package de.spieleck.app.cngram ;

/*	Please see the license information in the header below. */

/*
 NGramJ - n-gram based text classification
 Copyright (C) 2001- Frank S. Nestel (frank at spieleck.de)

 This program is free software; you can redistribute it and/or modify
 it under the terms of the GNU Lesser General Public License as published
 by the Free Software Foundation; either version 2.1 of the License, or
 (at your option) any later version.

 This program is distributed in the hope that it will be useful,
 but WITHOUT ANY WARRANTY; without even the implied warranty of
 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 GNU General Public License for more details.

 You should have received a copy of the GNU Lesser General Public License
 along with this program (lesser.txt); if not, write to the Free Software
 Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA  02111-1307, USA.
 */

import java.util.Iterator ;
import java.util.Comparator ;

/**
 * A device to keep a bunch of ngram statistics.
 * @author frank nestel
 * @author $Author: nestefan $
 * @version $Revision: 2 $ $Date: 2006-03-27 23:00:21 +0200 (Mo, 27 Mrz 2006) $ $Author: nestefan $
 */
public interface NGramProfile
{
    public static final String NGRAM_PROFILE_EXTENSION = "ngp" ;

    public static final String NORMALIZATION_STR = "ngram_count" ;

    public static final String FINISHREAD_STR = "#END" ;

    public static final NGram[] NO_NGRAM = new NGram[ 0 ] ;

    public final static Comparator CHAR_SEQ_COMPARATOR = new Comparator()
    {
        public int compare( Object o1 , Object o2 )
        {
            CharSequence c1 = (CharSequence)o1 ;
            CharSequence c2 = (CharSequence)o2 ;

            for ( int i = 0 ; i < c1.length() && i < c2.length() ; i++ )
            {
                int d = c1.charAt( i ) - c2.charAt( i ) ;

                if ( d != 0 )
                {
                    return d ;
                }
            }
            return c2.length() - c1.length() ;
        }
    } ;

    /**
     * Return sorted ngrams
     *
     * @return sorted ngrams
     */
    public Iterator getSorted() ;

    /**
     * @return Returns the number of ngrams.
     */
    public int getCount() ;

    /**
     * @return Returns the name.
     */
    public String getName() ;

    /**
     * Get the normalization of all NGrams contained.
     */
    public int getNormalization() ;

    /**
     * @return NGram corresponding to seq, null if not found.
     */
    public NGram get( CharSequence seq ) ;

}