/*  Part of SWI-Prolog

    Author:        Jan Wielemaker
    E-mail:        J.Wielemaker@vu.nl
    WWW:           http://www.swi-prolog.org
    Copyright (c)  2011-2014, VU University Amsterdam
    All rights reserved.

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    modification, are permitted provided that the following conditions
    are met:

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       notice, this list of conditions and the following disclaimer.

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       notice, this list of conditions and the following disclaimer in
       the documentation and/or other materials provided with the
       distribution.

    THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
    "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
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*/

:- module(isub,
          [ isub/4                      % +Text1, +Text2, +Normalize, -Distance
          ]).


:- use_foreign_library(foreign(isub)).

/** <module> isub: a string similarity measure

The library(isub) implements a similarity measure between strings, i.e.,
something similar to the _|Levenshtein distance|_.  This method is based
on the length of common substrings.

@author Giorgos Stoilos
@see    _|A string metric for ontology alignment|_ by Giorgos Stoilos,
        2005.
*/

%!  isub(+Text1:text, +Text2:text, +Normalize:bool,
%!       -Similarity:float) is det.
%
%   Similarity is a measure for the distance between Text1 and
%   Text2.  E.g.
%
%     ==
%     ?- isub('E56.Language', 'languange', true, D).
%     D = 0.711348.
%     ==
%
%   If Normalize is =true=, isub/4   applies string normalization as
%   implemented by the original authors: Text1  and Text2 are mapped
%   to lowercase and the characters  "._   "  are removed. Lowercase
%   mapping is done  with  the   C-library  function  towlower(). In
%   general, the required normalization is   domain dependent and is
%   better left to the caller.  See e.g., unaccent_atom/2.
%
%   @arg Text1 and Text2 are either an atom, string or a list of
%   characters or character codes.
%   @arg Similarity is a float in the range [0.0..1.0], where 1.0
%   means _|most similar|_

:- multifile sandbox:safe_primitive/1.

sandbox:safe_primitive(isub:isub(_,_,_,_)).