T
- Data type of element stored in Maybepublic interface Maybe<T> extends To<Maybe<T>>, MonadicValue<T>, Zippable<T>, java.util.function.Supplier<T>, ConvertableFunctor<T>, Filterable<T>, ApplicativeFunctor<T>, Matchable.ValueAndOptionalMatcher<T>
//eagerly load data
Optional.of(10)
.map(this::load);
//lazily tee up loading of data until needed
Maybe.of(10)
.map(this::load);
.
Maybe is tail recursive
{@code
Modifier and Type | Interface and Description |
---|---|
static class |
Maybe.Just<T> |
static class |
Maybe.Lazy<T> |
static class |
Maybe.Nothing<T> |
ApplicativeFunctor.Applicatives, ApplicativeFunctor.ApplyFunctions<T>
Value.ValueImpl<T>
Convertable.SupplierToConvertable<T>
Modifier and Type | Method and Description |
---|---|
static <T,R> Maybe<R> |
accumulateJust(CollectionX<Maybe<T>> maybes,
java.util.function.Function<? super T,R> mapper,
Monoid<R> reducer)
Accumulate the results only from those Maybes which have a value present, using the supplied mapping function to
convert the data from each Maybe before reducing them using the supplied Monoid (a combining BiFunction/BinaryOperator and identity element that takes two
input values of the same type and returns the combined result)
Monoids .. |
static <T,R> Maybe<R> |
accumulateJust(CollectionX<Maybe<T>> maybes,
Reducer<R> reducer)
Accummulating operation using the supplied Reducer (@see com.aol.cyclops.Reducers).
|
static <T> Maybe<T> |
accumulateJust(Monoid<T> reducer,
CollectionX<Maybe<T>> maybes)
Accumulate the results only from those Maybes which have a value present, using the supplied Monoid (a combining BiFunction/BinaryOperator and identity element that takes two
input values of the same type and returns the combined result)
Monoids . |
default <U> Maybe<U> |
cast(java.lang.Class<? extends U> type)
Cast all elements in a stream to a given type, possibly throwing a
ClassCastException . |
default <R> Maybe<R> |
coflatMap(java.util.function.Function<? super MonadicValue<T>,R> mapper)
Perform a coflatMap operation.
|
default Maybe<T> |
combine(java.util.function.BinaryOperator<Combiner<T>> combiner,
Combiner<T> app)
Combine two applicatives together using the provided BinaryOperator (Semigroup, Monoid and Reducer all
extend BinaryOperator - checkout Semigroups and Monoids for a large number of canned combinations).
|
default <T2,R> Maybe<R> |
combine(Value<? extends T2> app,
java.util.function.BiFunction<? super T,? super T2,? extends R> fn)
Lazily combine this ApplicativeFunctor with the supplied value via the supplied BiFunction
Example
|
default Maybe<T> |
combineEager(Monoid<T> monoid,
MonadicValue<? extends T> v2)
Eagerly combine two MonadicValues using the supplied monoid (@see ApplicativeFunctor for type appropraite i.e.
|
Maybe<T> |
filter(java.util.function.Predicate<? super T> fn)
Keep only elements for which the supplied predicates hold
e.g.
|
default Maybe<T> |
filterNot(java.util.function.Predicate<? super T> fn)
Remove any elements for which the predicate holds (inverse operation to filter)
e.g.
|
<R> Maybe<R> |
flatMap(java.util.function.Function<? super T,? extends MonadicValue<? extends R>> mapper)
A flattening transformation operation (@see
Optional.flatMap(Function) |
default <R> Maybe<R> |
flatMapIterable(java.util.function.Function<? super T,? extends java.lang.Iterable<? extends R>> mapper)
A flattening transformation operation that takes the first value from the returned Iterable.
|
default <R> Maybe<R> |
flatMapPublisher(java.util.function.Function<? super T,? extends org.reactivestreams.Publisher<? extends R>> mapper)
A flattening transformation operation that takes the first value from the returned Publisher.
|
default <R1,R> Maybe<R> |
forEach2(java.util.function.Function<? super T,? extends MonadicValue<R1>> value1,
java.util.function.BiFunction<? super T,? super R1,? extends R> yieldingFunction)
Perform a two level nested internal iteration over this MonadicValue and the
supplied MonadicValue
|
default <R1,R> Maybe<R> |
forEach2(java.util.function.Function<? super T,? extends MonadicValue<R1>> value1,
java.util.function.BiFunction<? super T,? super R1,java.lang.Boolean> filterFunction,
java.util.function.BiFunction<? super T,? super R1,? extends R> yieldingFunction)
Perform a two level nested internal iteration over this MonadicValue and the
supplied stream
|
default <T2,R1,R2,R> |
forEach3(java.util.function.Function<? super T,? extends MonadicValue<R1>> value1,
java.util.function.BiFunction<? super T,? super R1,? extends MonadicValue<R2>> value2,
TriFunction<? super T,? super R1,? super R2,? extends R> yieldingFunction)
Perform a three level nested internal iteration over this MonadicValue and the
supplied MonadicValues
|
default <T2,R1,R2,R> |
forEach3(java.util.function.Function<? super T,? extends MonadicValue<R1>> value1,
java.util.function.BiFunction<? super T,? super R1,? extends MonadicValue<R2>> value2,
TriFunction<? super T,? super R1,? super R2,java.lang.Boolean> filterFunction,
TriFunction<? super T,? super R1,? super R2,? extends R> yieldingFunction)
Perform a three level nested internal iteration over this MonadicValue and the
supplied MonadicValues
|
default <T2,R1,R2,R3,R> |
forEach4(java.util.function.Function<? super T,? extends MonadicValue<R1>> value1,
java.util.function.BiFunction<? super T,? super R1,? extends MonadicValue<R2>> value2,
TriFunction<? super T,? super R1,? super R2,? extends MonadicValue<R3>> value3,
QuadFunction<? super T,? super R1,? super R2,? super R3,? extends R> yieldingFunction)
Perform a four level nested internal iteration over this MonadicValue and the
supplied MonadicValues
|
default <T2,R1,R2,R3,R> |
forEach4(java.util.function.Function<? super T,? extends MonadicValue<R1>> value1,
java.util.function.BiFunction<? super T,? super R1,? extends MonadicValue<R2>> value2,
TriFunction<? super T,? super R1,? super R2,? extends MonadicValue<R3>> value3,
QuadFunction<? super T,? super R1,? super R2,? super R3,java.lang.Boolean> filterFunction,
QuadFunction<? super T,? super R1,? super R2,? super R3,? extends R> yieldingFunction)
Perform a four level nested internal iteration over this MonadicValue and the
supplied MonadicValues
Maybe.of(3)
.forEach4(a->Maybe.just(a+10),
(a,b)->Maybe.just(a+b),
(a,b,c)->Maybe.none(),
(a,b,c,d)->a+b+c<100,
(a,b,c,d)->a+b+c+d);
//Maybe.none
|
static <T> Maybe<T> |
fromEval(Eval<T> eval)
Construct a Maybe from the supplied Eval
|
static <T> Maybe<T> |
fromEvalNullable(Eval<T> eval) |
static <T> Maybe<T> |
fromEvalOf(Eval<T> eval)
Deprecated.
|
static <T> Maybe<T> |
fromEvalOptional(Eval<java.util.Optional<T>> value) |
static <T> Maybe<T> |
fromIterable(java.lang.Iterable<T> iterable)
Construct a Maybe that contains a single value extracted from the supplied Iterable
|
static <T> Maybe<T> |
fromOptional(java.util.Optional<T> opt)
Construct an equivalent Maybe from the Supplied Optional
|
static <T> Maybe<T> |
fromPublisher(org.reactivestreams.Publisher<T> pub)
Construct a Maybe that contains a single value extracted from the supplied reactive-streams Publisher
|
boolean |
isPresent() |
static <T> Maybe<T> |
just(T value)
Construct an Maybe which contains the provided (non-null) value.
|
<R> Maybe<R> |
map(java.util.function.Function<? super T,? extends R> mapper)
Transform this functor using the supplied transformation function
|
static <T> Maybe<T> |
narrow(Maybe<? extends T> broad)
Narrow covariant type parameter
|
default Maybe<MonadicValue<T>> |
nest()
cojoin pattern.
|
static <T> Maybe<T> |
none() |
default Maybe<T> |
notNull()
Filter elements retaining only values which are not null
|
static <T> Maybe<T> |
of(T value)
Construct an Maybe which contains the provided (non-null) value
Equivalent to @see
just(Object) |
static <T> Maybe<T> |
ofNullable(T value)
Maybe<Integer> maybe = Maybe.ofNullable(null);
//None
Maybe<Integer> maybe = Maybe.ofNullable(10);
//Maybe[10], Some[10]
|
default <U> Maybe<U> |
ofType(java.lang.Class<? extends U> type)
Keep only those elements in a stream that are of a given type.
|
default <R> Maybe<R> |
patternMatch(java.util.function.Function<Matchable.CheckValue1<T,R>,Matchable.CheckValue1<T,R>> case1,
java.util.function.Supplier<? extends R> otherwise)
Transform the elements of this Stream with a Pattern Matching case and default value
|
default Maybe<T> |
peek(java.util.function.Consumer<? super T> c)
Peek at the current value of this Functor, without transforming it
|
Maybe<T> |
recover(java.util.function.Supplier<T> value) |
Maybe<T> |
recover(T value) |
static <T> Maybe<ListX<T>> |
sequence(CollectionX<Maybe<T>> maybes)
Sequence operation, take a Collection of Maybes and turn it into a Maybe with a Collection
By constrast with
sequenceJust(CollectionX) if any Maybe types are None / empty
the return type will be an empty Maybe / None |
static <T> Maybe<ReactiveSeq<T>> |
sequence(java.util.stream.Stream<Maybe<T>> maybes)
Sequence operation, take a Stream of Maybes and turn it into a Maybe with a Stream
By constrast with
sequenceJust(CollectionX) Maybe#empty/ None types are
result in the returned Maybe being Maybe.empty / None |
static <T> Maybe<ListX<T>> |
sequenceJust(CollectionX<Maybe<T>> maybes)
Sequence operation, take a Collection of Maybes and turn it into a Maybe with a Collection
Only successes are retained.
|
default Maybe<T> |
toMaybe()
Returns a function result or a supplier result.
|
default <R> Maybe<R> |
trampoline(java.util.function.Function<? super T,? extends Trampoline<? extends R>> mapper)
Performs a map operation that can call a recursive method without running out of stack space
|
default <T> Maybe<T> |
unit(T unit) |
<R> R |
visit(java.util.function.Function<? super T,? extends R> some,
java.util.function.Supplier<? extends R> none)
The provided function is executed with the value stored in this Visitable if one is present,
otherwise the provided Supplier is executed instead.
|
default <T2,R> Maybe<R> |
zip(java.util.function.BiFunction<? super T,? super T2,? extends R> fn,
org.reactivestreams.Publisher<? extends T2> app)
Zip (combine) this Zippable with the supplied Publisher, using the supplied combining function
|
default <T2,R> Maybe<R> |
zip(java.lang.Iterable<? extends T2> app,
java.util.function.BiFunction<? super T,? super T2,? extends R> fn)
Zip (combine) this Zippable with the supplied Iterable using the supplied combining function
|
default <U> Maybe<org.jooq.lambda.tuple.Tuple2<T,U>> |
zip(java.lang.Iterable<? extends U> other)
Zip (combine) this Zippable with the supplied Iterable combining both into a Tuple2
|
default <U> Maybe<org.jooq.lambda.tuple.Tuple2<T,U>> |
zip(org.jooq.lambda.Seq<? extends U> other)
Zip (combine) this Zippable with the supplied Seq combining both into a Tuple2
|
default <U,R> Maybe<R> |
zip(org.jooq.lambda.Seq<? extends U> other,
java.util.function.BiFunction<? super T,? super U,? extends R> zipper)
Zip (combine) this Zippable with the supplied Seq, using the supplied combining function
|
default <U> Maybe<org.jooq.lambda.tuple.Tuple2<T,U>> |
zip(java.util.stream.Stream<? extends U> other)
Zip (combine) this Zippable with the supplied Stream combining both into a Tuple2
|
default <U,R> Maybe<R> |
zip(java.util.stream.Stream<? extends U> other,
java.util.function.BiFunction<? super T,? super U,? extends R> zipper)
Zip (combine) this Zippable with the supplied Stream, using the supplied combining function
|
anyM
applyFunctions
collect, fold, fold, generate, iterate, iterator, mapReduce, mkString, newSubscriber, stream, subscribe, test, toDequeX, toEvalAlways, toEvalLater, toEvalNow, toFeatureToggle, toFutureStream, toFutureStream, toIor, toLazyImmutable, toList, toListX, toMutable, toPBagX, toPOrderedSetX, toPQueueX, toPSetX, toPStackX, toPVectorX, toQueueX, toSetX, toSimpleReact, toSimpleReact, toSortedSetX, toTry, toTry, toTry, toXor, toXor, unapply
endsWith, endsWithIterable, findAny, findFirst, firstValue, foldable, foldRight, foldRight, foldRight, foldRightMapToType, get, groupBy, join, join, join, mapReduce, print, print, printErr, printOut, reduce, reduce, reduce, reduce, reduce, reduce, reduce, schedule, scheduleFixedDelay, scheduleFixedRate, single, single, singleOptional, startsWith, startsWithIterable, toConcurrentLazyCollection, toConcurrentLazyStreamable, toLazyCollection, validate, xMatch
collect, fromSupplier, get, orElse, orElseGet, orElseThrow, toAtomicReference, toCompletableFuture, toCompletableFutureAsync, toCompletableFutureAsync, toFutureW, toFutureWAsync, toFutureWAsync, toOptional, toOptionalAtomicReference, toStream
iterator, toOptional
matches
static final Maybe EMPTY
static <T> Maybe<T> none()
default <R> Maybe<R> flatMapIterable(java.util.function.Function<? super T,? extends java.lang.Iterable<? extends R>> mapper)
MonadicValue
Maybe.just(1).map(i->i+2).flatMapIterable(i->Arrays.asList(()->i*3,20);
//Maybe[9]
flatMapIterable
in interface MonadicValue<T>
mapper
- transformation functiondefault <R> Maybe<R> flatMapPublisher(java.util.function.Function<? super T,? extends org.reactivestreams.Publisher<? extends R>> mapper)
MonadicValue
FutureW.ofResult(1).map(i->i+2).flatMapPublisher(i->Flux.just(()->i*3,20);
//FutureW[9]
flatMapPublisher
in interface MonadicValue<T>
mapper
- transformation functionstatic <T> Maybe<T> fromPublisher(org.reactivestreams.Publisher<T> pub)
ReactiveSeq<Integer> stream = ReactiveSeq.of(1,2,3);
Maybe<Integer> maybe = Maybe.fromPublisher(stream);
//Maybe[1]
pub
- Publisher to extract value fromstatic <T> Maybe<T> fromIterable(java.lang.Iterable<T> iterable)
ReactiveSeq<Integer> stream = ReactiveSeq.of(1,2,3);
Maybe<Integer> maybe = Maybe.fromIterable(stream);
//Maybe[1]
iterable
- Iterable to extract value fromstatic <T> Maybe<T> fromOptional(java.util.Optional<T> opt)
Maybe<Integer> some = Maybe.fromOptional(Optional.of(10));
//Maybe[10], Some[10]
Maybe<Integer> none = Maybe.fromOptional(Optional.empty());
//Maybe.empty, None[]
opt
- Optional to construct Maybe fromstatic <T> Maybe<T> fromEval(Eval<T> eval)
Maybe<Integer> maybe = Maybe.fromEval(Eval.now(10));
//Maybe[10]
eval
- Eval to construct Maybe fromstatic <T> Maybe<T> just(T value)
of(Object)
Maybe<Integer> some = Maybe.just(10);
some.map(i->i*2);
value
- Value to wrap inside a Maybestatic <T> Maybe<T> of(T value)
just(Object)
Maybe<Integer> some = Maybe.of(10);
some.map(i->i*2);
static <T> Maybe<T> ofNullable(T value)
Maybe<Integer> maybe = Maybe.ofNullable(null);
//None
Maybe<Integer> maybe = Maybe.ofNullable(10);
//Maybe[10], Some[10]
value
- static <T> Maybe<T> narrow(Maybe<? extends T> broad)
broad
- Maybe with covariant type parameterstatic <T> Maybe<ListX<T>> sequenceJust(CollectionX<Maybe<T>> maybes)
sequence(CollectionX)
Maybe#empty/ None types are
tolerated and ignored.
Maybe<Integer> just = Maybe.of(10);
Maybe<Integer> none = Maybe.none();
Maybe<ListX<Integer>> maybes = Maybe.sequenceJust(ListX.of(just, none, Maybe.of(1)));
//Maybe.of(ListX.of(10, 1));
maybes
- Maybes to Sequencestatic <T> Maybe<ListX<T>> sequence(CollectionX<Maybe<T>> maybes)
sequenceJust(CollectionX)
if any Maybe types are None / empty
the return type will be an empty Maybe / None
Maybe<Integer> just = Maybe.of(10);
Maybe<Integer> none = Maybe.none();
Maybe<ListX<Integer>> maybes = Maybe.sequence(ListX.of(just, none, Maybe.of(1)));
//Maybe.none();
maybes
- Maybes to Sequencestatic <T> Maybe<ReactiveSeq<T>> sequence(java.util.stream.Stream<Maybe<T>> maybes)
sequenceJust(CollectionX)
Maybe#empty/ None types are
result in the returned Maybe being Maybe.empty / None
Maybe<Integer> just = Maybe.of(10);
Maybe<Integer> none = Maybe.none();
Maybe<ReactiveSeq<Integer>> maybes = Maybe.sequence(Stream.of(just, none, Maybe.of(1)));
//Maybe.none();
maybes
- Maybes to Sequencestatic <T,R> Maybe<R> accumulateJust(CollectionX<Maybe<T>> maybes, Reducer<R> reducer)
Maybe<Integer> just = Maybe.of(10);
Maybe<Integer> none = Maybe.none();
Maybe<PSetX<Integer>> maybes = Maybe.accumulateJust(ListX.of(just, none, Maybe.of(1)), Reducers.toPSetX());
//Maybe.of(PSetX.of(10, 1)));
maybes
- Maybes to accumulatereducer
- Reducer to accumulate values withstatic <T,R> Maybe<R> accumulateJust(CollectionX<Maybe<T>> maybes, java.util.function.Function<? super T,R> mapper, Monoid<R> reducer)
Monoids
..
Maybe<Integer> just = Maybe.of(10);
Maybe<Integer> none = Maybe.none();
Maybe<String> maybes = Maybe.accumulateJust(ListX.of(just, none, Maybe.of(1)), i -> "" + i,
Semigroups.stringConcat);
//Maybe.of("101")
maybes
- Maybes to accumulatemapper
- Mapping function to be applied to the result of each Maybereducer
- Monoid to combine values from each Maybestatic <T> Maybe<T> accumulateJust(Monoid<T> reducer, CollectionX<Maybe<T>> maybes)
Monoids
.
Maybe<Integer> maybes = Maybe.accumulateJust(Monoids.intSum,ListX.of(just, none, Maybe.of(1)));
//Maybe.of(11)
maybes
- Maybes to accumulatereducer
- Monoid to combine values from each Maybedefault <T2,R1,R2,R3,R> Maybe<R> forEach4(java.util.function.Function<? super T,? extends MonadicValue<R1>> value1, java.util.function.BiFunction<? super T,? super R1,? extends MonadicValue<R2>> value2, TriFunction<? super T,? super R1,? super R2,? extends MonadicValue<R3>> value3, QuadFunction<? super T,? super R1,? super R2,? super R3,? extends R> yieldingFunction)
MonadicValue
Maybe.of(3)
.forEach4(a->Maybe.just(a+10),
(a,b)->Maybe.just(a+b),
(a,b,c)->Maybe.none(),
(a,b,c,d)->a+b+c+d);
//Maybe.none
forEach4
in interface MonadicValue<T>
value1
- Nested MonadicValue to iterate overvalue2
- Nested MonadicValue to iterate overvalue3
- Nested MonadicValue to iterate overyieldingFunction
- Function with pointers to the current element from both
MonadicValue that generates the new elementsdefault <T2,R1,R2,R3,R> Maybe<R> forEach4(java.util.function.Function<? super T,? extends MonadicValue<R1>> value1, java.util.function.BiFunction<? super T,? super R1,? extends MonadicValue<R2>> value2, TriFunction<? super T,? super R1,? super R2,? extends MonadicValue<R3>> value3, QuadFunction<? super T,? super R1,? super R2,? super R3,java.lang.Boolean> filterFunction, QuadFunction<? super T,? super R1,? super R2,? super R3,? extends R> yieldingFunction)
MonadicValue
Maybe.of(3)
.forEach4(a->Maybe.just(a+10),
(a,b)->Maybe.just(a+b),
(a,b,c)->Maybe.none(),
(a,b,c,d)->a+b+c<100,
(a,b,c,d)->a+b+c+d);
//Maybe.none
forEach4
in interface MonadicValue<T>
value1
- Nested MonadicValue to iterate overvalue2
- Nested MonadicValue to iterate overvalue3
- Nested MonadicValue to iterate overfilterFunction
- Filter to apply over elements before passing non-filtered
values to the yielding functionyieldingFunction
- Function with pointers to the current element from both
MonadicValue that generates the new elementsdefault <T2,R1,R2,R> Maybe<R> forEach3(java.util.function.Function<? super T,? extends MonadicValue<R1>> value1, java.util.function.BiFunction<? super T,? super R1,? extends MonadicValue<R2>> value2, TriFunction<? super T,? super R1,? super R2,? extends R> yieldingFunction)
MonadicValue
Maybe.of(3)
.forEach3(a->Maybe.just(a+10),
(a,b)->Maybe.just(a+b),
(a,b,c)->a+b+c<100,
(a,b,c)->a+b+c);
//Maybe[32]
forEach3
in interface MonadicValue<T>
value1
- Nested MonadicValue to iterate overvalue2
- Nested MonadicValue to iterate overyieldingFunction
- Function with pointers to the current element from both
MonadicValue that generates the new elementsdefault <T2,R1,R2,R> Maybe<R> forEach3(java.util.function.Function<? super T,? extends MonadicValue<R1>> value1, java.util.function.BiFunction<? super T,? super R1,? extends MonadicValue<R2>> value2, TriFunction<? super T,? super R1,? super R2,java.lang.Boolean> filterFunction, TriFunction<? super T,? super R1,? super R2,? extends R> yieldingFunction)
MonadicValue
Maybe.of(3)
.forEach3(a->Maybe.just(a+10),
(a,b)->Maybe.just(a+b),
(a,b,c)->a+b+c<100,
(a,b,c)->a+b+c);
//Maybe[32]
forEach3
in interface MonadicValue<T>
value1
- Nested MonadicValue to iterate overvalue2
- Nested MonadicValue to iterate overfilterFunction
- Filter to apply over elements before passing non-filtered
values to the yielding functionyieldingFunction
- Function with pointers to the current element from both
MonadicValue that generates the new elementsdefault <R1,R> Maybe<R> forEach2(java.util.function.Function<? super T,? extends MonadicValue<R1>> value1, java.util.function.BiFunction<? super T,? super R1,? extends R> yieldingFunction)
MonadicValue
Maybe.of(3)
.forEach2(a->Maybe.none(),
(a,b)->a+b);
//Maybe.none()
forEach2
in interface MonadicValue<T>
value1
- Nested Monadic Type to iterate overyieldingFunction
- Function with pointers to the current element from both
monad types that generates the new elementsdefault <R1,R> Maybe<R> forEach2(java.util.function.Function<? super T,? extends MonadicValue<R1>> value1, java.util.function.BiFunction<? super T,? super R1,java.lang.Boolean> filterFunction, java.util.function.BiFunction<? super T,? super R1,? extends R> yieldingFunction)
MonadicValue
Maybe.of(3)
.forEach2(a->Maybe.none(),
a->b-> a<3 && b>10,
(a,b)->a+b);
//Maybe.none()
forEach2
in interface MonadicValue<T>
filterFunction
- Filter to apply over elements before passing non-filtered
values to the yielding functionyieldingFunction
- Function with pointers to the current element from both
Streams that generates the new elementsdefault <T2,R> Maybe<R> combine(Value<? extends T2> app, java.util.function.BiFunction<? super T,? super T2,? extends R> fn)
Combiner
Maybe<Integer> some = Maybe.just(10);
just.combine(Eval.now(20), this::add);
//Some[30]
Maybe<Integer> none = Maybe.none();
none.combine(Eval.now(20), this::add);
//None
default <T2,R> Maybe<R> zip(java.lang.Iterable<? extends T2> app, java.util.function.BiFunction<? super T,? super T2,? extends R> fn)
Zippable
default <T2,R> Maybe<R> zip(java.util.function.BiFunction<? super T,? super T2,? extends R> fn, org.reactivestreams.Publisher<? extends T2> app)
Zippable
default Maybe<T> combine(java.util.function.BinaryOperator<Combiner<T>> combiner, Combiner<T> app)
Combiner
combine
in interface Combiner<T>
Semigroup
,
Semigroups
,
Monoid
,
To lift any Semigroup (or monoid) up to handling Applicatives use the combineApplicatives operator in Semigroups
{@see com.aol.cyclops.Semigroups#combineApplicatives(BiFunction) } or Monoids
{ {@see com.aol.cyclops.Monoids#combineApplicatives(java.util.function.Function, com.aol.cyclops.Monoid)
}
{@code
BinaryOperator> sumMaybes = Semigroups.combineScalarFunctors(Semigroups.intSum);
Maybe.just(1)
.combine(sumMaybes, Maybe.just(5))
//Maybe.just(6));
}
default <U,R> Maybe<R> zip(org.jooq.lambda.Seq<? extends U> other, java.util.function.BiFunction<? super T,? super U,? extends R> zipper)
Zippable
default <U,R> Maybe<R> zip(java.util.stream.Stream<? extends U> other, java.util.function.BiFunction<? super T,? super U,? extends R> zipper)
Zippable
default <U> Maybe<org.jooq.lambda.tuple.Tuple2<T,U>> zip(java.util.stream.Stream<? extends U> other)
Zippable
default <U> Maybe<org.jooq.lambda.tuple.Tuple2<T,U>> zip(org.jooq.lambda.Seq<? extends U> other)
Zippable
default <U> Maybe<org.jooq.lambda.tuple.Tuple2<T,U>> zip(java.lang.Iterable<? extends U> other)
Zippable
default <T> Maybe<T> unit(T unit)
default <R> Maybe<R> coflatMap(java.util.function.Function<? super MonadicValue<T>,R> mapper)
MonadicValue
Maybe.none().coflatMap(m -> m.isPresent() ? m.get() : 10);
//Maybe[10]
coflatMap
in interface MonadicValue<T>
mapper
- Mapping / transformation functiondefault Maybe<MonadicValue<T>> nest()
MonadicValue
nest
in interface MonadicValue<T>
default Maybe<T> combineEager(Monoid<T> monoid, MonadicValue<? extends T> v2)
MonadicValue
Monoid<Integer> add = Monoid.of(1,Semigroups.intSum);
Maybe.of(10).combineEager(add,Maybe.none());
//Maybe[10]
Maybe.none().combineEager(add,Maybe.of(10));
//Maybe[10]
Maybe.none().combineEager(add,Maybe.none());
//Maybe.none()
Maybe.of(10).combineEager(add,Maybe.of(10));
//Maybe[20]
Monoid<Integer> firstNonNull = Monoid.of(null , Semigroups.firstNonNull());
Maybe.of(10).combineEager(firstNonNull,Maybe.of(10));
//Maybe[10]
combineEager
in interface MonadicValue<T>
default Maybe<T> toMaybe()
Value
boolean isPresent()
isPresent
in interface Convertable<T>
<R> Maybe<R> map(java.util.function.Function<? super T,? extends R> mapper)
Functor
of(1,2,3).map(i->i*2)
//[2,4,6]
map
in interface ConvertableFunctor<T>
map
in interface Functor<T>
map
in interface MonadicValue<T>
mapper
- Transformation function<R> Maybe<R> flatMap(java.util.function.Function<? super T,? extends MonadicValue<? extends R>> mapper)
MonadicValue
Optional.flatMap(Function)
Eval.now(1).map(i->i+2).flatMap(i->Eval.later(()->i*3);
//Eval[9]
flatMap
in interface MonadicValue<T>
mapper
- transformation function<R> R visit(java.util.function.Function<? super T,? extends R> some, java.util.function.Supplier<? extends R> none)
Visitable
visit
in interface Convertable<T>
visit
in interface Matchable.MatchableOptional<T>
visit
in interface Matchable.ValueAndOptionalMatcher<T>
visit
in interface Visitable<T>
some
- Function to execute if this Visitable has a valuenone
- Supplier to execute if this Visitable does not have a ValueMaybe<T> filter(java.util.function.Predicate<? super T> fn)
Filterable
of(1,2,3).filter(i->i>2);
//[3]
filter
in interface Filterable<T>
filter
in interface MonadicValue<T>
fn
- to filter elements by, retaining matchesdefault <U> Maybe<U> ofType(java.lang.Class<? extends U> type)
Filterable
// (1, 2, 3) ReactiveSeq.of(1, "a", 2, "b",3).ofType(Integer.class)
ofType
in interface Filterable<T>
default Maybe<T> filterNot(java.util.function.Predicate<? super T> fn)
Filterable
of(1,2,3).filter(i->i>2);
//[1,2]
filterNot
in interface Filterable<T>
fn
- to filter elements by, retaining matchesdefault Maybe<T> notNull()
Filterable
of(1,2,null,4).nonNull();
//[1,2,4]
notNull
in interface Filterable<T>
default <U> Maybe<U> cast(java.lang.Class<? extends U> type)
Functor
ClassCastException
.
// ClassCastException ReactiveSeq.of(1, "a", 2, "b", 3).cast(Integer.class)default Maybe<T> peek(java.util.function.Consumer<? super T> c)
Functor
of(1,2,3).map(System.out::println)
1
2
3
default <R> Maybe<R> trampoline(java.util.function.Function<? super T,? extends Trampoline<? extends R>> mapper)
Functor
ReactiveSeq.of(10,20,30,40)
.trampoline(i-> fibonacci(i))
.forEach(System.out::println);
Trampoline<Long> fibonacci(int i){
return fibonacci(i,1,0);
}
Trampoline<Long> fibonacci(int n, long a, long b) {
return n == 0 ? Trampoline.done(b) : Trampoline.more( ()->fibonacci(n-1, a+b, a));
}
55
6765
832040
102334155
ReactiveSeq.of(10_000,200_000,3_000_000,40_000_000)
.trampoline(i-> fibonacci(i))
.forEach(System.out::println);
completes successfully
trampoline
in interface Functor<T>
mapper
- TCO Transformation functiondefault <R> Maybe<R> patternMatch(java.util.function.Function<Matchable.CheckValue1<T,R>,Matchable.CheckValue1<T,R>> case1, java.util.function.Supplier<? extends R> otherwise)
Functor
List<String> result = CollectionX.of(1,2,3,4)
.patternMatch(
c->c.valuesWhere(i->"even", (Integer i)->i%2==0 )
)
// CollectionX["odd","even","odd","even"]
patternMatch
in interface Functor<T>
case1
- Function to generate a case (or chain of cases as a single case)otherwise
- Value if supplied case doesn't match