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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 }