* Why on earth is abbrev baked into the C code?
@ 2011-02-27 3:06 Daniel Colascione
2011-02-28 3:18 ` Stefan Monnier
0 siblings, 1 reply; 5+ messages in thread
From: Daniel Colascione @ 2011-02-27 3:06 UTC (permalink / raw)
To: Emacs development discussions
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I was looking into abbrev.el to figure out how to code up a change I
wanted to make (having undo undo the abbrev expansion without undoing
the self-insert-command that triggered the expansion), when I realized
to my surprise that abbrev is actually baked into the Emacs C core.
This defies common sense: why can't abbrev.el be a standalone module
that uses post-self-insert-hook or post-command-hook? I realize we're
not supposed to use hooks to communicate between components that are
part of GNU Emacs, but the alternative in this case seems unnecessarily
invasive.
(By the way: the comment in front of self-insert-command is no longer
valid; ISTR that dubious optimization was removed a while ago.)
=== modified file 'src/cmds.c'
--- src/cmds.c 2011-01-26 08:36:39 +0000
+++ src/cmds.c 2011-02-27 03:02:04 +0000
@@ -263,8 +263,6 @@
static int nonundocount;
-/* Note that there's code in command_loop_1 which typically avoids
- calling this. */
DEFUN ("self-insert-command", Fself_insert_command,
Sself_insert_command, 1, 1, "p",
doc: /* Insert the character you type.
Whichever character you type to run this command is inserted.
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^ permalink raw reply [flat|nested] 5+ messages in thread
* Re: Why on earth is abbrev baked into the C code?
2011-02-27 3:06 Why on earth is abbrev baked into the C code? Daniel Colascione
@ 2011-02-28 3:18 ` Stefan Monnier
[not found] ` <4D6BF0D7.3080005@gmail.com>
0 siblings, 1 reply; 5+ messages in thread
From: Stefan Monnier @ 2011-02-28 3:18 UTC (permalink / raw)
To: Daniel Colascione; +Cc: Emacs development discussions
> I was looking into abbrev.el to figure out how to code up a change I
> wanted to make (having undo undo the abbrev expansion without undoing
> the self-insert-command that triggered the expansion),
You should be able to use abbrev-expand-functions for that (it's
a wrapper hook, so it has complete control over the expansion, like an
`around' advice).
> when I realized
> to my surprise that abbrev is actually baked into the Emacs C core.
Until Emacs-22, the abbrev code was even all coded in C.
> This defies common sense: why can't abbrev.el be a standalone module
> that uses post-self-insert-hook or post-command-hook?
E.g. because post-self-insert-hook is brand new and post-command-hook
is inappropriate?
BTW, I haven't moved it to post-self-insert-hook because it is hooked
a bit more intimately into self-insert-command (e.g. the successful
expansion of an abbrev can prevent the char from being inserted and the
post-self-insert-hook from being run), so it is difficult to move it to
post-self-insert-hook without changing some of the subtle points of its
semantic.
> I realize we're not supposed to use hooks to communicate between
> components that are part of GNU Emacs, but the alternative in this
> case seems unnecessarily invasive.
Actually post-self-insert-hook is not nil by default, so this convention
is already broken for this hook.
> (By the way: the comment in front of self-insert-command is no longer
> valid; ISTR that dubious optimization was removed a while ago.)
Indeed, thanks. Please install the patch,
Stefan
^ permalink raw reply [flat|nested] 5+ messages in thread
* Re: Why on earth is abbrev baked into the C code?
[not found] ` <4D6BF0D7.3080005@gmail.com>
@ 2011-03-01 21:08 ` Daniel Colascione
2011-03-02 17:21 ` Richard Stallman
2011-03-02 17:55 ` Stefan Monnier
0 siblings, 2 replies; 5+ messages in thread
From: Daniel Colascione @ 2011-03-01 21:08 UTC (permalink / raw)
To: Stefan Monnier; +Cc: Emacs development discussions
;; This hack works for me, but there must be an easier, safer way.
(defun qtmstr-expand-abbrev-wrapper (orig-func &rest args)
(if (and qtmstr-abbrev-mode
(eq this-command 'self-insert-command)
(not executing-kbd-macro)
(not noninteractive)
(not (window-minibuffer-p (selected-window)))
(characterp last-command-event))
;; Our own implementation of expand-abbrev
(destructuring-bind (&optional sym name wordstart wordend)
(abbrev--before-point)
(when sym
(let ((value sym))
;; Now sym is the abbrev symbol.
(setq last-abbrev-text name)
(setq last-abbrev sym)
(setq last-abbrev-location wordstart)
;; Do what the self-insert-command would normally do
(insert-char last-command-event 1 t)
(undo-boundary)
(delete-char -1)
;; If this abbrev has an expansion, delete the abbrev
;; and insert the expansion.
(abbrev-insert sym name wordstart wordend))))
;; Otherwise, let the original expand-abbrev do its thing
(apply orig-func args)))
(add-hook 'abbrev-expand-functions #'qtmstr-expand-abbrev-wrapper)
^ permalink raw reply [flat|nested] 5+ messages in thread
* Re: Why on earth is abbrev baked into the C code?
2011-03-01 21:08 ` Daniel Colascione
@ 2011-03-02 17:21 ` Richard Stallman
2011-03-02 17:55 ` Stefan Monnier
1 sibling, 0 replies; 5+ messages in thread
From: Richard Stallman @ 2011-03-02 17:21 UTC (permalink / raw)
To: Daniel Colascione; +Cc: monnier, emacs-devel
Why on earth is abbrev baked into the C code?
For speed: I did not want SPC to run Lisp code in the usual case.
Maybe nowadays it would be acceptably fast.
--
Dr Richard Stallman
President, Free Software Foundation
51 Franklin St
Boston MA 02110
USA
www.fsf.org, www.gnu.org
^ permalink raw reply [flat|nested] 5+ messages in thread
* Re: Why on earth is abbrev baked into the C code?
2011-03-01 21:08 ` Daniel Colascione
2011-03-02 17:21 ` Richard Stallman
@ 2011-03-02 17:55 ` Stefan Monnier
1 sibling, 0 replies; 5+ messages in thread
From: Stefan Monnier @ 2011-03-02 17:55 UTC (permalink / raw)
To: Daniel Colascione; +Cc: Emacs development discussions
> ;; This hack works for me, but there must be an easier, safer way.
Haven't tried it, but saving buffer-undo-list before calling `orig-func'
and checking the result afterwards (adding an undo-boundary at the
saved location of buffer-undo-list when needed), might be "easier,
safer".
Stefan
^ permalink raw reply [flat|nested] 5+ messages in thread
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2011-02-27 3:06 Why on earth is abbrev baked into the C code? Daniel Colascione
2011-02-28 3:18 ` Stefan Monnier
[not found] ` <4D6BF0D7.3080005@gmail.com>
2011-03-01 21:08 ` Daniel Colascione
2011-03-02 17:21 ` Richard Stallman
2011-03-02 17:55 ` Stefan Monnier
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