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)  2010-2015, 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(snowball,
   36          [ snowball/3,                  % +Algorithm, +In, -Out
   37            snowball_current_algorithm/1 % ?algorithm
   38          ]).   39:- use_module(library(sandbox)).   40
   41/** <module> The Snowball multi-lingual stemmer library
   42
   43This module encapsulates "The C version  of the libstemmer library" from
   44the Snowball project. This library  provides   stemmers  in a variety of
   45languages.  The interface to this library is very simple:
   46
   47    * snowball/3 stems a word with a given algorithm
   48    * snowball_current_algorithm/1 enumerates the provided algorithms.
   49
   50Here is an example:
   51
   52    ==
   53    ?- snowball(english, walking, S).
   54    S = walk.
   55    ==
   56
   57@see http://snowball.tartarus.org/
   58*/
   59
   60:- use_foreign_library(foreign(snowball)).   61
   62%!  snowball(+Algorithm, +Input, -Stem) is det.
   63%
   64%   Apply the Snowball Algorithm on Input and unify the result
   65%   (an atom) with Stem.
   66%
   67%   The implementation maintains a cache of stemmers for each thread
   68%   that  accesses  snowball/3,   providing    high-perfomance   and
   69%   thread-safety without locking.
   70%
   71%   @param  Algorithm is the (english) name for desired algorithm
   72%           or an 2 or 3 letter ISO 639 language code.
   73%   @param  Input is the word to be stemmed.  It is either an
   74%           atom, string or list of chars/codes.  The library
   75%           accepts Unicode characters.  Input must be
   76%           _lowercase_.  See downcase_atom/2.
   77%   @error domain_error(snowball_algorithm, Algorithm)
   78%   @error type_error(atom, Algorithm)
   79%   @error type_error(text, Input)
   80
   81%!  snowball_current_algorithm(?Algorithm) is nondet.
   82%
   83%   True if Algorithm is the official  name of an algorithm suported
   84%   by snowball/3. The predicate is =semidet= if Algorithm is given.
   85
   86term_expansion(snowball_current_algorithm(dummy), Clauses) :-
   87    snowball_algorithms(Algos),
   88    maplist(wrap, Algos, Clauses).
   89
   90wrap(X, snowball_current_algorithm(X)).
   91
   92snowball_current_algorithm(dummy).
   93
   94:- multifile
   95    sandbox:safe_primitive/1.   96
   97sandbox:safe_primitive(snowball:snowball(_,_,_))