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org.codehaus.groovy.ast.expr
[Java] Class ElvisOperatorExpression

java.lang.Object
  org.codehaus.groovy.ast.ASTNode
      org.codehaus.groovy.ast.AnnotatedNode
          org.codehaus.groovy.ast.expr.Expression
              org.codehaus.groovy.ast.expr.TernaryExpression
                  org.codehaus.groovy.ast.expr.ElvisOperatorExpression

public class ElvisOperatorExpression
extends TernaryExpression

Represents a short ternary expression x ?: y, which is equal to 

 def truePart = x
 def booleanPart = truePart as boolean
 booleanPart? truePart : y
Even if x is no atomic expression, x will be evaluated only once. Example: 
 class Foo { 
   def index=0 
   def getX(){ index++; return index }
 }
 def foo = new Foo()
 def result = foo.x ?: "false case" 
 assert foo.index == 1
 assert result == 1 
 
 
Authors:
Jochen Theodorou
Since:
1.5



































    

    

    
    Constructor Summary
    

    
        

        
            ElvisOperatorExpression(Expression base, Expression falseExpression)
            

            

        		
        

    
    

     






    

    

    
    Method Summary
    

    
        

        
            Expression
        
        
            transformExpression(ExpressionTransformer transformer)
            

            

        		
        

    
        

        
            void
        
        
            visit(GroovyCodeVisitor visitor)
            

            

        		
        

    
    

     


                

                Methods inherited from class TernaryExpression
                

                
getBooleanExpression, getFalseExpression, getText, getTrueExpression, getType, toString, transformExpression, visit

                

                 

                

                Methods inherited from class Expression
                

                
getType, setType, transformExpression, transformExpressions, transformExpressions

                

                 

                

                Methods inherited from class AnnotatedNode
                

                
addAnnotation, addAnnotations, getAnnotations, getAnnotations, getDeclaringClass, hasNoRealSourcePosition, isSynthetic, setDeclaringClass, setHasNoRealSourcePosition, setSynthetic

                

                 

                

                Methods inherited from class ASTNode
                

                
copyNodeMetaData, getColumnNumber, getLastColumnNumber, getLastLineNumber, getLineNumber, getNodeMetaData, getText, putNodeMetaData, removeNodeMetaData, setColumnNumber, setLastColumnNumber, setLastLineNumber, setLineNumber, setNodeMetaData, setSourcePosition, visit

                

                 

                

                Methods inherited from class java.lang.Object
                

                
java.lang.Object#wait(long), java.lang.Object#wait(long, int), java.lang.Object#wait(), java.lang.Object#equals(java.lang.Object), java.lang.Object#toString(), java.lang.Object#hashCode(), java.lang.Object#getClass(), java.lang.Object#notify(), java.lang.Object#notifyAll()

                

                 




























    

    

    
    Constructor Detail
    

    

    
        

        ElvisOperatorExpression

        
public ElvisOperatorExpression(Expression base, Expression falseExpression)

        

        

        

        

        

        

    
     






    

    

    
    Method Detail
    

    

    
        

        transformExpression

        
public Expression transformExpression(ExpressionTransformer transformer)

        

        

        

        

        

        

    
        

        visit

        
public void visit(GroovyCodeVisitor visitor)

        

        

        

        

        

        

    
     




Groovy Documentation