RE: nxml-mode: Derive from prog-mode instead of text-mode

[Drew Adams]

> >> > This probably could be unified, too. The big difference here is modes
> >> > that are neither text nor programming — I call them application modes
> >> > — such as dired, calendar, or compilation — because they don’t need
> >>
> >> These should supposedly derive from special-mode.
> >
> > Absolutely not, for Dired.  It should not derive from
> > special-mode, tabulated-list-mode, or anything else.
> 
> I'm curious why not special-mode. My observation of special-mode is
> that it handles: 1) quit, 2) refresh, and 3) unbind everything else.

Quit (`q') and refresh (`g') - that's all.  Oh, and `h' too - but
not `?'.

Like `?', all of the `special-mode' keys besides `q', `g', and `h'
are inappropriate - Dired uses them for other things.

Sure, Dired could override those other bindings, but it makes no
sense to derive from special mode just to get the mundane bindings
for `q', `g', and `h' - providing just `quit-window', `revert-buffer',
and `describe-mode' hardly makes for a "special" mode.

And Dired has its own hooks.  I see no reason for Dired to
respect/use `special-mode-hook'.