[issue4565] Rewrite the IO stack in C

[Jean-Paul Calderone]

Jean-Paul Calderone <exarkun at divmod.com> added the comment:

Hi Antoine,

> > Surely the majority of the burden is imposed by the C
implementation.  I expect that 90% of the time spent fixing bugs will be
spent fixing them in C.

> Hmm, it depends. It's probably true in general, but I suspect a fair
amount of work also went into getting the Python implementation correct,
since there are things in there that are tricky regardless of the
implementation language (I'm especially thinking of the TextOWrapper
seek() and tell() methods). (and there are still bugs in the Python
implementation btw.)

Indeed, I'm sure a lot of work went into the Python implementation - and
hopefully that work *saved* a huge amount of work when doing the C
implementation.  That's why people prototype things in Python, right? :)
 So it seems to me that keeping the Python implementation is useful for
CPython, since if it made working on the C implementation easier in the
past, it will probably do so again in the future.

Basically, my point is that maintaining C and Python versions is
*cheaper* than just maintaining the C version alone.  The stuff I said
about other VMs is true too, but it doesn't seem like anyone here is
going to be convinced by it ;)  (and I haven't spoked to any developers
for other VMs about whether they really want it, anyway).

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Python tracker <report at bugs.python.org>
<http://bugs.python.org/issue4565>
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