diff options
| -rw-r--r-- | lib/future.ml | 9 | ||||
| -rw-r--r-- | lib/future.mli | 4 |
2 files changed, 13 insertions, 0 deletions
diff --git a/lib/future.ml b/lib/future.ml index 6001da30d..c1fb176df 100644 --- a/lib/future.ml +++ b/lib/future.ml @@ -47,6 +47,10 @@ let is_val x = match !x with | Val _ -> true | Exn _ | Closure _ | Delegated | Dropped -> false +let is_exn x = match !x with + | Exn _ -> true + | Val _ | Closure _ | Delegated | Dropped -> false + let peek_val x = match !x with | Val (v, _) -> Some v | Exn _ | Closure _ | Delegated | Dropped -> None @@ -103,6 +107,11 @@ let chain ?(id="none") ?(pure=false) c f = ref (match !c with let create_here f = chain ~pure:false (from_here ()) f +let replace x y = + match !x with + | Exn _ -> x := Closure (fun () -> force ~pure:false y) + | _ -> Errors.anomaly (Pp.str "Only Exn futures can be replaced") + let purify f x = let state = !freeze () in try diff --git a/lib/future.mli b/lib/future.mli index f07d325e0..a1535b13d 100644 --- a/lib/future.mli +++ b/lib/future.mli @@ -22,6 +22,9 @@ val from_val : 'a -> 'a computation type 'a assignement = [ `Val of 'a | `Exn of exn | `Comp of 'a computation] val create_delegate : unit -> 'a computation * ('a assignement -> unit) +(* Given a computation that is_exn, replace it by another one *) +val replace : 'a computation -> 'a computation -> unit + (* Variants to stock a copy of the current environment *) val create_here : (unit -> 'a) -> 'a computation val from_here : 'a -> 'a computation @@ -29,6 +32,7 @@ val from_here : 'a -> 'a computation (* Inspect a computation *) val is_over : 'a computation -> bool val is_val : 'a computation -> bool +val is_exn : 'a computation -> bool val peek_val : 'a computation -> 'a option (* Chain computations. |