DCGLibrary.java

/*
 * #%L
 * prolobjectlink-jpi-jtrolog
 * %%
 * Copyright (C) 2012 - 2018 WorkLogic Project
 * %%
 * This program is free software: you can redistribute it and/or modify
 * it under the terms of the GNU Lesser General Public License as
 * published by the Free Software Foundation, either version 2.1 of the
 * License, or (at your option) any later version.
 * 
 * This program 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 Lesser Public License for more details.
 * 
 * You should have received a copy of the GNU General Lesser Public
 * License along with this program.  If not, see
 * <http://www.gnu.org/licenses/lgpl-2.1.html>.
 * #L%
 */
/*
 * tuProlog - Copyright (C) 2001-2002  aliCE team at deis.unibo.it
 *
 * This library is free software; you can redistribute it and/or
 * modify it under the terms of the GNU Lesser General Public
 * License as published by the Free Software Foundation; either
 * version 2.1 of the License, or (at your option) any later version.
 *
 * This library 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
 * Lesser General Public License for more details.
 *
 * You should have received a copy of the GNU Lesser General Public
 * License along with this library; if not, write to the Free Software
 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
 */
package jTrolog.lib;

/**
 * Library for managing DCGs. Library/Theory dependency: BasicLibrary
 */
@SuppressWarnings("serial")
public class DCGLibrary extends Library {

	public DCGLibrary() {
	}

	public String getTheory() {
		return ":- op(1200, xfx, '-->').  " + ":- op(200, xfx, '\\').  " +

		"phrase(Category,String,Left, SyntaxTree) :- dcg_parse(Category,String\\Left, SyntaxTree). " + "phrase(Category,[H|T], SyntaxTree) :- dcg_parse(Category,[H|T]\\[], SyntaxTree). " +

		"dcg_parse(A,Tokens,  A < SubTree) :- " + "not list(A), " + "(A --> B), " + "dcg_parse(B,Tokens, SubTree). " + "dcg_parse((A,B),(Tokens \\ Xs), [SubTreeA|SubTreeB]) :- "
				+ "dcg_parse(A,(Tokens \\ Tokens1), SubTreeA), " + "dcg_parse(B,(Tokens1 \\ Xs), SubTreeB). " + "dcg_parse(A, Tokens, A) :- " + "list(A), " + "dcg_connect(A,Tokens). "
				+ "dcg_parse({A},(Xs \\ Xs), []) :- A. " +

				"dcg_connect([],(Xs \\ Xs)). " + "dcg_connect([W|Ws],([W|Xs] \\ Ys)) :- dcg_connect(Ws,(Xs \\ Ys)). ";
	}
}