ai.idylnlp.nlp.tokenizers.BreakIteratorTokenizer Maven / Gradle / Ivy

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/*******************************************************************************
 * Copyright 2018 Mountain Fog, Inc.
 * 
 * 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 ai.idylnlp.nlp.tokenizers;

import java.text.BreakIterator;
import java.util.ArrayList;
import java.util.LinkedList;
import java.util.List;
import java.util.Locale;

import org.apache.commons.lang3.NotImplementedException;

import com.neovisionaries.i18n.LanguageCode;

import ai.idylnlp.model.nlp.Span;
import ai.idylnlp.model.nlp.Stemmer;
import ai.idylnlp.model.nlp.Tokenizer;

/**
 * A {@link Tokenizer} that uses a {@link BreakIterator}.
 * 
 * @author Mountain Fog, Inc.
 *
 */
public class BreakIteratorTokenizer implements Tokenizer {

	private BreakIterator breakIterator;
	
	public BreakIteratorTokenizer(String languageCode) {
		
		Locale locale = new Locale.Builder().setLanguage(languageCode).build();
		
		breakIterator = BreakIterator.getWordInstance(locale);
		
	}
	
	public BreakIteratorTokenizer(LanguageCode languageCode) {

		breakIterator = BreakIterator.getWordInstance(languageCode.toLocale());
		
	}
	
	/**
	 * Creates a tokenizer.
	 * 
	 * @param locale The {@link Locale} for the tokenizer.
	 */
	public BreakIteratorTokenizer(Locale locale) {
		breakIterator = BreakIterator.getWordInstance(locale);
	}
	
	@Override
	public List getLanguageCodes() {
		
		List languageCodes = new LinkedList<>();
		
		for(Locale locale : BreakIterator.getAvailableLocales()) {
			languageCodes.add(LanguageCode.getByLocale(locale).getAlpha3().toString());
		}
		
		return languageCodes;
		
	}

	@Override
	public String[] tokenize(String s) {
		return Span.spansToStrings(tokenizePos(s), s);
	}

	@Override
	public Span[] tokenizePos(String d) {

		List tokens = new ArrayList<>();

		breakIterator.setText(d);

		int lastIndex = breakIterator.first();

		while (lastIndex != BreakIterator.DONE) {

			int firstIndex = lastIndex;
			lastIndex = breakIterator.next();

			if (lastIndex != BreakIterator.DONE
					&& Character.isLetterOrDigit(d.charAt(firstIndex))) {
				tokens.add(new Span(firstIndex, lastIndex));
			}

		}

		return tokens.toArray(new Span[tokens.size()]);

	}

	@Override
	public String[] tokenize(String s, Stemmer stemmer) {
		// TODO: Implement this.
		throw new NotImplementedException("Not yet implemented.");
	}

}