CLevenshteinDistance.java

  1. /*
  2.  * @cond LICENSE
  3.  * ######################################################################################
  4.  * # LGPL License                                                                       #
  5.  * #                                                                                    #
  6.  * # This file is part of the LightJason AgentSpeak(L++)                                #
  7.  * # Copyright (c) 2015-19, LightJason (info@lightjason.org)                            #
  8.  * # This program is free software: you can redistribute it and/or modify               #
  9.  * # it under the terms of the GNU Lesser General Public License as                     #
  10.  * # published by the Free Software Foundation, either version 3 of the                 #
  11.  * # License, or (at your option) any later version.                                    #
  12.  * #                                                                                    #
  13.  * # This program is distributed in the hope that it will be useful,                    #
  14.  * # but WITHOUT ANY WARRANTY; without even the implied warranty of                     #
  15.  * # MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the                      #
  16.  * # GNU Lesser General Public License for more details.                                #
  17.  * #                                                                                    #
  18.  * # You should have received a copy of the GNU Lesser General Public License           #
  19.  * # along with this program. If not, see http://www.gnu.org/licenses/                  #
  20.  * ######################################################################################
  21.  * @endcond
  22.  */

  23. package org.lightjason.agentspeak.consistency.metric;


  24. import org.lightjason.agentspeak.language.CCommon;
  25. import org.lightjason.agentspeak.language.ITerm;

  26. import java.util.stream.Collectors;
  27. import java.util.stream.Stream;


  28. /**
  29.  * metric based on levenshtein distance
  30.  *
  31.  * @see https://en.wikipedia.org/wiki/Levenshtein_distance
  32.  */
  33. public final class CLevenshteinDistance implements IMetric
  34. {
  35.     /**
  36.      * cost / weight of insert operation
  37.      */
  38.     private final double m_insertweight;
  39.     /**
  40.      * cost / weight of replace operation
  41.      */
  42.     private final double m_replaceweight;
  43.     /**
  44.      * cost / weight of delete operation
  45.      */
  46.     private final double m_deleteweight;

  47.     /**
  48.      * ctor
  49.      */
  50.     public CLevenshteinDistance()
  51.     {
  52.         this( 1, 1, 1 );
  53.     }

  54.     /**
  55.      * ctor
  56.      *
  57.      * @param p_insertweight weight / cost of insert character
  58.      * @param p_replaceweight weight / cost of replace character
  59.      * @param p_deleteweight weight / cost of delete character
  60.      */
  61.     public CLevenshteinDistance( final double p_insertweight, final double p_replaceweight, final double p_deleteweight )
  62.     {
  63.         m_insertweight = p_insertweight;
  64.         m_replaceweight = p_replaceweight;
  65.         m_deleteweight = p_replaceweight;
  66.     }


  67.     @Override
  68.     public final Double apply( final Stream<? extends ITerm> p_first, final Stream<? extends ITerm> p_second )
  69.     {
  70.         return CCommon.levenshtein(
  71.             p_first.map( Object::toString ).collect( Collectors.joining( "" ) ),
  72.             p_second.map( Object::toString ).collect( Collectors.joining( "" ) ),
  73.             m_insertweight, m_replaceweight, m_deleteweight
  74.         );
  75.     }

  76. }