src/org/apache/xalan/xsltc/compiler/LocationPathPattern.java

/*
 * @(#)$Id$
 *
 * The Apache Software License, Version 1.1
 *
 *
 * Copyright (c) 2001 The Apache Software Foundation.  All rights
 * reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 *
 * 1. Redistributions of source code must retain the above copyright
 *    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.
 *
 * 3. The end-user documentation included with the redistribution,
 *    if any, must include the following acknowledgment:
 *       "This product includes software developed by the
 *        Apache Software Foundation (http://www.apache.org/)."
 *    Alternately, this acknowledgment may appear in the software itself,
 *    if and wherever such third-party acknowledgments normally appear.
 *
 * 4. The names "Xalan" and "Apache Software Foundation" must
 *    not be used to endorse or promote products derived from this
 *    software without prior written permission. For written
 *    permission, please contact apache@apache.org.
 *
 * 5. Products derived from this software may not be called "Apache",
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 *
 * THIS SOFTWARE IS PROVIDED ``AS IS'' AND ANY EXPRESSED OR IMPLIED
 * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
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 * ITS CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
 * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF
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 * ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
 * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT
 * OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
 * SUCH DAMAGE.
 * ====================================================================
 *
 * This software consists of voluntary contributions made by many
 * individuals on behalf of the Apache Software Foundation and was
 * originally based on software copyright (c) 2001, Sun
 * Microsystems., http://www.sun.com.  For more
 * information on the Apache Software Foundation, please see
 * <http://www.apache.org/>.
 *
 * @author Jacek Ambroziak
 * @author Santiago Pericas-Geertsen
 * @author Morten Jorgensen
 *
 */

package org.apache.xalan.xsltc.compiler;

import org.apache.xalan.xsltc.compiler.util.Type;
import org.apache.xalan.xsltc.compiler.util.*;

public abstract class LocationPathPattern extends Pattern {
    private Template _template;
    private int _importPrecedence;
    private double _priority = Double.NaN;
    private int _position = 0;

    public Type typeCheck(SymbolTable stable) throws TypeCheckError {
	return Type.Void;		// TODO
    }

    public void translate(ClassGenerator classGen, MethodGenerator methodGen) {
	// TODO: What does it mean to translate a Pattern ?
    }
	
    public void setTemplate(final Template template) {
	_template = template;
	_priority = template.getPriority();
	_importPrecedence = template.getImportPrecedence();
	_position = template.getPosition();
    }
		
    public Template getTemplate() {
	return _template;
    }
		
    public final double getPriority() {
	return Double.isNaN(_priority) ? getDefaultPriority() : _priority;
    }
		
    public double getDefaultPriority() {
	return 0.5;
    }

    /**
     * This method is used by the Mode class to prioritise patterns and
     * template. This method is called for templates that are in the same
     * mode and that match on the same core pattern. The rules used are:
     *  o) first check precedence - highest precedence wins
     *  o) then check priority - highest priority wins
     *  o) then check the position - the template that occured last wins
     */
    public boolean noSmallerThan(LocationPathPattern other) {
	if (_importPrecedence > other._importPrecedence) {
	    return true;
	}
	else if (_importPrecedence == other._importPrecedence) {
	    if (_priority > other._priority) {
		return true;
	    }
	    else if (_priority == other._priority) {
		if (_position > other._position) {
		    return true;
		}
	    }
	}
	return false;
    }
    
    /** return last pattern (matching the current node) */
    public abstract StepPattern getKernelPattern();
	
    public abstract void reduceKernelPattern();
		
    public abstract boolean isWildcard();

    public String toString() {
	return "root()";
    }
}