Re: simplifying beginning-of-defun

[Andreas Roehler <andreas.roehler@online.de>]

Stefan Monnier wrote:
>>>> simplifying forms as below should ease maintenance and speed up execution.
>>> To what extent does it preserve compatibility?
>> Don't see anything incompatible for the moment.
> 
> I actually mentionned obvious incompatibilities in the email to which
> you reply.
> 
>> With `beginning-of-defun-function',
>> `end-of-defun-function' python-mode for example
>> https://launchpad.net/python-mode
>> may set its own function and M-x beginning-of-defun then
>> will work still - which is not the case presently and my point of
>> depart here.
> 
> I do not understand the above paragraph.
> 
>>> Apparently it makes beginning-of-defun-raw ignore
>>> beginning-of-defun-function, and it calls end-of-defun-function with one
>>> argument contrary to the current situation where it's called without
>>> any argument.
>> An argument is useful here: as a repeat or specifier.
> 
> I was pointing out incompatibilities. 


Can't see any. If you write

>>> Apparently it makes beginning-of-defun-raw ignore
>>> beginning-of-defun-function,

it should do exactly that IMHO. Beginning-of-defun-function
was already called  by beginning-of-defun in my scheme - if necessary.


 Also the current way
> end-of-defun-function is defined, it does not need a repeat because it
> only jumps from the beginning of a defun to its end (i.e. it doesn't do
> the same as end-of-defun).
> 


Why not let modes say what they want and need? An argument must not mean a
repeat BTW. In python-mode is a selection to deliver too.



>>> Which performance problem is it trying to solve?
>> All which useless code execution causes.
>> Regard the lines of code saved that way to have an approximation.
> 
> This is much too general: OT1H it's not true (larger code is not
> necessarily slower), OTOH (and more importantly) it doesn't help me
> understand which specific performance problem this is aiming to address.
> 
>> open-paren-in-column-0-is-defun-start is purely redundant, as the
>> regexp may specify that - and indeed does already(?) its just that
>> what I read with "^\\s("
> 
> Again, please move this discussion to a separate thread.
> 
>> Mentioned code of a end-of-defun-function in lisp.el is a bug.
>> Suggest to cancel it.
> 
> I do not know which code nor which bug you talking about.  Your code?
> Emacs's code?

from GNU lisp.el.

"(defvar end-of-defun-function
  (lambda () ...."

Giving it a value here, it will be called. Which is
to avoid, as only languages-modes should set and use it.

This setting reintroduces all the mess, beginning/end-of-defun-function are invented for.



> 
>> Let the -raw functions do everything needed for emacs-lisp.
> 
> AFAICT, that's already the way it's designed (that's why it doesn't set
> the mark, for example).
> 
>> Funcalls of beginning-of-defun-function, end-of-defun-function should
>> be reserved for progmodes.
> 
> I have no idea what you mean by "progmodes".

Modes of other programming languages than emacs-lisp

> 
>> BTW if mode-specific, probably it should be introduced as a local var
>> from the very beginning?
> 
> I'm not sure I understand.  Are you suggesting we
> (make-varible-buffer-local 'beginning-of-defun-function)?
> 

Yes, that's the question. I.e it should be mode-specific, in any case not global.

Andreas
> 
>         Stefan
> 
> 
>