Package science.aist.jack.stream

Class FunctionUtil

  • public final class FunctionUtil
extends Object

    Util class to provide different helper function for java.util.function

    Since:
    2.0
    Author:
    Andreas Pointner

    • Method Detail

      • emptyConsumer

        public static <T> Consumer<T> emptyConsumer()

        Returns an empty consumer

        This helps to avoid the creation of a huge amount of new consumer objects

        Type Parameters:
        T - of any type
        Returns:
        empty consumer, that does basically nothing.

      • emptyBiConsumer

        public static <T,​U> BiConsumer<T,​U> emptyBiConsumer()

        returns an empty bi consumer

        This helps to avoid the creation of a huge amount of new consumer objects

        Type Parameters:
        T - any type
        U - any type
        Returns:
        empty bi-consumer, that does nothing

      • identity

        public static <T> Function<T,​T> identity()

        Does the same as Function.identity() but does not always create a new lambda object, instead always returns the same one

        Type Parameters:
        T - any type
        Returns:
        a function that returns the input value as output

      • toFunction

        public static <T,​R> Function<T,​R> toFunction​(Function<T,​R> func)

        Some sort of hack to convert a method reference to a Function.

        So instead of casting anything to use it as a function: 

             Function<In, Out> func = (Function<In, Out>)obj::method
        you can use: 
             Function<In, Out> func = toFunction(obj::method);
        This is especially useful when using andThen: 
             Function<In, Out2> func = ((Function<In, Out>)obj::method).andThen(obj2:method2);
        simply use: 
             Function<In, Out2> func = toFunction(obj::method).andThen(obj2:method2);
        Type Parameters:
        T - the input type
        R - the result type
        Parameters:
        func - the function
        Returns:
        the converted function