Re: Why does adding a useless copy-sequence and discarding the result make my ELisp 40 times faster?

[Andreas Politz <politza@hochschule-trier.de>]

Clément Pit-Claudel <cpitclaudel@gmail.com> writes:

> On 2017-03-25 06:38, Andreas Politz wrote:
>> The limiting factor may also be python itself...
>>
>> ;; python2
>> ((0.114342188 0 0.0)
>>  (0.715895279 0 0.0)
>>  (2.120252213 0 0.0)
>>  (1.02429565 0 0.0))
>>
>> ;; bash = "while read;do : ;done"
>> ((2.008305836 0 0.0)
>>  (1.999825023 0 0.0)
>>  (2.026715753 0 0.0)
>>  (2.060320318 0 0.0))
>
> Interesting! But doesn't this just show that bash is uniformly slow?

This suggests to me, that the deciding factor in these numbers is python
and not Emacs.

Maybe it has a read buffer of a certain size, let's say 65536 ;O), and
if that buffer runs out of space, things get stalled.

-ap