Re: Incorporating caching into defgroup/defcustom/defvar for Emacs 25

["Stephen J. Turnbull" <stephen@xemacs.org>]

Artur Malabarba writes:
 > On 2 Feb 2015 01:07, "Stephen J. Turnbull" <stephen@xemacs.org> wrote:

 > > Why not?  Custom provides a "reset" functionality if the user *wants*
 > > to reset.  It's not clear to me that a user wouldn't want changes to
 > > customizable variables to persist.
 > 
 > I wasn't saying defcustoms shouldn't be persistent, I was just
 > saying they already have a great mechanism for that so they don't
 > need to use this caching mechanism that is being suggested for
 > internal variables.

Yes, they might.  A user who is testing out a new custom setting might
like the setting to persist without explicitly saving it if Emacs
crashes or he runs out of memory and needs to stop and restart Emacs,
or something like that.

 > > What does stash provide that a session manager such as desktop.el
 > > doesn't?  That wasn't clear to me from your long email.
 > 
 > With stash, a package can specify that a global variable is supposed to be
 > persistent, and this variable will automatically be saved/loaded from disk.
 > 
 > I understand desktop.el provides similar functionality, but, IIUC,
 > desktop.el is more of a user interface. By that I mean sessions are
 > only saved/loaded if desktop-mode is enabled,

The people I know who use desktop generally enable it in init.el.  The
only way to disable it AFAIK is -q.

 > Stash provides a simple abstraction for a variable that will be
 > persistent accross sessions. You just declare a variable to be
 > persistent (Sean suggested a `defvar*' macro,

Ah, OK, so the important thing is that the programmer controls it, not
the user.