org.apache.ctakes.smokingstatus.context.negation.NegationContextAnalyzer Maven / Gradle / Ivy

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/**
 * 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
 *
 * 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 org.apache.ctakes.smokingstatus.context.negation;

import java.util.List;
import java.util.Set;

import org.apache.ctakes.core.fsm.output.NegationIndicator;
import org.apache.ctakes.core.fsm.token.TextToken;
import org.apache.ctakes.necontexts.ContextHit;
import org.apache.ctakes.smokingstatus.context.NamedEntityContextAnalyzer;
import org.apache.ctakes.smokingstatus.machine.NegationFSM;
import org.apache.uima.analysis_engine.AnalysisEngineProcessException;
import org.apache.uima.jcas.tcas.Annotation;


public class NegationContextAnalyzer extends NamedEntityContextAnalyzer {
	private NegationFSM _negIndicatorFSM = new NegationFSM();

	/**
	 * This method analyzes a list of tokens looking for a negation pattern as
	 * specified by the class NegationFSM.
	 * 
	 * @see NegationFSM
	 */
	public ContextHit analyzeContext(List contextTokens, int scopeOrientation)
			throws AnalysisEngineProcessException {
		List fsmTokenList = wrapAsFsmTokens(contextTokens);

		try {
			Set s = _negIndicatorFSM.execute(fsmTokenList);

			if (s.size() > 0) {
				NegationIndicator neg = s.iterator().next();
				return new ContextHit(neg.getStartOffset(), neg.getEndOffset());
			} else {
				return null;
			}
		} catch (Exception e) {
			throw new AnalysisEngineProcessException(e);
		}
	}
}