001    /*
002     $Id: MethodCallExpression.java,v 1.7 2005/04/08 17:57:07 phk 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.GroovyCodeVisitor;
051    import org.codehaus.groovy.classgen.AsmClassGenerator;
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: 1.7 $
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        }
079    
080        public void visit(GroovyCodeVisitor visitor) {
081            visitor.visitMethodCallExpression(this);
082        }
083    
084        public Expression transformExpression(ExpressionTransformer transformer) {
085            MethodCallExpression answer =
086                new MethodCallExpression(transformer.transform(objectExpression), method, transformer.transform(arguments));
087            answer.setSafe(safe);
088            return answer;
089        }
090    
091        protected void resolveType(AsmClassGenerator resolver) {
092            this.objectExpression.resolve(resolver);
093            this.arguments.resolve(resolver);
094            resolver.resolve(this);
095        }
096    
097        public Expression getArguments() {
098            return arguments;
099        }
100    
101        public String getMethod() {
102            return method;
103        }
104    
105        public Expression getObjectExpression() {
106            return objectExpression;
107        }
108    
109        public String getText() {
110            return objectExpression.getText() + "." + method + arguments.getText();
111        }
112    
113        /**
114         * @return is this a safe method call, i.e. if true then if the source object is null
115         * then this method call will return null rather than throwing a null pointer exception
116         */
117        public boolean isSafe() {
118            return safe;
119        }
120    
121        public void setSafe(boolean safe) {
122            this.safe = safe;
123        }
124    
125        public boolean isSpreadSafe() {
126            return spreadSafe;
127        }
128    
129        public void setSpreadSafe(boolean value) {
130            spreadSafe = value;
131        }
132    
133        /**
134         * @return true if no object expression was specified otherwise if 
135         * some expression was specified for the object on which to evaluate
136         * the method then return false
137         */
138        public boolean isImplicitThis() {
139            return implicitThis;
140        }
141    
142        public void setImplicitThis(boolean implicitThis) {
143            this.implicitThis = implicitThis;
144        }
145    
146        public String toString() {
147            return super.toString()
148                + "[object: "
149                + objectExpression
150                + " method: "
151                + method
152                + " arguments: "
153                + arguments
154                + "]";
155        }
156    
157        public static boolean isSuperMethodCall(MethodCallExpression call) {
158            Expression expression = call.getObjectExpression();
159            if (expression instanceof VariableExpression) {
160                VariableExpression varExp = (VariableExpression) expression;
161                String variable = varExp.getVariable();
162                return variable.equals("super");
163            }
164            return false;
165        }
166    
167        public void setMethod(MetaMethod mmeth) {
168            this.metaMethod = mmeth;
169            super.setTypeClass(mmeth.getReturnType());
170        }
171    }