IxaLemmatizer.java

/*
 * Copyright 2016
 * Ubiquitous Knowledge Processing (UKP) Lab
 * Technische Universität Darmstadt
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *   http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */
package de.tudarmstadt.ukp.dkpro.core.ixa;

import static org.apache.uima.fit.util.JCasUtil.indexCovered;
import static org.apache.uima.fit.util.JCasUtil.select;
import static org.apache.uima.fit.util.JCasUtil.toText;
import static org.apache.uima.util.Level.INFO;

import java.io.InputStream;
import java.util.Collection;
import java.util.Map;

import org.apache.uima.UimaContext;
import org.apache.uima.analysis_engine.AnalysisEngineProcessException;
import org.apache.uima.fit.component.JCasAnnotator_ImplBase;
import org.apache.uima.fit.descriptor.ConfigurationParameter;
import org.apache.uima.fit.descriptor.TypeCapability;
import org.apache.uima.jcas.JCas;
import org.apache.uima.resource.ResourceInitializationException;

import de.tudarmstadt.ukp.dkpro.core.api.lexmorph.type.pos.POS;
import de.tudarmstadt.ukp.dkpro.core.api.parameter.ComponentParameters;
import de.tudarmstadt.ukp.dkpro.core.api.resources.CasConfigurableProviderBase;
import de.tudarmstadt.ukp.dkpro.core.api.resources.ModelProviderBase;
import de.tudarmstadt.ukp.dkpro.core.api.segmentation.type.Lemma;
import de.tudarmstadt.ukp.dkpro.core.api.segmentation.type.Sentence;
import de.tudarmstadt.ukp.dkpro.core.api.segmentation.type.Token;
import de.tudarmstadt.ukp.dkpro.core.ixa.internal.IxaLemmatizerTagsetDescriptionProvider;
import eus.ixa.ixa.pipe.lemma.LemmatizerME;
import eus.ixa.ixa.pipe.lemma.LemmatizerModel;

/**
 * Lemmatizer using the OpenNLP-based Ixa implementation.
 */
@TypeCapability(
        inputs = { 
                "de.tudarmstadt.ukp.dkpro.core.api.segmentation.type.Sentence",
                "de.tudarmstadt.ukp.dkpro.core.api.segmentation.type.Token",
                "de.tudarmstadt.ukp.dkpro.core.api.lexmorph.type.pos.POS" }, 
        outputs = {
                "de.tudarmstadt.ukp.dkpro.core.api.segmentation.type.Lemma" })
public class IxaLemmatizer
    extends JCasAnnotator_ImplBase
{
    /**
     * Use this language instead of the document language to resolve the model.
     */
    public static final String PARAM_LANGUAGE = ComponentParameters.PARAM_LANGUAGE;
    @ConfigurationParameter(name = PARAM_LANGUAGE, mandatory = false)
    protected String language;

    /**
     * Override the default variant used to locate the model.
     */
    public static final String PARAM_VARIANT = ComponentParameters.PARAM_VARIANT;
    @ConfigurationParameter(name = PARAM_VARIANT, mandatory = false)
    protected String variant;

    /**
     * Load the model from this location instead of locating the model automatically.
     */
    public static final String PARAM_MODEL_LOCATION = ComponentParameters.PARAM_MODEL_LOCATION;
    @ConfigurationParameter(name = PARAM_MODEL_LOCATION, mandatory = false)
    protected String modelLocation;

    /**
     * Log the tag set(s) when a model is loaded.
     *
     * Default: {@code false}
     */
    public static final String PARAM_PRINT_TAGSET = ComponentParameters.PARAM_PRINT_TAGSET;
    @ConfigurationParameter(name = PARAM_PRINT_TAGSET, mandatory = true, defaultValue="false")
    protected boolean printTagSet;

    private CasConfigurableProviderBase<LemmatizerME> modelProvider;

    @Override
    public void initialize(UimaContext aContext)
        throws ResourceInitializationException
    {
        super.initialize(aContext);

        modelProvider = new ModelProviderBase<LemmatizerME>(this, "lemmatizer")
        {
            @Override
            protected LemmatizerME produceResource(InputStream aStream)
                throws Exception
            {
                LemmatizerModel model = new LemmatizerModel(aStream);

                // Extract tagset information from the model
                IxaLemmatizerTagsetDescriptionProvider tsdp = new IxaLemmatizerTagsetDescriptionProvider(
                        getResourceMetaData().getProperty("pos.tagset"), POS.class,
                        model.getLemmatizerSequenceModel(), "t0");
                addTagset(tsdp, false);

                if (printTagSet) {
                    getContext().getLogger().log(INFO, tsdp.toString());
                }
                
                return new LemmatizerME(model);
            }

        };
    }

    @Override
    public void process(JCas aJCas)
        throws AnalysisEngineProcessException
    {
        modelProvider.configure(aJCas.getCas());
        LemmatizerME analyzer = modelProvider.getResource();

        // Iterate over all sentences
        Map<Sentence, Collection<Token>> index = indexCovered(aJCas, Sentence.class, Token.class);
        for (Sentence sentence : select(aJCas, Sentence.class)) {
            Collection<Token> tokens = index.get(sentence);
            String[] tokenTexts = toText(tokens).toArray(new String[tokens.size()]);
            String[] tokenPos = tokens.stream()
                    .map(t -> { return t.getPos().getPosValue(); })
                    .toArray(s -> { return new String[tokens.size()]; });
            
            String[] encodedLemmas = analyzer.lemmatize(tokenTexts, tokenPos);
            String[] lemmas = analyzer.decodeLemmas(tokenTexts, encodedLemmas);
            
            int i = 0;
            for (Token t : tokens) {
                String lemmaString = lemmas[i];
                if (lemmaString == null) {
                    lemmaString = t.getCoveredText();
                }
                Lemma l = new Lemma(aJCas, t.getBegin(), t.getEnd());
                l.setValue(lemmaString);
                l.addToIndexes();

                t.setLemma(l);
                i++;
            }
        }
    }
}