Maybe to Future

maybeToFuture.js

// Courtesy https://gitter.im/sanctuary-js/sanctuary

//    maybeToFuture :: a -> Maybe b -> Future a b
const maybeToFuture = S.curry2((x, maybe) =>
  S.maybe(Future.reject(x), Future.of, maybe)
);

//  Collapse a `Future String (Maybe Integer)` into a `Future String Integer`.
S.chain(maybeToFuture('parseInt: "XXX" does not represent an integer'),
        Future.of(S.Nothing));