[stdlib-sig] Proposal: new "interpreter" module

[Benjamin Peterson]

On Fri, Apr 4, 2008 at 10:27 AM, Benjamin Peterson <
musiccomposition at gmail.com> wrote:

>
>
> On Fri, Apr 4, 2008 at 10:01 AM, Steven Bethard <steven.bethard at gmail.com>
> wrote:
>
> > On Fri, Apr 4, 2008 at 11:27 AM, Christian Heimes <christian at cheimes.de>
> > wrote:
> > >  Once the pyvm module is implemented the sys module should only
> > contain
> > >  system methods which can be implemented by all flavors of Python.
> >
> > On Fri, Apr 4, 2008 at 5:44 AM, Brett Cannon <brett at python.org> wrote:
> > > This is exactly the type of separation I want to see.
> > [snip]
> > > Sound good to people? If so, who wants to take this on?
> >
> > 2008/4/4 Benjamin Peterson <musiccomposition at gmail.com>:
> > > If there is further support, I will.
> >
> > I don't know how much more further support you need, but I'm 100%
> > behind the idea. If you need any more help, let me know.
>
> I'm starting the PEP now...
>
And here it is: This is my first PEP, so do be brutal with your feedback.

PEP: XXX
Title: The interpreter module
Version: $Revision$
Last-Modified: $Date$
Author: Benjamin Peterson
Status: Draft
Type: Standards Track
Content-Type: text/x-rst
Created: 4-April-2008
Python-Version: 3.0


Abstract
========

This PEP proposes a new low-level module for CPython-specific interpreter
functions in order to clean out the sys module and separate general Python
functionality from implementation details.


Rationale
=========

The sys module currently contains functions and data that can be put into
two
major groups:

1. Data and functions that are available in all Python implementations and
deal
   with the general running of a Python VM.

   - display_hook, stdout, stdin, and stderr
   - flags and warn_options
   - settrace, and setprofile
   - traceback, excepthook
   - etc...


2. Data and function that affect the CPython interpreter.

   - get/setrecursionlimit
   - get/setcheckinterval
   - _getframe and _current_frame
   - getrefcount
   - getdlopenflags

The second collections of items has been steadily increasing over the years
causing clutter in sys.  Guido has even said he doesn't recognize some of
things
in it [#bug-1522]_!

Other implementations have clearly struggled with what to do about the
contents
of sys they can't implement but must to retain compatibility.  For example,
Jython's sys module has dud set/getrecursionlimit functions.  Moving these
items
items off to another module would send a clear message about what functions
need
and need not be implemented.

It has also been proposed that the contents of types module be distributed
across the standard library [#types-removal]_; the interpreter module would
provide an excellent resting place for internal types like frames and code
objects.

Specification
=============

A new builtin module named "interpreter" (see `Naming`_) will be added.  The
functions mentioned in the above list will be moved to it.


Transition Plan
===============

Once implemented in 3.x, the interpreter module will be back-ported to 2.6.
Py3k warnings will be added the the sys functions it replaces.


Open Issues
===========

Naming
------

The author proposes the name "interpreter" for the new module.  "pyvm" has
also
been suggested [#pyvm-name]_.


References
==========

.. [#bug-1522]

   http://bugs.python.org/issue1522

.. [#types-removal]

   http://mail.python.org/pipermail/stdlib-sig/2008-April/000172.html

.. [#pyvm-name]

   http://mail.python.org/pipermail/python-3000/2007-November/011351.html

Copyright
=========

    This document has been placed in the public domain.



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>
>
> >
> > Steve
> > --
> > I'm not *in*-sane. Indeed, I am so far *out* of sane that you appear a
> > tiny blip on the distant coast of sanity.
> >        --- Bucky Katt, Get Fuzzy
> >
>
>
>
> --
> Cheers,
> Benjamin Peterson




-- 
Cheers,
Benjamin Peterson
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