Re: lisp-outline-level.

[David Kastrup]

Lute Kamstra <address@hidden> writes:

> David Kastrup <address@hidden> writes:
>
>> Lute Kamstra <address@hidden> writes:
>>
>>> In (Emacs) Lisp mode, outline-regexp is ";;;;* [^ \t\n]\\|(" and
>>> outline-level is lisp-outline-level:
>>>
>>> (defun lisp-outline-level ()
>>>   "Lisp mode `outline-level' function."
>>>   (if (looking-at "(\\|;;;###autoload")
>>>       1000
>>>     (looking-at outline-regexp)
>>>     (- (match-end 0) (match-beginning 0))))
>>>
>>> This is a bit strange as outline-regexp doesn't match
>>> ";;;###autoload".
>>
>> Why is that strange?  outline-regexp is not even consulted when
>> ;###autoload is found, so I don't see how it would come into play
>> here.
>>
>>> Shall I commit the patch below?
>>
>>> *** lisp/emacs-lisp/lisp-mode.el    1 Feb 2005 15:48:50 -0000       1.171
>>> --- lisp/emacs-lisp/lisp-mode.el    13 Feb 2005 11:03:02 -0000
>>> ***************
>>> *** 212,223 ****
>>>   
>>>   (defun lisp-outline-level ()
>>>     "Lisp mode `outline-level' function."
>>> !   (if (looking-at "(\\|;;;###autoload")
>>>         1000
>>> -     (looking-at outline-regexp)
>>>       (- (match-end 0) (match-beginning 0))))
>>>   
>>> - 
>>> --- 212,221 ----
>>>   
>>>   (defun lisp-outline-level ()
>>>     "Lisp mode `outline-level' function."
>>> !   (if (eq (following-char) ?\()
>>>         1000
>>>       (- (match-end 0) (match-beginning 0))))
>>
>> The patch is completely nonsensical.  It returns rubbish in almost all
>> cases since it is the "looking-at" that established match-end and
>> match-beginning in the first place.
>
> The variables outline-regexp and outline-level are used by Outline
> minor mode.  Did you take a look at their docstrings?  Outline minor
> mode searches for matches of outline-regexp and at each match the
> function in outline-level is called to determine the nesting level:
>
> ,----[ C-h v outline-level RET ]
> | outline-level's value is outline-level
> | 
> | *Function of no args to compute a header's nesting level in an outline.
> | It can assume point is at the beginning of a header line and that the match
> | data reflects the `outline-regexp'.
> | 
> | Defined in `outline'.
> `----
>
> Does my patch make more sense now?

Ok, I did not realize that those functions were essentially hook
functions, sorry.  However, I find that within a Lisp buffer I have

outline-regexp's value is ";;;;* [^     \n]\\|("
Local in buffer loaddefs.el; global value is "[*\f]+"

*Regular expression to match the beginning of a heading.
Any line whose beginning matches this regexp is considered to start a heading.
Note that Outline mode only checks this regexp at the start of a line,
so the regexp need not (and usually does not) start with `^'.
The recommended way to set this is with a Local Variables: list
in the file it applies to.  See also `outline-heading-end-regexp'.

You can customize this variable.

Defined in `outline'.

[back]

and this just barely manages to avoid matching ;;;###autoload.  I am
not sure whether this really is intentional.  Especially in light of
the lisp-outline-level definition.

So while I have no clue about the matter at hand, I would just want to
suggest that it might be possible from the look of the previous code
that outline-regexp was intended to also match ;;;###autoload, or at
least that it was considered a valid possibility for a user
customization of outline-regexp in Lisp mode.  In either case it would
not be wrong to keep the check.

-- 
David Kastrup, Kriemhildstr. 15, 44793 Bochum