Re: region-active-p

[Stephen J. Turnbull]

Stefan Monnier writes:
 > >> What about to introduce `region-active-p' and/or
 > >> `region-exists-p' for
 > 
 > >> (and mark-active transient-mark-mode)
 > 
 > >     I think this is a good idea.  Instead of putting everywhere
 > >     a complex condition:
 > 
 > > I agree.  But we need to decide whether (not (eq (region-beginning)
 > > (region-end))) should be part of it.
 > 
 > I think it should be part of it.  All the commands I can think of that use
 > this kind of feature make the command work on the selected region instead of
 > just "at point".  So an empty region isn't very meaningful for them.

Please implement this interpretation.  It is the interpretation used
by XEmacs since time immemorial (to me, anyway):

------------------------------------------------------------------------
`region-active-p' is a compiled Lisp function
  -- loaded from "/playpen/src/XEmacs/git-staging/lisp/simple.elc"
(region-active-p)

Documentation:
Return non-nil if the region is active in the current buffer.
If `zmacs-regions' is true, this is equivalent to `region-exists-p'.
Otherwise, this function always returns false.
------------------------------------------------------------------------

I believe `zmacs-regions' is the variable that `transient-mark-mode'
emulates.