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.INVOKEVIRTUAL;
  import org.apache.bcel.generic.InstructionList;
  import org.apache.xalan.xsltc.compiler.util.ClassGenerator;
  import org.apache.xalan.xsltc.compiler.util.ErrorMsg;
  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
   * @author Morten Jorgensen
   */
  final class StartsWithCall extends FunctionCall {
  
      private Expression _base = null;
      private Expression _token = null;
  
      /**
       * Create a starts-with() call - two arguments, both strings
       */
      public StartsWithCall(QName fname, Vector arguments) {
  	super(fname, arguments);
      }
  
      /**
       * Type check the two parameters for this function
       */
      public Type typeCheck(SymbolTable stable) throws TypeCheckError {
  
  	// Check that the function was passed exactly two arguments
  	if (argumentCount() != 2) {
  	    ErrorMsg err = new ErrorMsg(ErrorMsg.ILLEGAL_ARG_ERR,
  					getName(), this);
  	    throw new TypeCheckError(err);
  	}
  
  	// The first argument must be a String, or cast to a String
  	_base = argument(0);
  	Type baseType = _base.typeCheck(stable);	
  	if (baseType != Type.String)
  	    _base = new CastExpr(_base, Type.String);
  
  	// The second argument must also be a String, or cast to a String
  	_token = argument(1);
  	Type tokenType = _token.typeCheck(stable);	
  	if (tokenType != Type.String)
  	    _token = new CastExpr(_token, Type.String);
  
  	return _type = Type.Boolean;
      }
  
      /**
       * Compile the expression - leave boolean expression on stack
       */
      public void translate(ClassGenerator classGen, MethodGenerator methodGen) {
  	final ConstantPoolGen cpg = classGen.getConstantPool();
  	final InstructionList il = methodGen.getInstructionList();
  	_base.translate(classGen, methodGen);
  	_token.translate(classGen, methodGen);
  	il.append(new INVOKEVIRTUAL(cpg.addMethodref(STRING_CLASS,
  						     "startsWith", 
  						     "("+STRING_SIG+")Z")));
      }
  }
  