kone.maybe/dev.lounres.kone.maybe

Package-level declarations

Types

sealed interface Maybe<out Element>

Container interface that is used to describe that there is either some value wrapped in the data class Some or the None data object. It's a copy of Option from Rust stdlib.

None

data object None : Maybe<Nothing>

Just a simple marker of a value absence that is a part of Maybe purpose. See its docs for more.

Some

data class Some<out Element>(val value: Element) : Maybe<Element>

Just a simple value container that is a part of Maybe purpose. See its docs for more.

Functions

computeOn

inline fun <Element, Result> Maybe<Element>.computeOn(compute: (Element) -> Result): Maybe<Result>

Computes the compute on the value and returns it wrapped in Some if the value is present or just returns None otherwise.

computeOnOrDefault

inline fun <Element, Result> Maybe<Element>.computeOnOrDefault(default: Result, compute: (Element) -> Result): Result

Computes the compute on the value and returns it if the value is present or just returns default one otherwise.

computeOnOrElse

inline fun <Element, Result> Maybe<Element>.computeOnOrElse(default: () -> Result, compute: (Element) -> Result): Result

Computes the compute on the value and returns it if the value is present or just computes and returns default one otherwise.

flatten

fun <Element> Maybe<Maybe<Element>>.flatten(): Maybe<Element>

Returns the wrapped in Some instance of type Maybe<E> if it is present or None otherwise.

isNone

fun Maybe<*>.isNone(): Boolean

Returns true if the value is absent.

isSome

fun Maybe<*>.isSome(): Boolean

Returns true if the value is present.

notNullMaybe

fun <Element : Any> Element?.notNullMaybe(): Maybe<Element>

Wraps this value in Some if it is not null or returns None otherwise.

orDefault

fun <Element> Maybe<Element>.orDefault(default: Element): Element

Returns the value if it is present or default one otherwise.

orElse

inline fun <Element> Maybe<Element>.orElse(default: () -> Element): Element

Returns the value if it is present or computes and returns default one otherwise.

orThrow

inline fun <Element> Maybe<Element>.orThrow(error: () -> Throwable): Element

Returns the value if it is present or throws the provided exception otherwise.

transformNotNullMaybe

fun <Element : Any, Result> Element?.transformNotNullMaybe(transform: (Element) -> Result): Maybe<Result>

Transforms this value with transform function and wraps result in Some if this value is not null or returns None otherwise.