ligo/src/lib_base/p2p_version.ml
2018-02-05 23:34:05 +01:00

41 lines
1.4 KiB
OCaml

(**************************************************************************)
(* *)
(* Copyright (c) 2014 - 2018. *)
(* Dynamic Ledger Solutions, Inc. <contact@tezos.com> *)
(* *)
(* All rights reserved. No warranty, explicit or implicit, provided. *)
(* *)
(**************************************************************************)
type t = {
name : string ;
major : int ;
minor : int ;
}
let pp ppf { name ; major ; minor } =
Format.fprintf ppf "%s.%d.%d" name major minor
let encoding =
let open Data_encoding in
conv
(fun { name; major; minor } -> (name, major, minor))
(fun (name, major, minor) -> { name; major; minor })
(obj3
(req "name" string)
(req "major" int8)
(req "minor" int8))
(* the common version for a pair of peers, if any, is the maximum one,
in lexicographic order *)
let common la lb =
let la = List.sort (fun l r -> compare r l) la in
let lb = List.sort (fun l r -> compare r l) lb in
let rec find = function
| [], _ | _, [] -> None
| ((a :: ta) as la), ((b :: tb) as lb) ->
if a = b then Some a
else if a < b then find (ta, lb)
else find (la, tb)
in find (la, lb)