[Patches] [ python-Patches-580331 ] xreadlines caching, file iterator

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Patches item #580331, was opened at 2002-07-11 17:45
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Category: Core (C code)
Group: Python 2.3
Status: Open
Resolution: None
>Priority: 3
Submitted By: Oren Tirosh (orenti)
Assigned to: Guido van Rossum (gvanrossum)
Summary: xreadlines caching, file iterator

Initial Comment:
Calling f.xreadlines() multiple times returns the same 
xreadlines object.

A file is an iterator - __iter__() returns self and next() calls 
the cached xreadlines object's next method.



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>Comment By: Guido van Rossum (gvanrossum)
Date: 2002-07-17 13:50

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Alas, there's a fatal flaw. The file object and the
xreadlines object now both have pointers to each other,
creating an unbreakable cycle (since neither participates in
GC). Weak refs can't be used to resolve this dilemma. I
personally think that's enough to just stick with the status
quo (I was never more than +0 on the idea of making the file
an interator anyway). But I'll leave it to Oren to come up
with another hack (please use this same SF patch).

Oren, if you'd like to give up, please say so and I'll close
the item in a jiffy. In fact, I positively encourage you to
give up. But I don't expect you to take this offer. :-)

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Comment By: Guido van Rossum (gvanrossum)
Date: 2002-07-16 21:33

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I'm reviewing this and will check it in, or something like
it (probably).

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Comment By: Oren Tirosh (orenti)
Date: 2002-07-16 01:26

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Now invalidates cache on a seek.



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Comment By: Guido van Rossum (gvanrossum)
Date: 2002-07-15 10:38

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I posted some comments to python-dev.

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