(*
Copyright © 2011 MLstate
This file is part of OPA.
OPA is free software: you can redistribute it and/or modify it under the
terms of the GNU Affero General Public License, version 3, as published by
the Free Software Foundation.
OPA is distributed in the hope that it will be useful, but WITHOUT ANY
WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS
FOR A PARTICULAR PURPOSE. See the GNU Affero General Public License for
more details.
You should have received a copy of the GNU Affero General Public License
along with OPA. If not, see .
*)
type 'a label = 'a ref * exn
let return (r,e) value =
r := value;
raise e
let set_checkpoint_either f =
let r = ref (Obj.magic 0) in
let module M = struct exception Return end in
(* defining a local exception, it is different from any other one *)
try
Base.Left (f (r,M.Return))
with
| M.Return -> Base.Right !r
let set_checkpoint_opt f =
match set_checkpoint_either f with
| Base.Left () -> None
| Base.Right a -> Some a
let set_checkpoint f =
match set_checkpoint_either f with
| Base.Left a -> a
| Base.Right a -> a
let set_checkpoint_none f =
match set_checkpoint_either f with
| Base.Left a -> Some a
| Base.Right () -> None