refactor: remove uses of [Stdune.Fdecl] (#1399)

Signed-off-by: Rudi Grinberg <[email protected]>

lsp-fiber/src/import.ml

@@ -1,9 +1,32 @@
 module List = Stdlib.ListLabels
 module Code_error = Stdune.Code_error
-module Fdecl = Stdune.Fdecl
 module Header = Lsp.Header
 module Io = Lsp.Io
 
+module Fdecl : sig
+  type 'a t
+
+  val get : 'a t -> 'a
+  val set : 'a t -> 'a -> unit
+  val create : unit -> 'a t
+end = struct
+  type 'a t = 'a option ref
+
+  let create () = ref None
+
+  let set t x =
+    match !t with
+    | Some _ -> invalid_arg "Fdecl.create: already set"
+    | None -> t := Some x
+  ;;
+
+  let get t =
+    match !t with
+    | None -> invalid_arg "Fdecl.get: not set"
+    | Some t -> t
+  ;;
+end
+
 module Json = struct
   include Lsp.Import.Json
 
@@ -74,7 +97,7 @@ module Log = struct
   ;;
 end
 
-let sprintf = Stdune.sprintf
+let sprintf = Printf.sprintf
 
 module Types = Lsp.Types
 module Client_request = Lsp.Client_request

lsp-fiber/src/lsp_fiber.ml

@@ -7,4 +7,5 @@ module Json = Import.Json
 
 module Private = struct
   module Log = Import.Log
+  module Fdecl = Import.Fdecl
 end

lsp-fiber/src/rpc.ml

@@ -219,7 +219,7 @@ struct
     let t =
       { io
       ; state = Waiting_for_init
-      ; session = Fdecl.create Dyn.opaque
+      ; session = Fdecl.create ()
       ; initialized = Fiber.Ivar.create ()
       ; req_id = 1
       ; pending = Table.create 32

ocaml-lsp-server/src/import.ml

@@ -6,7 +6,6 @@ include struct
   module Code_error = Code_error
   module Comparable = Comparable
   module Exn_with_backtrace = Exn_with_backtrace
-  module Fdecl = Fdecl
   module Fpath = Path
   module Int = Int
   module Table = Table
@@ -212,6 +211,7 @@ module Format = Merlin_utils.Std.Format
 include struct
   open Lsp_fiber
   module Log = Private.Log
+  module Fdecl = Private.Fdecl
   module Reply = Rpc.Reply
   module Server = Server
   module Lazy_fiber = Lsp_fiber.Lazy_fiber

ocaml-lsp-server/src/ocaml_lsp_server.ml

@@ -787,7 +787,7 @@ let on_notification server (notification : Client_notification.t) : State.t Fibe
 
 let start stream =
   let detached = Fiber.Pool.create () in
-  let server = Fdecl.create Dyn.opaque in
+  let server = Fdecl.create () in
   let store = Document_store.make server detached in
   let handler =
     let on_request = { Server.Handler.on_request } in