[m-rev.] for review: Add thread.spawn_native/4 and thread.spawn/4.

[Peter Wang]

On Fri, 27 Jun 2014 16:52:36 +1000 (EST), Julien Fischer <jfischer at opturion.com> wrote:
> >
> > Even then, why do you need to make a separate thread_id type visible to
> > the user?   Thread handles could be defined as follows:
> >
> >    :- type thread
> > 	--->	thread_handle(
> > 		    thread_id    :: <<target specific thread id>>,
> >                    thread_state :: <<ref to some heap cell>>
> >                    etc etc.
> >                 ).
> >
> > Comparison and unification of thread handles would be done using the
> > first field of the above structure (i.e. what happens by default.)
> 
> Obviously, that is *not* what happens by default!  It's Friday afternoon
> ...

Yeah, okay, either the first fields are not equal, or the top-level
addresses are equal, so therefore the later fields are never considered.

I'd still be more comfortable with map(thread_id, T) where thread_id
values are plain Mercury terms, and not special casing for
pretty-printing is nice, too.  Anyway...

Peter