Maybe

Maps the value of a maybe with a possibility to discard it.

Maybe::Just(4)
|> Maybe.andThen((num : Number) : Maybe(String) {
  if (num > 4) {
    Maybe::Just(Number.toString(num))
  } else {
    Maybe::Nothing
  }
})

Flattens a nested maybe.

(Maybe.just("A")
|> Maybe.just()
|> Maybe.flatten()) == Maybe.just("A")

Returns whether or not the maybe is just a value or not.

 Maybe.isJust(Maybe.just("A")) == true
 Maybe.isJust(Maybe.nothing()) == false

Returns whether or not the maybe is just nothing or not.

Maybe.isNothing(Maybe.just("A")) == false
Maybe.isNothing(Maybe.nothing("A")) == false

Returns a maybe containing just the given value.

Maps the value of a maybe.

(Maybe.just(1)
|> Maybe.map((number : Number) : Number { number + 2 })) == 3

Returns nothing.

Returns the first maybe with value of the array or nothing if all are nothing.

Maybe.oneOf([Maybe.just("A"), Maybe.nothing()]) == Maybe.just("A")

Converts the maybe to a result using the given value as the error.

Maybe.toResult(Maybe.nothing(), "Error") == Result.error("Error")
Maybe.toResult(Maybe.just("A"), "Error") == Result.ok("A")

Returns the value of a maybe or the given value if it's nothing.

Maybe.withDefault(Maybe.nothing(), "A") == "A"
Maybe.withDefault(Maybe.just("B"), "A") == "B"

Returns the value of a maybe, or calls the given func otherwise.

Maybe.withLazyDefault(Maybe.nothing(), () { "A" }) == "A"
Maybe.withLazyDefault(Maybe.just("B"), () { "A" }) == "B"