code: /*
   * Licensed to the Apache Software Foundation (ASF) under one
   * or more contributor license agreements. See the NOTICE file
   * distributed with this work for additional information
   * regarding copyright ownership. The ASF licenses this file
   * to you under the Apache License, Version 2.0 (the  "License");
   * you may not use this file except in compliance with the License.
   * You may obtain a copy of the License at
   *
   *     http://www.apache.org/licenses/LICENSE-2.0
   *
   * Unless required by applicable law or agreed to in writing, software
   * distributed under the License is distributed on an "AS IS" BASIS,
   * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
   * See the License for the specific language governing permissions and
   * limitations under the License.
   */
  /*
   * $Id$
   */
  
  package org.apache.xalan.xsltc.compiler;
  
  import org.apache.bcel.generic.ConstantPoolGen;
  import org.apache.bcel.generic.GOTO;
  import org.apache.bcel.generic.IFNE;
  import org.apache.bcel.generic.INVOKEVIRTUAL;
  import org.apache.bcel.generic.InstructionList;
  import org.apache.bcel.generic.PUSH;
  import org.apache.xalan.xsltc.compiler.util.ClassGenerator;
  import org.apache.xalan.xsltc.compiler.util.MethodGenerator;
  import org.apache.xalan.xsltc.compiler.util.Type;
  import org.apache.xalan.xsltc.compiler.util.TypeCheckError;
  
  /**
   * @author Jacek Ambroziak
   * @author Santiago Pericas-Geertsen
   */
  abstract class IdKeyPattern extends LocationPathPattern {
  
      protected RelativePathPattern _left = null;;
      private String _index = null;
      private String _value = null;;
  
      public IdKeyPattern(String index, String value) {
  	_index = index;
  	_value = value;
      }
  
      public String getIndexName() {
  	return(_index);
      }
  
      public Type typeCheck(SymbolTable stable) throws TypeCheckError {
  	return Type.NodeSet;
      }
      
      public boolean isWildcard() {
  	return false;
      }
      
      public void setLeft(RelativePathPattern left) {
  	_left = left;
      }
  
      public StepPattern getKernelPattern() {
  	return(null);
      }
      
      public void reduceKernelPattern() { }
  
      public String toString() {
  	return "id/keyPattern(" + _index + ", " + _value + ')';
      }
  
      /**
       * This method is called when the constructor is compiled in
       * Stylesheet.compileConstructor() and not as the syntax tree is traversed.
       */
      public void translate(ClassGenerator classGen,
  			  MethodGenerator methodGen) {
  
  	final ConstantPoolGen cpg = classGen.getConstantPool();
  	final InstructionList il = methodGen.getInstructionList();
  
  	// Returns the KeyIndex object of a given name
  	final int getKeyIndex = cpg.addMethodref(TRANSLET_CLASS,
  						 "getKeyIndex",
  						 "(Ljava/lang/String;)"+
  						 KEY_INDEX_SIG);
  	
  	// Initialises a KeyIndex to return nodes with specific values
  	final int lookupId = cpg.addMethodref(KEY_INDEX_CLASS,
  					      "containsID",
  					      "(ILjava/lang/Object;)I");
  	final int lookupKey = cpg.addMethodref(KEY_INDEX_CLASS,
  					       "containsKey",
  					       "(ILjava/lang/Object;)I");
  	final int getNodeIdent = cpg.addInterfaceMethodref(DOM_INTF,
  							   "getNodeIdent",
  							   "(I)"+NODE_SIG);				       
  
  	// Call getKeyIndex in AbstractTranslet with the name of the key
  	// to get the index for this key (which is also a node iterator).
  	il.append(classGen.loadTranslet());
  	il.append(new PUSH(cpg,_index));
  	il.append(new INVOKEVIRTUAL(getKeyIndex));
  	
  	// Now use the value in the second argument to determine what nodes
  	// the iterator should return.
  	il.append(SWAP);
  	il.append(new PUSH(cpg,_value));
  	if (this instanceof IdPattern)
  	{
  	    il.append(new INVOKEVIRTUAL(lookupId));
  	}
  	else
  	{
  	    il.append(new INVOKEVIRTUAL(lookupKey));
  	}
  
  	_trueList.add(il.append(new IFNE(null)));
  	_falseList.add(il.append(new GOTO(null)));
      }
  
  }
  
  