
    012     * @author Carlos Gomez Rodriguez
    013     *
    014     */
    015    public class PlanarArcEagerOracle extends Oracle {
    016
    017            public PlanarArcEagerOracle(DependencyParserConfig manager, GuideUserHistory history) throws MaltChainedException {
    018                    super(manager, history);
    019                    setGuideName("Planar");
    020            }
    021
    022            public GuideUserAction predict(DependencyStructure gold, ParserConfiguration config) throws MaltChainedException {
    023                    PlanarConfig planarConfig = (PlanarConfig)config;
    024                    DependencyStructure dg = planarConfig.getDependencyGraph();
    025                    DependencyNode stackPeek = planarConfig.getStack().peek();
    026                    int stackPeekIndex = stackPeek.getIndex();
    027                    int inputPeekIndex = planarConfig.getInput().peek().getIndex();
    028
    029                    if (!stackPeek.isRoot() && gold.getTokenNode(stackPeekIndex).getHead().getIndex() == inputPeekIndex
    030                                    && !checkIfArcExists ( dg , inputPeekIndex , stackPeekIndex ) )  {
    031                            return updateActionContainers(Planar.LEFTARC, gold.getTokenNode(stackPeekIndex).getHeadEdge().getLabelSet());
    032                    } else if (gold.getTokenNode(inputPeekIndex).getHead().getIndex() == stackPeekIndex
    033                                    && !checkIfArcExists ( dg , stackPeekIndex , inputPeekIndex ) ) {
    034                            return updateActionContainers(Planar.RIGHTARC, gold.getTokenNode(inputPeekIndex).getHeadEdge().getLabelSet());
    035                    } else if (gold.getTokenNode(inputPeekIndex).hasLeftDependent() &&
    036                                    gold.getTokenNode(inputPeekIndex).getLeftmostDependent().getIndex() < stackPeekIndex) {
    037                            return updateActionContainers(Planar.REDUCE, null);
    038                    } else if (gold.getTokenNode(inputPeekIndex).getHead().getIndex() < stackPeekIndex) {
    039                            return updateActionContainers(Planar.REDUCE, null);
    040                    } else {
    041                            return updateActionContainers(Planar.SHIFT, null);
    042                    }
    043
    044            }
    045
    046            private boolean checkIfArcExists ( DependencyStructure dg , int index1 , int index2 ) throws MaltChainedException
    047            {
    048                    return dg.getTokenNode(index2).hasHead() && dg.getTokenNode(index2).getHead().getIndex() == index1;
    049            }
    050
    051            public void finalizeSentence(DependencyStructure dependencyGraph) throws MaltChainedException {}
    052
    053            public void terminate() throws MaltChainedException {}
    054    }