[Python-Dev] Switch statement

[M.-A. Lemburg]

Michael Walter wrote:
> Maybe "switch" became a keyword with the patch..

Ah, right. Good catch :-)

> Regards,
> Michael
> 
> On 6/12/06, M.-A. Lemburg <mal at egenix.com> wrote:
>> Thomas Lee wrote:
>> > Hi all,
>> >
>> > As the subject of this e-mail says, the attached patch adds a "switch"
>> > statement to the Python language.
>> >
>> > However, I've been reading through PEP 275 and it seems that the PEP
>> > calls for a new opcode - SWITCH - to be added to support the new
>> > construct.
>> >
>> > I got a bit lost as to why the SWITCH opcode is necessary for the
>> > implementation of the PEP. The reasoning seems to be
>> > improving performance, but I'm not sure how a new opcode could improve
>> > performance.
>> >
>> > Anybody care to take the time to explain this to me, perhaps within the
>> > context of my patch?
>>
>> Could you upload your patch to SourceForge ? Then I could add
>> it to the PEP.
>>
>> Thomas wrote a patch which implemented the switch statement
>> using an opcode. The reason was probably that switch works
>> a lot like e.g. the for-loop which also opens a new block.
>>
>> Could you explain how your patch works ?
>>
>> BTW, I think this part doesn't belong into the patch:
>>
>> > Index: Lib/distutils/extension.py
>> > ===================================================================
>> > --- Lib/distutils/extension.py        (revision 46818)
>> > +++ Lib/distutils/extension.py        (working copy)
>> > @@ -185,31 +185,31 @@
>> >                  continue
>> >
>> >              suffix = os.path.splitext(word)[1]
>> > -            switch = word[0:2] ; value = word[2:]
>> > +            switch_word = word[0:2] ; value = word[2:]
>>
>> -- 
>> Marc-Andre Lemburg
>> eGenix.com
>>
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-- 
Marc-Andre Lemburg
eGenix.com

Professional Python Services directly from the Source  (#1, Jun 13 2006)
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2006-07-03: EuroPython 2006, CERN, Switzerland              19 days left

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