com.aol.cyclops.control.monads.transformers

Class XorT<T>

java.lang.Object

com.aol.cyclops.control.monads.transformers.XorT<T>

Type Parameters:

T - The type contained on the Xor within

public class XorT<T>
extends java.lang.Object

Monad transformer for JDK Xor XorT consists of an AnyM instance that in turns wraps anoter Monad type that contains an Xor XorT>>> XorT allows the deeply wrapped Xor to be manipulating within it's nested /contained context

Method Summary

Modifier and Type	Method and Description
XorT<T>	filter(java.util.function.Predicate<? super T> test) Filter the wrapped Xor
<B> XorT<B>	flatMap(java.util.function.Function<? super T,XorT<? extends B>> f) Flat Map the wrapped Xor
static <A> XorT<A>	fromAnyM(AnyM<A> anyM) Construct an XorT from an AnyM that contains a monad type that contains type other than Xor The values in the underlying monad will be mapped to Xor
static <U,R> java.util.function.Function<XorT<U>,XorT<R>>	lift(java.util.function.Function<? super U,? extends R> fn) Lift a function into one that accepts and returns an XorT This allows multiple monad types to add functionality to existing functions and methods e.g.
static <U1,U2,R> java.util.function.BiFunction<XorT<U1>,XorT<U2>,XorT<R>>	lift2(java.util.function.BiFunction<? super U1,? super U2,? extends R> fn) Lift a BiFunction into one that accepts and returns XorTs This allows multiple monad types to add functionality to existing functions and methods e.g.
<B> XorT<B>	map(java.util.function.Function<? super T,? extends B> f) Map the wrapped Xor
static <A> XorT<A>	of(AnyM<Xor<?,A>> monads) Construct an XorT from an AnyM that wraps a monad containing Xors
XorT<T>	peek(java.util.function.Consumer<? super T> peek) Peek at the current value of the Xor
java.lang.String	toString()
AnyM<Xor<?,T>>	unwrap()

Methods inherited from class java.lang.Object

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

Method Detail

unwrap

public AnyM<Xor<?,T>> unwrap()

Returns:

The wrapped AnyM

peek

public XorT<T> peek(java.util.function.Consumer<? super T> peek)

Peek at the current value of the Xor

  
    XorT.of(AnyM.fromStream(Xor.of(10))
             .peek(System.out::println);
             
     //prints 10        
 
 

Parameters:

peek - Consumer to accept current value of Xor

Returns:

XorT with peek call

filter

public XorT<T> filter(java.util.function.Predicate<? super T> test)

Filter the wrapped Xor

  
    XorT.of(AnyM.fromStream(Xor.of(10))
             .filter(t->t!=10);
             
     //XorT<AnyM<Stream<Xor.empty>>>
 
 

Parameters:

test - Predicate to filter the wrapped Xor

Returns:

XorT that applies the provided filter

map

public <B> XorT<B> map(java.util.function.Function<? super T,? extends B> f)

Map the wrapped Xor

  
  XorT.of(AnyM.fromStream(Xor.of(10))
             .map(t->t=t+1);
  
  
  //XorT<AnyM<Stream<Xor[11]>>>
 
 

Parameters:

f - Mapping function for the wrapped Xor

Returns:

XorT that applies the map function to the wrapped Xor

flatMap

public <B> XorT<B> flatMap(java.util.function.Function<? super T,XorT<? extends B>> f)

Flat Map the wrapped Xor

  
  XorT.of(AnyM.fromStream(Xor.of(10))
             .flatMap(t->Xor.empty();
  
  
  //XorT<AnyM<Stream<Xor.empty>>>
 
 

Parameters:

f - FlatMap function

Returns:

XorT that applies the flatMap function to the wrapped Xor

lift

public static <U,R> java.util.function.Function<XorT<U>,XorT<R>> lift(java.util.function.Function<? super U,? extends R> fn)

Lift a function into one that accepts and returns an XorT This allows multiple monad types to add functionality to existing functions and methods e.g. to add null handling (via Xor) and iteration (via Stream) to an existing function

 {
     @code
     Function add2 = i -> i + 2;
     Function, XorT> optTAdd2 = XorT.lift(add2);
 
     Stream withNulls = Stream.of(1, 2, null);
     AnyM stream = AnyM.ofMonad(withNulls);
     AnyM> streamOpt = stream.map(Xor::ofNullable);
     List results = optTAdd2.apply(XorT.of(streamOpt)).unwrap().>> unwrap()
             .filter(Xor::isPresent).map(Xor::get).collect(Collectors.toList());
 
     // Arrays.asList(3,4);
 
 }
 

Parameters:

fn - Function to enhance with functionality from Xor and another monad type

Returns:

Function that accepts and returns an XorT

lift2

public static <U1,U2,R> java.util.function.BiFunction<XorT<U1>,XorT<U2>,XorT<R>> lift2(java.util.function.BiFunction<? super U1,? super U2,? extends R> fn)

Lift a BiFunction into one that accepts and returns XorTs This allows multiple monad types to add functionality to existing functions and methods e.g. to add null handling (via Xor), iteration (via Stream) and asynchronous execution (CompletableFuture) to an existing function

 {
     @code
     BiFunction add = (a, b) -> a + b;
     BiFunction, XorT, XorT> optTAdd2 = XorT.lift2(add);
 
     Stream withNulls = Stream.of(1, 2, null);
     AnyM stream = AnyM.ofMonad(withNulls);
     AnyM> streamOpt = stream.map(Xor::ofNullable);
 
     CompletableFuture> two = CompletableFuture.supplyAsync(() -> Xor.of(2));
     AnyM> future = AnyM.ofMonad(two);
     List results = optTAdd2.apply(XorT.of(streamOpt), XorT.of(future)).unwrap()
             .>> unwrap().filter(Xor::isPresent).map(Xor::get)
             .collect(Collectors.toList());
     // Arrays.asList(3,4);
 }
 

Parameters:

fn - BiFunction to enhance with functionality from Xor and another monad type

Returns:

Function that accepts and returns an XorT

fromAnyM

public static <A> XorT<A> fromAnyM(AnyM<A> anyM)

Construct an XorT from an AnyM that contains a monad type that contains type other than Xor The values in the underlying monad will be mapped to Xor

Parameters:

anyM - AnyM that doesn't contain a monad wrapping an Xor

Returns:

XorT

of

public static <A> XorT<A> of(AnyM<Xor<?,A>> monads)

Construct an XorT from an AnyM that wraps a monad containing Xors

Parameters:

monads - AnyM that contains a monad wrapping an Xor

Returns:

XorT

toString

public java.lang.String toString()

Overrides:

toString in class java.lang.Object