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1   /*
2    * reserved comment block
3    * DO NOT REMOVE OR ALTER!
4    */
5   /*
6    * Copyright 2001-2004 The Apache Software Foundation.
7    *
8    * Licensed under the Apache License, Version 2.0 (the "License");
9    * you may not use this file except in compliance with the License.
10   * You may obtain a copy of the License at
11   *
12   *     http://www.apache.org/licenses/LICENSE-2.0
13   *
14   * Unless required by applicable law or agreed to in writing, software
15   * distributed under the License is distributed on an "AS IS" BASIS,
16   * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
17   * See the License for the specific language governing permissions and
18   * limitations under the License.
19   */
20  /*
21   * $Id: StartsWithCall.java,v 1.2.4.1 2005/09/05 09:05:28 pvedula Exp $
22   */
23  
24  package com.sun.org.apache.xalan.internal.xsltc.compiler;
25  
26  import java.util.Vector;
27  
28  import com.sun.org.apache.bcel.internal.generic.ConstantPoolGen;
29  import com.sun.org.apache.bcel.internal.generic.INVOKEVIRTUAL;
30  import com.sun.org.apache.bcel.internal.generic.InstructionList;
31  import com.sun.org.apache.xalan.internal.xsltc.compiler.util.ClassGenerator;
32  import com.sun.org.apache.xalan.internal.xsltc.compiler.util.ErrorMsg;
33  import com.sun.org.apache.xalan.internal.xsltc.compiler.util.MethodGenerator;
34  import com.sun.org.apache.xalan.internal.xsltc.compiler.util.Type;
35  import com.sun.org.apache.xalan.internal.xsltc.compiler.util.TypeCheckError;
36  
37  /**
38   * @author Jacek Ambroziak
39   * @author Santiago Pericas-Geertsen
40   * @author Morten Jorgensen
41   */
42  final class StartsWithCall extends FunctionCall {
43  
44      private Expression _base = null;
45      private Expression _token = null;
46  
47      /**
48       * Create a starts-with() call - two arguments, both strings
49       */
50      public StartsWithCall(QName fname, Vector arguments) {
51          super(fname, arguments);
52      }
53  
54      /**
55       * Type check the two parameters for this function
56       */
57      public Type typeCheck(SymbolTable stable) throws TypeCheckError {
58  
59          // Check that the function was passed exactly two arguments
60          if (argumentCount() != 2) {
61              ErrorMsg err = new ErrorMsg(ErrorMsg.ILLEGAL_ARG_ERR,
62                                          getName(), this);
63              throw new TypeCheckError(err);
64          }
65  
66          // The first argument must be a String, or cast to a String
67          _base = argument(0);
68          Type baseType = _base.typeCheck(stable);
69          if (baseType != Type.String)
70              _base = new CastExpr(_base, Type.String);
71  
72          // The second argument must also be a String, or cast to a String
73          _token = argument(1);
74          Type tokenType = _token.typeCheck(stable);
75          if (tokenType != Type.String)
76              _token = new CastExpr(_token, Type.String);
77  
78          return _type = Type.Boolean;
79      }
80  
81      /**
82       * Compile the expression - leave boolean expression on stack
83       */
84      public void translate(ClassGenerator classGen, MethodGenerator methodGen) {
85          final ConstantPoolGen cpg = classGen.getConstantPool();
86          final InstructionList il = methodGen.getInstructionList();
87          _base.translate(classGen, methodGen);
88          _token.translate(classGen, methodGen);
89          il.append(new INVOKEVIRTUAL(cpg.addMethodref(STRING_CLASS,
90                                                       "startsWith",
91                                                       "("+STRING_SIG+")Z")));
92      }
93  }