cyclops.function

Interface Reducer<T,U>

Type Parameters:

T - Type this Reducer operates on

All Superinterfaces:

java.util.function.BiFunction<T,T,T>, BinaryFunction<T>, java.util.function.BinaryOperator<T>, Function2<T,T,T>, Monoid<T>, Semigroup<T>, To<Function2<T,T,T>>

public interface Reducer<T,U>
extends Monoid<T>

A class that extends Monoid to include a transform operation to transform to the type of the identity element first (to make reduction to immutable collections, for example, easier to work with in Java 8 Streams).

Nested Class Summary

Nested classes/interfaces inherited from interface cyclops.function.Function2

Function2.FunctionalOperations<T1,T2,R>

Method Summary

Modifier and Type	Method and Description
java.util.function.Function<? super U,T>	conversion()
default T	foldMap(java.util.stream.Stream<U> toReduce)
static <T,U> Reducer<T,U>	fromMonoid(Monoid<T> monoid, java.util.function.Function<? super U,T> mapper)
default java.util.stream.Stream<T>	mapToType(java.util.stream.Stream<U> stream) Map this reducer to the supported Type t.
static <T,U> Reducer<T,U>	narrow(Reducer<? extends T,U> reducer)
static <T,U> Reducer<T,U>	of(T zero, java.util.function.BiFunction<T,T,T> combiner, java.util.function.Function<? super U,T> mapToType)
static <T,U> Reducer<T,U>	of(T zero, java.util.function.Function<T,java.util.function.Function<T,T>> combiner, java.util.function.Function<? super U,T> mapToType)
default java.util.function.BiFunction<T,? super U,T>	reducer()

Methods inherited from interface cyclops.function.Monoid

fold, fold, foldLeft, foldLeft, foldLeft, foldLeftAsync, foldMap, foldMap, foldMap, foldMap, foldRight, foldRight, foldRight, foldRightAsync, fromBiFunction, of, of, zero

Methods inherited from interface cyclops.function.Semigroup

apply

Methods inherited from interface java.util.function.BinaryOperator

maxBy, minBy

Methods inherited from interface cyclops.function.Function2

andThen, apply, curry, flatMapFn, functionOps, lazyLift, lift, lift, liftTry, mapFn, memoize, memoize, memoizeAsync, memoizeAsync, of, reverse, λ, λv

Methods inherited from interface com.oath.cyclops.types.foldable.To

to

Method Detail

reducer

default java.util.function.BiFunction<T,? super U,T> reducer()

conversion

java.util.function.Function<? super U,T> conversion()

mapToType

default java.util.stream.Stream<T> mapToType(java.util.stream.Stream<U> stream)

Map this reducer to the supported Type t. Default implementation is a simple cast.

Parameters:

stream - Stream to convert

Returns:

Converted Stream

foldMap

default T foldMap(java.util.stream.Stream<U> toReduce)

fromMonoid

static <T,U> Reducer<T,U> fromMonoid(Monoid<T> monoid,
                                     java.util.function.Function<? super U,T> mapper)

of

static <T,U> Reducer<T,U> of(T zero,
                             java.util.function.BiFunction<T,T,T> combiner,
                             java.util.function.Function<? super U,T> mapToType)

of

static <T,U> Reducer<T,U> of(T zero,
                             java.util.function.Function<T,java.util.function.Function<T,T>> combiner,
                             java.util.function.Function<? super U,T> mapToType)

narrow

static <T,U> Reducer<T,U> narrow(Reducer<? extends T,U> reducer)