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

[Dmitry Gutov]

On 15/11/2023 14:14, João Távora wrote:
> > > But say I did that seq-do, then what is the seq-contains-p generic good
> > > for then?  Why some many redundant generics that the user learns the
> > > hard way have to be consistent with each other?
> > So any new type gets a lot of functions implemented very easily, and
> > could add specialized implementations for performance.
> Fair enough.  Except, as you noted, those optimizations can be
> completely nullified overnight, when trying to optimize something
> else.

I don't see where they would be "completely nullified". The gains seem 
consistent, even if they don't extend as much to certain scenarios, like 
custom test-fn. Even that one should be improved, though.

More importantly, I'm not seeing any meaningful regressions, in any 
related or different scenario.

> > the switchover would tank the performance of its callers.
> > As long as the observable behavior stays the same (aside from
> > performance), that seems fine.
> I don't think this is "fine" at all to tank user code performance,
> not from any library, much less such a basic foundation library.

If that is the only drawback we can find, it is an unavoidable one.

But that is the price one has to pay for correcting a design mistake. 
We're not going to do this every Tuesday.