[Types-sig] Optional static typing and Python interfaces

Bill Janssen janssen@parc.xerox.com
Tue, 24 Nov 1998 17:35:53 PST

Excerpts from ext.python: 23-Nov-98 Re: PRE-PROPOSAL: Python In.. Jim
Fulton@digicool.com (1966*)

> I think they are two different problems and I expect different solutions.
> They need not be competing.

One might be useful to the other.  For example, in the proposal we were
bouncing around 3 years ago, the progression of adding optional static
typing went:

	1)  Add interface descriptions (.pi files) which used a slightly
different syntax in that they allowed some kind of optional static
typing declarations.  These serve as documentation; no compilers need
muck with them.  Work out the details of the optional static typing
syntax at this stage.

	2)  Add a program which takes module descriptions for some modules,
along with some Python code which uses those modules, and does some type
inferencing on the code to find detectable (not all) errors in uses of
the module.  It can also check for other errors, such as missing

	3)  Modify the Python parser to allow optional static typing in the
Python code, using the syntax developed in phase 1.  Beef up the
cross-checking program developed in phase 2 to use these type
declarations to aid it in type inferencing.