[C-u M-q] -> unfill-paragraph

[C-u M-q] -> unfill-paragraph

[Tom Roche]

I'm running

$ lsb_release -ds
Linux Mint Debian Edition # Update Pack 3
$ uname -rv
2.6.39-2-amd64 #1 SMP Tue Jul 5 02:51:22 UTC 2011
$ emacs --version
GNU Emacs 23.3.1

on which M-q "runs the command fill-paragraph". Therefore ISTM
C-u M-q should run the command unfill-paragraph ... but it does not.
How to accomplish that? I tried

- (define-key global-map "\C-u\M-q" 'unfill-paragraph)

but that fails with error=

- Lisp error: (error "Key sequence C-u M-q starts with non-prefix key C-u")

Apologies if this is a FAQ: feel free to send links to RTFM.

TIA, Tom Roche <Tom_Roche@pobox.com>

Re: [C-u M-q] -> unfill-paragraph

[Eric Abrahamsen]

On Thu, Nov 10 2011, Tom Roche wrote:

> I'm running
>
> $ lsb_release -ds
> Linux Mint Debian Edition # Update Pack 3
> $ uname -rv
> 2.6.39-2-amd64 #1 SMP Tue Jul 5 02:51:22 UTC 2011
> $ emacs --version
> GNU Emacs 23.3.1
>
> on which M-q "runs the command fill-paragraph". Therefore ISTM
> C-u M-q should run the command unfill-paragraph ... but it does not.
> How to accomplish that? I tried

First of all, on my setup (emacs 24) there's no `unfill-paragraph'
command, are you sure you've got one? I had to make my own.

Your basic problem is that C-u is a prefix argument: ie, it's used to
feed a numerical argument (specifically, 4) to whatever command you call
next. You can't actually bind it as part of a key sequence to call a
specific command. Prefix keys have to be defined specially, and C-u
isn't.

In order for a command to change its behavior in the presence of a
prefix argument, the function definition itself has to look for the
argument and handle it. A function that doesn't handle it just ignores
it. In this case, `fill-paragraph' does handle a prefix argument, but
takes it to mean that you want to justify the paragraph.

You would have to rewrite the function definition to make it treat a
prefix argument differently. Even then, you wouldn't bind any new
function to C-u M-q, you'd just call `fill-paragraph' with a prefix
argument (which is the key combination C-u M-q), and the function would
behave differently.

So, provided you actually have an `unfill-paragraph' command, you'll
have to bind it to some other key (like C-M-q).

Sure hope that makes sense,

Eric

> - (define-key global-map "\C-u\M-q" 'unfill-paragraph)
>
> but that fails with error=
>
> - Lisp error: (error "Key sequence C-u M-q starts with non-prefix key C-u")
>
> Apologies if this is a FAQ: feel free to send links to RTFM.
>
> TIA, Tom Roche <Tom_Roche@pobox.com>
>
>

-- 
GNU Emacs 24.0.91.1 (i686-pc-linux-gnu, GTK+ Version 2.24.6)
 of 2011-11-07 on pellet

Re: [C-u M-q] -> unfill-paragraph

[Tom Roche]

Tom Roche Wed, 09 Nov 2011 16:15:00 -0500
>> $ emacs --version
>> GNU Emacs 23.3.1

>> on which M-q "runs the command fill-paragraph". Therefore ISTM
>> C-u M-q should run the command unfill-paragraph ... but it does not.

Eric Abrahamsen Thu, 10 Nov 2011 11:55:56 +0800
> First of all, on my setup (emacs 24) there's no `unfill-paragraph'
> command, are you sure you've got one?

Turns out nxhtml

http://ourcomments.org/Emacs/nXhtml/doc/nxhtml.html

provides unfill-paragraph:

`C-h f`
>>> unfill-paragraph is an interactive compiled Lisp function in
>>> `ourcomments-util.el'.

nxhtml_2.08/util/ourcomments-util.el (slightly edited for email)
>>>> ;;; Unfilling
>>>> ;
>>>> ; The idea is from
>>>> ; http://interglacial.com/~sburke/pub/emacs/sburke_dot_emacs.config

>>>> ;;;###autoload
>>>> (defun unfill-paragraph ()
>>>>   "Unfill the current paragraph."
>>>>   (interactive) (with-unfilling 'fill-paragraph))

>>>> ;;;###autoload
>>>> (defun unfill-region ()
>>>>   "Unfill the current region."
>>>>   (interactive) (with-unfilling 'fill-region))

>>>> ;;;###autoload
>>>> (defun unfill-individual-paragraphs ()
>>>>   "Unfill individual paragraphs in the current region."
>>>>   (interactive) (with-unfilling 'fill-individual-paragraphs))

>>>> (defun with-unfilling (fn)
>>>>   "Unfill using the fill function FN."
>>>>   (let ((fill-column (1+ (point-max)))) (call-interactively fn)))

> In order for a command to change its behavior in the presence of a
> prefix argument, the function definition itself has to look for the
> argument and handle it. A function that doesn't handle it just ignores
> it. In this case, `fill-paragraph' does handle a prefix argument, but
> takes it to mean that you want to justify the paragraph.

Which I don't want.

> You would have to rewrite the function definition to make it treat a
> prefix argument differently. Even then, you wouldn't bind any new
> function to C-u M-q, you'd just call `fill-paragraph' with a prefix
> argument (which is the key combination C-u M-q)

So is there an easy, userland way to write one's own `fill-paragraph' façade such that

* my `fill-paragraph' would hide (e.g., be earlier in a $PATH) the emacs-provided `fill-paragraph'

* my `fill-paragraph' could delegate to the emacs-provided `fill-paragraph' except when called with prefix argument

? Your assistance is appreciated, Tom Roche <Tom_Roche@pobox.com>

Re: [C-u M-q] -> unfill-paragraph

[Scott Frazer]

On 11/10/11 12:29 PM, Tom Roche wrote:
>
> Tom Roche Wed, 09 Nov 2011 16:15:00 -0500
>>> $ emacs --version
>>> GNU Emacs 23.3.1
>
>>> on which M-q "runs the command fill-paragraph". Therefore ISTM
>>> C-u M-q should run the command unfill-paragraph ... but it does not.

Try this:

(defun my-fill-paragraph (&optional arg)
   (interactive "P")
   (let ((fill-column (if arg (point-max) fill-column)))
     (fill-paragraph)))

(global-set-key (kbd "M-q") 'my-fill-paragraph)

Re: [C-u M-q] -> unfill-paragraph

[Tom Roche]

Tom Roche Thu, 10 Nov 2011 12:29:33 -0500
>> [How] to write one's own `fill-paragraph' façade such that

>> * my `fill-paragraph' would hide (e.g., be earlier in a $PATH) the
>>   emacs-provided `fill-paragraph'

>> * my `fill-paragraph' could delegate to the emacs-provided
>>   `fill-paragraph' except when called with prefix argument

Scott Frazer Thu, 10 Nov 2011 14:00:14 -0500
> (defun my-fill-paragraph (&optional arg)
>   (interactive "P")
>   (let ((fill-column (if arg (point-max) fill-column)))
>     (fill-paragraph)))

> (global-set-key (kbd "M-q") 'my-fill-paragraph)

Thanks! that seems to work as desired.

Re: [C-u M-q] -> unfill-paragraph

[Tom Roche]

[Text-mode table enclosed--best viewed in monospace font.]

Tom Roche Thu, 10 Nov 2011 12:29:33 -0500
>> [How] to write one's own `fill-paragraph' façade such that

>> * [my-fill-paragraph] would hide [the] emacs-provided
>>   `fill-paragraph'

>> * [my-fill-paragraph] could delegate to the emacs-provided
>>   `fill-paragraph' except when called with prefix argument

Scott Frazer Thu, 10 Nov 2011 14:00:14 -0500
> (defun my-fill-paragraph (&optional arg)
>   (interactive "P")
>   (let ((fill-column (if arg (point-max) fill-column)))
>     (fill-paragraph)))

> (global-set-key (kbd "M-q") 'my-fill-paragraph)

That works, except for region handling. What the code above does is

+----------------------------------------------------------------+
|                    | M-q                | C-u M-q              |
+----------------------------------------------------------------+
| no region selected | fill the paragraph | unfill the paragraph |
|                    | surrounding or     | surrounding or       |
|                    | following point    | following point      |
+----------------------------------------------------------------+
| region selected    | nothing            | unfills first (only) |
|                    |                    | paragraph in region  |
+----------------------------------------------------------------+

What I want is

+------------------------------------------------------------------+
|                    | M-q                 | C-u M-q               |
+------------------------------------------------------------------+
| no region selected | fill the paragraph  | unfill the paragraph  |
|                    | surrounding or      | surrounding or        |
|                    | following point     | following point       |
+------------------------------------------------------------------+
| region selected    | fill all paragraphs | unfill all paragraphs |
|                    | in the region       | in the region         |
+------------------------------------------------------------------+

Note that the wanted region-handling behaviors are those which one gets using M-x, i.e., with region selected

* `M-x fill-paragraph' fills all paragraphs in the selected region

* `M-x unfill-paragraph' unfills all paragraphs in the selected region

How to fix? Apologies for elisp lameness. One Of These Days I really gotta sit down and learn the tool. But right now, I gotta learn more fortran first :-(

Your assistance is appreciated, Tom Roche <Tom_Roche@pobox.com>

Re: [C-u M-q] -> unfill-paragraph

[Eric Abrahamsen]

On Sun, Nov 13 2011, Tom Roche wrote:

> [Text-mode table enclosed--best viewed in monospace font.]
>
> Tom Roche Thu, 10 Nov 2011 12:29:33 -0500
>>> [How] to write one's own `fill-paragraph' façade such that
>
>>> * [my-fill-paragraph] would hide [the] emacs-provided
>>>   `fill-paragraph'
>
>>> * [my-fill-paragraph] could delegate to the emacs-provided
>>>   `fill-paragraph' except when called with prefix argument
>
> Scott Frazer Thu, 10 Nov 2011 14:00:14 -0500
>> (defun my-fill-paragraph (&optional arg)
>>   (interactive "P")
>>   (let ((fill-column (if arg (point-max) fill-column)))
>>     (fill-paragraph)))
>
>> (global-set-key (kbd "M-q") 'my-fill-paragraph)
>
> That works, except for region handling. What the code above does is
>
> +----------------------------------------------------------------+
> |                    | M-q                | C-u M-q              |
> +----------------------------------------------------------------+
> | no region selected | fill the paragraph | unfill the paragraph |
> |                    | surrounding or     | surrounding or       |
> |                    | following point    | following point      |
> +----------------------------------------------------------------+
> | region selected    | nothing            | unfills first (only) |
> |                    |                    | paragraph in region  |
> +----------------------------------------------------------------+
>
> What I want is
>
> +------------------------------------------------------------------+
> |                    | M-q                 | C-u M-q               |
> +------------------------------------------------------------------+
> | no region selected | fill the paragraph  | unfill the paragraph  |
> |                    | surrounding or      | surrounding or        |
> |                    | following point     | following point       |
> +------------------------------------------------------------------+
> | region selected    | fill all paragraphs | unfill all paragraphs |
> |                    | in the region       | in the region         |
> +------------------------------------------------------------------+
>
> Note that the wanted region-handling behaviors are those which one gets using M-x, i.e., with region selected
>
> * `M-x fill-paragraph' fills all paragraphs in the selected region
>
> * `M-x unfill-paragraph' unfills all paragraphs in the selected region
>
> How to fix? Apologies for elisp lameness. One Of These Days I really gotta sit down and learn the tool. But right now, I gotta learn more fortran first :-(

Scott's basic approach is still correct: bind M-q to what you want, not
what emacs provides. But then you can delegate:


(defun my-fill-paragraph (&optional arg)
  (interactive "P")
  (if arg
      (call-interactively 'unfill-paragraph)
    (call-interactively 'fill-paragraph)))

`call-interactively' ensures that whatever prefix arguments
`fill-paragraph' and `unfill-paragraph' might take (the region being the
important one here) are passed to those commands properly.

Hope that does the trick,

Eric

-- 
GNU Emacs 24.0.91.1 (i686-pc-linux-gnu, GTK+ Version 2.24.6)
 of 2011-11-07 on pellet

Re: [C-u M-q] -> unfill-paragraph

[Tom Roche]

[Text-mode tables enclosed--best viewed in monospace font--
 and there's also some utf-8]

Tom Roche Thu, 10 Nov 2011 12:29:33 -0500
>>>> [How] to write one's own `fill-paragraph' façade such that

>>>> * [my-fill-paragraph hides] the emacs-provided `fill-paragraph'

>>>> * [my-fill-paragraph delegates] to the emacs-provided
>>>>   `fill-paragraph' except when called with [C-u]

Scott Frazer Thu, 10 Nov 2011 14:00:14 -0500
>>> (defun my-fill-paragraph (&optional arg)
>>>   (interactive "P")
>>>   (let ((fill-column (if arg (point-max) fill-column)))
>>>     (fill-paragraph)))

>>> (global-set-key (kbd "M-q") 'my-fill-paragraph)

Tom Roche Sun, 13 Nov 2011 10:52:44 -0500
>> That works, except for region handling[, i.e.,]

>> +--------------------------------------------------------------+
>> |                    | M-q              | C-u M-q              |
>> +--------------------------------------------------------------+
>> | no region selected | fill paragraph   | unfill paragraph     |
>> |                    | surrounding or   | surrounding or       |
>> |                    | following point  | following point      |
>> +--------------------------------------------------------------+
>> | region selected    | nothing          | unfills (only)       |
>> |                    |                  | first paragraph      |
>> |                    |                  | in the region        |
>> +--------------------------------------------------------------+

>> What I want is

>> +-----------------------------------------------------------+
>> |                    | M-q              | C-u M-q           |
>> +-----------------------------------------------------------+
>> | no region selected | fill paragraph   | unfill paragraph  |
>> |                    | surrounding or   | surrounding or    |
>> |                    | following point  | following point   |
>> +-----------------------------------------------------------+
>> | region selected    | fill all         | unfill all        |
>> |                    | paragraphs in    | paragraphs in     |
>> |                    | the region       | the region        |
>> +-----------------------------------------------------------+

>> Note that the wanted region-handling behaviors are those which one
>> gets using M-x, i.e., with region selected

>> * `M-x fill-paragraph' fills all paragraphs in the selected region

>> * `M-x unfill-paragraph' unfills all paragraphs in the selected region

Eric Abrahamsen Mon, 14 Nov 2011 11:44:11 +0800
> Scott's basic approach is still correct: bind M-q to what you want,

Yes, that I understand.

> `call-interactively' ensures that whatever prefix arguments
> `fill-paragraph' and `unfill-paragraph' might take (the region being
> the important one here) are passed to those commands properly.

Thanks! This indeed seems to work as desired:

(defun my-fill-paragraph (&optional arg)
  (interactive "P")
  (if arg
    (call-interactively 'unfill-paragraph)
    (call-interactively 'fill-paragraph)))

(global-set-key (kbd "M-q") 'my-fill-paragraph)

I'll "field-test" today then post gnu-emacs-sources (with attribution).