kresult-core/io.kresult.core

Package-level declarations

The core package hosts the main entrypoint of the library: The KResult class. It provides builders, transformers and extractors for result values and failures.

Types

KResult

sealed class KResult<out E, out T>

KResult and its inheritors Success and Failure provide an opinionated, functional result type. While Kotlin has its own kotlin.Result already, the intent of KResult is to be more functional, usable and better integrated.

MultiErrorKResult

typealias MultiErrorKResult<E, T> = KResult<List<E>, T>

Typealias to represent KResult types that have a List type on the Failure side

MultiValueKResult

typealias MultiValueKResult<E, T> = KResult<E, List<T>>

Typealias to represent KResult types that have a List type on the Success side

Functions

asFailure

fun <A> A.asFailure(): KResult<A, Nothing>

Transforms any element to a KResult, carrying the given element on Failure side

asFailureList

fun <A> A.asFailureList(): KResult<List<A>, Nothing>

Transforms any element to a MultiErrorKResult, carrying a list of elements on Failure side

asKResult

fun <T> Result<T>.asKResult(): KResult<Throwable, T>

Transforms a Kotlin native kotlin.Result to a KResult

asResult

fun <E : Throwable, T> KResult<E, T>.asResult(): Result<T>

Transforms a KResult to a Kotlin native kotlin.Result

asSuccess

fun <A> A.asSuccess(): KResult<Nothing, A>

Transforms any element to a KResult, carrying the given element on Success side

asSuccessList

fun <A> A.asSuccessList(): MultiValueKResult<Nothing, A>

Transforms any element to a MultiValueKResult, carrying a list of elements on Success side

combine

fun <E, T> KResult<E, T>.combine(other: KResult<E, T>, combineFailure: (E, E) -> E, combineSuccess: (T, T) -> T): KResult<E, T>

compareTo

operator fun <E : Comparable<E>, T : Comparable<T>> KResult<E, T>.compareTo(other: KResult<E, T>): Int

errors

fun <E, T> MultiErrorKResult<E, T>.errors(): List<E>

Returns a list of errors

failureOrDefault

infix inline fun <E, T> KResult<E, T>.failureOrDefault(default: (T) -> E): E

Returns the error of the Failure side, or the result of the default function otherwise

filter

inline fun <E, T> KResult<E, T>.filter(failureValue: E, condition: (success: T) -> Boolean): KResult<E, T>

Syntactic sugar for filter where instead of a failure function, a value can be provided

inline fun <E, T> KResult<E, T>.filter(failureFn: (success: T) -> E, condition: (success: T) -> Boolean): KResult<E, T>

Filters Success results and transforms to Failure of failureFn if condition result is false

flatMap

inline fun <E, T, T1> KResult<E, T>.flatMap(f: (success: T) -> KResult<E, T1>): KResult<E, T1>

flatMapFailure

fun <E, T, E1> KResult<E, T>.flatMapFailure(f: (failure: E) -> KResult<E1, T>): KResult<E1, T>

flatten

fun <E, T> KResult<E, KResult<E, T>>.flatten(): KResult<E, T>

flattenFailure

fun <E, T> KResult<KResult<E, T>, T>.flattenFailure(): KResult<E, T>

getOrDefault

infix inline fun <E, T> KResult<E, T>.getOrDefault(default: (E) -> T): T

Returns the value of the Success side, or the result of the default function otherwise

getOrElse

infix inline fun <E, T> KResult<E, T>.~~getOrElse~~(default: (E) -> T): T

getOrThrow

fun <E : Throwable, T> KResult<E, T>.getOrThrow(): T

If a KResult has a Throwable on failure side, this either returns the Success.value or throws the Failure.error

merge

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

validate

inline fun <E, T> MultiErrorKResult<E, T>.validate(failureValue: E, expectationFn: (success: T) -> Boolean): MultiErrorKResult<E, T>

Validates a Success or a FailureWithValue against a predicate (expectationFn] and applies failureValue if not fulfilled