Re: Oort Gnus v0.19 is released

[Jesper Harder <harder@myrealbox.com>]

Simon Josefsson <jas@extundo.com> writes:

> Jesper Harder <harder@myrealbox.com> writes:
>
>> There is a grain of truth in the warnings, i.e. that pop is a tiny bit
>> less efficient when we don't use the return value -- not that I think
>> anyone would notice the difference.
>
> The warning has been removed, but I'm not sure I agree it had even a
> tiny grain of truth in it -- the docstring for `pop' says "Remove and
> return the head of the list stored in PLACE.", and I assume this is
> what CL `pop' is supposed to do.  Using it in that way in elisp should
> never generate a warning IMHO.

I agree that the warning is too pedantic.  But it's still true,
though.  The part to notice in the docstring is

   and return the head of the list
 
If we don't use the return value from pop, then

  (setq x (cdr x))

is obviously more efficient than 

  (pop x) == (car (prog1 x (setq x (cdr x))))