org.codehaus.groovy.ast.expr
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 
 




Since:
  
1.5
Author:
  
Jochen Theodorou








Constructor Summary
ElvisOperatorExpression(Expression base,
                        Expression falseExpression)



           
 



Method Summary




 Expression
transformExpression(ExpressionTransformer transformer)



          Return a copy of the expression calling the transformer on any nested expressions



 void
visit(GroovyCodeVisitor visitor)



           


 
Methods inherited from class org.codehaus.groovy.ast.expr.TernaryExpression
getBooleanExpression, getFalseExpression, getText, getTrueExpression, getType, toString
 
Methods inherited from class org.codehaus.groovy.ast.expr.Expression
setType, transformExpressions, transformExpressions
 
Methods inherited from class org.codehaus.groovy.ast.AnnotatedNode
addAnnotation, addAnnotations, getAnnotations, getAnnotations, getDeclaringClass, hasNoRealSourcePosition, isSynthetic, setDeclaringClass, setHasNoRealSourcePosition, setSynthetic
 
Methods inherited from class org.codehaus.groovy.ast.ASTNode
copyNodeMetaData, getColumnNumber, getLastColumnNumber, getLastLineNumber, getLineNumber, getNodeMetaData, putNodeMetaData, removeNodeMetaData, setColumnNumber, setLastColumnNumber, setLastLineNumber, setLineNumber, setNodeMetaData, setSourcePosition
 
Methods inherited from class java.lang.Object
clone, equals, finalize, getClass, hashCode, notify, notifyAll, wait, wait, wait
 





Constructor Detail



ElvisOperatorExpression
public ElvisOperatorExpression(Expression base,
                               Expression falseExpression)






Method Detail



visit
public void visit(GroovyCodeVisitor visitor)


Overrides:
visit in class TernaryExpression








transformExpression
public Expression transformExpression(ExpressionTransformer transformer)

Description copied from class: Expression
Return a copy of the expression calling the transformer on any nested expressions


Overrides:
transformExpression in class TernaryExpression