Why does fill-paragraph insert a "-" char on wrapped lines?

Why does fill-paragraph insert a "-" char on wrapped lines?

[Lennart Borgman (gmail)]

When fill-paragraph is applied to

  ;; - This is a long line that will wrap when it is filled.

it is filled like this

  ;; - This is a long line that will wrap when it is
  ;; - filled.

I do not understand why there is a "-" char on the second line above. I 
would expect that it looked like

  ;; - This is a long line that will wrap when it is
  ;;   filled.

Re: Why does fill-paragraph insert a "-" char on wrapped lines?

[Andreas Schwab]

"Lennart Borgman (gmail)" <lennart.borgman@gmail.com> writes:

> When fill-paragraph is applied to
>
>  ;; - This is a long line that will wrap when it is filled.
>
> it is filled like this
>
>  ;; - This is a long line that will wrap when it is
>  ;; - filled.
>
> I do not understand why there is a "-" char on the second line above.

adaptive-fill-mode is a variable defined in `fill.el'.
Its value is t

Documentation:
*Non-nil means determine a paragraph's fill prefix from its text.

Andreas.

-- 
Andreas Schwab, SuSE Labs, schwab@suse.de
SuSE Linux Products GmbH, Maxfeldstraße 5, 90409 Nürnberg, Germany
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"And now for something completely different."

Re: Why does fill-paragraph insert a "-" char on wrapped lines?

[Lennart Borgman (gmail)]

Andreas Schwab wrote:
> "Lennart Borgman (gmail)" <lennart.borgman@gmail.com> writes:
> 
>> When fill-paragraph is applied to
>>
>>  ;; - This is a long line that will wrap when it is filled.
>>
>> it is filled like this
>>
>>  ;; - This is a long line that will wrap when it is
>>  ;; - filled.
>>
>> I do not understand why there is a "-" char on the second line above.
> 
> adaptive-fill-mode is a variable defined in `fill.el'.
> Its value is t
> 
> Documentation:
> *Non-nil means determine a paragraph's fill prefix from its text.


Thanks, but turning off adaptive-filll-mode instead gives me

   ;; - This is a long line that will wrap when it is
   ;; filled.

I would instead like

   ;; - This is a long line that will wrap when it is
   ;;   filled.

Re: Why does fill-paragraph insert a "-" char on wrapped lines?

[Stefan Monnier]

> When fill-paragraph is applied to

>  ;; - This is a long line that will wrap when it is filled.

> it is filled like this

>  ;; - This is a long line that will wrap when it is
>  ;; - filled.

> I do not understand why there is a "-" char on the second line
> above. I would expect that it looked like

>  ;; - This is a long line that will wrap when it is
>  ;;   filled.

It's a limitation of the current adaptive-fill-mode code.
It actually works in my local Emacs implementation, because I've added
various hacks to it, but this is post-22.


        Stefan

Re: Why does fill-paragraph insert a "-" char on wrapped lines?

[Lennart Borgman (gmail)]

Stefan Monnier wrote:
>> When fill-paragraph is applied to
> 
>>  ;; - This is a long line that will wrap when it is filled.
> 
>> it is filled like this
> 
>>  ;; - This is a long line that will wrap when it is
>>  ;; - filled.
> 
>> I do not understand why there is a "-" char on the second line
>> above. I would expect that it looked like
> 
>>  ;; - This is a long line that will wrap when it is
>>  ;;   filled.
> 
> It's a limitation of the current adaptive-fill-mode code.
> It actually works in my local Emacs implementation, because I've added
> various hacks to it, but this is post-22.


Thanks, I hoped it was something simple we could agree upon now.