Package com.ezylang.evalex.functions

Interface FunctionIfc

All Known Implementing Classes:

AbsFunction, AbstractFunction, AbstractMinMaxFunction, AcosFunction, AcosHFunction, AcosRFunction, AcotFunction, AcotHFunction, AcotRFunction, AsinFunction, AsinHFunction, AsinRFunction, Atan2Function, Atan2RFunction, AtanFunction, AtanHFunction, AtanRFunction, AverageFunction, CeilingFunction, CoalesceFunction, CosFunction, CosHFunction, CosRFunction, CotFunction, CotHFunction, CotRFunction, CscFunction, CscHFunction, CscRFunction, DateTimeFormatFunction, DateTimeNewFunction, DateTimeNowFunction, DateTimeParseFunction, DateTimeTodayFunction, DateTimeToEpochFunction, DegFunction, DurationFromMillisFunction, DurationNewFunction, DurationParseFunction, DurationToMillisFunction, FactFunction, FloorFunction, IfFunction, Log10Function, LogFunction, MaxFunction, MinFunction, NotFunction, RadFunction, RandomFunction, RoundFunction, SecFunction, SecHFunction, SecRFunction, SinFunction, SinHFunction, SinRFunction, SqrtFunction, StringContains, StringEndsWithFunction, StringFormatFunction, StringLeftFunction, StringLengthFunction, StringLowerFunction, StringMatchesFunction, StringRightFunction, StringSplitFunction, StringStartsWithFunction, StringSubstringFunction, StringTrimFunction, StringUpperFunction, SumFunction, SwitchFunction, TanFunction, TanHFunction, TanRFunction

public interface FunctionIfc

Interface that is required for all functions in a function dictionary for evaluation of expressions.

Method Summary

Modifier and Type	Method	Description
EvaluationValue	evaluate(Expression expression, Token functionToken, EvaluationValue... parameterValues)	Performs the function logic and returns an evaluation result.
default int	getCountOfNonVarArgParameters()	Returns the count of non-var-arg parameters defined by this function.
java.util.List<FunctionParameterDefinition>	getFunctionParameterDefinitions()	Returns the list of parameter definitions.
boolean	hasVarArgs()	Checks whether the function has a variable number of arguments parameter.
default boolean	isParameterLazy(int parameterIndex)	Checks if the parameter is a lazy parameter.
void	validatePreEvaluation(Token token, EvaluationValue... parameterValues)	Validates the evaluation parameters, called before the actual evaluation.

Method Detail

getFunctionParameterDefinitions

java.util.List<FunctionParameterDefinition> getFunctionParameterDefinitions()

Returns the list of parameter definitions. Is never empty or null.

Returns:

The parameter definition list.

evaluate

EvaluationValue evaluate(Expression expression,
                         Token functionToken,
                         EvaluationValue... parameterValues)
                  throws EvaluationException

Performs the function logic and returns an evaluation result.

Parameters:

expression - The expression, where this function is executed. Can be used to access the expression configuration.

functionToken - The function token from the parsed expression.

parameterValues - The parameter values.

Returns:

The evaluation result in form of a EvaluationValue.

Throws:

EvaluationException - In case there were problems during evaluation.

validatePreEvaluation

void validatePreEvaluation(Token token,
                           EvaluationValue... parameterValues)
                    throws EvaluationException

Validates the evaluation parameters, called before the actual evaluation.

Parameters:

token - The function token.

parameterValues - The parameter values

Throws:

EvaluationException - in case of any validation error

hasVarArgs

boolean hasVarArgs()

Checks whether the function has a variable number of arguments parameter.

Returns:

true or false:

isParameterLazy

default boolean isParameterLazy(int parameterIndex)

Checks if the parameter is a lazy parameter.

Parameters:

parameterIndex - The parameter index, starts at 0 for the first parameter. If the index is bigger than the list of parameter definitions, the last parameter definition will be checked.

Returns:

true if the specified parameter is defined as lazy.

getCountOfNonVarArgParameters

default int getCountOfNonVarArgParameters()

Returns the count of non-var-arg parameters defined by this function. If the function has var-args, the result is the count of parameter definitions - 1.

Returns:

the count of non-var-arg parameters defined by this function.