EitherLens

java.lang.Object

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

public final class EitherLens extends Object

Lenses for Either.

Constructor Summary

Constructors

Modifier

Constructor

Description

private

EitherLens()
Method Summary

Modifier and Type

Method

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

Constructor Details
- EitherLens
  
  private EitherLens()
Method Details
- _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