Re: Creating a git branch for cond*

[Eli Zaretskii <eliz@gnu.org>]

> Date: Thu, 25 Jan 2024 16:37:44 +0000
> Cc: rms@gnu.org, eliz@gnu.org, emacs-devel@gnu.org
> From: Alan Mackenzie <acm@muc.de>
> 
> > I hope it goes to master directly, it is a single file that doesn't
> > affect anything else.  And _if_ existing code is updated to use cond*
> > that will get much more milage.
> 
> It does affect other things, in particular, other .el files which are
> adapted to use cond*.

Please don't make any changes except installing cond* and fixing it.
There's no decision yet to start converting any code to use it, nor do
I envision such a decision any time soon.

> If that happens on master, then both cond* and
> the conversion need to be perfect before the file can be committed.

Once again: we are not converting anything, at least not yet.  We are
only discussing how best to handle installation of cond*.

> What I want to do early on in cond* development is convert
> lisp/emacs-lisp/macroexp.el from pcase to cond*.

I don't agree with such a change, so please don't do anything like
that.

> Currently, pcase.el is dependent upon macroexp.el and macroexp.el is
> dependent upon pcase.el.  This leads to an unlovely artifice in the
> bootstrapping file, loadup.el, and this has caused me grief in
> another branch I'm working on.

We are not going to make any such changes just because we can, or just
because you have problems on some branch you'd like to avoid fixing.
cond* is a new construct, and once it is in Emacs, and documented as
it should be, we should collect experience with using it before we
even think about converting existing code.

Please don't forget that Emacs is a stable program: we don't make
changes just because we can.  Changes to code that was with us for
years are only justified if we have a very good reason.

> No doubt Eli will have something to say about this idea.  ;-)

He does, see above.  You don't have my okay for making any changes
except installing cond* and fixing it and its documentation.

Btw, we should also have tests for it.

> There are advantages to the branch, as well as advantages to having it
> on master.

Yes.  But, as you say, let's hear what Richard thinks about this.