Re: Modern Conventions for Emacs Lisp files?

[Thorsten Jolitz <tjolitz@gmail.com>]

Eli Zaretskii <eliz@gnu.org> writes:

>> From: Thorsten Jolitz <tjolitz@gmail.com>
>> Date: Mon, 15 Apr 2013 10:37:21 +0200
>> Cc: Bastien <bzg@gnu.org>
>> 
>> | ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
>> | ;;
>> | ;;; Commentary:
>> | ;;
>> | 
>> | [...]
>> `------------------------------------------------------------------------------
>> 
>> I would prefer in this case not to investigate why this line causes such
>> problems but rather to consider writing such a line a bug. 
>> 
>> So maybe Bastien could consider this a bug-report and remove this line?
>> Because otherwise org.el with its more than 23000 lines is just a
>> perfect example were the use of outline/outshine and navi-mode for file
>> structuring, high-level (over)views on the file and easy navigation
>> makes sense.
>
> There are about 60 non-Org *.el files in Emacs which have similar
> lines, and about 40 in lisp/org/.  So IMO asking people not to use
> that runs a risk of being a quixotic battle.

This line actually shows another disadvantage of using only
comment-chars for signalling headlines (^;;;+ ): people feel free to do
whatever they want with comment-chars, even drawing ascii art or invent
their own section separators or so, which then interferes with the
matching of headlines.

I don't want to take the risk of fighting a quixotic battle. The problem
lies in the following function from outshine.el which is actually copied
from Fabrice Niessen who probably copied/adapted it from Org-mode:

,---------------------------------------------------------------------------------
| (defun outshine-fontify-headlines (outline-regexp)
|   ;; highlight the headings
|   ;; see http://www.gnu.org/software/emacs/manual/html_node/emacs/Font-Lock.html
|   ;; use `M-x customize-apropos-faces' to customize faces
|   ;; to find the corresponding face for each outline level, see
|   ;; `org-faces.el'
| 
|   ;; Added `\n?', after having read the following chunk of code (from org.el):
|   ;; `(,(if org-fontify-whole-heading-line
|   ;;        "^\\(\\**\\)\\(\\* \\)\\(.*\n?\\)"
|   ;;      "^\\(\\**\\)\\(\\* \\)\\(.*\\)")
| 
|   (let ((outshine-fontify-whole-heading-line "") ; "\n?")
|         (heading-1-regexp
|          (concat (substring outline-regexp 0 -1) 
|                  "\\{1\\} \\(.*" outshine-fontify-whole-heading-line "\\)"))
|          [... snip ...]
|         (heading-8-regexp
|          (concat (substring outline-regexp 0 -1)
|                  "\\{8,\\} \\(.*" outshine-fontify-whole-heading-line "\\)")))
|     (font-lock-add-keywords
|      nil
|      `((,heading-1-regexp 1 'outshine-level-1 t)
|         [... snip ...]
|        (,heading-8-regexp 1 'outshine-level-8 t)))))
`---------------------------------------------------------------------------------

Its the '-1' that causes the problem:

,----------------------------------------
| (concat (substring outline-regexp 0 -1)
`----------------------------------------

=> Result: "^;;[;]+\\{1\\} \\(.*\\)"

When I delete it

,----------------------------------------
| (concat (substring outline-regexp 0)
`----------------------------------------

=> Result: "^;;[;]+ \\{1\\} \\(.*\\)"

the problem is gone - but fontification doesn't work anymore. 

This is probably more suited for emacs-help, because I would need some
help on this, but since this thread is already on emacs-devel I ask it
here:

How can I get the best of both worlds in this case (no infinite loops
but working fontification)?

-- 
cheers,
Thorsten