com.jnape.palatable.lambda.functor

Interface Applicative<A,App extends Applicative<?,App>>

Type Parameters:

A - The type of the parameter

App - The unification parameter to more tightly type-constrain Applicatives to themselves

All Superinterfaces:

Functor<A,App>

All Known Subinterfaces:

BiMonoidFactory<A,B,C>, BiPredicate<A,B>, BiSemigroupFactory<A,B,C>, Effect<A>, Fn0<A>, Fn1<A,B>, Fn2<A,B,C>, Fn3<A,B,C,D>, Fn4<A,B,C,D,E>, Fn5<A,B,C,D,E,F>, Fn6<A,B,C,D,E,F,G>, Fn7<A,B,C,D,E,F,G,H>, Fn8<A,B,C,D,E,F,G,H,I>, Iso<S,T,A,B>, Iso.Simple<S,A>, Kleisli<A,B,M,MB>, Lens<S,T,A,B>, Lens.Simple<S,A>, Monad<A,M>, MonadError<E,A,M>, MonadReader<R,A,MR>, MonadRec<A,M>, MonadT<M,A,MT,T>, MonadWriter<W,A,MW>, Monoid<A>, MonoidFactory<A,B>, Predicate<A>, Prism<S,T,A,B>, Prism.Simple<S,A>, Schema<Values>, Semigroup<A>, SemigroupFactory<A,B>, TypeSafeKey<A,B>, TypeSafeKey.Simple<A>

All Known Implementing Classes:

Absent, AddAll, All, Alter, And, Any, AutoBracket, Between, Both, Bracket, CartesianProduct, CatMaybes, Choice2, Choice3, Choice4, Choice5, Choice6, Choice7, Choice8, Clamp, CmpEq, CmpEqBy, Coalesce, Collapse, Collapse, Compose, Compose, Compose, Concat, Cons, Const, Constantly, Cycle, Difference, Distinct, Downcast, Drop, DropWhile, Either, EitherT, Empty, Endo, EndoK, Eq, Filter, Find, First, Flatten, FoldLeft, FoldRight, Force, GroupBy, GT, GTBy, GTE, GTEBy, Head, Id, Identity, IdentityT, IfThenElse, InGroupsOf, Init, Inits, Intersection, Intersperse, Into, Into1, Into3, Into4, Into5, Into6, Into7, Into8, IO, Iterate, Join, LambdaIterable, Last, Last, Lazy, LazyRec, LazyT, LeftAll, LeftAll, LeftAny, LeftAny, LiftA2, LiftA3, LiftA4, LiftA5, LiftA6, LiftA7, LT, LTBy, LTE, LTEBy, Magnetize, MagnetizeBy, Map, Market, Matching, Max, MaxBy, Maybe, MaybeT, Merge, Merge, MergeMaps, Min, MinBy, Not, Occurrences, Or, Over, Partition, Peek, Peek2, Pre, PrependAll, Present, PutAll, RateLimit, Re, ReaderT, RecursiveResult, ReduceLeft, ReduceRight, Repeat, Replicate, Reverse, RightAll, RightAll, RightAny, RightAny, RunAll, RunAll, SafeT, ScanLeft, Sequence, Set, SingletonHList, Size, Slide, Snoc, Sort, SortBy, SortWith, Span, State, StateT, Tagged, Tail, Tails, Take, TakeWhile, These, Times, ToArray, ToCollection, ToMap, Trampoline, Trivial, Try, Tuple2, Tuple3, Tuple4, Tuple5, Tuple6, Tuple7, Tuple8, Tupler2, Uncons, Under, Unfoldr, Union, Until, Upcast, View, Writer, WriterT, Xor, Zip, ZipWith

public interface Applicative<A,App extends Applicative<?,App>>
extends Functor<A,App>

An interface representing applicative functors - functors that can have their results combined with other functors of the same instance in a context-free manner.

The same rules that apply to Functor apply to Applicative, along with the following additional 4 laws:

• identity: v.zip(pureId).equals(v)
• composition: w.zip(v.zip(u.zip(pureCompose))).equals((w.zip(v)).zip(u))
• homomorphism: pureX.zip(pureF).equals(pureFx)
• interchange: pureY.zip(u).equals(u.zip(pure(f -> f.apply(y))))

As with Functor, Applicative instances that do not satisfy all of the functor laws, as well as the above applicative laws, are not well-behaved and often break down in surprising ways.

For more information, read about Applicative Functors.

Method Summary

Modifier and Type	Method and Description
default <B> Applicative<B,App>	discardL(Applicative<B,App> appB) Sequence both this Applicative and appB, discarding this Applicative's result and returning appB.
default <B> Applicative<A,App>	discardR(Applicative<B,App> appB) Sequence both this Applicative and appB, discarding appB's result and returning this Applicative.
default <B> Applicative<B,App>	fmap(Fn1<? super A,? extends B> fn) Covariantly transmute this functor's parameter using the given mapping function.
default <B> Lazy<? extends Applicative<B,App>>	lazyZip(Lazy<? extends Applicative<Fn1<? super A,? extends B>,App>> lazyAppFn) Given a lazy instance of this applicative over a mapping function, "zip" the two instances together using whatever application semantics the current applicative supports.
<B> Applicative<B,App>	pure(B b) Lift the value b into this applicative functor.
<B> Applicative<B,App>	zip(Applicative<Fn1<? super A,? extends B>,App> appFn) Given another instance of this applicative over a mapping function, "zip" the two instances together using whatever application semantics the current applicative supports.

Methods inherited from interface com.jnape.palatable.lambda.functor.Functor

coerce

Method Detail

pure

<B> Applicative<B,App> pure(B b)

Lift the value b into this applicative functor.

Type Parameters:

B - the type of the returned applicative's parameter

Parameters:

b - the value

Returns:

an instance of this applicative over b

zip

<B> Applicative<B,App> zip(Applicative<Fn1<? super A,? extends B>,App> appFn)

Given another instance of this applicative over a mapping function, "zip" the two instances together using whatever application semantics the current applicative supports.

Type Parameters:

B - the resulting applicative parameter type

Parameters:

appFn - the other applicative instance

Returns:

the mapped applicative

lazyZip

default <B> Lazy<? extends Applicative<B,App>> lazyZip(Lazy<? extends Applicative<Fn1<? super A,? extends B>,App>> lazyAppFn)

Given a lazy instance of this applicative over a mapping function, "zip" the two instances together using whatever application semantics the current applicative supports. This is useful for applicatives that support lazy evaluation and early termination.

Type Parameters:

B - the resulting applicative parameter type

Parameters:

lazyAppFn - the lazy other applicative instance

Returns:

the mapped applicative

See Also:

Maybe, Either

discardL

default <B> Applicative<B,App> discardL(Applicative<B,App> appB)

Sequence both this Applicative and appB, discarding this Applicative's result and returning appB. This is generally useful for sequentially performing side-effects.

Type Parameters:

B - the type of the returned Applicative's parameter

Parameters:

appB - the other Applicative

Returns:

appB

discardR

default <B> Applicative<A,App> discardR(Applicative<B,App> appB)

Sequence both this Applicative and appB, discarding appB's result and returning this Applicative. This is generally useful for sequentially performing side-effects.

Type Parameters:

B - the type of appB's parameter

Parameters:

appB - the other Applicative

Returns:

this Applicative

fmap

default <B> Applicative<B,App> fmap(Fn1<? super A,? extends B> fn)

Covariantly transmute this functor's parameter using the given mapping function. Generally this method is specialized to return an instance of the class implementing Functor.

Specified by:

fmap in interface Functor<A,App extends Applicative<?,App>>

Type Parameters:

B - the new parameter type

Parameters:

fn - the mapping function

Returns:

a functor over B (the new parameter type)