Either

sealed class Either<out L, out R>

Disjoint union. The instance might be either Left or Right.

This type is based on scala.Either.

Parameters

Type of Left

Type of Right

Functions

all

common

inline fun all(predicate: (R) -> Boolean): Boolean

Returns the result of applying the predicate to the value if this is Right or true if this is Left.

any

common

inline fun any(predicate: (R) -> Boolean): Boolean

Returns the result of applying the predicate to the value if this is Right or false if this is Left.

contains

common

abstract operator fun contains(element: Any): Boolean

Returns true if the element is equal to the value of this Either, or false otherwise.

filter

common

inline fun filter(predicate: (R) -> Boolean): Either<L, R>?

Returns the same Right if the predicate is satisfied for the value.

filterIsInstance

common

inline fun <T> filterIsInstance(): Either<L, T>?

Returns the same Right casted to type T if it is T.

filterIsInstanceToOption

common

inline fun <T> filterIsInstanceToOption(): Option<Either<L, T>>

Returns Some containing the same Right casted to type T if it is T.

filterNot

common

inline fun filterNot(predicate: (R) -> Boolean): Either<L, R>?

Returns the same Right if the predicate is not satisfied for the value.

filterNotToOption

common

inline fun filterNotToOption(predicate: (R) -> Boolean): Option<Either<L, R>>

Returns Some containing the same Right if the predicate is not satisfied for the value.

filterToOption

common

inline fun filterToOption(predicate: (R) -> Boolean): Option<Either<L, R>>

Returns Some containing the same Right if the predicate is satisfied for the value.

fold

common

inline fun <T> fold(leftTransform: (L) -> T, rightTransform: (R) -> T): T

Transforms Left with leftTransform or Right with rightTransform.

forEach

common

inline fun forEach(action: (R) -> Unit)

Runs action if this is a Right.

get

common

fun get(): R

Gets value of this Right.

getOrNull

common

fun getOrNull(): R?

Gets value of this Right or null if this is Left.

map

common

inline fun <T> map(transform: (R) -> T): Either<L, T>

Maps value of this Right using transform.

none

common

inline fun none(predicate: (R) -> Boolean): Boolean

Returns false if the predicate is met by the value if this is Right or true otherwise.

swap

common

abstract fun swap(): Either<R, L>

Swaps Left to Right and Right to Left.

toOption

common

fun toOption(): Option<R>

Returns a Some containing the Right value if it exists, or a None if this is a Left.

Properties

isLeft

common

abstract val isLeft: Boolean

Returns true if this is a Left or false if this is Right.

isRight

common

abstract val isRight: Boolean

Returns true if this is a Right or false if this is Left.

left

common

val left: LeftProjection<L, R>

Projects Either as Left.

right

common

val right: RightProjection<L, R>

Projects Either as Right.

Inheritors

Left

Right

Extensions

filterNotNull

common

fun <L, R> Either<L, R?>.filterNotNull(): Either<L, R>?

Returns the same Right if its value is not null.

filterNotNullToOption

common

fun <L, R> Either<L, R?>.filterNotNullToOption(): Option<Either<L, R>>

Returns Some containing the same Right if its value is not null.

filterOrElse

common

inline fun <L, R> Either<L, R>.filterOrElse(predicate: (R) -> Boolean, zero: () -> L): Either<L, R>?

Returns the same Right if the predicate is satisfied for the value, Left(zero) if the predicate is not satisfied for the value, or the same Left if this is Left.

flatMap

common

inline fun <L, R, T> Either<L, R>.flatMap(transform: (R) -> Either<L, T>): Either<L, T>

Maps value of this Right to a new Either using transform.

getOrElse

common

inline fun <L, R> Either<L, R>.getOrElse(default: () -> R): R

Gets value of this Right or default value if this is Left.

joinLeft

common

fun <L, R> Either<Either<L, R>, R>.joinLeft(): Either<L, R>

Returns this if this is Right.

joinRight

common

fun <L, R> Either<L, Either<L, R>>.joinRight(): Either<L, R>

Returns this if this is Left.

merge

common

fun <T> Either<T, T>.merge(): T

Merges Left and Right of the same type to a single value.