com.singularsys.jep.functions
Class PostfixMathCommand

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

All Implemented Interfaces:

PostfixMathCommandI, java.io.Serializable

Direct Known Subclasses:

Abs, Add, ArcCosine, ArcCosineH, ArcSine, ArcSineH, ArcTangent, ArcTangent2, ArcTanH, Arg, Assign, Average, BigDecAdd, BigDecDiv, BigDecMod, BigDecMul, BigDecNegate, BigDecPow, BigDecRelational, BigDecSub, Binomial, Ceil, Comparative, ComplexPFMC, Conjugate, Cosine, CosineH, Cross, Divide, Dot, Ele, Exp, ExtendedOperatorSet.Factorial, Floor, If, Imaginary, LazyLogical, List, Logarithm, LogBase2, Logical, MacroFunction, MinMax, Modulus, Multiply, NaturalLogarithm, Not, Polar, Power, Random, Real, Round, Sine, SineH, SquareRoot, Str, StrictNaturalLogarithm, Subtract, Sum, Tangent, TanH, UMinus

public abstract class PostfixMathCommand
extends java.lang.Object
implements PostfixMathCommandI, java.io.Serializable

Function classes extend this class. It is an implementation of the PostfixMathCommandI interface.

It includes a numberOfParameters member, that is checked when parsing the expression. This member should be initialized to an appropriate value for all classes extending this class. If an arbitrary number of parameters should be allowed, initialize this member to -1.

See Also:

Serialized Form

Field Summary

protected int	curNumberOfParameters Number of parameters to be used for the next run() invocation.
protected int	numberOfParameters Number of parameters a the function requires.

Constructor Summary

PostfixMathCommand()
Creates a new PostfixMathCommand class.

PostfixMathCommand(int nParam)
Creates a new PostfixMathCommand class.

Method Summary

boolean	checkNumberOfParameters(int n) Checks the number of parameters of the function.
protected void	checkStack(java.util.Stack inStack) Check whether the stack is not null, throw a EvaluationException if it is.
int	getNumberOfParameters() Return the required number of parameters.
void	setCurNumberOfParameters(int n) Sets the number of current number of parameters used in the next call of run().

Methods inherited from class java.lang.Object

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

Methods inherited from interface com.singularsys.jep.PostfixMathCommandI

run

Field Detail

numberOfParameters

protected int numberOfParameters

Number of parameters a the function requires. Initialize this value to -1 if any number of parameters should be allowed.

curNumberOfParameters

protected transient int curNumberOfParameters

Number of parameters to be used for the next run() invocation. Applies only if the required umber of parameters is variable (numberOfParameters = -1).

Constructor Detail

PostfixMathCommand

public PostfixMathCommand()

Creates a new PostfixMathCommand class.

PostfixMathCommand

public PostfixMathCommand(int nParam)

Creates a new PostfixMathCommand class.

Parameters:

nParam - number of parameters for the function

Method Detail

checkStack

protected void checkStack(java.util.Stack inStack)
                   throws EvaluationException

Check whether the stack is not null, throw a EvaluationException if it is.

Throws:

EvaluationException

getNumberOfParameters

public int getNumberOfParameters()

Return the required number of parameters.

Specified by:

getNumberOfParameters in interface PostfixMathCommandI

setCurNumberOfParameters

public void setCurNumberOfParameters(int n)

Sets the number of current number of parameters used in the next call of run(). This method is only called when the reqNumberOfParameters is -1.

Specified by:

setCurNumberOfParameters in interface PostfixMathCommandI

checkNumberOfParameters

public boolean checkNumberOfParameters(int n)

Checks the number of parameters of the function. Functions which set numberOfParameter=-1 should overload this method

Specified by:

checkNumberOfParameters in interface PostfixMathCommandI

Parameters:

n - number of parameters function will be called with.

Returns:

false if an illegal number of parameters is supplied, true otherwise.