csheets.core.formula
Interface Function

All Known Implementing Classes:

And, Average, Count, Do, Factorial, False, If, Not, NumericFunction, Or, Sum, True

public interface Function

A function that can be used in a formula.

Author:

Einar Pehrson

Method Summary

Value	applyTo(Expression[] args) Invokes the function using the given arguments and returns the result.
String	getIdentifier() Returns the operator's string identirifer.
FunctionParameter[]	getParameters() Returns the parameters of the function.
boolean	isVarArg() Returns whether the function accepts a variable number of arguments, i.e. whether the function's parameter list is unbounded.

Method Detail

getIdentifier

String getIdentifier()

Returns the operator's string identirifer.

Returns:

a string representation of the operator.

applyTo

Value applyTo(Expression[] args)
              throws IllegalValueTypeException

Invokes the function using the given arguments and returns the result.

Returns:

the result of the operation

Throws:

IllegalValueTypeException

getParameters

FunctionParameter[] getParameters()

Returns the parameters of the function.

Returns:

the parameters of the function

isVarArg

boolean isVarArg()

Returns whether the function accepts a variable number of arguments, i.e. whether the function's parameter list is unbounded.

Returns:

true if the function accepts a variable number of arguments