1/*  Part of SWI-Prolog
    2
    3    Author:        Jan Wielemaker
    4    E-mail:        J.Wielemaker@vu.nl
    5    WWW:           http://www.swi-prolog.org
    6    Copyright (c)  2011-2014, VU University Amsterdam
    7    All rights reserved.
    8
    9    Redistribution and use in source and binary forms, with or without
   10    modification, are permitted provided that the following conditions
   11    are met:
   12
   13    1. Redistributions of source code must retain the above copyright
   14       notice, this list of conditions and the following disclaimer.
   15
   16    2. Redistributions in binary form must reproduce the above copyright
   17       notice, this list of conditions and the following disclaimer in
   18       the documentation and/or other materials provided with the
   19       distribution.
   20
   21    THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
   22    "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
   23    LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
   24    FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
   25    COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
   26    INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
   27    BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
   28    LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
   29    CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
   30    LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN
   31    ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
   32    POSSIBILITY OF SUCH DAMAGE.
   33*/
   34
   35:- module(isub,
   36          [ isub/4                      % +Text1, +Text2, +Normalize, -Distance
   37          ]).   38
   39
   40:- use_foreign_library(foreign(isub)).   41
   42/** <module> isub: a string similarity measure
   43
   44The library(isub) implements a similarity measure between strings, i.e.,
   45something similar to the _|Levenshtein distance|_.  This method is based
   46on the length of common substrings.
   47
   48@author Giorgos Stoilos
   49@see    _|A string metric for ontology alignment|_ by Giorgos Stoilos,
   50        2005.
   51*/
   52
   53%!  isub(+Text1:text, +Text2:text, +Normalize:bool,
   54%!       -Similarity:float) is det.
   55%
   56%   Similarity is a measure for the distance between Text1 and
   57%   Text2.  E.g.
   58%
   59%     ==
   60%     ?- isub('E56.Language', 'languange', true, D).
   61%     D = 0.711348.
   62%     ==
   63%
   64%   If Normalize is =true=, isub/4   applies string normalization as
   65%   implemented by the original authors: Text1  and Text2 are mapped
   66%   to lowercase and the characters  "._   "  are removed. Lowercase
   67%   mapping is done  with  the   C-library  function  towlower(). In
   68%   general, the required normalization is   domain dependent and is
   69%   better left to the caller.  See e.g., unaccent_atom/2.
   70%
   71%   @arg Text1 and Text2 are either an atom, string or a list of
   72%   characters or character codes.
   73%   @arg Similarity is a float in the range [0.0..1.0], where 1.0
   74%   means _|most similar|_
   75
   76:- multifile sandbox:safe_primitive/1.   77
   78sandbox:safe_primitive(isub:isub(_,_,_,_))