com.jnape.palatable.lambda.adt.choice

Class Choice3<A,B,C>

java.lang.Object

com.jnape.palatable.lambda.adt.choice.Choice3<A,B,C>

Type Parameters:

A - the first possible type

B - the second possible type

C - the third possible type

All Implemented Interfaces:

CoProduct3<A,B,C,Choice3<A,B,C>>, Applicative<C,Choice3<A,B,?>>, Bifunctor<B,C,Choice3<A,?,?>>, BoundedBifunctor<B,C,Object,Object,Choice3<A,?,?>>, Functor<C,Choice3<A,B,?>>, Monad<C,Choice3<A,B,?>>, MonadRec<C,Choice3<A,B,?>>, Traversable<C,Choice3<A,B,?>>

public abstract class Choice3<A,B,C>
extends Object
implements CoProduct3<A,B,C,Choice3<A,B,C>>, MonadRec<C,Choice3<A,B,?>>, Bifunctor<B,C,Choice3<A,?,?>>, Traversable<C,Choice3<A,B,?>>

Canonical ADT representation of CoProduct3.

See Also:

Choice2, Choice4

Method Summary

Modifier and Type	Method and Description
static <A,B,C> Choice3<A,B,C>	a(A a) Static factory method for wrapping a value of type A in a Choice3.
static <A,B,C> Choice3<A,B,C>	b(B b) Static factory method for wrapping a value of type A in a Choice3.
<D,E> Choice3<A,D,E>	biMap(Fn1<? super B,? extends D> lFn, Fn1<? super C,? extends E> rFn) Dually map covariantly over both the left and right parameters.
<D> Choice3<A,D,C>	biMapL(Fn1<? super B,? extends D> fn) Covariantly map over the left parameter.
<D> Choice3<A,B,D>	biMapR(Fn1<? super C,? extends D> fn) Covariantly map over the right parameter.
static <A,B,C> Choice3<A,B,C>	c(C c) Static factory method for wrapping a value of type A in a Choice3.
Choice2<A,B>	converge(Fn1<? super C,? extends CoProduct2<A,B,?>> convergenceFn) Converge this coproduct down to a lower order coproduct by mapping the last possible type into an earlier possible type.
<D> Choice3<A,B,D>	discardL(Applicative<D,Choice3<A,B,?>> appB) Sequence both this Applicative and appB, discarding this Applicative's result and returning appB.
<D> Choice3<A,B,C>	discardR(Applicative<D,Choice3<A,B,?>> appB) Sequence both this Applicative and appB, discarding appB's result and returning this Applicative.
<D> Choice4<A,B,C,D>	diverge() Diverge this coproduct by introducing another possible type that it could represent.
<D> Choice3<A,B,D>	flatMap(Fn1<? super C,? extends Monad<D,Choice3<A,B,?>>> f) Chain dependent computations that may continue or short-circuit based on previous results.
<D> Choice3<A,B,D>	fmap(Fn1<? super C,? extends D> fn) Covariantly transmute this functor's parameter using the given mapping function.
<D> Lazy<Choice3<A,B,D>>	lazyZip(Lazy<? extends Applicative<Fn1<? super C,? extends D>,Choice3<A,B,?>>> 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.
Tuple3<Maybe<A>,Maybe<B>,Maybe<C>>	project() Specialize this choice's projection to a Tuple3.
<D> Choice3<A,B,D>	pure(D d) Lift the value b into this applicative functor.
static <A,B> Pure<Choice3<A,B,?>>	pureChoice() The canonical Pure instance for Choice3.
<D> Choice3<A,B,D>	trampolineM(Fn1<? super C,? extends MonadRec<RecursiveResult<C,D>,Choice3<A,B,?>>> fn) Given some operation yielding a RecursiveResult inside this MonadRec, internally trampoline the operation until it yields a termination instruction.
<D,App extends Applicative<?,App>,TravB extends Traversable<D,Choice3<A,B,?>>,AppTrav extends Applicative<TravB,App>> AppTrav	traverse(Fn1<? super C,? extends Applicative<D,App>> fn, Fn1<? super TravB,? extends AppTrav> pure) Apply fn to each element of this traversable from left to right, and collapse the results into a single resulting applicative, potentially with the assistance of the applicative's pure function.
<D> Choice3<A,B,D>	zip(Applicative<Fn1<? super C,? extends D>,Choice3<A,B,?>> 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 class java.lang.Object

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

Methods inherited from interface com.jnape.palatable.lambda.adt.coproduct.CoProduct3

embed, match, projectA, projectB, projectC

Methods inherited from interface com.jnape.palatable.lambda.monad.Monad

join

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

coerce

Method Detail

project

public Tuple3<Maybe<A>,Maybe<B>,Maybe<C>> project()

Specialize this choice's projection to a Tuple3.

Specified by:

project in interface CoProduct3<A,B,C,Choice3<A,B,C>>

Returns:

a Tuple3

See Also:

CoProduct2.project()

diverge

public final <D> Choice4<A,B,C,D> diverge()

Diverge this coproduct by introducing another possible type that it could represent.

Specified by:

diverge in interface CoProduct3<A,B,C,Choice3<A,B,C>>

Type Parameters:

D - the additional possible type of this coproduct

Returns:

a CoProduct4<A, B, C, D>

See Also:

CoProduct2.diverge()

converge

public final Choice2<A,B> converge(Fn1<? super C,? extends CoProduct2<A,B,?>> convergenceFn)

Converge this coproduct down to a lower order coproduct by mapping the last possible type into an earlier possible type. This is the categorical dual of CoProduct2.diverge(), which introduces the type C and raises the order from 2 to 3.

The following laws hold for any two coproducts of single order difference:

• Cancellation: coProductN.diverge().converge(CoProductN::a) == coProductN

Specified by:

converge in interface CoProduct3<A,B,C,Choice3<A,B,C>>

Parameters:

convergenceFn - function from last possible type to earlier type

Returns:

a CoProduct2<A, B>

fmap

public final <D> Choice3<A,B,D> fmap(Fn1<? super C,? extends D> 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 Applicative<C,Choice3<A,B,?>>

Specified by:

fmap in interface Functor<C,Choice3<A,B,?>>

Specified by:

fmap in interface Monad<C,Choice3<A,B,?>>

Specified by:

fmap in interface MonadRec<C,Choice3<A,B,?>>

Specified by:

fmap in interface Traversable<C,Choice3<A,B,?>>

Type Parameters:

D - the new parameter type

Parameters:

fn - the mapping function

Returns:

a functor over B (the new parameter type)

biMapL

public final <D> Choice3<A,D,C> biMapL(Fn1<? super B,? extends D> fn)

Covariantly map over the left parameter.

Specified by:

biMapL in interface Bifunctor<B,C,Choice3<A,?,?>>

Specified by:

biMapL in interface BoundedBifunctor<B,C,Object,Object,Choice3<A,?,?>>

Type Parameters:

D - the new left parameter type

Parameters:

fn - the mapping function

Returns:

a bifunctor over C (the new left parameter) and B (the same right parameter)

biMapR

public final <D> Choice3<A,B,D> biMapR(Fn1<? super C,? extends D> fn)

Covariantly map over the right parameter. For all bifunctors that are also functors, it should hold that biMapR(f) == fmap(f).

Specified by:

biMapR in interface Bifunctor<B,C,Choice3<A,?,?>>

Specified by:

biMapR in interface BoundedBifunctor<B,C,Object,Object,Choice3<A,?,?>>

Type Parameters:

D - the new right parameter type

Parameters:

fn - the mapping function

Returns:

a bifunctor over A (the same left parameter) and C (the new right parameter)

biMap

public final <D,E> Choice3<A,D,E> biMap(Fn1<? super B,? extends D> lFn,
                                        Fn1<? super C,? extends E> rFn)

Dually map covariantly over both the left and right parameters. This is isomorphic to biMapL(lFn).biMapR(rFn).

Specified by:

biMap in interface Bifunctor<B,C,Choice3<A,?,?>>

Specified by:

biMap in interface BoundedBifunctor<B,C,Object,Object,Choice3<A,?,?>>

Type Parameters:

D - the new left parameter type

E - the new right parameter type

Parameters:

lFn - the left parameter mapping function

rFn - the right parameter mapping function

Returns:

a bifunctor over C (the new left parameter type) and D (the new right parameter type)

pure

public <D> Choice3<A,B,D> pure(D d)

Lift the value b into this applicative functor.

Specified by:

pure in interface Applicative<C,Choice3<A,B,?>>

Specified by:

pure in interface Monad<C,Choice3<A,B,?>>

Specified by:

pure in interface MonadRec<C,Choice3<A,B,?>>

Type Parameters:

D - the type of the returned applicative's parameter

Parameters:

d - the value

Returns:

an instance of this applicative over b

zip

public <D> Choice3<A,B,D> zip(Applicative<Fn1<? super C,? extends D>,Choice3<A,B,?>> appFn)

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

Specified by:

zip in interface Applicative<C,Choice3<A,B,?>>

Specified by:

zip in interface Monad<C,Choice3<A,B,?>>

Specified by:

zip in interface MonadRec<C,Choice3<A,B,?>>

Type Parameters:

D - the resulting applicative parameter type

Parameters:

appFn - the other applicative instance

Returns:

the mapped applicative

lazyZip

public <D> Lazy<Choice3<A,B,D>> lazyZip(Lazy<? extends Applicative<Fn1<? super C,? extends D>,Choice3<A,B,?>>> 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.

Specified by:

lazyZip in interface Applicative<C,Choice3<A,B,?>>

Specified by:

lazyZip in interface Monad<C,Choice3<A,B,?>>

Specified by:

lazyZip in interface MonadRec<C,Choice3<A,B,?>>

Type Parameters:

D - the resulting applicative parameter type

Parameters:

lazyAppFn - the lazy other applicative instance

Returns:

the mapped applicative

See Also:

Maybe, Either

discardL

public <D> Choice3<A,B,D> discardL(Applicative<D,Choice3<A,B,?>> appB)

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

Specified by:

discardL in interface Applicative<C,Choice3<A,B,?>>

Specified by:

discardL in interface Monad<C,Choice3<A,B,?>>

Specified by:

discardL in interface MonadRec<C,Choice3<A,B,?>>

Type Parameters:

D - the type of the returned Applicative's parameter

Parameters:

appB - the other Applicative

Returns:

appB

discardR

public <D> Choice3<A,B,C> discardR(Applicative<D,Choice3<A,B,?>> appB)

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

Specified by:

discardR in interface Applicative<C,Choice3<A,B,?>>

Specified by:

discardR in interface Monad<C,Choice3<A,B,?>>

Specified by:

discardR in interface MonadRec<C,Choice3<A,B,?>>

Type Parameters:

D - the type of appB's parameter

Parameters:

appB - the other Applicative

Returns:

this Applicative

flatMap

public <D> Choice3<A,B,D> flatMap(Fn1<? super C,? extends Monad<D,Choice3<A,B,?>>> f)

Chain dependent computations that may continue or short-circuit based on previous results.

Specified by:

flatMap in interface Monad<C,Choice3<A,B,?>>

Specified by:

flatMap in interface MonadRec<C,Choice3<A,B,?>>

Type Parameters:

D - the resulting monad parameter type

Parameters:

f - the dependent computation over A

Returns:

the new monad instance

trampolineM

public <D> Choice3<A,B,D> trampolineM(Fn1<? super C,? extends MonadRec<RecursiveResult<C,D>,Choice3<A,B,?>>> fn)

Given some operation yielding a RecursiveResult inside this MonadRec, internally trampoline the operation until it yields a termination instruction.

Stack-safety depends on implementations guaranteeing that the growth of the call stack is a constant factor independent of the number of invocations of the operation. For various examples of how this can be achieved in stereotypical circumstances, see the referenced types.

Specified by:

trampolineM in interface MonadRec<C,Choice3<A,B,?>>

Type Parameters:

D - the ultimate resulting carrier type

Parameters:

fn - the function to internally trampoline

Returns:

the trampolined MonadRec

See Also:

for a basic implementation, for a {@link CoProduct2 coproduct} implementation, for an implementation leveraging an already stack-safe {@link Monad#flatMap(Fn1)}, for a {@link MonadT monad transformer} implementation

traverse

public <D,App extends Applicative<?,App>,TravB extends Traversable<D,Choice3<A,B,?>>,AppTrav extends Applicative<TravB,App>> AppTrav traverse(Fn1<? super C,? extends Applicative<D,App>> fn,
                                                                                                                                              Fn1<? super TravB,? extends AppTrav> pure)

Apply fn to each element of this traversable from left to right, and collapse the results into a single resulting applicative, potentially with the assistance of the applicative's pure function.

Specified by:

traverse in interface Traversable<C,Choice3<A,B,?>>

Type Parameters:

D - the resulting element type

App - the result applicative type

TravB - this Traversable instance over B

AppTrav - the full inferred resulting type from the traversal

Parameters:

fn - the function to apply

pure - the applicative pure function

Returns:

the traversed Traversable, wrapped inside an applicative

a

public static <A,B,C> Choice3<A,B,C> a(A a)

Static factory method for wrapping a value of type A in a Choice3.

Type Parameters:

A - the first possible type

B - the second possible type

C - the third possible type

Parameters:

a - the value

Returns:

the wrapped value as a Choice3<A, B, C>

b

public static <A,B,C> Choice3<A,B,C> b(B b)

Static factory method for wrapping a value of type A in a Choice3.

Type Parameters:

A - the first possible type

B - the second possible type

C - the third possible type

Parameters:

b - the value

Returns:

the wrapped value as a Choice3<A, B, C>

c

public static <A,B,C> Choice3<A,B,C> c(C c)

Static factory method for wrapping a value of type A in a Choice3.

Type Parameters:

A - the first possible type

B - the second possible type

C - the third possible type

Parameters:

c - the value

Returns:

the wrapped value as a Choice3<A, B, C>

pureChoice

public static <A,B> Pure<Choice3<A,B,?>> pureChoice()

The canonical Pure instance for Choice3.

Type Parameters:

A - the first possible type

B - the second possible type

Returns:

the Pure instance