IRetagger.java

package edu.northwestern.at.utils.corpuslinguistics.postagger.iretagger;

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

import java.util.*;

import edu.northwestern.at.utils.*;
import edu.northwestern.at.utils.corpuslinguistics.adornedword.*;
import edu.northwestern.at.utils.corpuslinguistics.partsofspeech.*;
import edu.northwestern.at.utils.corpuslinguistics.postagger.*;
import edu.northwestern.at.utils.corpuslinguistics.postagger.unigram.*;

/**	"I" retagger.
 *
 *	<p>
 *	This retagger applies a short list of rules to improve tagging
 *	of "I" spellings.
 *	</p>
 */

public class IRetagger
	extends UnigramTagger
	implements PartOfSpeechRetagger
{
	/**	Part of speech tags. */

	protected static PartOfSpeechTags posTags;

	/**	Create proper noun retagger.
	 */

	public IRetagger()
	{
		super();
	}

	/**	Retag a sentence.
	 *
	 *	@param	sentence	The sentence as an
	 *						{@link edu.northwestern.at.utils.corpuslinguistics.adornedword.AdornedWord} .
	 *
	 *	@return				The sentence with words retagged.
	 */

	@SuppressWarnings("unchecked")
	public<T extends AdornedWord> List<T> retagSentence
	(
		List<T> sentence
	)
	{
								//	Get noun part of speech tags
								//	if we don't already have them.

		if ( posTags == null )
		{
			posTags	= getLexicon().getPartOfSpeechTags();
		}
								//	Find all "I." spellings in the sentence.
								//	Split off the trailing period into a
								//	new adorned word for those
								//	marked as pronouns.

		int i = 1;

		while ( i < sentence.size() )
		{
								//	Get next word in sentence.

			T adornedWord	= sentence.get( i );

								//	Is spelling "I."?

			if ( adornedWord.getSpelling().equals( "I." ) )
			{
				String partsOfSpeech	= adornedWord.getPartsOfSpeech();

								//	Is this "I." a pronoun?
								//	If so, change its spelling to
								//	"I", and add a new period token
								//	right after.

				if ( posTags.isPronounTag( partsOfSpeech ) )
				{
					adornedWord.setToken( "I" );
					adornedWord.setSpelling( "I" );
					adornedWord.setStandardSpelling( "I" );

					AdornedWord period	= new BaseAdornedWord( "." , "." );

					sentence.set( i , adornedWord );
					sentence.add( i + 1 , (T)period );
				}
			}

			i++;
		}
								//	Return updated sentence.
		return sentence;
	}

	/**	Can retagger add or delete words in the original sentence?
	 *
	 *	@return		true if retagger can add or delete words.
	 */

	public boolean canAddOrDeleteWords()
	{
		return true;
	}

	/**	Return retagger description.
	 *
	 *	@return		Retagger description.
	 */

	public String toString()
	{
		return "I retagger";
	}
}

/*
Copyright (c) 2008, 2009 by Northwestern University.
All rights reserved.

Developed by:
   Academic and Research Technologies
   Northwestern University
   http://www.it.northwestern.edu/about/departments/at/

Permission is hereby granted, free of charge, to any person
obtaining a copy of this software and associated documentation
files (the "Software"), to deal with the Software without
restriction, including without limitation the rights to use,
copy, modify, merge, publish, distribute, sublicense, and/or
sell copies of the Software, and to permit persons to whom the
Software is furnished to do so, subject to the following
conditions:

    * Redistributions of source code must retain the above copyright
      notice, this list of conditions and the following disclaimers.

    * Redistributions in binary form must reproduce the above
      copyright notice, this list of conditions and the following
      disclaimers in the documentation and/or other materials provided
      with the distribution.

    * Neither the names of Academic and Research Technologies,
      Northwestern University, nor the names of its contributors may be
      used to endorse or promote products derived from this Software
      without specific prior written permission.

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EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES
OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
NONINFRINGEMENT. IN NO EVENT SHALL THE CONTRIBUTORS OR
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LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR
OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE
SOFTWARE OR THE USE OR OTHER DEALINGS WITH THE SOFTWARE.
*/