whenJusts

whenJusts<Xs, M>(xs, f): ArgJust<Xs> extends never[] ? Nothing : [Nothing] extends [Xs[number]] ? Nothing | M : M

whenJusts takes a tuple of Maybes and a function that takes the values of the Justs and returns a Maybe of the result of the function.

Example

whenJusts([{ right: 'foo' }, { right: 'bar' }], ([x0, x1]) => `${x0}${x1}`)
// => "foobar"

whenJusts([{ left: 'bar' }, { right: 'fooz' }], ([x0, x1]) => `${x0}${x1}`)
// => { left: "bar" }

Type Parameters

• Xs extends unknown[]

The maybe types.

• M extends unknown

The mapped type.

Parameters

xs

readonly [Xs]

The maybe values.

f

(x) => M

The map function.

Returns

ArgJust<Xs> extends never[] ? Nothing : [Nothing] extends [Xs[number]] ? Nothing | M : M

The mapped value if just.