org.maltparserx.parser.algorithm.nivre.ArcEagerOracle Maven / Gradle / Ivy
package org.maltparserx.parser.algorithm.nivre;
import org.maltparserx.core.exception.MaltChainedException;
import org.maltparserx.core.syntaxgraph.DependencyStructure;
import org.maltparserx.core.syntaxgraph.node.DependencyNode;
import org.maltparserx.parser.DependencyParserConfig;
import org.maltparserx.parser.Oracle;
import org.maltparserx.parser.ParserConfiguration;
import org.maltparserx.parser.history.GuideUserHistory;
import org.maltparserx.parser.history.action.GuideUserAction;
/**
* @author Johan Hall
*
*/
public class ArcEagerOracle extends Oracle {
public ArcEagerOracle(DependencyParserConfig manager, GuideUserHistory history) throws MaltChainedException {
super(manager, history);
setGuideName("ArcEager");
}
public GuideUserAction predict(DependencyStructure gold, ParserConfiguration config) throws MaltChainedException {
final NivreConfig nivreConfig = (NivreConfig)config;
final DependencyNode stackPeek = nivreConfig.getStack().peek();
final int stackPeekIndex = stackPeek.getIndex();
final int inputPeekIndex = nivreConfig.getInput().peek().getIndex();
if (!stackPeek.isRoot() && gold.getTokenNode(stackPeekIndex).getHead().getIndex() == inputPeekIndex) {
return updateActionContainers(ArcEager.LEFTARC, gold.getTokenNode(stackPeekIndex).getHeadEdge().getLabelSet());
} else if (gold.getTokenNode(inputPeekIndex).getHead().getIndex() == stackPeekIndex) {
return updateActionContainers(ArcEager.RIGHTARC, gold.getTokenNode(inputPeekIndex).getHeadEdge().getLabelSet());
} else if (!nivreConfig.isAllowReduce() && !stackPeek.hasHead()) {
return updateActionContainers(ArcEager.SHIFT, null);
} else if (gold.getTokenNode(inputPeekIndex).hasLeftDependent() &&
gold.getTokenNode(inputPeekIndex).getLeftmostDependent().getIndex() < stackPeekIndex) {
return updateActionContainers(ArcEager.REDUCE, null);
} else if (gold.getTokenNode(inputPeekIndex).getHead().getIndex() < stackPeekIndex &&
(!gold.getTokenNode(inputPeekIndex).getHead().isRoot() || nivreConfig.isAllowRoot())) {
return updateActionContainers(ArcEager.REDUCE, null);
} else {
return updateActionContainers(ArcEager.SHIFT, null);
}
}
public void finalizeSentence(DependencyStructure dependencyGraph) throws MaltChainedException {}
public void terminate() throws MaltChainedException {}
}