com.aol.cyclops.hkt.instances.pcollections

Class PQueueInstances

java.lang.Object

com.aol.cyclops.hkt.instances.pcollections.PQueueInstances

public class PQueueInstances
extends java.lang.Object

Companion class for creating Type Class instances for working with PQueues

Constructor Summary

Constructors

Constructor and Description
PQueueInstances()

Method Summary

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

PQueueInstances

public PQueueInstances()

Method Detail

functor

public static <T,R> Functor<PQueueType.µ> functor()

Transform a list, mulitplying every element by 2

  
  PQueueType<Integer> list = PQueues.functor().map(i->i*2, PQueueType.widen(Arrays.asPQueue(1,2,3));
  
  //[2,4,6]
  
 
 
 

An example fluent api working with PQueues

  
   PQueueType<Integer> list = PQueues.unit()
                                       .unit("hello")
                                       .then(h->PQueues.functor().map((String v) ->v.length(), h))
                                       .convert(PQueueType::narrowK);
 
 
 

Returns:

A functor for PQueues

unit

public static <T> Unit<PQueueType.µ> unit()

  
 PQueueType<String> list = PQueues.unit()
                                     .unit("hello")
                                     .convert(PQueueType::narrowK);
        
        //Arrays.asPQueue("hello"))
 
 
 

Returns:

A factory for PQueues

zippingApplicative

public static <T,R> Applicative<PQueueType.µ> zippingApplicative()

  
 import static com.aol.cyclops.hkt.jdk.PQueueType.widen;
 import static com.aol.cyclops.util.function.Lambda.l1;
 import static java.util.Arrays.asPQueue;
 
       PQueues.zippingApplicative()
            .ap(widen(asPQueue(l1(this::multiplyByTwo))),widen(asPQueue(1,2,3)));
 
 //[2,4,6]
 
 

Example fluent API

  
 PQueueType<Function<Integer,Integer>> listFn =PQueues.unit()
                                                  .unit(Lambda.l1((Integer i) ->i*2))
                                                  .convert(PQueueType::narrowK);
        
        PQueueType<Integer> list = PQueues.unit()
                                      .unit("hello")
                                      .then(h->PQueues.functor().map((String v) ->v.length(), h))
                                      .then(h->PQueues.zippingApplicative().ap(listFn, h))
                                      .convert(PQueueType::narrowK);
        
        //Arrays.asPQueue("hello".length()*2))
 
 
 

Returns:

A zipper for PQueues

monad

public static <T,R> Monad<PQueueType.µ> monad()

  
 import static com.aol.cyclops.hkt.jdk.PQueueType.widen;
 PQueueType<Integer> list  = PQueues.monad()
                                      .flatMap(i->widen(PQueueX.range(0,i)), widen(Arrays.asPQueue(1,2,3)))
                                      .convert(PQueueType::narrowK);
 
 

Example fluent API

  
    PQueueType<Integer> list = PQueues.unit()
                                        .unit("hello")
                                        .then(h->PQueues.monad().flatMap((String v) ->PQueues.unit().unit(v.length()), h))
                                        .convert(PQueueType::narrowK);
        
        //Arrays.asPQueue("hello".length())
 
 
 

Returns:

Type class with monad functions for PQueues

monadZero

public static <T,R> MonadZero<PQueueType.µ> monadZero()

  
  PQueueType<String> list = PQueues.unit()
                                     .unit("hello")
                                     .then(h->PQueues.monadZero().filter((String t)->t.startsWith("he"), h))
                                     .convert(PQueueType::narrowK);
        
       //Arrays.asPQueue("hello"));
 
 
 

Returns:

A filterable monad (with default value)

monadPlus

public static <T> MonadPlus<PQueueType.µ> monadPlus()

  
  PQueueType<Integer> list = PQueues.<Integer>monadPlus()
                                      .plus(PQueueType.widen(Arrays.asPQueue()), PQueueType.widen(Arrays.asPQueue(10)))
                                      .convert(PQueueType::narrowK);
        //Arrays.asPQueue(10))
 
 
 

Returns:

Type class for combining PQueues by concatenation

monadPlus

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

  
  Monoid<PQueueType<Integer>> m = Monoid.of(PQueueType.widen(Arrays.asPQueue()), (a,b)->a.isEmpty() ? b : a);
        PQueueType<Integer> list = PQueues.<Integer>monadPlus(m)
                                      .plus(PQueueType.widen(Arrays.asPQueue(5)), PQueueType.widen(Arrays.asPQueue(10)))
                                      .convert(PQueueType::narrowK);
        //Arrays.asPQueue(5))
 
 
 

Parameters:

m - Monoid to use for combining PQueues

Returns:

Type class for combining PQueues

traverse

public static <C2,T> Traverse<PQueueType.µ> traverse()

Returns:

Type class for traversables with traverse / sequence operations

foldable

public static <T> Foldable<PQueueType.µ> foldable()

  
 int sum  = PQueues.foldable()
                        .foldLeft(0, (a,b)->a+b, PQueueType.widen(Arrays.asPQueue(1,2,3,4)));
        
        //10
 
 
 

Returns:

Type class for folding / reduction operations