bug#18729: [PATCH] subr.el (set-key): New macro making creating new bindings more concise.

[Stefan Monnier <monnier@iro.umontreal.ca>]

> (I would still argue :args syntax is also convenient though).

The :args syntax has the problem that it can only be explained/defined
by explaining how args work for functions and how `interactive' works,
so from a conceptual point of view (say, explaining to someone who doesn't
know Elisp yet) it's not really simpler than the full (lambda
...) form.  IOW the only gain is a few characters.

>> (define-key MAP KEY '(dired "foo"))
[...]
> Thing I'm worried about here is that the function will not get
> byte-compiled, whereas with set-key macro it will.  Also, I'm not
> entirely sure whether the function should use lexical-binding.

Indeed, that's incompatible with lexical-binding.
As you know, I find this to be a *major* downer.  But the only
alternative would be to define a new macro (like you've done), which
implies a larger change, and added complexity: since we're not
going to deprecate define-key, it means we'd simply have yet another
slightly different way to define key bindings.  I already dislike
global-set-key and local-set-key, FWIW.

I think if we want to make it easier for users to customize
key-bindings, we should take a step back and look at the
larger picture, trying to see exactly what it is that's hard.

Maybe then we'll get a need for something that's substantially different
from define-key (and in which your ideas can then easily be integrated).

I'm thinking of things like tweaking key-bindings via Customize, and/or
being able to specify keybindings for specific major modes (without
needing to go through add-hook or eval-after-load), ...


        Stefan