/*-------------------------------------------------------------------------*
 * GNU Prolog                                                              *
 *                                                                         *
 * Part  : Prolog buit-in predicates                                       *
 * File  : oper.pl                                                         *
 * Descr.: operator management                                             *
 * Author: Daniel Diaz                                                     *
 *                                                                         *
 * Copyright (C) 1999-2012 Daniel Diaz                                     *
 *                                                                         *
 * This file is part of GNU Prolog                                         *
 *                                                                         *
 * GNU Prolog is free software: you can redistribute it and/or             *
 * modify it under the terms of either:                                    *
 *                                                                         *
 *   - the GNU Lesser General Public License as published by the Free      *
 *     Software Foundation; either version 3 of the License, or (at your   *
 *     option) any later version.                                          *
 *                                                                         *
 * or                                                                      *
 *                                                                         *
 *   - the GNU General Public License as published by the Free             *
 *     Software Foundation; either version 2 of the License, or (at your   *
 *     option) any later version.                                          *
 *                                                                         *
 * or both in parallel, as here.                                           *
 *                                                                         *
 * GNU Prolog is distributed in the hope that it will be useful,           *
 * but WITHOUT ANY WARRANTY; without even the implied warranty of          *
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU       *
 * General Public License for more details.                                *
 *                                                                         *
 * You should have received copies of the GNU General Public License and   *
 * the GNU Lesser General Public License along with this program.  If      *
 * not, see http://www.gnu.org/licenses/.                                  *
 *-------------------------------------------------------------------------*/

/* $Id: oper.pl,v 1.18 2012/01/10 17:46:01 diaz Exp $ */

:-	built_in.

'$use_oper'.

op(Prec, Specif, Oper) :-
	set_bip_name(op, 3),
	'$check_atom_or_atom_list'(Oper),
	(   atom(Oper) ->
	    '$op2'(Prec, Specif, Oper)
	;   '$op1'(Oper, Specif, Prec)
	).


'$op1'([], _, _).

'$op1'([Oper|LOper], Specif, Prec) :-
	'$op2'(Prec, Specif, Oper),
	'$op1'(LOper, Specif, Prec).


'$op2'(Prec, Specif, Oper) :-
	'$call_c'('Pl_Op_3'(Prec, Specif, Oper)).




current_op(Prec, Specif, Oper) :-
	set_bip_name(current_op, 3),
	'$call_c_test'('Pl_Current_Op_3'(Prec, Specif, Oper)).


'$current_op_alt' :-                % used by C code to create a choice-point
	'$call_c_test'('Pl_Current_Op_Alt_0').
