[Python-ideas] Move more parts of interpreter core to stdlib

[Draic Kin]

On Mon, Aug 26, 2013 at 9:27 PM, Brett Cannon <brett at python.org> wrote:

>
>
>
> On Mon, Aug 26, 2013 at 2:54 PM, Ned Batchelder <ned at nedbatchelder.com>wrote:
>
>> On 8/26/13 1:55 PM, Antoine Pitrou wrote:
>>
>>> On Mon, 26 Aug 2013 16:36:53 +0200
>>> Draic Kin <drekin at gmail.com> wrote:
>>>
>>>> Hello, it would be nice if reference pure Python implementation existed
>>>> for
>>>> more parts of interpreter core and the core actually used them. This was
>>>> done for import machinery in Python 3.3 making importlib library.
>>>>
>>>> One potential target for this would be moving the logic of what
>>>> python.exe
>>>> does – parsing its arguments, finding the script to run, compiling its
>>>> code
>>>> and running as __main__ module, running REPL if it's in interactive mode
>>>> afterwards. There could be a stdlib module exposing this logic, using
>>>> argparse to parse the arguments, overhauled version of runpy to run the
>>>> __main__ module and overhauled version of code to run the REPL.
>>>> Python.exe
>>>> would be just thin wrapper which bootstraps the interpreter and runs
>>>> this
>>>> runner module.
>>>>
>>> The interpreter needs a lot of information to be bootstrapped; you are
>>> proposing that the code which extracts that information be run *after*
>>> the interpreter is bootstrapped, which creates a nasty temporal problem.
>>>
>>> In the end, it may make maintenance *more* difficult, rather than less,
>>> to rewrite that code in Python.
>>>
>> It seems to me that this argument could have been made against the import
>> rewrite in Python.
>
>
> Not quite. Antoine's point is that the flags used to start Python are
> needed to set up certain things that may influence how using e.g. argparse
> works. Importlib is in a unique position because I wrote it from the
> beginning to be bootstrapped, so I designed it to deal with bootstrapping
> issues. It also led to the code being a little odd and having to work
> around things like lacking imports, etc. Argparse (and any of its
> dependencies) have not been designed in such a fashion, especially if they
> are directly involved in setting key settings in the interpreter.
>

But even if flags have to be parsed before argparse can be used, the
startup functionality of localizing code to be run as __main__, running it
and running REPL could be moved to stdlib or are there similar issues?
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://mail.python.org/pipermail/python-ideas/attachments/20130826/c821e039/attachment.html>