com.aol.cyclops.hkt.instances.jdk

Class QueueInstances

java.lang.Object

com.aol.cyclops.hkt.instances.jdk.QueueInstances

public class QueueInstances
extends java.lang.Object

Companion class for creating Type Class instances for working with Queues

Constructor Summary

Constructors

Constructor and Description
QueueInstances()

Method Summary

Modifier and Type	Method and Description
static <T> Foldable<com.aol.cyclops.hkt.jdk.QueueType.µ>	foldable() int sum = Queues.foldable() .foldLeft(0, (a,b)->a+b, QueueType.widen(QueueX.of(1,2,3,4))); //10
static <T,R> Functor<com.aol.cyclops.hkt.jdk.QueueType.µ>	functor() Transform a queue, mulitplying every element by 2
static void	main(java.lang.String[] args)
static <T,R> Monad<com.aol.cyclops.hkt.jdk.QueueType.µ>	monad() import static com.aol.cyclops.hkt.jdk.QueueType.widen; QueueType<Integer> queue = Queues.monad() .flatMap(i->widen(QueueX.range(0,i)), widen(QueueX.of(1,2,3))) .convert(QueueType::narrowK);
static <T> MonadPlus<com.aol.cyclops.hkt.jdk.QueueType.µ>	monadPlus() QueueType<Integer> queue = Queues.<Integer>monadPlus() .plus(QueueType.widen(QueueX.of()), QueueType.widen(QueueX.of(10))) .convert(QueueType::narrowK); //QueueX.of(10))
static <T> MonadPlus<com.aol.cyclops.hkt.jdk.QueueType.µ>	monadPlus(com.aol.cyclops.Monoid<com.aol.cyclops.hkt.jdk.QueueType<T>> m) Monoid<QueueType<Integer>> m = Monoid.of(QueueType.widen(QueueX.of()), (a,b)->a.isEmpty() ? b : a); QueueType<Integer> queue = Queues.<Integer>monadPlus(m) .plus(QueueType.widen(QueueX.of(5)), QueueType.widen(QueueX.of(10))) .convert(QueueType::narrowK); //QueueX.of(5))
static <T,R> MonadZero<com.aol.cyclops.hkt.jdk.QueueType.µ>	monadZero() QueueType<String> queue = Queues.unit() .unit("hello") .then(h->Queues.monadZero().filter((String t)->t.startsWith("he"), h)) .convert(QueueType::narrowK); //QueueX.of("hello"));
static <C2,T> Traverse<com.aol.cyclops.hkt.jdk.QueueType.µ>	traverse()
static <T> Unit<com.aol.cyclops.hkt.jdk.QueueType.µ>	unit() QueueType<String> queue = Queues.unit() .unit("hello") .convert(QueueType::narrowK); //QueueX.of("hello"))
static <T,R> Applicative<com.aol.cyclops.hkt.jdk.QueueType.µ>	zippingApplicative() import static com.aol.cyclops.hkt.jdk.QueueType.widen; import static com.aol.cyclops.util.function.Lambda.l1; import static java.util.QueueX.of; Queues.zippingApplicative() .ap(widen(asQueue(l1(this::multiplyByTwo))),widen(asQueue(1,2,3))); //[2,4,6]

Methods inherited from class java.lang.Object

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

Constructor Detail

QueueInstances

public QueueInstances()

Method Detail

main

public static void main(java.lang.String[] args)

functor

public static <T,R> Functor<com.aol.cyclops.hkt.jdk.QueueType.µ> functor()

Transform a queue, mulitplying every element by 2

  
  QueueType<Integer> queue = Queues.functor().map(i->i*2, QueueType.widen(QueueX.of(1,2,3));
  
  //[2,4,6]
  
 
 
 

An example fluent api working with Queues

  
   QueueType<Integer> queue = Queues.unit()
                                       .unit("hello")
                                       .then(h->Queues.functor().map((String v) ->v.length(), h))
                                       .convert(QueueType::narrowK);
 
 
 

Returns:

A functor for Queues

unit

public static <T> Unit<com.aol.cyclops.hkt.jdk.QueueType.µ> unit()

  
 QueueType<String> queue = Queues.unit()
                                     .unit("hello")
                                     .convert(QueueType::narrowK);
        
        //QueueX.of("hello"))
 
 
 

Returns:

A factory for Queues

zippingApplicative

public static <T,R> Applicative<com.aol.cyclops.hkt.jdk.QueueType.µ> zippingApplicative()

  
 import static com.aol.cyclops.hkt.jdk.QueueType.widen;
 import static com.aol.cyclops.util.function.Lambda.l1;
 import static java.util.QueueX.of;
 
       Queues.zippingApplicative()
            .ap(widen(asQueue(l1(this::multiplyByTwo))),widen(asQueue(1,2,3)));
 
 //[2,4,6]
 
 

Example fluent API

  
 QueueType<Function<Integer,Integer>> queueFn =Queues.unit()
                                                  .unit(Lambda.l1((Integer i) ->i*2))
                                                  .convert(QueueType::narrowK);
        
        QueueType<Integer> queue = Queues.unit()
                                      .unit("hello")
                                      .then(h->Queues.functor().map((String v) ->v.length(), h))
                                      .then(h->Queues.zippingApplicative().ap(queueFn, h))
                                      .convert(QueueType::narrowK);
        
        //QueueX.of("hello".length()*2))
 
 
 

Returns:

A zipper for Queues

monad

public static <T,R> Monad<com.aol.cyclops.hkt.jdk.QueueType.µ> monad()

  
 import static com.aol.cyclops.hkt.jdk.QueueType.widen;
 QueueType<Integer> queue  = Queues.monad()
                                      .flatMap(i->widen(QueueX.range(0,i)), widen(QueueX.of(1,2,3)))
                                      .convert(QueueType::narrowK);
 
 

Example fluent API

  
    QueueType<Integer> queue = Queues.unit()
                                        .unit("hello")
                                        .then(h->Queues.monad().flatMap((String v) ->Queues.unit().unit(v.length()), h))
                                        .convert(QueueType::narrowK);
        
        //QueueX.of("hello".length())
 
 
 

Returns:

Type class with monad functions for Queues

monadZero

public static <T,R> MonadZero<com.aol.cyclops.hkt.jdk.QueueType.µ> monadZero()

  
  QueueType<String> queue = Queues.unit()
                                     .unit("hello")
                                     .then(h->Queues.monadZero().filter((String t)->t.startsWith("he"), h))
                                     .convert(QueueType::narrowK);
        
       //QueueX.of("hello"));
 
 
 

Returns:

A filterable monad (with default value)

monadPlus

public static <T> MonadPlus<com.aol.cyclops.hkt.jdk.QueueType.µ> monadPlus()

  
  QueueType<Integer> queue = Queues.<Integer>monadPlus()
                                      .plus(QueueType.widen(QueueX.of()), QueueType.widen(QueueX.of(10)))
                                      .convert(QueueType::narrowK);
        //QueueX.of(10))
 
 
 

Returns:

Type class for combining Queues by concatenation

monadPlus

public static <T> MonadPlus<com.aol.cyclops.hkt.jdk.QueueType.µ> monadPlus(com.aol.cyclops.Monoid<com.aol.cyclops.hkt.jdk.QueueType<T>> m)

  
  Monoid<QueueType<Integer>> m = Monoid.of(QueueType.widen(QueueX.of()), (a,b)->a.isEmpty() ? b : a);
        QueueType<Integer> queue = Queues.<Integer>monadPlus(m)
                                      .plus(QueueType.widen(QueueX.of(5)), QueueType.widen(QueueX.of(10)))
                                      .convert(QueueType::narrowK);
        //QueueX.of(5))
 
 
 

Parameters:

m - Monoid to use for combining Queues

Returns:

Type class for combining Queues

traverse

public static <C2,T> Traverse<com.aol.cyclops.hkt.jdk.QueueType.µ> traverse()

Returns:

Type class for traversables with traverse / sequence operations

foldable

public static <T> Foldable<com.aol.cyclops.hkt.jdk.QueueType.µ> foldable()

  
 int sum  = Queues.foldable()
                        .foldLeft(0, (a,b)->a+b, QueueType.widen(QueueX.of(1,2,3,4)));
        
        //10
 
 
 

Returns:

Type class for folding / reduction operations