fill-paragraph / fill region in latex (auctex) buffer

fill-paragraph / fill region in latex (auctex) buffer

[David Reitter]

When I do fill-paragraph on a long line that starts with a %, the  
line is correctly wrapped and a % is added in front of each line.
This is in latex-mode (AUCTeX).

fill-paragraph-function is nil.

When I select a region with the same text, the behavior is different  
- no %'s are inserted, and I get an undesirable result.
This is annoying, because I would want to use fill-region on a whole  
buffer in order to wrap lines, and it turns all the commented out  
stuff into text that appears in my latex document...

Is this a bug?
If so, is it due to Emacs or to AUCTeX?

Re: fill-paragraph / fill region in latex (auctex) buffer

[Stefan Monnier]

> When I select a region with the same text, the behavior is different  - no
> %'s are inserted, and I get an undesirable result.
> This is annoying, because I would want to use fill-region on a whole  buffer
> in order to wrap lines, and it turns all the commented out  stuff into text
> that appears in my latex document...

> Is this a bug?

Yes.

> If so, is it due to Emacs or to AUCTeX?

Emacs.


        Stefan

Re: fill-paragraph / fill region in latex (auctex) buffer

[Ralf Angeli]

* Stefan Monnier (2005-11-22) writes:

>> When I select a region with the same text, the behavior is different  - no
>> %'s are inserted, and I get an undesirable result.
>> This is annoying, because I would want to use fill-region on a whole  buffer
>> in order to wrap lines, and it turns all the commented out  stuff into text
>> that appears in my latex document...
>
>> Is this a bug?
>
> Yes.
>
>> If so, is it due to Emacs or to AUCTeX?
>
> Emacs.

In which sense?  That you cannot hook specialized filling functions
into `fill-region'?

-- 
Ralf

Re: fill-paragraph / fill region in latex (auctex) buffer

[Stefan Monnier]

>>> When I select a region with the same text, the behavior is different  - no
>>> %'s are inserted, and I get an undesirable result.
>>> This is annoying, because I would want to use fill-region on a whole  buffer
>>> in order to wrap lines, and it turns all the commented out  stuff into text
>>> that appears in my latex document...
>> 
>>> Is this a bug?
>> Yes.
>>> If so, is it due to Emacs or to AUCTeX?
>> Emacs.
> In which sense?  That you cannot hook specialized filling functions
> into `fill-region'?

Either that, or that fill-region doesn't understand the fact that blocks of
comments are paragraphs (actually fill-paragraph doesn't quite understand
it either: it only works when you're inside the comment, and even then only
in some cases).


        Stefan

Re: fill-paragraph / fill region in latex (auctex) buffer

[Ralf Angeli]

* Stefan Monnier (2005-11-23) writes:

>> In which sense?  That you cannot hook specialized filling functions
>> into `fill-region'?
>
> Either that, or that fill-region doesn't understand the fact that blocks of
> comments are paragraphs (actually fill-paragraph doesn't quite understand
> it either: it only works when you're inside the comment, and even then only
> in some cases).

`fill-region' should probably call a comment-aware function for
filling paragraphs.  I managed to improve this a bit by using
	    (if (and fill-paragraph-handle-comment
		     comment-start (equal comment-end "")
		     (setq fill-pfx (fill-comment-paragraph)))
		(goto-char end)
	      (setq fill-pfx (fill-region-as-paragraph (point) end justify
						       nosqueeze)))
instead of the simple `fill-region-as-paragraph' call (in the else
part of the above form) currently in `fill-region' and making `end' a
marker.  But it would probably make more sense to make
`fill-region-as-paragraph' aware of comments.

Anyway, AUCTeX provides specialized filling functions using
specialized functions for moving forward and backward over paragraphs
and these functions as well as their key bindings are documented in
AUCTeX's manual.  The functions are able to fill paragraphs and
regions with comments correctly and are even capable of doing
syntax-aware indentation inside of comments.

So for the problem at hand the OP should simply use the functions
provided by AUCTeX instead of `fill-region'.  Of course it would be
nice if the specialized function(s) could be hooked into `fill-region'
because then the menu entry `Edit --> Fill' would work as well.

-- 
Ralf

Re: fill-paragraph / fill region in latex (auctex) buffer

[Stefan Monnier]

> instead of the simple `fill-region-as-paragraph' call (in the else
> part of the above form) currently in `fill-region' and making `end' a
> marker.  But it would probably make more sense to make
> `fill-region-as-paragraph' aware of comments.

I don't think so: fill-region-as-paragraph is really the function that fills
"one paragraph".  So to handle comments, the most important part is to
change fill-region so as to recognize that blocks of comments are paragraphs
on their own.  I.e. it's the forward-paragraph and backward-paragraph
functionality that needs to be made aware of comments (and strings,
incidentally).  Tho I'm unsure about the M-{ and M-} part: fill.el should
maybe have its notion of paragraphs.

> So for the problem at hand the OP should simply use the functions
> provided by AUCTeX instead of `fill-region'.  Of course it would be
> nice if the specialized function(s) could be hooked into `fill-region'
> because then the menu entry `Edit --> Fill' would work as well.

I'd rather add something like fill-paragraph-forward-function should could
then be used both by fill-region and by fill-paragraph.


        Stefan