* bug#19066: 25.0.50; nadvice and interactive-form
@ 2014-11-16 10:00 Leo Liu
2021-05-28 2:11 ` Lars Ingebrigtsen
0 siblings, 1 reply; 5+ messages in thread
From: Leo Liu @ 2014-11-16 10:00 UTC (permalink / raw)
To: 19066
1. Start emacs and load a file with these lines:
--8<---------------cut here---------------start------------->8---
(advice-add 'just-one-space :before #'change-interactive-form)
(defun change-interactive-form (&optional x y)
(interactive (list 1 1))
(princ (list x y)))
--8<---------------cut here---------------end--------------->8---
M-x just-one-space prints (1 nil)
2. Start emacs and load a file with these lines:
--8<---------------cut here---------------start------------->8---
(defun change-interactive-form (&optional x y)
(interactive (list 1 1))
(princ (list x y)))
(advice-add 'just-one-space :before #'change-interactive-form)
--8<---------------cut here---------------end--------------->8---
M-x just-one-space errs: apply: Wrong number of arguments: (0 . 1), 2
Leo
^ permalink raw reply [flat|nested] 5+ messages in thread
* bug#19066: 25.0.50; nadvice and interactive-form
2014-11-16 10:00 bug#19066: 25.0.50; nadvice and interactive-form Leo Liu
@ 2021-05-28 2:11 ` Lars Ingebrigtsen
2021-05-30 17:26 ` Stefan Monnier via Bug reports for GNU Emacs, the Swiss army knife of text editors
0 siblings, 1 reply; 5+ messages in thread
From: Lars Ingebrigtsen @ 2021-05-28 2:11 UTC (permalink / raw)
To: Leo Liu; +Cc: 19066, Stefan Monnier
Leo Liu <sdl.web@gmail.com> writes:
> 1. Start emacs and load a file with these lines:
>
> (advice-add 'just-one-space :before #'change-interactive-form)
> (defun change-interactive-form (&optional x y)
> (interactive (list 1 1))
> (princ (list x y)))
>
> M-x just-one-space prints (1 nil)
>
> 2. Start emacs and load a file with these lines:
>
> (defun change-interactive-form (&optional x y)
> (interactive (list 1 1))
> (princ (list x y)))
> (advice-add 'just-one-space :before #'change-interactive-form)
>
> M-x just-one-space errs: apply: Wrong number of arguments: (0 . 1), 2
So whether this works depends on whether `change-interactive-form' is
defined or not when `advice-add' is run? (The only difference here is
the order.)
Perhaps Stefan has some insights here; added to the CCs.
--
(domestic pets only, the antidote for overdose, milk.)
bloggy blog: http://lars.ingebrigtsen.no
^ permalink raw reply [flat|nested] 5+ messages in thread
* bug#19066: 25.0.50; nadvice and interactive-form
2021-05-28 2:11 ` Lars Ingebrigtsen
@ 2021-05-30 17:26 ` Stefan Monnier via Bug reports for GNU Emacs, the Swiss army knife of text editors
2021-05-31 5:43 ` Lars Ingebrigtsen
0 siblings, 1 reply; 5+ messages in thread
From: Stefan Monnier via Bug reports for GNU Emacs, the Swiss army knife of text editors @ 2021-05-30 17:26 UTC (permalink / raw)
To: Lars Ingebrigtsen; +Cc: Leo Liu, 19066
Lars Ingebrigtsen [2021-05-28 04:11:13] wrote:
> Leo Liu <sdl.web@gmail.com> writes:
>> 1. Start emacs and load a file with these lines:
>>
>> (advice-add 'just-one-space :before #'change-interactive-form)
>> (defun change-interactive-form (&optional x y)
>> (interactive (list 1 1))
>> (princ (list x y)))
>>
>> M-x just-one-space prints (1 nil)
>>
>> 2. Start emacs and load a file with these lines:
>>
>> (defun change-interactive-form (&optional x y)
>> (interactive (list 1 1))
>> (princ (list x y)))
>> (advice-add 'just-one-space :before #'change-interactive-form)
>>
>> M-x just-one-space errs: apply: Wrong number of arguments: (0 . 1), 2
>
> So whether this works depends on whether `change-interactive-form' is
> defined or not when `advice-add' is run? (The only difference here is
> the order.)
> Perhaps Stefan has some insights here; added to the CCs.
[ Side note: the correct/desired behavior is the one described by (2),
i.e. it should signal a "Wrong number of arguments" (tho after
printing (1 1)). ]
`advice-add` creates a new function object which is a "composition" of
the old function and the advice that's added to it.
In the case where `change-interactive-form` is defined later, one way to
make this work right would be for `advice-add` to put some kind of
"watcher" on (symbol-function 'change-interactive-form) to recompute the
interactive form of the "composed function".
Another way would be to make the interactive form of the "compose
function" more dynamic: make it re-checks the interactive form of every
advice function every time. That's probably the better option.
Stefan
^ permalink raw reply [flat|nested] 5+ messages in thread
* bug#19066: 25.0.50; nadvice and interactive-form
2021-05-30 17:26 ` Stefan Monnier via Bug reports for GNU Emacs, the Swiss army knife of text editors
@ 2021-05-31 5:43 ` Lars Ingebrigtsen
2021-05-31 12:49 ` Stefan Monnier via Bug reports for GNU Emacs, the Swiss army knife of text editors
0 siblings, 1 reply; 5+ messages in thread
From: Lars Ingebrigtsen @ 2021-05-31 5:43 UTC (permalink / raw)
To: Stefan Monnier; +Cc: Leo Liu, 19066
Stefan Monnier <monnier@iro.umontreal.ca> writes:
> Another way would be to make the interactive form of the "compose
> function" more dynamic: make it re-checks the interactive form of every
> advice function every time. That's probably the better option.
That sounds like a good solution to me -- the interactive path isn't
normally performance critical, so adding more work in that case should
be fine.
--
(domestic pets only, the antidote for overdose, milk.)
bloggy blog: http://lars.ingebrigtsen.no
^ permalink raw reply [flat|nested] 5+ messages in thread
* bug#19066: 25.0.50; nadvice and interactive-form
2021-05-31 5:43 ` Lars Ingebrigtsen
@ 2021-05-31 12:49 ` Stefan Monnier via Bug reports for GNU Emacs, the Swiss army knife of text editors
0 siblings, 0 replies; 5+ messages in thread
From: Stefan Monnier via Bug reports for GNU Emacs, the Swiss army knife of text editors @ 2021-05-31 12:49 UTC (permalink / raw)
To: Lars Ingebrigtsen; +Cc: Leo Liu, 19066
Lars Ingebrigtsen [2021-05-31 07:43:34] wrote:
> Stefan Monnier <monnier@iro.umontreal.ca> writes:
>> Another way would be to make the interactive form of the "compose
>> function" more dynamic: make it re-checks the interactive form of every
>> advice function every time. That's probably the better option.
> That sounds like a good solution to me -- the interactive path isn't
> normally performance critical, so adding more work in that case should
> be fine.
Yes, performance is not an issue. But preserving the semantics 100% is
currently somewhere between hard and impossible. 99.9% is fairly easy,
OTOH (IIRC the main problem has to do with how the args get represented
in `command-history`).
Stefan
^ permalink raw reply [flat|nested] 5+ messages in thread
end of thread, other threads:[~2021-05-31 12:49 UTC | newest]
Thread overview: 5+ messages (download: mbox.gz / follow: Atom feed)
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2014-11-16 10:00 bug#19066: 25.0.50; nadvice and interactive-form Leo Liu
2021-05-28 2:11 ` Lars Ingebrigtsen
2021-05-30 17:26 ` Stefan Monnier via Bug reports for GNU Emacs, the Swiss army knife of text editors
2021-05-31 5:43 ` Lars Ingebrigtsen
2021-05-31 12:49 ` Stefan Monnier via Bug reports for GNU Emacs, the Swiss army knife of text editors
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