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

[Michal Nazarewicz <mina86@mina86.com>]

On Wed, Oct 15 2014, Stefan Monnier <monnier@iro.umontreal.ca> wrote:
>> +(defmacro set-key (keymap key &rest def)

> I'm not convinced the added complexity is worth the trouble, I'm afraid.
> I don't see a real benefit in
>
>    (set-key :global KEY CMD)

You wouldn't normally put “:global” here…

>    (set-key :local KEY CMD)
>    (set-key MAP KEY CMD)
>
> over
>
>    (global-set-key KEY CMD)
>    (local-set-key KEY CMD)
>    (define-key MAP KEY CMD)
[…]

…but I can see your point and it's true that for those cases, the saving
is not that big.

> I also don't see the benefit of (:args ARGS INTERACTIVE . BODY)
> over (lambda ARGS (interactive INTERACTIVE) . BODY).
>
> The only thing I think is really valuable is things like
>
>    (set-key ... KEY (dired "foo"))

Indeed, this is the main reason I've created the macro (I would still
argue :args syntax is also convenient though).

> For which there is also a precedent in easy-define-menu (where the CMD
> can be either a symbol or an expression, in which case that expression
> gets wrapped in (lambda () (interactive) ...)).
>
> Maybe we could simply extend define-key to accept
>
>    (define-key MAP KEY '(dired "foo"))

So are you think about something like:

diff --git a/src/keymap.c b/src/keymap.c
index c7c7d19..4b8251b 100644
--- a/src/keymap.c
+++ b/src/keymap.c
@@ -786,6 +786,9 @@ store_in_keymap (Lisp_Object keymap, register Lisp_Object idx, Lisp_Object def)
       && (EQ (XCAR (def), Qmenu_item) || STRINGP (XCAR (def))))
     def = Fcons (XCAR (def), XCDR (def));
 
+  if (CONSP (def) && !EQ (XCAR (quoted), Qlambda) && !EQ (XCAR (quoted), Qclosure))
+    def = Fcons (Qlambda, Fcons (Qnil, Fcons (Fcons (Qinteractive, Qnil), def)));
+
   if (!CONSP (keymap) || !EQ (XCAR (keymap), Qkeymap))
     error ("attempt to define a key in a non-keymap");
 
?  Or am I looking at completely wrong place.

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.

--
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.o. | Liege of Serenely Enlightened Majesty of      o' \,=./ `o
..o | Computer Science,  Michał “mina86” Nazarewicz    (o o)
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