Revision 45d4f8972ba48b3f89f8d14d707fa532358c70ef authored by Nic Volanschi on 03 January 2024, 14:23:24 UTC, committed by Marge Bot on 04 January 2024, 09:23:35 UTC
1 parent 26c74a7
delayed_write_monad.ml
(*****************************************************************************)
(* *)
(* Open Source License *)
(* Copyright (c) 2022 Nomadic Labs, <contact@nomadic-labs.com> *)
(* *)
(* Permission is hereby granted, free of charge, to any person obtaining a *)
(* copy of this software and associated documentation files (the "Software"),*)
(* to deal in the Software without restriction, including without limitation *)
(* the rights to use, copy, modify, merge, publish, distribute, sublicense, *)
(* and/or sell copies of the Software, and to permit persons to whom the *)
(* Software is furnished to do so, subject to the following conditions: *)
(* *)
(* The above copyright notice and this permission notice shall be included *)
(* in all copies or substantial portions of the Software. *)
(* *)
(* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR*)
(* IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, *)
(* FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL *)
(* THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER*)
(* LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING *)
(* FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER *)
(* DEALINGS IN THE SOFTWARE. *)
(* *)
(*****************************************************************************)
type ('a, 'store) t = {
result : 'a;
write : ('store -> unit tzresult Lwt.t) option;
}
let no_write result = {result; write = None}
let delay_write result write = {result; write = Some write}
let map f {result; write} = {result = f result; write}
let map_es f {result; write} =
let open Lwt_result_syntax in
let+ result = f result in
{result; write}
let bind f {result; write = write1} =
let open Lwt_result_syntax in
let {result; write = write2} = f result in
let write =
match (write1, write2) with
| None, None -> None
| Some write, None | None, Some write -> Some write
| Some write1, Some write2 ->
Some
(fun node_ctxt ->
let* () = write1 node_ctxt in
write2 node_ctxt)
in
{result; write}
let apply node_ctxt {result; write} =
let open Lwt_result_syntax in
let+ () =
match write with None -> return_unit | Some write -> write node_ctxt
in
result
let ignore {result; _} = result
module Lwt_result_syntax = struct
let bind f a =
let open Lwt_result_syntax in
let* a in
let* b = f a.result in
let write =
match (a.write, b.write) with
| None, None -> None
| Some write, None | None, Some write -> Some write
| Some write1, Some write2 ->
Some
(fun node_ctxt ->
let* () = write1 node_ctxt in
write2 node_ctxt)
in
return {result = b.result; write}
let map f a = Lwt_result.map (map f) a
let ( let>* ) a f = bind f a
let ( let>+ ) a f = map f a
let return x = Lwt_result.return (no_write x)
let list_fold_left_i_es f acc l =
List.fold_left_i_es
(fun i acc x ->
let>* acc = Lwt.return_ok acc in
f i acc x)
(no_write acc)
l
end
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