/*  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.

    Redistribution and use in source and binary forms, with or without
    modification, are permitted provided that the following conditions
    are met:

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       notice, this list of conditions and the following disclaimer.

    2. Redistributions in binary form must reproduce the above copyright
       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
    LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
    FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
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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:atomic, +Text2:atomic, +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.
%
%   @param  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(_,_,_,_)).