Re: [PATCH] What's the quickest way to contribute?

[Stefan Monnier]

>> Finally, I attach one more patch that I'd like some feedback on.
>> I was browsing replace.el and found this type of code:
>>
>> (delq nil (mapcar #'(lambda (buf)
>>                       (when (buffer-live-p buf) buf))
>>                   bufs))
>>
>> instead of this:
>>
>> (cl-remove-if-not #'buffer-live-p bufs)
>>
>> If this were my package, I would change it without batting an eye,
>> since the latter code is more clear and algorithmically faster.

I think algorithmically, it's equivalent (both are O(N), basically).
I wouldn't be able to predict which one will be faster, but my guess is
that it'll be a wash (and I'd expect the `delq' loop to be negligible
compared to the `mapcar' loop).

So the clarity aspect is the more important argument.

> Using `cl-' functions is allowed, but I guess there remains some amount of
> prejudice against the CL coding style, and using those (more complicated)
> functions when simpler ones can work just as well.

Yes, cl-* functions are definitely allowed.  There is of course a lot of
carried prejudice from when cl-* functions didn't exist (and we just
had the `remove-if-not' instead, whose use was not accepted in Emacs's
own code), but there is also still a restriction in this respect: cl-*
functions still can't be used from preloaded files (because that would
require preloading cl-lib).


        Stefan