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 java.util.Vector;
  
  import org.apache.bcel.generic.ConstantPoolGen;
  import org.apache.bcel.generic.ILOAD;
  import org.apache.bcel.generic.INVOKESTATIC;
  import org.apache.bcel.generic.InstructionList;
  import org.apache.xalan.xsltc.compiler.util.ClassGenerator;
  import org.apache.xalan.xsltc.compiler.util.FilterGenerator;
  import org.apache.xalan.xsltc.compiler.util.MethodGenerator;
  import org.apache.xalan.xsltc.compiler.util.StringType;
  import org.apache.xalan.xsltc.compiler.util.Type;
  import org.apache.xalan.xsltc.compiler.util.TypeCheckError;
  
  /**
   * @author Morten Jorgensen
   */
  final class LangCall extends FunctionCall {
      private Expression _lang;
      private Type _langType;
  
      /**
       * Get the parameters passed to function:
       *   lang(string)
       */
      public LangCall(QName fname, Vector arguments) {
  	super(fname, arguments);
  	_lang = argument(0);
      }
  
      /**
       *
       */
      public Type typeCheck(SymbolTable stable) throws TypeCheckError {
  	_langType = _lang.typeCheck(stable);
  	if (!(_langType instanceof StringType)) {
  	    _lang = new CastExpr(_lang, Type.String);
  	}
  	return Type.Boolean;
      }
  
      /**
       *
       */
      public Type getType() {
  	return(Type.Boolean);
      }
  
      /**
       * 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();
  
  	final int tst = cpg.addMethodref(BASIS_LIBRARY_CLASS,
  					 "testLanguage",
  					 "("+STRING_SIG+DOM_INTF_SIG+"I)Z");
  	_lang.translate(classGen,methodGen);
  	il.append(methodGen.loadDOM());
  	if (classGen instanceof FilterGenerator)
  	    il.append(new ILOAD(1));
  	else
  	    il.append(methodGen.loadContextNode());
  	il.append(new INVOKESTATIC(tst));
      }
  }
  