On Thu, Feb 9, 2017 at 1:57 AM, Jeremy Yallop <yallop@gmail.com> wrote:

> >
> > let state_of_value v = match v with
> >   | `Red  | `Blue  | `Green -> ?????
> >   | `Missing -> Missing
>
>   let state_of_value v = match v with
>     | (`Red  | `Blue  | `Green) as c -> Color (color_index c)
>     | `Missing -> Missing
>

perfect, thanks!

martin