cyclops.companion

Class Functions

java.lang.Object

cyclops.companion.Functions

public class Functions
extends java.lang.Object

Collection of useful functions Also see Semigroups Monoids Predicates Curry CurryVariance CurryConsumer PartialApplicator Memoize FluentFunctions Fn1 Fn2 Fn3 Fn4

Constructor Summary

Constructors

Constructor and Description
Functions()

Method Summary

Modifier and Type	Method and Description
static <T,CRE> Fn1<? super T,? extends Higher<CRE,T>>	arrow(Monad<CRE> monad)
static <T,W extends WitnessType<W>> Fn1<? super T,? extends AnyM<W,T>>	arrowM(W w) KleisliM arrow : A function that takes an input value t and embeds it inside a monadic context.
static <T,W extends Unit<T>> Fn1<? super T,? extends W>	arrowUnit(Unit<?> w) Use an existing instance of a type that implements Unit to create a KleisliM arrow for that type
static <T,R> Fn1<? super T,? extends R>	constant(R r)
static <T> Fn1<? super java.lang.Iterable<T>,? extends T>	head()
static <T> Fn1<? super T,? extends T>	identity()
static <T> Fn1<? super T,? extends Maybe<? extends T>>	lifted()
static <T,R> java.util.function.Function<T,R>	narrow(java.util.function.Function<? super T,? extends R> fn)
static <T> Fn1<? super java.lang.Iterable<T>,? extends T>	reduce(Monoid<T> monoid)
static <T> Fn1<? super java.lang.Iterable<T>,? extends T>	tail()

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Constructor Detail

Functions

public Functions()

Method Detail

constant

public static final <T,R> Fn1<? super T,? extends R> constant(R r)

identity

public static final <T> Fn1<? super T,? extends T> identity()

lifted

public static final <T> Fn1<? super T,? extends Maybe<? extends T>> lifted()

arrowM

public static final <T,W extends WitnessType<W>> Fn1<? super T,? extends AnyM<W,T>> arrowM(W w)

KleisliM arrow : A function that takes an input value t and embeds it inside a monadic context. arrowM makes use of Witness Types to simulate higher-kinded types, and wraps the new monadic type inside an AnyM. AnyM makes use of sub-type polymorphism (Object Orientd inheritance) to define monadic functions (map / flatMap etc) on the returned Object (for parametric polymorphism use arrow(cyclops.typeclasses.monad.Monad<CRE>)

Type Parameters:

T - Value type to be embedded inside a monad

W - The type of the WitnessType (Witness.stream, Witness.Future, Witness.list and so on)

Parameters:

w - WitnessType Object: defines the returned monad type (e.g. see Witness.stream for HKT encoding for Streams)

Returns:

A function that can embed a value inisde a Monad

arrowUnit

public static final <T,W extends Unit<T>> Fn1<? super T,? extends W> arrowUnit(Unit<?> w)

Use an existing instance of a type that implements Unit to create a KleisliM arrow for that type

     
      ListX<Integer> myList = ListX.of(1,2,3);
            Fn1<? super String, ? extends ListX<String>> arrow = Functions.arrowUnit(myList);

            ListX<String> list = arrow.applyHKT("hello world");

     
 

Type Parameters:

T -

W -

Parameters:

w -

Returns:

arrow

public static final <T,CRE> Fn1<? super T,? extends Higher<CRE,T>> arrow(Monad<CRE> monad)

head

public static final <T> Fn1<? super java.lang.Iterable<T>,? extends T> head()

tail

public static final <T> Fn1<? super java.lang.Iterable<T>,? extends T> tail()

reduce

public static final <T> Fn1<? super java.lang.Iterable<T>,? extends T> reduce(Monoid<T> monoid)

narrow

public static <T,R> java.util.function.Function<T,R> narrow(java.util.function.Function<? super T,? extends R> fn)