Re: Smarter M-x that filters on major-mode

[Alan Mackenzie]

Hello, Stefan.

On Sun, Feb 14, 2021 at 10:11:47 -0600, Stefan Kangas wrote:
> Alan Mackenzie <acm@muc.de> writes:

> > Filtering out stuff from an M-x search is a minor feature.  You're
> > proposing turning the structures of Emacs upside down in implementing
> > it.  This is disproportionate, and will bring unforeseen problems with
> > it.

> > `interactive' currently does one thing and does it well - it says how to
> > call a function interactively.  You're advocating adding unrelated stuff
> > into `interactive'.  That is ugly, horribly ugly.

> > You're proposing making the .elc format backward incompatible, all for
> > what?  For some minor feature to do with M-x.  A feature which not
> > everybody wants (I certainly don't), and not everybody will use.

> FWIW, I disagree:

> - This feature is extremely useful, I think a big improvement in user
>   experience and one of the things to be excited about for Emacs 28.

I'm not implying it isn't.  But at the same time it's still a minor
feature.  It doesn't come anywhere close in importance to things like
the mechanism for calling interactive functions, which is essential for
Emacs to work at all.  Yet it will disrupt these important things.

> - This is a clean and natural expansion of `interactive'.

How can you say this?  The new stuff going into `interactive' has
nothing to do with its current function.  See above.  Please answer this
point.

> - I'm not sure what it means to turn things upside down.

Sorry, that's a bit of English idiom.  It means moving things around a
lot, changing lots of things, usually with the implication that the
result won't have justified the extent of the required effort.

>   I assume you mean that a horrible mess has been made?  If so, I must
>   disagree with that, too.

No, see above.  But `interactive' will end up being used for two
entirely different purposes, unrelated to eachother.  That seems like a
mess to me.

Why do we need such deep, incompatible changes to implement this
feature?  Why can't it just be implemented using the normal
unobjectionable means like symbol properties?  This is what I don't
understand.  I feel at the moment that I'm going mad, seeing such far
reaching, destructive things going on, and everybody else just seems to
think these things normal, the sort of thing one does every day.

-- 
Alan Mackenzie (Nuremberg, Germany).