com.singularsys.jep.functions
Class Assign

java.lang.Object
  com.singularsys.jep.functions.PostfixMathCommand
      com.singularsys.jep.functions.Assign

All Implemented Interfaces:

CallbackEvaluationI, PostfixMathCommandI, java.io.Serializable

public class Assign
extends PostfixMathCommand
implements CallbackEvaluationI

An assignment operator so we can do x=3+4. This function implements the CallbackEvaluationI interface so that it handles setting the value of a variable. Any Variable or functions which implements LValueI can appear on the left hand side of the equation.

Author:

Rich Morris Created on 18-Nov-2003

See Also:

Serialized Form

Nested Class Summary

Nested classes/interfaces inherited from interface com.singularsys.jep.functions.CallbackEvaluationI

CallbackEvaluationI.Runnable

Field Summary

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

curNumberOfParameters, name, NaN, numberOfParameters

Constructor Summary

Assign()

Method Summary

java.lang.Object	evaluate(Node node, Evaluator pv) For assignment set the value of the variable on the lhs to value returned by evaluating the right-hand side.
void	run(java.util.Stack<java.lang.Object> aStack) Run the function on the stack.

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

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

Methods inherited from class java.lang.Object

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

Constructor Detail

Assign

public Assign()

Method Detail

evaluate

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

For assignment set the value of the variable on the lhs to value returned by evaluating the right-hand side.

Specified by:

evaluate in interface CallbackEvaluationI

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

See Also:

Evaluator

run

public void run(java.util.Stack<java.lang.Object> aStack)
         throws EvaluationException

Description copied from interface: PostfixMathCommandI

Run the function on the stack. Pops the arguments from the stack, and pushes the result on the top of the stack.

Specified by:

run in interface PostfixMathCommandI

Throws:

EvaluationException