T
- The type contained on the Optional withinpublic class OptionalT<T>
extends java.lang.Object
Modifier and Type | Method and Description |
---|---|
OptionalT<T> |
filter(java.util.function.Predicate<? super T> test)
Filter the wrapped Optional
|
<B> OptionalT<B> |
flatMap(java.util.function.Function<? super T,OptionalT<? extends B>> f)
Flat Map the wrapped Optional
|
static <A> OptionalT<A> |
fromAnyM(AnyM<A> anyM)
|
static <U,R> java.util.function.Function<OptionalT<U>,OptionalT<R>> |
lift(java.util.function.Function<U,R> fn)
Lift a function into one that accepts and returns an OptionalT
This allows multiple monad types to add functionality to existing functions and methods
e.g.
|
static <U1,U2,R> java.util.function.BiFunction<OptionalT<U1>,OptionalT<U2>,OptionalT<R>> |
lift2(java.util.function.BiFunction<? super U1,? super U2,? extends R> fn)
Lift a BiFunction into one that accepts and returns OptionalTs
This allows multiple monad types to add functionality to existing functions and methods
e.g.
|
<B> OptionalT<B> |
map(java.util.function.Function<? super T,? extends B> f)
Map the wrapped Optional
|
static <A> OptionalT<A> |
of(AnyM<java.util.Optional<A>> monads)
Construct an OptionalT from an AnyM that wraps a monad containing Optionals
|
OptionalT<T> |
peek(java.util.function.Consumer<? super T> peek)
Peek at the current value of the Optional
|
java.lang.String |
toString() |
AnyM<java.util.Optional<T>> |
unwrap() |
public OptionalT<T> peek(java.util.function.Consumer<? super T> peek)
OptionalT.of(AnyM.fromStream(Optional.of(10))
.peek(System.out::println);
//prints 10
peek
- Consumer to accept current value of Optionalpublic OptionalT<T> filter(java.util.function.Predicate<? super T> test)
OptionalT.of(AnyM.fromStream(Optional.of(10))
.filter(t->t!=10);
//OptionalT<AnyM<Stream<Optional.empty>>>
test
- Predicate to filter the wrapped Optionalpublic <B> OptionalT<B> map(java.util.function.Function<? super T,? extends B> f)
OptionalT.of(AnyM.fromStream(Optional.of(10))
.map(t->t=t+1);
//OptionalT<AnyM<Stream<Optional[11]>>>
f
- Mapping function for the wrapped Optionalpublic <B> OptionalT<B> flatMap(java.util.function.Function<? super T,OptionalT<? extends B>> f)
OptionalT.of(AnyM.fromStream(Optional.of(10))
.flatMap(t->Optional.empty();
//OptionalT<AnyM<Stream<Optional.empty>>>
f
- FlatMap functionpublic static <U,R> java.util.function.Function<OptionalT<U>,OptionalT<R>> lift(java.util.function.Function<U,R> fn)
Function<Integer,Integer> add2 = i -> i+2;
Function<OptionalT<Integer>, OptionalT<Integer>> optTAdd2 = OptionalT.lift(add2);
Stream<Integer> withNulls = Stream.of(1,2,null);
AnyM<Integer> stream = AnyM.ofMonad(withNulls);
AnyM<Optional<Integer>> streamOpt = stream.map(Optional::ofNullable);
List<Integer> results = optTAdd2.apply(OptionalT.of(streamOpt))
.unwrap()
.<Stream<Optional<Integer>>>unwrap()
.filter(Optional::isPresent)
.map(Optional::get)
.collect(Collectors.toList());
//Arrays.asList(3,4);
fn
- Function to enhance with functionality from Optional and another monad typepublic static <U1,U2,R> java.util.function.BiFunction<OptionalT<U1>,OptionalT<U2>,OptionalT<R>> lift2(java.util.function.BiFunction<? super U1,? super U2,? extends R> fn)
BiFunction<Integer,Integer,Integer> add = (a,b) -> a+b;
BiFunction<OptionalT<Integer>,OptionalT<Integer>, OptionalT<Integer>> optTAdd2 = OptionalT.lift2(add);
Stream<Integer> withNulls = Stream.of(1,2,null);
AnyM<Integer> stream = AnyM.ofMonad(withNulls);
AnyM<Optional<Integer>> streamOpt = stream.map(Optional::ofNullable);
CompletableFuture<Optional<Integer>> two = CompletableFuture.supplyAsync(()->Optional.of(2));
AnyM<Optional<Integer>> future= AnyM.ofMonad(two);
List<Integer> results = optTAdd2.apply(OptionalT.of(streamOpt),OptionalT.of(future))
.unwrap()
.<Stream<Optional<Integer>>>unwrap()
.filter(Optional::isPresent)
.map(Optional::get)
.collect(Collectors.toList());
//Arrays.asList(3,4);
fn
- BiFunction to enhance with functionality from Optional and another monad typepublic static <A> OptionalT<A> fromAnyM(AnyM<A> anyM)
anyM
- AnyM that doesn't contain a monad wrapping an Optionalpublic static <A> OptionalT<A> of(AnyM<java.util.Optional<A>> monads)
monads
- AnyM that contains a monad wrapping an Optionalpublic java.lang.String toString()
toString
in class java.lang.Object