How to set outline-level in the first line?

How to set outline-level in the first line?

[Heinz Tuechler]

Dear All,

To adapt outline-minor-mode to the comment form I use in R, I tried to
adjust the outline-regexp and the outline-level.

The outline-level should be:
(setq outline-level (defun outline-level ()
  "adjust outline-level to R-comments"	 
		      (interactive)
		      (cond ((looking-at "#\\{5\\} ") 1)
			    ((looking-at "#### ") 2)
			    ((looking-at "### ") 3)
			    ((looking-at "## ") 4)  
			    (t 1000))))

I tried to do this in the first line by something like 
outline-level: (defun outline-level () (interactive) (cond ((looking-at
"##### ") 1)((looking-at "#### ") 2)((looking-at "### ") 3)((looking-at "##
") 4)  (t 1000)))
but I did not find the right way.

Only if I use eval: (setq outline-level ... it does what I want.

So finally my first line looks as follows:
-*- mode: text; mode:outline-minor; outline-regexp:"#\\{2,5\\} "; eval:
(setq outline-level (defun outline-level () (interactive) (cond
((looking-at "##### ") 1)((looking-at "#### ") 2)((looking-at "### ")
3)((looking-at "## ") 4)  (t 1000)))) -*-

What I would like to know is, how to set the outline-level without "eval:"?

version information:
GNU Emacs 21.3.1 (i386-mingw-nt5.1.2600) of 2004-03-10 on NYAUMO

Thanks,
Heinz

Re: How to set outline-level in the first line?

[Heinz Tuechler]

Dear All,

some days ago I sent the message below to the list. Until now, I did not
receive any answer.
I assume, this means, it is not possible to set outline-level as local
variable in the first line (except by eval:).
Could one of you experts confirm this opinion? I would be happy about some
yes/no answer.

Thanks,
Heinz

At 12:40 06.05.2007 +0100, Heinz Tuechler wrote:
>Dear All,
>
>To adapt outline-minor-mode to the comment form I use in R, I tried to
>adjust the outline-regexp and the outline-level.
>
>The outline-level should be:
>(setq outline-level (defun outline-level ()
>  "adjust outline-level to R-comments"	 
>		      (interactive)
>		      (cond ((looking-at "#\\{5\\} ") 1)
>			    ((looking-at "#### ") 2)
>			    ((looking-at "### ") 3)
>			    ((looking-at "## ") 4)  
>			    (t 1000))))
>
>I tried to do this in the first line by something like 
>outline-level: (defun outline-level () (interactive) (cond ((looking-at
>"##### ") 1)((looking-at "#### ") 2)((looking-at "### ") 3)((looking-at "##
>") 4)  (t 1000)))
>but I did not find the right way.
>
>Only if I use eval: (setq outline-level ... it does what I want.
>
>So finally my first line looks as follows:
>-*- mode: text; mode:outline-minor; outline-regexp:"#\\{2,5\\} "; eval:
>(setq outline-level (defun outline-level () (interactive) (cond
>((looking-at "##### ") 1)((looking-at "#### ") 2)((looking-at "### ")
>3)((looking-at "## ") 4)  (t 1000)))) -*-
>
>What I would like to know is, how to set the outline-level without "eval:"?
>
>version information:
>GNU Emacs 21.3.1 (i386-mingw-nt5.1.2600) of 2004-03-10 on NYAUMO
>
>Thanks,
>Heinz
>
>
>
>
>_______________________________________________
>help-gnu-emacs mailing list
>help-gnu-emacs@gnu.org
>http://lists.gnu.org/mailman/listinfo/help-gnu-emacs
>

Re: How to set outline-level in the first line?

[Stefan Monnier]

> some days ago I sent the message below to the list.  Until now, I did not
> receive any answer.
> I assume, this means, it is not possible to set outline-level as local
> variable in the first line (except by eval:).
> Could one of you experts confirm this opinion? I would be happy about some
> yes/no answer.

It's definitely possible.  But since it's dangerous (in case the file comes
from someone you don't trust), Emacs should try to make it a bit harder.

>> The outline-level should be:
>> (setq outline-level (defun outline-level ()
>> "adjust outline-level to R-comments"	 
>> (interactive)
>> (cond ((looking-at "#\\{5\\} ") 1)
>> ((looking-at "#### ") 2)
>> ((looking-at "### ") 3)
>> ((looking-at "## ") 4)  
>> (t 1000))))

This can't be right.  `defun' is a command which is used for its
side-effect, not its return value.  Use:

(setq outline-level (lambda ()
		      "Adjust outline-level to R-comments."
		      (interactive)
		      (cond ((looking-at "#\\{5\\} ") 1)
			    ((looking-at "#### ") 2)
			    ((looking-at "### ") 3)
			    ((looking-at "## ") 4)
			    (t 1000))))

instead, or

(defun my-R-outline-level ()
  "Adjust outline-level to R-comments."
  (interactive)
  (cond ((looking-at "#\\{5\\} ") 1)
        ((looking-at "#### ") 2)
	((looking-at "### ") 3)
	((looking-at "## ") 4)
	(t 1000))))

(setq outline-level 'my-R-outline-level)


>> I tried to do this in the first line by something like
>> outline-level: (defun outline-level () (interactive) (cond ((looking-at
>> "##### ") 1)((looking-at "#### ") 2)((looking-at "### ") 3)((looking-at "##
>> ") 4)  (t 1000)))
>> but I did not find the right way.

The expression after the : should be a *value*, not an expression: it will
not be evaluated but just directly assigned to the variable.
I.e.

       foo-bar: (+ 3 4)

will not set `foo-bar' to 7 but to the 3-element list containing the
symbol + and the integers 3 and 4.  Luckily (lambda () ...) *is* a value, so

 outline-level: (lambda () (interactive) (cond ((looking-at
 "##### ") 1)((looking-at "#### ") 2)((looking-at "### ") 3)((looking-at "##
 ") 4)  (t 1000)))

might work (provided you add the necessary -*- around, of course.

Another option might be to change your R mode with

   (add-hook 'R-mode-hook 'my-R-outline-level)


-- Stefan

Re: How to set outline-level in the first line?

[Heinz Tuechler]

Dear Stefan!

Thank you for your answer and the explanation. Now it works well.
The first line, I tested is:
-*- mode: text; mode:outline-minor; outline-regexp:"#\\{2,5\\} ";
outline-level: (lambda () (interactive) (cond ((looking-at "##### ")
1)((looking-at "#### ") 2)((looking-at "### ") 3)((looking-at "## ") 4)  (t
1000))) -*-

For me it has the same effect as:
-*- mode: text; mode:outline-minor; outline-regexp:"#\\{2,5\\} "; eval:
(setq outline-level (defun outline-level () (interactive) (cond
((looking-at "##### ") 1)((looking-at "#### ") 2)((looking-at "### ")
3)((looking-at "## ") 4)  (t 1000)))) -*-

I wanted to solve this problem by local variables, because in this way
others may use it on a per file basis. For my own use I did as you
suggested and added a hook in my .emacs file.

Thanks again,

Heinz

At 01:08 11.05.2007 -0400, Stefan Monnier wrote:
>> some days ago I sent the message below to the list.  Until now, I did not
>> receive any answer.
>> I assume, this means, it is not possible to set outline-level as local
>> variable in the first line (except by eval:).
>> Could one of you experts confirm this opinion? I would be happy about some
>> yes/no answer.
>
>It's definitely possible.  But since it's dangerous (in case the file comes
>>from someone you don't trust), Emacs should try to make it a bit harder.
>
>>> The outline-level should be:
>>> (setq outline-level (defun outline-level ()
>>> "adjust outline-level to R-comments"	 
>>> (interactive)
>>> (cond ((looking-at "#\\{5\\} ") 1)
>>> ((looking-at "#### ") 2)
>>> ((looking-at "### ") 3)
>>> ((looking-at "## ") 4)  
>>> (t 1000))))
>
>This can't be right.  `defun' is a command which is used for its
>side-effect, not its return value.  Use:
>
>(setq outline-level (lambda ()
>		      "Adjust outline-level to R-comments."
>		      (interactive)
>		      (cond ((looking-at "#\\{5\\} ") 1)
>			    ((looking-at "#### ") 2)
>			    ((looking-at "### ") 3)
>			    ((looking-at "## ") 4)
>			    (t 1000))))
>
>instead, or
>
>(defun my-R-outline-level ()
>  "Adjust outline-level to R-comments."
>  (interactive)
>  (cond ((looking-at "#\\{5\\} ") 1)
>        ((looking-at "#### ") 2)
>	((looking-at "### ") 3)
>	((looking-at "## ") 4)
>	(t 1000))))
>
>(setq outline-level 'my-R-outline-level)
>
>
>>> I tried to do this in the first line by something like
>>> outline-level: (defun outline-level () (interactive) (cond ((looking-at
>>> "##### ") 1)((looking-at "#### ") 2)((looking-at "### ") 3)((looking-at
"##
>>> ") 4)  (t 1000)))
>>> but I did not find the right way.
>
>The expression after the : should be a *value*, not an expression: it will
>not be evaluated but just directly assigned to the variable.
>I.e.
>
>       foo-bar: (+ 3 4)
>
>will not set `foo-bar' to 7 but to the 3-element list containing the
>symbol + and the integers 3 and 4.  Luckily (lambda () ...) *is* a value, so
>
> outline-level: (lambda () (interactive) (cond ((looking-at
> "##### ") 1)((looking-at "#### ") 2)((looking-at "### ") 3)((looking-at "##
> ") 4)  (t 1000)))
>
>might work (provided you add the necessary -*- around, of course.
>
>Another option might be to change your R mode with
>
>   (add-hook 'R-mode-hook 'my-R-outline-level)
>
>
>-- Stefan
>_______________________________________________
>help-gnu-emacs mailing list
>help-gnu-emacs@gnu.org
>http://lists.gnu.org/mailman/listinfo/help-gnu-emacs
>

Re: How to set outline-level in the first line?

[Johan Bockgård]

Stefan Monnier <monnier@iro.umontreal.ca> writes:

> This can't be right. `defun' is a command which is used for its
> side-effect, not its return value.

Emacs Lisp is not Scheme.

(defun foo ())   =>   foo

-- 
Johan Bockgård

Re: How to set outline-level in the first line?

[Stefan Monnier]

>> This can't be right. `defun' is a command which is used for its
>> side-effect, not its return value.

> Emacs Lisp is not Scheme.
> (defun foo ())   =>   foo

Believe me I know.  But that doesn't mean that the code I had quoted was
right or that `defun' is a command used for its return value.


        Stefan