diff options
Diffstat (limited to 'lib')
| -rw-r--r-- | lib/util.ml | 9 | ||||
| -rw-r--r-- | lib/util.mli | 5 |
2 files changed, 14 insertions, 0 deletions
diff --git a/lib/util.ml b/lib/util.ml index 36282b2da..6de012da0 100644 --- a/lib/util.ml +++ b/lib/util.ml @@ -171,3 +171,12 @@ let open_utf8_file_in fname = let s = Bytes.make 3 ' ' in if input in_chan s 0 3 < 3 || not (is_bom s) then seek_in in_chan 0; in_chan + +(** A trick which can typically be used to store on the fly the + computation of values in the "when" clause of a "match" then + retrieve the evaluated result in the r.h.s of the clause *) + +let set_temporary_memory () = + let a = ref None in + (fun x -> assert (!a = None); a := Some x; x), + (fun () -> match !a with Some x -> x | None -> assert false) diff --git a/lib/util.mli b/lib/util.mli index d910e7e28..c54f5825c 100644 --- a/lib/util.mli +++ b/lib/util.mli @@ -137,3 +137,8 @@ val sym : ('a, 'b) eq -> ('b, 'a) eq val open_utf8_file_in : string -> in_channel (** Open an utf-8 encoded file and skip the byte-order mark if any. *) + +val set_temporary_memory : unit -> ('a -> 'a) * (unit -> 'a) +(** A trick which can typically be used to store on the fly the + computation of values in the "when" clause of a "match" then + retrieve the evaluated result in the r.h.s of the clause *) |