package edu.northwestern.at.utils.corpuslinguistics.stopwords;

/*	Please see the license information at the end of this file. */

import java.util.*;

import edu.northwestern.at.utils.ListFactory;
import edu.northwestern.at.utils.SetFactory;

/**	Base stop word list.
 *
 *	<p>
 *	Creates a stop word list.
 *	</p>
 */

public class BaseStopWords implements StopWords
{
	/**	Save stop words as a set. */

	protected Set<String> stopWordsSet	=
		SetFactory.createNewSet();

	/**	Create empty stop word list.
	 */

	public BaseStopWords()
	{
	}

	/**	Create stop word list from a collection.
	 */

	public BaseStopWords( Collection<String> stopWords )
	{
		addStopWords( stopWords );
	}

	/**	Add word to stop word list.
	 *
	 *	@param	stopWord	Stop word to add.
	 */

	public void addStopWord( String stopWord )
	{
		stopWordsSet.add( stopWord );
	}

	/**	Add words to stop word list.
	 *
	 *	@param	stopWords	Collection of stop words to add.
	 */

	public void addStopWords( Collection<String> stopWords )
	{
		stopWordsSet.addAll( stopWords );
	}

	/**	Tests if a specified word is a stop word.
	 *
	 *	@param	stopWord	The word to check.
	 *
	 *	@return				true if word is a stop word.
	 */

	public boolean isStopWord( String stopWord )
	{
		return stopWordsSet.contains( stopWord );
	}

	/**	Return stop words as a List.
	 *
	 *	@return		String list of stop words.
	 */

	public List<String> getStopWords()
	{
		return ListFactory.createNewList( new TreeSet<String>( stopWordsSet ) );
	}
}

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