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    1   /*
    2    $Id: MethodCallExpression.java,v 1.10 2006/01/19 00:06:51 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
    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.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: 1.10 $
    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          answer.setSourcePosition(this);
    94          return answer;
    95      }
    96
    97      public Expression getArguments() {
    98          return arguments;
    99      }
    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.getName();
    162             return variable.equals("super");
    163         }
    164         return false;
    165     }
    166
    167     public void setMethod(MetaMethod mmeth) {
    168         this.metaMethod = mmeth;
    169         super.setType(ClassHelper.make(mmeth.getReturnType()));
    170     }
    171 }