001    /*
002     $Id: MethodCallExpression.java,v 1.9 2005/11/13 16:42:09 blackdrag Exp $
003    
004     Copyright 2003 (C) James Strachan and Bob Mcwhirter. All Rights Reserved.
005    
006     Redistribution and use of this software and associated documentation
007     ("Software"), with or without modification, are permitted provided
008     that the following conditions are met:
009    
010     1. Redistributions of source code must retain copyright
011        statements and notices.  Redistributions must also contain a
012        copy of this document.
013    
014     2. Redistributions in binary form must reproduce the
015        above copyright notice, this list of conditions and the
016        following disclaimer in the documentation and/or other
017        materials provided with the distribution.
018    
019     3. The name "groovy" must not be used to endorse or promote
020        products derived from this Software without prior written
021        permission of The Codehaus.  For written permission,
022        please contact info@codehaus.org.
023    
024     4. Products derived from this Software may not be called "groovy"
025        nor may "groovy" appear in their names without prior written
026        permission of The Codehaus. "groovy" is a registered
027        trademark of The Codehaus.
028    
029     5. Due credit should be given to The Codehaus -
030        http://groovy.codehaus.org/
031    
032     THIS SOFTWARE IS PROVIDED BY THE CODEHAUS AND CONTRIBUTORS
033     ``AS IS'' AND ANY EXPRESSED OR IMPLIED WARRANTIES, INCLUDING, BUT
034     NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND
035     FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL
036     THE CODEHAUS OR ITS CONTRIBUTORS BE LIABLE FOR ANY DIRECT,
037     INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
038     (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
039     SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
040     HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
041     STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
042     ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED
043     OF THE POSSIBILITY OF SUCH DAMAGE.
044    
045     */
046    package org.codehaus.groovy.ast.expr;
047    
048    import groovy.lang.MetaMethod;
049    
050    import org.codehaus.groovy.ast.ClassHelper;
051    import org.codehaus.groovy.ast.GroovyCodeVisitor;
052    
053    /**
054     * A method call on an object or class
055     * 
056     * @author <a href="mailto:james@coredevelopers.net">James Strachan</a>
057     * @version $Revision: 1.9 $
058     */
059    public class MethodCallExpression extends Expression {
060    
061        private Expression objectExpression;
062        private String method;
063        private Expression arguments;
064        private boolean spreadSafe = false;
065        private boolean safe = false;
066        private boolean implicitThis;
067    
068        public MetaMethod getMetaMethod() {
069            return metaMethod;
070        }
071    
072        private MetaMethod metaMethod = null;
073    
074        public MethodCallExpression(Expression objectExpression, String method, Expression arguments) {
075            this.objectExpression = objectExpression;
076            this.method = method;
077            this.arguments = arguments;
078            //TODO: set correct type here
079            // if setting type and a methodcall is the last expresssion in a method,
080            // then the method will return null if the method itself is not void too!
081            // (in bytecode after call: aconst_null, areturn)
082            this.setType(ClassHelper.DYNAMIC_TYPE);
083        }
084    
085        public void visit(GroovyCodeVisitor visitor) {
086            visitor.visitMethodCallExpression(this);
087        }
088    
089        public Expression transformExpression(ExpressionTransformer transformer) {
090            MethodCallExpression answer =
091                new MethodCallExpression(transformer.transform(objectExpression), method, transformer.transform(arguments));
092            answer.setSafe(safe);
093            return answer;
094        }
095    
096        public Expression getArguments() {
097            return arguments;
098        }
099    
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    }