net.christopherschultz.evaluator.function
Class IfFunction

java.lang.Object
  net.christopherschultz.evaluator.function.IfFunction

All Implemented Interfaces:

Function

public class IfFunction
extends Object
implements Function

Implements an if-then-else construct as a function.

Usage: if(predicate, then-expression, else-expression)

This function returns the result of the then-expression if the predicate evaluates to true, or returns the result of the else-expression if predicate evaluates to false. null is returned if the predicate returns null.

Version:

$Revision: 1.2 $ $Date: 2008-06-20 22:58:48 $

Author:

Chris Schultz

Constructor Summary

IfFunction()
Creates a new IfFunction object.

Method Summary

Object	call(EvaluationContext ec, String functionName, List argumentExpressions) Invokes the function with the specified argument expressions in the specified evaluation context.
String	toString()

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, wait, wait, wait

Constructor Detail

IfFunction

public IfFunction()

Creates a new IfFunction object.

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.

toString

public String toString()

Overrides:

toString in class Object