com.singularsys.jep.misc.nullwrapper.functions

Class NullWrappedIf

java.lang.Object

com.singularsys.jep.functions.PostfixMathCommand

com.singularsys.jep.functions.If

com.singularsys.jep.misc.nullwrapper.functions.NullWrappedIf

All Implemented Interfaces:

CallbackEvaluationI, NullWrappedFunctionI, PostfixMathCommandI, java.io.Serializable

public class NullWrappedIf
extends If
implements NullWrappedFunctionI

NullWrapped version of the if function. If the first argument is null then null is returned otherwise results are the same as the standard if function.

Since:

3.4

Author:

Richard Morris

See Also:

If, Serialized Form

Field Summary

Fields inherited from class com.singularsys.jep.functions.If

falseValue

Fields inherited from class com.singularsys.jep.functions.PostfixMathCommand

curNumberOfParameters, name, NaN, numberOfParameters

Constructor Summary

Constructors

Constructor and Description
NullWrappedIf()
NullWrappedIf(java.lang.Object falseValue)

Method Summary

Modifier and Type	Method and Description
java.lang.Object	evaluate(Node node, Evaluator pv) Performs some special evaluation on the node.
PostfixMathCommandI	getRoot() Get to function which this function wraps.

Methods inherited from class com.singularsys.jep.functions.If

checkNumberOfParameters, getFalseValue

Methods inherited from class com.singularsys.jep.functions.PostfixMathCommand

asArray, asBool, asDouble, asInt, asLong, asStrictInt, asString, getName, getNumberOfParameters, run, setCurNumberOfParameters, setName, toString, toString

Methods inherited from class java.lang.Object

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

Constructor Detail

NullWrappedIf

public NullWrappedIf()

NullWrappedIf

public NullWrappedIf(java.lang.Object falseValue)

Parameters:

falseValue -

Method Detail

getRoot

public PostfixMathCommandI getRoot()

Description copied from interface: NullWrappedFunctionI

Get to function which this function wraps.

Specified by:

getRoot in interface NullWrappedFunctionI

Returns:

the root function, may be "this".

evaluate

public java.lang.Object evaluate(Node node,
                                 Evaluator pv)
                          throws EvaluationException

Description copied from interface: CallbackEvaluationI

Performs some special evaluation on the node. This method has the responsibility for evaluating the children of the node and it should generally call

 pv.eval(node.jjtGetChild(i))   
 

for each child. The SymbolTable is not passed as an argument. This is because it is better practice to get and set variable values by using node.getVar().setValue() rather that through the SymbolTable with requires a hashtable lookup.

Specified by:

evaluate in interface CallbackEvaluationI

Overrides:

evaluate in class If

Parameters:

node - The current node

pv - The visitor, can be used evaluate the children

Returns:

the value after evaluation. This value will be passed to other functions higher up the node tree. The value can be any type including Double or Vector<Object>

Throws:

EvaluationException - if the calculation cannot be performed

See Also:

Evaluator