PrefixSplitter.java

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 * Copyright 2015-2016 - CNRS (Centre National de Recherche Scientifique)
 *
 * Licensed to the Apache Software Foundation (ASF) under one
 * or more contributor license agreements.  See the NOTICE file
 * distributed with this work for additional information
 * regarding copyright ownership.  The ASF licenses this file
 * to you 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
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 * 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
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package eu.project.ttc.engines.morpho;

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.ExternalResource;
import org.apache.uima.jcas.JCas;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

import com.google.common.collect.HashMultimap;
import com.google.common.collect.Multimap;

import eu.project.ttc.history.TermHistory;
import eu.project.ttc.history.TermHistoryResource;
import eu.project.ttc.models.Term;
import eu.project.ttc.models.VariationType;
import eu.project.ttc.models.Word;
import eu.project.ttc.resources.PrefixTree;
import eu.project.ttc.resources.TermIndexResource;
import eu.project.ttc.utils.TermSuiteConstants;

public class PrefixSplitter extends JCasAnnotator_ImplBase {
	private static final Logger LOGGER = LoggerFactory.getLogger(PrefixSplitter.class);

	public static final String TASK_NAME = "Morphosyntactic analysis (prefix)";

	@ExternalResource(key=TermIndexResource.TERM_INDEX, mandatory=true)
	private TermIndexResource termIndexResource;
	
	@ExternalResource(key=PrefixTree.PREFIX_TREE, mandatory=true)
	private PrefixTree prefixTree;

	@ExternalResource(key =TermHistoryResource.TERM_HISTORY, mandatory = true)
	private TermHistoryResource historyResource;

	public static final String CHECK_IF_MORPHO_EXTENSION_IS_IN_CORPUS = "CheckIfMorphoExtensionInCorpus";
	@ConfigurationParameter(name=CHECK_IF_MORPHO_EXTENSION_IS_IN_CORPUS, mandatory=false, defaultValue = "true")
	private boolean checkIfMorphoExtensionInCorpus;
	
	@Override
	public void process(JCas aJCas) throws AnalysisEngineProcessException {
		// do nothing
	}
	
	@Override
	public void collectionProcessComplete() throws AnalysisEngineProcessException {
		LOGGER.info("Starting {} for TermIndex {}", TASK_NAME, termIndexResource.getTermIndex().getName());
		Multimap<String, Term> lemmaIndex = HashMultimap.create();
		int nb = 0;
		String prefixExtension, lemma, pref;
		for(Term swt:termIndexResource.getTermIndex().getTerms()) {
			if(!swt.isSingleWord())
				continue;
			else {
				lemmaIndex.put(swt.getLemma(), swt);
			}
		}
		for(Term swt:termIndexResource.getTermIndex().getTerms()) {
			if(!swt.isSingleWord())
				continue;

			Word word = swt.getWords().get(0).getWord();
			lemma = word.getLemma();
			pref = prefixTree.getPrefix(lemma);
			if(pref != null && pref.length() < lemma.length()) {
				prefixExtension = lemma.substring(pref.length(),lemma.length());
				if(LOGGER.isTraceEnabled())
					LOGGER.trace("Found prefix: {} for word {}", pref, lemma);
				if(checkIfMorphoExtensionInCorpus) {
					if(!lemmaIndex.containsKey(prefixExtension)) {
						if(LOGGER.isTraceEnabled())
							LOGGER.trace("Prefix extension: {} for word {} is not found in corpus. Aborting composition for this word.", prefixExtension, lemma);
						continue;
					} else {
						for(Term target:lemmaIndex.get(prefixExtension)) {
							watch(swt, target);
							swt.addTermVariation(target, VariationType.IS_PREFIX_OF, TermSuiteConstants.EMPTY_STRING);
						}
					}
				}
				nb++;
			}
		}
		LOGGER.debug("Number of words with prefix composition: {} out of {}", 
				nb, 
				termIndexResource.getTermIndex().getWords().size());
	}

	private void watch(Term swt, Term target) {
		TermHistory history = historyResource.getHistory();
		if(history.isWatched(swt.getGroupingKey()))
			history.saveEvent(
				swt.getGroupingKey(), 
				this.getClass(), 
				"Term is prefix of term " + target);
		if(history.isWatched(target.getGroupingKey()))
			history.saveEvent(
					target.getGroupingKey(), 
				this.getClass(), 
				"Term has a new found prefix: " + swt);

	}
}