[Python-Dev] [Python-checkins] cpython: Avoid useless "++" at the end of functions

[Guido van Rossum]

On Thu, May 26, 2011 at 10:59 AM, Terry Reedy <tjreedy at udel.edu> wrote:
> On 5/26/2011 10:34 AM, Ronald Oussoren wrote:
>>
>> On 26 May, 2011, at 16:10, Eric Smith wrote:
>>>
>>>
>>>> and make silent the Clang Static Analyzer :-)
>>>
>>> I care less about that than maintainability and future-proofing.
>
>
>> Have to looked at the patch? The patch and resulting code look sane to me,
>> and if anything at most of the updated segments look cleaner after the
>> patch.
>
> Lets assume that the function currently does what it is supposed to do, as
> verified by tests. Then adding an unneeded increment in case the function is
> redefined in the future so that it needs more code strikes me as YAGNI.
> Certainly, reading it today with an unused increment suggests to me that
> something is missing that would use the incremented value. This strike me as
> different from adding a comma at the end of a Python sequence display.

Sorry to butt in here, but I agree with Eric that it was better
before. There is a common idiom, *pointer++ = <something>, and
whenever you see that you know that you are appending something to an
output buffer. Perhaps the most important idea here is that this
maintains the *invariant* "pointer points just after the last thing in
the buffer". Always maintaining the invariant is better than trying to
micro-optimize things so as to avoid updating dead values. The
compiler is better at that.

-- 
--Guido van Rossum (python.org/~guido)