com.jnape.palatable.lambda.adt.coproduct

Interface CoProduct4<A,B,C,D,CP4 extends CoProduct4<A,B,C,D,?>>

Type Parameters:

A - the first possible type

B - the second possible type

C - the third possible type

D - the fourth possible type

CP4 - the recursive type of this coproduct (used for embedding)

All Known Implementing Classes:

Choice4

Functional Interface:

This is a functional interface and can therefore be used as the assignment target for a lambda expression or method reference.

@FunctionalInterface
public interface CoProduct4<A,B,C,D,CP4 extends CoProduct4<A,B,C,D,?>>

A generalization of the coproduct of four types.

See Also:

CoProduct2

Method Summary

Modifier and Type	Method and Description
default CoProduct3<A,B,C,? extends CoProduct3<A,B,C,?>>	converge(Fn1<? super D,? extends CoProduct3<A,B,C,?>> convergenceFn) Converge this coproduct down to a lower order coproduct by mapping the last possible type into an earlier possible type.
default <E> CoProduct5<A,B,C,D,E,? extends CoProduct5<A,B,C,D,E,?>>	diverge() Diverge this coproduct by introducing another possible type that it could represent.
default <R> R	embed(Fn1<? super CP4,? extends R> aFn, Fn1<? super CP4,? extends R> bFn, Fn1<? super CP4,? extends R> cFn, Fn1<? super CP4,? extends R> dFn) Embed this coproduct inside another value; that is, given morphisms from this coproduct to R, apply the appropriate morphism to this coproduct as a whole.
<R> R	match(Fn1<? super A,? extends R> aFn, Fn1<? super B,? extends R> bFn, Fn1<? super C,? extends R> cFn, Fn1<? super D,? extends R> dFn) Type-safe convergence requiring a match against all potential types.
default Product4<Maybe<A>,Maybe<B>,Maybe<C>,Maybe<D>>	project() Project this coproduct onto a product.
default Maybe<A>	projectA() Convenience method for projecting this coproduct onto a product and then extracting the first slot value.
default Maybe<B>	projectB() Convenience method for projecting this coproduct onto a product and then extracting the second slot value.
default Maybe<C>	projectC() Convenience method for projecting this coproduct onto a product and then extracting the third slot value.
default Maybe<D>	projectD() Convenience method for projecting this coproduct onto a product and then extracting the fourth slot value.

Method Detail

match

<R> R match(Fn1<? super A,? extends R> aFn,
            Fn1<? super B,? extends R> bFn,
            Fn1<? super C,? extends R> cFn,
            Fn1<? super D,? extends R> dFn)

Type-safe convergence requiring a match against all potential types.

Type Parameters:

R - result type

Parameters:

aFn - morphism A -> R

bFn - morphism B -> R

cFn - morphism C -> R

dFn - morphism D -> R

Returns:

the result of applying the appropriate morphism from whichever type is represented by this coproduct to R

See Also:

CoProduct2.match(Fn1, Fn1)

diverge

default <E> CoProduct5<A,B,C,D,E,? extends CoProduct5<A,B,C,D,E,?>> diverge()

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

Type Parameters:

E - the additional possible type of this coproduct

Returns:

a Coproduct5<A, B, C, D, E>

See Also:

CoProduct2.diverge()

converge

default CoProduct3<A,B,C,? extends CoProduct3<A,B,C,?>> converge(Fn1<? super D,? extends CoProduct3<A,B,C,?>> convergenceFn)

Converge this coproduct down to a lower order coproduct by mapping the last possible type into an earlier possible type.

Parameters:

convergenceFn - function from last possible type to earlier type

Returns:

a CoProduct3<A, B, C>

See Also:

CoProduct3.converge(com.jnape.palatable.lambda.functions.Fn1<? super C, ? extends com.jnape.palatable.lambda.adt.coproduct.CoProduct2<A, B, ?>>)

project

default Product4<Maybe<A>,Maybe<B>,Maybe<C>,Maybe<D>> project()

Project this coproduct onto a product.

Returns:

a product of the coproduct projection

See Also:

CoProduct2.project()

projectA

default Maybe<A> projectA()

Convenience method for projecting this coproduct onto a product and then extracting the first slot value.

Returns:

an optional value representing the projection of the "a" type index

projectB

default Maybe<B> projectB()

Convenience method for projecting this coproduct onto a product and then extracting the second slot value.

Returns:

an optional value representing the projection of the "b" type index

projectC

default Maybe<C> projectC()

Convenience method for projecting this coproduct onto a product and then extracting the third slot value.

Returns:

an optional value representing the projection of the "c" type index

projectD

default Maybe<D> projectD()

Convenience method for projecting this coproduct onto a product and then extracting the fourth slot value.

Returns:

an optional value representing the projection of the "d" type index

embed

default <R> R embed(Fn1<? super CP4,? extends R> aFn,
                    Fn1<? super CP4,? extends R> bFn,
                    Fn1<? super CP4,? extends R> cFn,
                    Fn1<? super CP4,? extends R> dFn)

Embed this coproduct inside another value; that is, given morphisms from this coproduct to R, apply the appropriate morphism to this coproduct as a whole. Like match(com.jnape.palatable.lambda.functions.Fn1<? super A, ? extends R>, com.jnape.palatable.lambda.functions.Fn1<? super B, ? extends R>, com.jnape.palatable.lambda.functions.Fn1<? super C, ? extends R>, com.jnape.palatable.lambda.functions.Fn1<? super D, ? extends R>), but without unwrapping the value.

Type Parameters:

R - result type

Parameters:

aFn - morphism A v B v C v D -> R, applied in the A case

bFn - morphism A v B v C v D -> R, applied in the B case

cFn - morphism A v B v C v D -> R, applied in the C case

dFn - morphism A v B v C v D -> R, applied in the D case

Returns:

the result of applying the appropriate morphism to this coproduct