[Types-sig] Greg Stein's writeup (was RFC 0.1)

Tim Hochberg tim.hochberg@ieee.org
Mon, 13 Dec 1999 14:17:00 -0700

> My comments below come from a writeup that is posted at:
>   http://www.foretec.com/python/workshops/1998-11/greg-type-ideas.html
> The writeup is from a discussion last year, between Fred, Sjoerd, and
> myself. I'm not going to replicate the details of that writeup here, but
> will simply highlight some points. Hit the link to see the background.

I just read Greg's writeup and I like it quite a bit. With the exception of
those nasty !s, it seems very Pythonic. My question is: is there a reason
that a digraph couldn't be used instead of the !. In particular "foo->Int"
can be read as "foo evaluates_to Int" which seems to have all of the correct
associations. Or does this result in ambiguous syntax? All of Greg's
examples seem to be OK:

x = value->Int
(x,y) = value->Coord
(x,y) = value->(Int, String)
while foo()->Int:
def foo(x->String)->Int:

Of course there is the problem that -> has a very different meaning in
C/C++, but then so does !.

Just my two cents,