net.christopherschultz.evaluator.function
Class UnsetVariableFunction

java.lang.Object
  extended by net.christopherschultz.evaluator.function.UnsetVariableFunction
All Implemented Interfaces:
Function

public class UnsetVariableFunction
extends Object
implements Function

Removes the value for any number of identifiers. Note that this is different than setting their values to null.

Usage: unset(id [id id id...])

Returns the old value for the last identifier mentioned or null if that identifier has no value.

Version:
$Revision: 1.2 $ $Date: 2008-06-20 22:58:48 $
Author:
Chris Schultz

Constructor Summary
UnsetVariableFunction()
           
 
Method Summary
 Object call(EvaluationContext ec, String functionName, List argumentExpressions)
          Invokes the function with the specified argument expressions in the specified evaluation context.
 
Methods inherited from class java.lang.Object
clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait
 

Constructor Detail

UnsetVariableFunction

public UnsetVariableFunction()
Method Detail

call

public Object call(EvaluationContext ec,
                   String functionName,
                   List argumentExpressions)
            throws EvaluationException
Description copied from interface: Function
Invokes the function with the specified argument expressions in the specified evaluation context.

Specified by:
call in interface Function
Parameters:
ec - The EvaluationContext in which this function is being called.
functionName - The name of the function being called.
argumentExpressions - The expressions which, when evaluated, result in the arguments to the function.
Returns:
The result of the function.
Throws:
EvaluationException - If there is a problem evaluating any of the arguments' expressions, or if there is an error during function execution.