[Python-Dev] Splitting up the PVM

[Guido van Rossum]

Tim wrote:

> Sorry, Chris!  Just a case of "no time" here.  Of *course* you
> should continue, and Guido should pop in with an encouraging word
> too -- or a "forget it".  I think this design opens the doors to a
> world of interesting ideas, but that's based on informed prejudice
> rather than careful study of your code.  Cheer up: if everyone
> thought you were a lame ass, we all would have studied your code
> intensely by now <wink>.

No time here either...

I did try to have a quick peek and my first impression is that it's
*very* tricky code!  You know what I think of that...

Here's what I think we should do first (I've mentioned this before but
nobody cheered me on :-).  I'd like to see this as the basis for 1.6.

We should structurally split the Python Virtual Machine and related
code up into different parts -- both at the source code level and at
the runtime level.  The core PVM becomes a replaceable component, and
so do a few other parts like the parser, the bytecode compiler, the
import code, and the interactive read-eval-print loop.  Most object
implementations are shared between all -- or at least the interfaces
are interchangeable.  Clearly, a few object types are specific to one
or another PVM (e.g. frames).  The collection of builtins is also a
separate component (though some builtins may again be specific to a
PVM -- details, details!).

The goal of course, is to create a market for 3rd party components
here, e.g. Chris' flat PVM, or Skip's bytecode optimizer, or Greg's
importer, and so on.

Thoughts?

--Guido van Rossum (home page: http://www.python.org/~guido/)