SingleTagTaggedStrings.java

package edu.northwestern.at.utils;

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

import java.util.*;

/**	A tagged strings implementation where all strings have the same tag value.
 *
 *	<p>
 *	Since all the strings have the same tag value, we use a sorted string
 *	array to hold the strings.  We use binary search to locate the
 *	strings of interest.  While using an array is slower than using
 *	a hash map (binary search = o(n*log(n)), hash = o(1)), the array
 *	saves lots of memory.
 *	</p>
 */

public class SingleTagTaggedStrings implements TaggedStrings
{
	/**	Array of string values. */

	protected String[] strings	= null;

	/**	The common tag for all the string values. */

	protected String tag		= null;

	/**	Create SingleTagTaggedStrings object.
	 *
	 *	@param	strings		String array of strings.
	 *	@param	tag			The common tag for all the strings.
	 */

	public SingleTagTaggedStrings( String[] strings , String tag )
	{
		this.strings	= strings;
		this.tag		= tag;

		if ( strings != null )
		{
			Arrays.sort( strings );
		}
	}

	/**	See if specified string exists.
	 *
	 *	@param	string	The string.
	 *
	 *	@return			True if specified string exists.
	 */

	public boolean containsString( String string )
	{
		boolean result	= false;

		if ( strings != null )
		{
			result	= ( Arrays.binarySearch( strings , string ) >= 0 );
		}

		return result;
	}

	/**	Get the tag value associated with a string.
	 *
	 *	@param	string	The string.
	 *
	 *	@return			The tag value associated with the string.
	 *					May be null.
	 */

	public String getTag( String string )
	{
		String result	= null;

		int index		= Arrays.binarySearch( strings , string );

		if ( index >= 0 ) result = tag;

		return result;
	}

	/**	Get number of strings.
	 *
	 *	@return		Number of strings.
	 */

	public int getStringCount()
	{
		int result	= 0;

		if ( strings != null ) result = strings.length;

		return result;
	}

	/**	Get set of all unique string values.
	 *
	 *	@return		Set of all strings.
	 */

	public Set<String> getAllStrings()
	{
		Set<String> result	= SetFactory.createNewSet();

		result.addAll( Arrays.asList( strings ) );

		return result;
	}

	/**	Get set of all unique tag values.
	 *
	 *	@return		Set of all unique tag values.
	 *
	 *	<p>
	 *	The result always contains just one value, the common tag value
	 *	associated with all the strings.
	 *	</p>
	 */

	public Set<String> getAllTags()
	{
		Set<String> result	= SetFactory.createNewSet();

		if ( tag != null ) result.add( tag );

		return result;
	}

	/**	Set the tag value associated with a string.
	 *
	 *	@param	string	The string.
	 *	@param	tag		The tag.
	 *
	 *	<p>
	 *	This is a no-op in this implementation.
	 *	</p>
	 */

	public void putTag( String string , String tag )
	{
	}

}

/*
Copyright (c) 2008, 2009 by Northwestern University.
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Developed by:
   Academic and Research Technologies
   Northwestern University
   http://www.it.northwestern.edu/about/departments/at/

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obtaining a copy of this software and associated documentation
files (the "Software"), to deal with the Software without
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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.

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      Northwestern University, nor the names of its contributors may be
      used to endorse or promote products derived from this Software
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