cyclops.function

Interface Monoid<T>

Type Parameters:

T -

All Superinterfaces:

java.util.function.BiFunction<T,T,T>, BinaryFn<T>, java.util.function.BinaryOperator<T>, Fn2<T,T,T>, org.jooq.lambda.function.Function2<T,T,T>, Semigroup<T>

All Known Subinterfaces:

Reducer<T>

public interface Monoid<T>
extends Semigroup<T>

An interface that represents a Monoid https://en.wikipedia.org/wiki/Monoid#Monoids_in_computer_science Also inteded for use with Java 8 Streams (reduce method) Practically the method signature to reduce matches the Monoid interface Monoids could regrarded as immutable equivalents to JDK Collectors for Immutable Reduction

Nested Class Summary

Nested classes/interfaces inherited from interface cyclops.function.Fn2

Fn2.FunctionalOperations<T1,T2,R>

Method Summary

Modifier and Type	Method and Description
static <T> Monoid<T>	fromBiFunction(T zero, java.util.function.BiFunction<T,T,T> combiner) Construct a Monoid from the supplied identity element and combining function
static <T> Monoid<T>	of(T zero, java.util.function.Function<T,java.util.function.Function<T,T>> combiner) Construct a Monoid from the supplied identity element and combining function
static <T> Monoid<T>	of(T zero, Semigroup<T> group) Construct a Monoid from the supplied identity element and Semigroup (combiner)
default T	reduce(java.util.stream.Stream<T> toReduce) Perform a reduction operation on the supplied Stream
T	zero() An element that when provided as a parameter to the combiner with another value, results in the other value being returned e.g.

Methods inherited from interface cyclops.function.Semigroup

apply

Methods inherited from interface java.util.function.BinaryOperator

maxBy, minBy

Methods inherited from interface cyclops.function.Fn2

andThen, apply, curry, fnOps, lift, lift, liftF, liftOpt, liftTry, memoize, memoize, reverse, λ, λv

Methods inherited from interface org.jooq.lambda.function.Function2

apply, applyPartially, applyPartially, applyPartially, applyPartially, curry, curry, curry, curry, from, toBiFunction

Method Detail

zero

T zero()

An element that when provided as a parameter to the combiner with another value, results in the other value being returned e.g.

  0  + 1  = 1
  
  0 is zero()
  
  1 * 2 = 2
  
   1 is zero()
   
   "" + "hello" = "hello"
   
  "" is zero()
  

Returns:

Identity element

reduce

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

Perform a reduction operation on the supplied Stream

Parameters:

toReduce - Stream to reduce

Returns:

Reduced value

of

static <T> Monoid<T> of(T zero,
                        Semigroup<T> group)

Construct a Monoid from the supplied identity element and Semigroup (combiner)

Parameters:

zero - Identity element (@see zero()

group - Combining function or Semigroup

Returns:

Monoid consisting of the supplied identity element and combiner

See Also:

Semigroups

of

static <T> Monoid<T> of(T zero,
                        java.util.function.Function<T,java.util.function.Function<T,T>> combiner)

Construct a Monoid from the supplied identity element and combining function

Parameters:

zero - Identity element (@see zero()

combiner - Combining function

Returns:

Monoid consisting of the supplied identity element and combiner

fromBiFunction

static <T> Monoid<T> fromBiFunction(T zero,
                                    java.util.function.BiFunction<T,T,T> combiner)

Construct a Monoid from the supplied identity element and combining function

Parameters:

zero - Identity element (@see zero()

combiner - Combining function

Returns:

Monoid consisting of the supplied identity element and combiner