Re: [PATCH]: New Add defun org-mode-or-derived-mode-p

[Cassio Koshikumo <ckoshikumo@gmail.com>]

Hi, all,

On the last few days I've been working on a major mode derived from org-mode.
While I was at it, I've encoutered some difficulties related to those reported
by the OP (Stefan). Specifically: in a lot of places, org-mode will check if
it's the current major-mode and, if it's not, will refuse to perform some
important task.

But this poses a problem: a derived mode will always fail the test

(eq major-mode 'org-mode)

So, as long as org-mode relies on this test to perform some tasks, a derived
mode will have non-functional pieces and bugs.

Before this patch, all the checking was centralized in the defsubst
`org-mode-p'. While I was developing my mode, I just changed it to

(defsubst org-mode-p ()
  (derived-mode-p 'org-mode))

Of course, this was just a temporary workaround, but I was actually planning on
submitting a patch that implemented the (already discussed)
`org-mode-or-derived-mode-p' alternative, replacing all calls to `org-mode-p'
with calls to it.

But then comes this patch, which removes `org-mode-p' altogether. So, now, there
are several instances of the always-failing test on the code. Clearly, this is a
big problem for anyone writing derived modes (there doesn't seem to be a lot of
people doing that, but still).

So, finally, here's my question: would it be possible to change all the (eq
major-mode 'org-mode) tests and replace them with (derived-mode-p 'org-mode)? Is
there any reason not to do this?

That's effectively what happened when I changed the defsubst and I haven't
noticed any problems. After all, org-mode will continue to always pass that test
-- it's just that the derived modes will start to pass it too.

If no ones' against it, I think I could create the patch. I haven't signed the
FSF papers, but this change falls neatly into the "repetitive" category.

Cheers,

-- 
Cássio Koshikumo


At Sat, 22 Oct 2011 11:31:21 +0200,
Bastien wrote:
> 
> Hi Tassilo,
> 
> Tassilo Horn <tassilo@member.fsf.org> writes:
> 
> > Ups, I've slightly misread your suggestion.  Currently, there is only
> > one place in org-src.el that check for being a mode derived from
> > org-mode or org-mode itself.  The second is useless, because
> > (derived-mode-p 'org-mode) is true for org-mode, too.
> >
> > But as I've said, I've misread your suggestion and made a patch that
> > completely erases org-mode-p and all its calls.  Feel free to apply or
> > discard it. :-)
> 
> I applied this patch -- thanks for it.
> 
> IMHO another reason for using (eq major-mode 'org-mode) instead of
> (org-mode-p) is that new contributors are likely to use this more
> explicit (though longer) expression before they find out that a 
> defsubst is available for that.
> 
> -- 
>  Bastien
> 
>