mte/unikernel/duniverse/mirage/lib/functoria/context.ml
2025-11-11 02:07:51 +01:00

50 lines
1.7 KiB
OCaml

(*
* Copyright (c) 2013-2020 Thomas Gazagnaire <thomas@gazagnaire.org>
* Copyright (c) 2013-2020 Anil Madhavapeddy <anil@recoil.org>
* Copyright (c) 2015-2020 Gabriel Radanne <drupyog@zoho.com>
*
* Permission to use, copy, modify, and distribute this software for any
* purpose with or without fee is hereby granted, provided that the above
* copyright notice and this permission notice appear in all copies.
*
* THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
* WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
* MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
* ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
* WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
* ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
* OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
*)
type 'a key = { name : string; put : 'a -> exn; get : exn -> 'a }
let new_key (type a) name =
let module M = struct
exception E of a
end in
let put a = M.E a in
let get = function
| M.E a -> a
| _ -> raise @@ Invalid_argument ("duplicate key: " ^ name)
in
{ name; put; get }
module Map = Map.Make (String)
type t = exn Map.t
let empty = Map.empty
let add k v (t : t) : t = Map.add k.name (k.put v) t
let mem k (t : t) = Map.mem k.name t
let find k (t : t) =
if Map.mem k.name t then Some (k.get @@ Map.find k.name t) else None
let dump : t Fmt.t =
let pp_elt ppf (k, v) = Fmt.pf ppf "[%s: %a]" k Fmt.exn v in
let map_iter f = Map.iter (fun k v -> f (k, v)) in
Fmt.box ~indent:2 @@ Fmt.(iter ~sep:(any "@ ")) map_iter pp_elt
let merge ~default m =
let aux _ _ v = Some v in
Map.union aux default m