arrow-core/arrow.core/Either/Left

Left

data class Left<out A>(val value: A) : Either<A, Nothing>

The left side of the disjoint union, as opposed to the Right side.

Constructors

fun <out A> Left(value: A)

Types

object Companion

Functions

inline fun all(predicate: (Nothing) -> Boolean): Boolean

Returns true if Left or returns the result of the application of the given predicate to the Right value.

inline fun <C> bifoldLeft( c: C, f: (C, A) -> C, g: (C, Nothing) -> C): C

inline fun <C> bifoldMap( MN: Monoid<C>, f: (A) -> C, g: (Nothing) -> C): C

inline fun <C, D> bimap(leftOperation: (A) -> C, rightOperation: (Nothing) -> D): Either<C, D>

Map over Left and Right of this Either

inline fun <AA, C> bitraverse(fe: (A) -> Iterable<AA>, fa: (Nothing) -> Iterable<C>): List<Either<AA, C>>

bitraverseNullable

inline fun <AA, C> bitraverseNullable(fl: (A) -> AA?, fr: (Nothing) -> C?): Either<AA, C>?

bitraverseOption

inline fun <AA, C> bitraverseOption(fl: (A) -> Option<AA>, fr: (Nothing) -> Option<C>): Option<Either<AA, C>>

bitraverseValidated

inline fun <AA, C, D> bitraverseValidated(fe: (A) -> Validated<AA, C>, fa: (Nothing) -> Validated<AA, D>): Validated<AA, Either<C, D>>

inline fun exists(predicate: (Nothing) -> Boolean): Boolean

Returns false if Left or returns the result of the application of the given predicate to the Right value.

inline fun findOrNull(predicate: (Nothing) -> Boolean): Nothing?

inline fun <C> fold(ifLeft: (A) -> C, ifRight: (Nothing) -> C): C

Applies ifLeft if this is a Left or ifRight if this is a Right.

inline fun <C> foldLeft(initial: C, rightOperation: (C, Nothing) -> C): C

fun <C> foldMap(MN: Monoid<C>, f: (Nothing) -> C): C

fun isEmpty(): Boolean

Returns true if Left

fun isLeft(): Boolean

fun isNotEmpty(): Boolean

Returns true if Right

fun isRight(): Boolean

inline fun <C> map(f: (Nothing) -> C): Either<A, C>

The given function is applied if this is a Right.

inline fun <C> mapLeft(f: (A) -> C): Either<C, Nothing>

The given function is applied if this is a Left.

fun orNone(): Option<Nothing>

fun orNull(): Nothing?

Returns the right value if it exists, otherwise null

fun replicate(n: Int): Either<A, List<Nothing>>

fun swap(): Either<Nothing, A>

If this is a Left, then return the left value in Right or vice versa.

inline fun tap(f: (Nothing) -> Unit): Either<A, Nothing>

The given function is applied as a fire and forget effect if this is a Right. When applied the result is ignored and the original Either value is returned

inline fun tapLeft(f: (A) -> Unit): Either<A, Nothing>

The given function is applied as a fire and forget effect if this is a Left. When applied the result is ignored and the original Either value is returned

open override fun toString(): String

fun toValidated(): Validated<A, Nothing>

fun toValidatedNel(): ValidatedNel<A, Nothing>

inline fun <C> traverse(fa: (Nothing) -> Option<C>): Option<Either<A, C>>

inline fun <AA, C> traverse(fa: (Nothing) -> Validated<AA, C>): Validated<AA, Either<A, C>>

inline fun <C> traverse(fa: (Nothing) -> Iterable<C>): List<Either<A, C>>

traverseNullable

inline fun <C> traverseNullable(fa: (Nothing) -> C?): Either<A, C>?

~~inline~~ ~~fun~~ <C> ~~traverseOption~~(fa: (Nothing) -> Option<C>): Option<Either<A, C>>

traverseValidated

~~inline~~ ~~fun~~ <AA, C> ~~traverseValidated~~(fa: (Nothing) -> Validated<AA, C>): Validated<AA, Either<A, C>>

fun void(): Either<A, Unit>

Properties

val value: A