[Types-sig] RE: [meta-sig] The Types-SIG is comatose. Let's retire it.

Martijn Faassen m.faassen@vet.uu.nl
Fri, 03 Dec 1999 19:17:26 +0100

Jeremy Hylton wrote:
> Paul Prescod proposes a new charter for the types-sig:
> > * the goal is a optional static type system for version 2.
> > * presume that the type/class dichotomy has been removed in V2
> > * backwards compatibility with current code is relatively important
> > * compatibility with the Python 1.x interpreter is NOT important
> > * interfaces are not an issue
> > * parameterized (template) types are not available
> > * names are type checked, not expressions
> > * got now, only named types (types and classes) can be declared, not
> >lists and tuples of types
> If you're going to develop a static type system to describe Python
> programs (optional or otherwise), then I think you can't punt on all
> the things you want to punt on.

I probably agree with you (at least partially). See my previous post.

> > * interfaces are not an issue
> Yes, they are :-).

Why, exactly?
> > * parameterized (template) types are not available
> They need to be.

Why, exactly? :)
> > * names are type checked, not expressions
> Expressions need type checking, too!  I'm thinking of the "the"
> special form in Common Lisp.  (I don't have much experience with CL,
> so I'd appreciate input from someone who is.)

I'm even less familiar with CL than you are, so I don't know...

> Regardless of these minor quibbles, my largest complaint is:
> > * the goal is a optional static type system for version 2.
> What exactly is the deliverable.  Saying an "optional static type
> system" is a bit vague.  What is it specifically?  A formal
> specification of the type system?  A stand-alone utility that reports
> type errors?  A new compiler?

Very good question. We need to agree on a deliverable.

> If this is a type system for Python 2, it seems that the best a SIG
> can hope for right now is a specification of the type system

Unfortunately this kind of goal may be too vague to actually involve
people. Not being able to try things out in some kind of implementation
may disconnect the discussion from reality.

> Since
> Py2 design hasn't even started.

When will this start, by the way? Anybody know or is this still pure
speculation? The conference? I started wondering when I saw this in the
'A Date with Tim Peters...' post by Guido on comp.lang.python:

- a developers' day where the feature set of Python 2.0 is worked out.