[Python-3000] Python 3.0a2 release

Walter Dörwald walter at livinglogic.de
Tue Nov 20 19:16:40 CET 2007

Guido van Rossum wrote:
> On Nov 19, 2007 3:06 PM, Amaury Forgeot d'Arc <amauryfa at gmail.com> wrote:
>> Guido van Rossum wrote:
>>> Is there anything that you (or anyone else!) would really like to see
>>> added to or fixed in 3.0a2? Now's the time!
>> I am currently having a look at http://bugs.python.org/issue1460 .
>> It's a problem in the utf-7 decoder (there is no such function
>> PyUnicode_DecodeUTF7Stateful), but I was surprised to see that
>> codec.StreamReader duplicates a lot of code already present in io.py:
>> an underlying binary stream, a decoder, a buffer (of 72 chars), some
>> code to handle \r\n and so on.
>> I wonder if it is possible to remove this class: are there differences
>> between codec.StreamReader and io.TextIOWrapper ?
> Good point. The redundancy is historic; StreamReader is older, and
> performed the same function in 2.x that TextIOWrapper performs in 3.x,
> but the latter was written from scratch (and in fact without looking
> at the former) to match the API provided by text files in 2.x more
> closely. If you see anything in StreamReader that could make
> TextIOWrapper faster, I'd love to hear about it. I expect that in 3.0
> final, the classes in codecs will probably be implemented using
> TextIOWrapper.

Reimplementing the streamreaders via TextIOWrapper basically would make
much of the streamreader code go away. The streamreaders are supposed to
be encoding specific wrappers for streams. TextIOWrapper implements this
in *one* class (which uses the appropriate incremental decoder). A
streamreader is basically just a TextIOWrapper where the encoding
argument is fixed.

The only question remaining is: do we need the streamreader classes at all.


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