With the improvements to the module system in ocaml 3.12 extending a
signature just got much much lighter. Suppose I want the signature of
the module which in every respects is like StdLabels excepted that the
String module has an extra "is_prefix_of" I can write:
module String : sig
include module type of StdLabels.String
val is_prefix_of : string -> string -> bool
end
include module type of StdLabels with module String := String
I know of no way to extend the implementation in a similarly concise
way (for which the length of the solution does not depend on the
number of top level items in StdLabels). Have I overlooked anything
obvious?
Till
P.S.: FYI existing solution for the implementation:
module String = struct
include StringLabels
let is_prefix_of (needle:string) (haystack:string) : bool =
let len = length needle in
len <= length haystack && (sub haystack ~pos:0 ~len = needle)
end
(* Haven't quite found out how to include a module hiding another one... *)
module List = ListLabels
module Array = ArrayLabels
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