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1   /*
2    $Id: MethodCallExpression.java,v 1.5 2004/07/10 03:31:37 bran 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
39   SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
40   HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
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.GroovyCodeVisitor;
51  import org.codehaus.groovy.classgen.AsmClassGenerator2;
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: 1.5 $
58   */
59  public class MethodCallExpression extends Expression {
60  
61      private Expression objectExpression;
62      private String method;
63      private Expression arguments;
64      private boolean safe;
65      private boolean implicitThis;
66  
67      public MetaMethod getMetaMethod() {
68          return metaMethod;
69      }
70  
71      private MetaMethod metaMethod = null;
72  
73      public MethodCallExpression(Expression objectExpression, String method, Expression arguments) {
74          this.objectExpression = objectExpression;
75          this.method = method;
76          this.arguments = arguments;
77      }
78  
79      public void visit(GroovyCodeVisitor visitor) {
80          visitor.visitMethodCallExpression(this);
81      }
82  
83      public Expression transformExpression(ExpressionTransformer transformer) {
84          MethodCallExpression answer =
85              new MethodCallExpression(transformer.transform(objectExpression), method, transformer.transform(arguments));
86          answer.setSafe(safe);
87          return answer;
88      }
89  
90      protected void resolveType(AsmClassGenerator2 resolver) {
91          this.objectExpression.resolve(resolver);
92          this.arguments.resolve(resolver);
93          resolver.resolve(this);
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     /***
125      * @return true if no object expression was specified otherwise if 
126      * some expression was specified for the object on which to evaluate
127      * the method then return false
128      */
129     public boolean isImplicitThis() {
130         return implicitThis;
131     }
132 
133     public void setImplicitThis(boolean implicitThis) {
134         this.implicitThis = implicitThis;
135     }
136 
137     public String toString() {
138         return super.toString()
139             + "[object: "
140             + objectExpression
141             + " method: "
142             + method
143             + " arguments: "
144             + arguments
145             + "]";
146     }
147 
148     public static boolean isSuperMethodCall(MethodCallExpression call) {
149         Expression expression = call.getObjectExpression();
150         if (expression instanceof VariableExpression) {
151             VariableExpression varExp = (VariableExpression) expression;
152             String variable = varExp.getVariable();
153             return variable.equals("super");
154         }
155         return false;
156     }
157 
158     public void setMethod(MetaMethod mmeth) {
159         this.metaMethod = mmeth;
160         super.setTypeClass(mmeth.getReturnType());
161     }
162 }