maybeToLeft

Callable

• maybeToLeft<T, R>(x: T, right: R): [Nothing] extends [T] ? IsEqual<T, Nothing> extends true ? Right<R> : Either<Just<T>, R> : Left<T>

---

• Transforms a Maybe value into an Either type, returning a Left containing the Just value. If the Maybe is Nothing, it returns a Right with a specified default value.

  Example

  maybeToLeft("foo", "fallback")
  // => {left: "foo"}
  
  maybeToLeft(Nothing, "fallback")
  // => {right: "fallback"}

  ---

  Type parameters

  • T

    The type held by Just in the Maybe.

  • R

    The type of the Right value in the returned Either.

  Parameters

  • x: T

    The Maybe value to transform. If it is a Just, it is returned as the Left part of an Either.

  • right: R

    The default value to use for the Right part if x is Nothing.

  Returns [Nothing] extends [T] ? IsEqual<T, Nothing> extends true ? Right<R> : Either<Just<T>, R> : Left<T>

  Either a Left containing the Just value or a Right with the default value.