bug#6774: Cut and paste with C-w/mouse-2 not working?

[David De La Harpe Golden]

On 06/08/10 11:50, Eli Zaretskii wrote:
> > From: Stefan Monnier<monnier@iro.umontreal.ca>
> > Cc: David De La Harpe Golden<david@harpegolden.net>,  cyd@stupidchicken.com,  
> > 6774@debbugs.gnu.org,  angelo.graziosi@alice.it
> > Date: Fri, 06 Aug 2010 11:13:50 +0200
> >
> > > But that would mean setting the selection each time the user does a
> > > C-w or M-w or any other action that pushes text on the kill ring,
> > > won't it?
> >
> > Isn't that what Emacs has been doing for the last 10 years?
>
> Not as far as I know.  Maybe I was living in some pipe dream, but I
> always thought the actual copying happened only when some other
> application actually requests the selection.

I was talking about a second level of intra-emacs laziness that exists 
in the present select-active-regions implementation, not 
inter-application stuff.

See, on X11 you can x-set-selection the _emacs-level_ selection (stored 
internally on selection_alist) to a non-string value that merely 
references a buffer, so that when/if another application requests the 
selection, it is looked up all the way back to a buffer (or cons of 
markers).  The current select-active-regions implementation works that 
way, and thereby avoids an emacs-internal string copy sometimes (in 
cases like C-w/M-w that internal copy happens anyway).

My proposal was to consider that a premature optimization, go back to 
basics, then re-optimise by reintroducing some emacs-internal laziness 
in a more controlled fashion.