| /* |
| * @(#)$Id$ |
| * |
| * 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", |
| * nor may "Apache" appear in their name, without prior written |
| * permission of the Apache Software Foundation. |
| * |
| * 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 |
| * DISCLAIMED. IN NO EVENT SHALL THE APACHE SOFTWARE FOUNDATION OR |
| * 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 |
| * USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND |
| * 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 java.util.Vector; |
| import java.util.Enumeration; |
| import org.apache.xalan.xsltc.compiler.util.Type; |
| import org.apache.xalan.xsltc.compiler.util.ReferenceType; |
| import org.apache.bcel.generic.*; |
| import org.apache.xalan.xsltc.compiler.util.*; |
| |
| class FilterExpr extends Expression { |
| private Expression _primary; |
| private final Vector _predicates; |
| |
| public FilterExpr(Expression primary, Vector predicates) { |
| _primary = primary; |
| _predicates = predicates; |
| primary.setParent(this); |
| } |
| |
| protected Expression getExpr() { |
| if (_primary instanceof CastExpr) |
| return ((CastExpr)_primary).getExpr(); |
| else |
| return _primary; |
| } |
| |
| public void setParser(Parser parser) { |
| super.setParser(parser); |
| _primary.setParser(parser); |
| if (_predicates != null) { |
| final int n = _predicates.size(); |
| for (int i = 0; i < n; i++) { |
| final Expression exp = (Expression)_predicates.elementAt(i); |
| exp.setParser(parser); |
| exp.setParent(this); |
| } |
| } |
| } |
| |
| public String toString() { |
| return "filter-expr(" + _primary + ", " + _predicates + ")"; |
| } |
| |
| /** |
| * Type check a FilterParentPath. If the filter is not a node-set add a |
| * cast to node-set only if it is of reference type. This type coercion |
| * is needed for expressions like $x where $x is a parameter reference. |
| */ |
| public Type typeCheck(SymbolTable stable) throws TypeCheckError { |
| Type ptype = _primary.typeCheck(stable); |
| |
| if (ptype instanceof NodeSetType == false) { |
| if (ptype instanceof ReferenceType) { |
| _primary = new CastExpr(_primary, Type.NodeSet); |
| } |
| else { |
| throw new TypeCheckError(this); |
| } |
| } |
| |
| int n = _predicates.size(); |
| for (int i = 0; i < n; i++) { |
| Expression pred = (Expression)_predicates.elementAt(i); |
| pred.typeCheck(stable); |
| } |
| return _type = Type.NodeSet; |
| } |
| |
| /** |
| * Translate a filter expression by pushing the appropriate iterator |
| * onto the stack. |
| */ |
| public void translate(ClassGenerator classGen, MethodGenerator methodGen) { |
| if (_predicates.size() > 0) { |
| translatePredicates(classGen, methodGen); |
| } |
| else { |
| _primary.translate(classGen, methodGen); |
| _primary.startResetIterator(classGen, methodGen); |
| } |
| } |
| |
| /** |
| * Translate a sequence of predicates. |
| * Each predicate is translated by constructing an instance |
| * of <code>CurrentNodeListIterator</code> which is initialized from |
| * another iterator (recursive call), a filter and a closure |
| * (call to translate on the predicate) and "this". |
| */ |
| public void translatePredicates(ClassGenerator classGen, |
| MethodGenerator methodGen) { |
| final ConstantPoolGen cpg = classGen.getConstantPool(); |
| final InstructionList il = methodGen.getInstructionList(); |
| |
| if (_predicates.size() == 0) { |
| translate(classGen, methodGen); |
| } |
| else { |
| final int initCNLI = cpg.addMethodref(CURRENT_NODE_LIST_ITERATOR, |
| "<init>", |
| "("+NODE_ITERATOR_SIG+"Z"+ |
| CURRENT_NODE_LIST_FILTER_SIG + |
| NODE_SIG+TRANSLET_SIG+")V"); |
| |
| Predicate predicate = (Predicate)_predicates.lastElement(); |
| _predicates.remove(predicate); |
| |
| if (predicate.isNthPositionFilter()) { |
| final int start = cpg.addInterfaceMethodref(NODE_ITERATOR, |
| "setStartNode", |
| "(I)"+ |
| NODE_ITERATOR_SIG); |
| final int reset = cpg.addInterfaceMethodref(NODE_ITERATOR, |
| "reset", |
| "()"+ |
| NODE_ITERATOR_SIG); |
| translatePredicates(classGen, methodGen); // get the base itr. |
| predicate.translate(classGen, methodGen); // get the position |
| il.append(new INVOKEINTERFACE(start,2)); |
| il.append(new INVOKEINTERFACE(reset,1)); |
| |
| final int sngl = cpg.addMethodref(BASIS_LIBRARY_CLASS, |
| "getSingleNode", |
| "("+NODE_ITERATOR_SIG+")"+ |
| NODE_ITERATOR_SIG); |
| il.append(new INVOKESTATIC(sngl)); |
| } |
| else { |
| // create new CurrentNodeListIterator |
| il.append(new NEW(cpg.addClass(CURRENT_NODE_LIST_ITERATOR))); |
| il.append(DUP); |
| translatePredicates(classGen, methodGen); // recursive call |
| il.append(ICONST_1); |
| predicate.translate(classGen, methodGen); |
| il.append(methodGen.loadCurrentNode()); |
| il.append(classGen.loadTranslet()); |
| il.append(new INVOKESPECIAL(initCNLI)); |
| } |
| } |
| } |
| } |