org.jfree.formula.function

Interface Function

All Superinterfaces:
Serializable
Known Implementing Classes:
AbsFunction, AndFunction, AverageFunction, ChooseFunction, DateDifFunction, DateFunction, DateValueFunction, DayFunction, EvenFunction, ExactFunction, FalseFunction, FindFunction, HasChangedFunction, HourFunction, IfFunction, IntFunction, IsBlankFunction, IsErrFunction, IsErrorFunction, IsEvenFunction, IsLogicalFunction, IsNaFunction, IsNonTextFunction, IsNumberFunction, IsOddFunction, IsRefFunction, IsTextFunction, LeftFunction, LenFunction, LowerFunction, MappedFunction, MidFunction, MonthFunction, NaFunction, NotFunction, NowFunction, OddFunction, OrFunction, ReplaceFunction, ReptFunction, RightFunction, SubstituteFunction, SumFunction, TextFunction, TFunction, TimeFunction, TodayFunction, TrimFunction, TrueFunction, UpperFunction, URLEncodeFunction, WeekDayFunction, XorFunction, YearFunction

public interface Function
extends Serializable

A function is an arbitary computation. A return value type is not available unless the function has been evaluated. Functions must be stateless, that means: Calling the same function with exactly the same parameters must always result in the same computed value.
Author:
Thomas Morgner

Method Summary

TypeValuePair
evaluate(FormulaContext context, ParameterCallback parameters)
String
getCanonicalName()

Method Details

evaluate

public TypeValuePair evaluate(FormulaContext context,
                              ParameterCallback parameters)
            throws EvaluationException,
                   TypeConversionException

getCanonicalName

public String getCanonicalName()