jchucomponents-core/com.jeluchu.jchucomponents.core.functional

Package-level declarations

Types

sealed class Either<out L, out R>

Represents a value of one of two possible types (a disjoint union). Instances of Either are either an instance of Left or Right. FP Convention dictates that Left is used for "failure" and Right is used for "success".

Functions

fun <A, B, C> (A) -> B.c(f: (B) -> C): (A) -> C

Composes 2 functions See Credits to Alex Hart.

flatMap

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

Right-biased flatMap() FP convention which means that Right is assumed to be the default case to operate on. If it is Left, operations like map, flatMap, ... return the Left value unchanged.

getOrElse

fun <L, R> Either<L, R>.getOrElse(value: R): R

Returns the value from this Right or the given argument if this is a Left. Right(12).getOrElse(17) RETURNS 12 and Left(12).getOrElse(17) RETURNS 17

map

fun <T, L, R> Either<L, R>.map(fn: (R) -> T): Either<L, T>

Right-biased map() FP convention which means that Right is assumed to be the default case to operate on. If it is Left, operations like map, flatMap, ... return the Left value unchanged.