[nem-en] Debug support

[Michal Moskal]

On 12/20/06, vc <vc at rsdn.ru> wrote:
> > > And I can't set breakpoint on begin match (on match keyword).
> > > The C# compiler add 'not' in begin and end all blacks (and some
> > statements)
> > > which allow set breakpoint.
> >
> > It works better now. I had to put emission of Nops in a few places,
> > which could in general be omitted,
>
> Hm... All the same I can't set breakpoint on match.

It should now work fine. The steps (sequence points) are:
  - the entire match
  - the body of the selected case
  - the entire match again
There are no steps for the matching process itself. You won't be able
to set breakpoint on a guard though (I think this should be fine).

This transform is not applied to two- and one-case matchings, in which
case you can still see some matching code being executed. I didn't
want to screw up ifs.

-- 
   Michał