Module `Prime_knowable`

Optional Values with Type-Level Information about Presence

type (+_, _) t = | Unknown : ('a, [> `Unknown ]) t | Known : 'a -> ('a, [> `Known ]) t: ('a, 'k) t is a type-enriched analogue of 'a option, where 'k determines whether the value is present or not.

val get : ('a, [ `Known ]) t -> 'a: know k is the value held by the type-assured knowledge of it.

val get_opt : ('a, [< `Known | `Unknown ]) t -> 'a option: get_opt k is Option.map know (inquire k).

val of_option : 'a option -> ('a, [> `Known | `Unknown ]) t: of_option None is Unknown and knowable_of_option (Some x) is Known x.

val inquire : ('a, [< `Known | `Unknown ]) t -> ('a, [> `Known ]) t option: inquire k checks if k is known, and, if so, assures this fact in the returned copy.