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1   /*
2    $Id: MethodCallExpression.java,v 1.9 2005/11/13 16:42:09 blackdrag Exp $
3   
4    Copyright 2003 (C) James Strachan and Bob Mcwhirter. All Rights Reserved.
5   
6    Redistribution and use of this software and associated documentation
7    ("Software"), with or without modification, are permitted provided
8    that the following conditions are met:
9   
10   1. Redistributions of source code must retain copyright
11      statements and notices.  Redistributions must also contain a
12      copy of this document.
13  
14   2. Redistributions in binary form must reproduce the
15      above copyright notice, this list of conditions and the
16      following disclaimer in the documentation and/or other
17      materials provided with the distribution.
18  
19   3. The name "groovy" must not be used to endorse or promote
20      products derived from this Software without prior written
21      permission of The Codehaus.  For written permission,
22      please contact info@codehaus.org.
23  
24   4. Products derived from this Software may not be called "groovy"
25      nor may "groovy" appear in their names without prior written
26      permission of The Codehaus. "groovy" is a registered
27      trademark of The Codehaus.
28  
29   5. Due credit should be given to The Codehaus -
30      http://groovy.codehaus.org/
31  
32   THIS SOFTWARE IS PROVIDED BY THE CODEHAUS AND CONTRIBUTORS
33   ``AS IS'' AND ANY EXPRESSED OR IMPLIED WARRANTIES, INCLUDING, BUT
34   NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND
35   FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL
36   THE CODEHAUS OR ITS CONTRIBUTORS BE LIABLE FOR ANY DIRECT,
37   INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
38   (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
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41   STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
42   ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED
43   OF THE POSSIBILITY OF SUCH DAMAGE.
44  
45   */
46  package org.codehaus.groovy.ast.expr;
47  
48  import groovy.lang.MetaMethod;
49  
50  import org.codehaus.groovy.ast.ClassHelper;
51  import org.codehaus.groovy.ast.GroovyCodeVisitor;
52  
53  /***
54   * A method call on an object or class
55   * 
56   * @author <a href="mailto:james@coredevelopers.net">James Strachan</a>
57   * @version $Revision: 1.9 $
58   */
59  public class MethodCallExpression extends Expression {
60  
61      private Expression objectExpression;
62      private String method;
63      private Expression arguments;
64      private boolean spreadSafe = false;
65      private boolean safe = false;
66      private boolean implicitThis;
67  
68      public MetaMethod getMetaMethod() {
69          return metaMethod;
70      }
71  
72      private MetaMethod metaMethod = null;
73  
74      public MethodCallExpression(Expression objectExpression, String method, Expression arguments) {
75          this.objectExpression = objectExpression;
76          this.method = method;
77          this.arguments = arguments;
78          //TODO: set correct type here
79          // if setting type and a methodcall is the last expresssion in a method,
80          // then the method will return null if the method itself is not void too!
81          // (in bytecode after call: aconst_null, areturn)
82          this.setType(ClassHelper.DYNAMIC_TYPE);
83      }
84  
85      public void visit(GroovyCodeVisitor visitor) {
86          visitor.visitMethodCallExpression(this);
87      }
88  
89      public Expression transformExpression(ExpressionTransformer transformer) {
90          MethodCallExpression answer =
91              new MethodCallExpression(transformer.transform(objectExpression), method, transformer.transform(arguments));
92          answer.setSafe(safe);
93          return answer;
94      }
95  
96      public Expression getArguments() {
97          return arguments;
98      }
99  
100     public String getMethod() {
101         return method;
102     }
103 
104     public Expression getObjectExpression() {
105         return objectExpression;
106     }
107 
108     public String getText() {
109         return objectExpression.getText() + "." + method + arguments.getText();
110     }
111 
112     /***
113      * @return is this a safe method call, i.e. if true then if the source object is null
114      * then this method call will return null rather than throwing a null pointer exception
115      */
116     public boolean isSafe() {
117         return safe;
118     }
119 
120     public void setSafe(boolean safe) {
121         this.safe = safe;
122     }
123 
124     public boolean isSpreadSafe() {
125         return spreadSafe;
126     }
127 
128     public void setSpreadSafe(boolean value) {
129         spreadSafe = value;
130     }
131 
132     /***
133      * @return true if no object expression was specified otherwise if 
134      * some expression was specified for the object on which to evaluate
135      * the method then return false
136      */
137     public boolean isImplicitThis() {
138         return implicitThis;
139     }
140 
141     public void setImplicitThis(boolean implicitThis) {
142         this.implicitThis = implicitThis;
143     }
144 
145     public String toString() {
146         return super.toString()
147             + "[object: "
148             + objectExpression
149             + " method: "
150             + method
151             + " arguments: "
152             + arguments
153             + "]";
154     }
155 
156     public static boolean isSuperMethodCall(MethodCallExpression call) {
157         Expression expression = call.getObjectExpression();
158         if (expression instanceof VariableExpression) {
159             VariableExpression varExp = (VariableExpression) expression;
160             String variable = varExp.getName();
161             return variable.equals("super");
162         }
163         return false;
164     }
165 
166     public void setMethod(MetaMethod mmeth) {
167         this.metaMethod = mmeth;
168         super.setType(ClassHelper.make(mmeth.getReturnType()));
169     }
170 }