Exact object types

[rrdelaney]

Flow object types are "open" in Reason terms. There is a way of defining a "closed" types in Flow, using exact object types.

Thanks to @bbqbaron for bringing this up 😄

Example

declare type t = {| foo: string, bar: number |}

should transform to an closed object type:

type t = Js.t {. foo : string, bar : float};