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Create a constraint between variant type and data list

Sylvain Le Gall
- bluestorm
  - Sylvain Le Gall
    - Maxence Guesdon
- Martin Jambon
  - Ashish Agarwal
- Maxence Guesdon
  - Sylvain Le Gall
- Julien Signoles
  - Julien Signoles
- Anil Madhavapeddy
- Sylvain Le Gall

Date:	-- (:)
From:	Sylvain Le Gall <sylvain@l...>
Subject:	Re: Create a constraint between variant type and data list

Hello all,

On 03-09-2010, Sylvain Le Gall <sylvain@le-gall.net> wrote:
> Hello all,
>
> I would like to somehow enforce that a variant type is associated with
> an entry in a data list. 
>
> For example, 
>
> I would like to define:
>
> type license = GPL | LGPL 
>
> and 
>
> let data = [ GPL, "GNU Public license"; 
>              LGPL, "GNU Lesser General Public license" ]
>
>

Thank you for all your answer. I pick the one from oleg@okmij.org, I
hide the license with a type and the creation of license is done in the
module. The to_string/from_string is done by registering extra data in
an Hashtable.

See the implementation here.
http://darcs.ocamlcore.org/cgi-bin/darcsweb.cgi?r=oasis;a=headblob;f=/src/oasis/OASISLicense.mli
http://darcs.ocamlcore.org/cgi-bin/darcsweb.cgi?r=oasis;a=headblob;f=/src/oasis/OASISLicense.ml

Regards,
Sylvain Le Gall