Type Specifier: (OR (FUNCTION ...) ...)

["Scott E. Fahlman" <Fahlman@C.CS.CMU.EDU>]

Your proposal for an extension of the current declaration machinery so
that there is a richer langauge in which to express constraints to the
compiler looks interesting.  I don't have any specific objections to
what you propose -- it may be the right thing.  However, I think that
this is an area in which there are several possible approaches, and I
would like to see some systematic exploration and some real experience
here before we start extending the language spec piecemeal.

I would suggest that if you want to experiment in this area, you develop
a non-standard but compatible superset of the current declaration
language, and that you install this in an experimental version of your
system along with a compiler that uses this information.  I'd like to
see this in a context that includes CommonLoops or New Flavors, since
there are some strong parallels between the kind of type-restricted
arguments that those systems support and the sort of thing that you
propose for declarations.  If actual experience shows that this is a
good way to go, then it would be time to seriously consider extending
the standard in this way.  If it is impractical for people out in
industry to try this, maybe it would make a good M.S. thesis project for
someone.

-- Scott