sqlite3

[Lars Ingebrigtsen]

I think many user experience things in Emacs would be better if Emacs
remembered more.

The bigger systems don't have this problem -- Gnus needs a large
.newsrc.eld file, and it maintains that.

The tiny things don't really have this problem, either: You save options
with `customize-save-variable', and that fine.

It's the many things that fall between these two extremes that have the
problem: Where you want to store some state, but figuring it's just too
much work to figure out Yet Another Storage Format, but the data is too
messy to stash in somebody's .emacs file via Customize (like lists of
stuff).

So there's a bunch of stuff that Emacs just forgets when you shut down,
where it perhaps shouldn't.

I've brought this up before, but I didn't really have a solution then,
but I think I do now: sqlite3.

sqlite3 is supported on more platforms than Emacs is, the interface is
small and stable, and (best of all) somebody has already created
interface functions for Emacs (via a module):

  https://github.com/syohex/emacs-sqlite3

I think it'd be good to bring that into core, and then write a small
wrapper library (well, a trivial ORM) for the rest of Emacs to use, so
that we don't have to write SQL all over the place.  That is:

(setf (persistent-data :namespace "emoji" :key "favorites") emoji--favorites)

I.e., what Emacs needs is a persistent key/value store, and this would
give us that.

In addition, if somebody really wants to write SQL stuff (it can be very
handy for some things), having sqlite3 in there gives us that in
addition for free.

This comes with questions about how the users are supposed be able to
clear out the data, for instance, but we could have a `M-x
list-persistent-data' where the users could blow out whatever they want
to.

-- 
(domestic pets only, the antidote for overdose, milk.)
   bloggy blog: http://lars.ingebrigtsen.no