Martin Jambon a écrit :
> You want something called "views" or "active patterns".
> You can do that in OCaml with mikmatch, which includes such syntax extension.
>
> See http://martin.jambon.free.fr/mikmatch-manual.html#htoc10
>
> Here is your example:
>
> let view Mod30 = fun x -> x mod 30 = 0
> (*
>    but not:
>      let view Mod m = fun x -> x mod m = 0
>
>    but it could be implemented without difficulty (if really needed).
> *)
>
>
> let test x =
>   match x with
>      %Mod30 -> ...
>    | ... ->
>
>
> Of course the whole point is to use %Mod30 within arbitrary patterns,
> otherwise it wouldn't be useful.
>
> I you want to match regular expressions over anything else than bytes, there's
> nothing out-of-the-box. You can define views on lists that would consume any
> number of elements, but it is pretty limited.
>   

Hello Martin,

That's an elegant way for writing custom pattern matches in OCaml code 
but that is not exactly what I am looking for. Your proposal fits well 
for fixed pattern matches while I would like to make the regular 
expressions customizable via the application command line (ie at 
run-time). A module dedicated to integer matches (like RegExp is to 
string matches) would fit better.

Regards,

Florent
VSYML - VHDL Symbolic Simulator in OCaml: 
http://users-tima.imag.fr/vds/ouchet/vsyml.html