Re: What's missing in ELisp that makes people want to use cl-lib?

[Dmitry Gutov]

On 10/11/2023 05:17, Po Lu wrote:
> > Hmmm, a bit vague, no?  Humor me: if it's really so easy and so
> > readable please write out your preferred equivalent of, say
> >
> >     (cl-set-difference l1 l2) ; hopefully obvious, like l1 - l2 in python
> (let ((list nil))
>    (dolist (x l1)
>      (unless (member x l2)
>        (push x list)))
>    (dolist (x l2)
>      (unless (member x l1)
>        (push x list)))
>    list)

Just to take this example, there are about 2 major bugs: 1) the list 
will come out reversed, 2) the code does XOR rather than subtraction.

To be clear, this is not to take a dig at your coding ability (which I'm 
convinced is quite high), but rather to make a point about the potential 
for problems when one uses lower-level tools and has to reinvent the wheel.