Quellcode-Bibliothek future.ml Sprache: SML

(************************************************************************)
(*         *      The Rocq Prover / The Rocq Development Team           *)
(*  v      *         Copyright INRIA, CNRS and contributors             *)
(* <O___,, * (see version control and CREDITS file for authors & dates) *)
(*   \VV/  **************************************************************)
(*    //   *    This file is distributed under the terms of the         *)
(*         *     GNU Lesser General Public License Version 2.1          *)
(*         *     (see LICENSE file for the text of the license)         *)
(************************************************************************)

let not_ready_msg = ref (fun name ->
      Pp.strbrk("The value you are asking for ("^name^") is not ready yet. "^
                "Please wait or pass "^
                "the \"-async-proofs off\" option to Rocqide to disable "^
                "asynchronous script processing and don't pass \"-vio\" to "^
                "rocq compile."))
let not_here_msg = ref (fun name ->
      Pp.strbrk("The value you are asking for ("^name^") is not available "^
                "in this process. If you really need this, pass "^
                "the \"-async-proofs off\" option to Rocqide to disable "^
                "asynchronous script processing and don't pass \"-vio\" to "^
                "rocq compile."))

exception NotReady of string
exception NotHere of string

let _ = CErrors.register_handler (function
  | NotReady name -> Some (!not_ready_msg name)
  | NotHere name -> Some (!not_here_msg name)
  | _ -> None)

type fix_exn = Stateid.exn_info option

let eval_fix_exn f (e, info) = match f with
| None -> (e, info)
| Some { Stateid.id; valid } ->
  match Stateid.get info with
  | Some _ -> (e, info)
  | None ->
    let loc = Loc.get_loc info in
    let msg = CErrors.iprint (e, info) in
    let qf = Result.value ~default:[] (Quickfix.from_exception e) in
    let () = Feedback.(feedback ~id (Message (Error, loc, qf, msg))) in
    (e, Stateid.add info ~valid id)

module UUID = struct
  type t = int
  let invalid = 0
  let fresh =
    let count = ref invalid in
    fun () -> incr count; !count

  let compare = compare
  let equal = (==)
end

module UUIDMap = Map.Make(UUID)
module UUIDSet = Set.Make(UUID)

type 'a assignment = [ `Val of 'a | `Exn of Exninfo.iexn | `Comp of (unit -> 'a)]

(* Val is not necessarily a final state, so the
   computation restarts from the state stocked into Val *)
and 'a comp =
  | Delegated of (Mutex.t * Condition.t) option
  | Closure of (unit -> 'a)
  | Val of 'a
  | Exn of Exninfo.iexn  (* Invariant: this exception is always "fixed" as in fix_exn *)

and 'a computation =
  | Ongoing of string * (UUID.t * fix_exn * 'a comp ref) CEphemeron.key

let unnamed = "unnamed"

let create ?(name=unnamed) ?(uuid=UUID.fresh ()) ~fix_exn x =
  Ongoing (name, CEphemeron.create (uuid, fix_exn, ref x))
let get x =
  match x with
  | Ongoing (name, x) ->
      try let uuid, fix, c = CEphemeron.get x in name, uuid, fix, c
      with CEphemeron.InvalidKey ->
        name, UUID.invalid, None, ref (Exn (NotHere name, Exninfo.null))

type 'a value = [ `Val of 'a | `Exn of Exninfo.iexn  ]

let is_over kx = let _, _, _, x = get kx in match !x with
  | Val _ | Exn _ -> true
  | Closure _ | Delegated _ -> false

let is_exn kx = let _, _, _, x = get kx in match !x with
  | Exn _ -> true
  | Val _ | Closure _ | Delegated _ -> false

let peek_val kx = let _, _, _, x = get kx in match !x with
  | Val v -> Some v
  | Exn _ | Closure _ | Delegated _ -> None

let uuid kx = let _, id, _, _ = get kx in id

let from_val v = create ~fix_exn:None (Val v)

let create_delegate ?(blocking=true) ~name fix_exn =
  let sync =
    if blocking then Some (Mutex.create (), Condition.create ())
    else None
  in
  let ck = create ~name ~fix_exn (Delegated sync) in
  let assignment = fun v ->
    let _, _, fix_exn, c = get ck in
    let sync = match !c with Delegated s -> s | _ -> assert false in
    begin match v with
    | `Val v -> c := Val v
    | `Exn e -> c := Exn (eval_fix_exn fix_exn e)
    | `Comp f -> c := Closure f end;
    let iter (lock, cond) = CThread.with_lock lock ~scope:(fun () -> Condition.broadcast cond) in
    Option.iter iter sync
  in
  ck, assignment

(* TODO: get rid of try/catch to be stackless *)
let rec compute ck : 'a value =
  let name, _, fix_exn, c = get ck in
  match !c with
  | Val x -> `Val x
  | Exn (e, info) -> `Exn (e, info)
  | Delegated None -> raise (NotReady name)
  | Delegated (Some (lock, cond)) ->
    CThread.with_lock lock ~scope:(fun () -> Condition.wait cond lock); compute ck
  | Closure f ->
      try
        let data = f () in
        c := Val data; `Val data
      with e ->
        let e = Exninfo.capture e in
        let e = eval_fix_exn fix_exn e in
        match e with
        | (NotReady _, _) -> `Exn e
        | _ -> c := Exn e; `Exn e

let force x = match compute x with
  | `Val v -> v
  | `Exn e -> Exninfo.iraise e

let chain ck f =
  let name, uuid, fix_exn, c = get ck in
  create ~uuid ~name ~fix_exn (match !c with
  | Closure _ | Delegated _ -> Closure (fun () -> f (force ck))
  | Exn _ as x -> x
  | Val v -> Val (f v))

let create ~fix_exn f = create ~fix_exn (Closure f)

let replace kx y =
  let _, _, _, x = get kx in
  match !x with
  | Exn _ -> x := Closure (fun () -> force y)
  | _ -> CErrors.anomaly
           (Pp.str "A computation can be replaced only if is_exn holds.")

let chain x f =
  let y = chain x f in
  if is_over x then ignore(force y);
  y

let print f kx =
  let open Pp in
  let name, uid, _, x = get kx in
  let uid =
    if UUID.equal uid UUID.invalid then str "[#:" ++ str name ++ str "]"
    else str "[" ++ int uid ++ str":" ++ str name ++ str "]"
  in
  match !x with
  | Delegated _ -> str "Delegated" ++ uid
  | Closure _ -> str "Closure" ++ uid
  | Val x -> str "PureVal" ++ uid ++ spc () ++ hov 0 (f x)
  | Exn (e, _) -> str "Exn"  ++ uid ++ spc () ++ hov 0 (str (Printexc.to_string e))

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¤ Die Informationen auf dieser Webseite wurden nach bestem Wissen sorgfältig zusammengestellt. Es wird jedoch weder Vollständigkeit, noch Richtigkeit, noch Qualität der bereit gestellten Informationen zugesichert.0.15Bemerkung: (vorverarbeitet) ¤

Wurzel

Suchen

Beweissystem der NASA

Beweissystem Isabelle

NIST Cobol Testsuite

Cephes Mathematical Library

Wiener Entwicklungsmethode

Haftungshinweis

Die Informationen auf dieser Webseite wurden nach bestem Wissen sorgfältig zusammengestellt. Es wird jedoch weder Vollständigkeit, noch Richtigkeit, noch Qualität der bereit gestellten Informationen zugesichert.

Bemerkung:

Die farbliche Syntaxdarstellung ist noch experimentell.