com.jnape.palatable.lambda.optics.lenses

Class EitherLens

java.lang.Object

com.jnape.palatable.lambda.optics.lenses.EitherLens

public final class EitherLens
extends Object

Lenses for Either.

Method Summary

Modifier and Type	Method and Description
static <L,R> Lens.Simple<Either<L,R>,Maybe<L>>	_left() Convenience static factory method for creating a lens over left values, wrapping them in a Maybe.
static <L,R> Lens.Simple<Either<L,R>,Maybe<R>>	_right() Convenience static factory method for creating a lens over right values, wrapping them in a Maybe.

Methods inherited from class java.lang.Object

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

Method Detail

_right

public static <L,R> Lens.Simple<Either<L,R>,Maybe<R>> _right()

Convenience static factory method for creating a lens over right values, wrapping them in a Maybe. When setting, a Maybe.nothing() value means to leave the Either unaltered, where as a Maybe.just(A) value replaces the either with a right over the Maybe.

Note that this lens is NOT lawful, since "you get back what you put in" fails for Maybe.nothing().

Type Parameters:

L - the left parameter type

R - the right parameter type

Returns:

a lens that focuses on right values

_left

public static <L,R> Lens.Simple<Either<L,R>,Maybe<L>> _left()

Convenience static factory method for creating a lens over left values, wrapping them in a Maybe. When setting, a Maybe.nothing() value means to leave the Either unaltered, where as a Maybe.just(A) value replaces the either with a left over the Maybe.

Note that this lens is NOT lawful, since "you get back what you put in" fails for Maybe.nothing().

Type Parameters:

L - the left parameter type

R - the right parameter type

Returns:

a lens that focuses on left values