com.mojang.datafixers.optics.profunctors

Interface Profunctor<P extends K2,Mu extends Profunctor _>

Type Parameters:

P - The container type.

Mu - The witness type for this profunctor.

All Superinterfaces:

Mu<P>, Kind2 P

All Known Subinterfaces:

AffineP<P,Mu>, Cartesian<P,Mu>, Closed<P,Mu>, Cocartesian<P,Mu>, GetterP<P,Mu>, Mapping<P,Mu>, Monoidal<P,Mu>, MonoidProfunctor<P,Mu>, ReCartesian<P,Mu>, ReCocartesian<P,Mu>, TraversalP<P,Mu>

All Known Implementing Classes:

Adapter.Instance, Affine.Instance, Forget.Instance, ForgetOpt.Instance, FunctionType.Instance, Lens.Instance, Prism.Instance, ProfunctorFunctorWrapper.Instance, ReForgetC.Instance, Traversal.Instance

public interface Profunctor<P extends K2,Mu extends Profunctor _>
extends Kind2 P

The profunctor type class defines a method, dimap(Function, Function), which transforms a mapping between types to a mapping between wrapped types.

This type class requires that the container P is contravariant in its first parameter.

Type Shape:

%.Type. %0

See Also:

Understanding profunctors

Method Summary

Modifier and Type	Method and Description
default <A,B,C,D> P<C,D>	dimap(P<A,B> arg, (C) -> A g, (B) -> D h) Takes an input container, a left mapping from output to input, and a right mapping from input to output, and returns an output container.
<A,B,C,D> (P<A,B>) -> P<C,D>	dimap((C) -> A g, (B) -> D h) Takes a function from the output type C to the input type A and a function from the input type B to the output type D, and returns a function from a container of A, B to a container of C, D.
default <A,B,C,D> P<C,D>	dimap(by-name P<A,B> arg, (C) -> A g, (B) -> D h) Takes an input container, a mapping from output to input, and a mapping from input to output, and returns an output container.
default <A,B,C> P<C,B>	lmap(P<A,B> input, (C) -> A g) Maps the first, or left hand, parameter of the given input.
default <A,B,D> P<A,D>	rmap(P<A,B> input, (B) -> D h) Maps the second, or left hand, parameter of the given input.

Method Detail

dimap

<A,B,C,D> (P<A,B>) -> P<C,D> dimap((C) -> A g,
                                   (B) -> D h)

Takes a function from the output type C to the input type A and a function from the input type B to the output type D, and returns a function from a container of A, B to a container of C, D.

A straightforward example of an implementation of dimap is the method Function.andThen(Function). For functions, the expression

 dimap(g, h).apply(f)
 

is equivalent to

 g.andThen(f).andThen(h)
 

Type Parameters:

A - The first input type.

B - The second input type.

C - The first output type.

D - The second output type.

Parameters:

g - A function from output to input.

h - A function from input to output.

Returns:

A function from an input container to an output container.

See Also:

dimap(App2, Function, Function)

dimap

default <A,B,C,D> P<C,D> dimap(P<A,B> arg,
                               (C) -> A g,
                               (B) -> D h)

Takes an input container, a left mapping from output to input, and a right mapping from input to output, and returns an output container.

Implementation Requirements:

This method is equivalent to dimap(g, h).apply(arg).

Type Parameters:

A - The first input type.

B - The second input type.

C - The first output type.

D - The second output type.

Parameters:

arg - The input container.

g - A function from output to input.

h - A function from input to output.

Returns:

An output container.

See Also:

dimap(Function, Function)

dimap

default <A,B,C,D> P<C,D> dimap(by-name P<A,B> arg,
                               (C) -> A g,
                               (B) -> D h)

Takes an input container, a mapping from output to input, and a mapping from input to output, and returns an output container.

Implementation Requirements:

This method is equivalent to dimap(arg.get(), g, h).

Type Parameters:

A - The first input type.

B - The second input type.

C - The first output type.

D - The second output type.

Parameters:

arg - The input container.

g - A function from output to input.

h - A function from input to output.

Returns:

An output container.

See Also:

dimap(App2, Function, Function), dimap(Function, Function)

lmap

default <A,B,C> P<C,B> lmap(P<A,B> input,
                            (C) -> A g)

Maps the first, or left hand, parameter of the given input.

Type Parameters:

A - The first input type.

B - The second input and output type.

C - The first output type.

Parameters:

input - The input container.

g - The mapping function.

Returns:

A container taking the mapped input and yielding the same output.

See Also:

dimap(App2, Function, Function)

rmap

default <A,B,D> P<A,D> rmap(P<A,B> input,
                            (B) -> D h)

Maps the second, or left hand, parameter of the given input.

Type Parameters:

A - The first input and output type.

B - The second input type.

D - The second output type.

Parameters:

input - The input container.

h - The mapping function.

Returns:

A container taking the same input and yielding the mapped output.

See Also:

dimap(App2, Function, Function)