Re: Bugs caused by recent use of define-derived-mode

[Luc Teirlinck]

Actually, there might be a more efficient way that would also make
adapting other related functions less awkward.  It corresponds to true
inheritance in that abbrev expansion would be called several times in
the different "active" abbrev tables until expansion occurs.  A more
local abbrev table gets used first and hence overrides more global
ones.  No copying between abbrev tables would take place.  There still
would remain work to be done in adapting related functions.  The most
efficient way to implement this seems to be directly in the C code.  I
do know C, but I am not terribly familiar with Emacs' C code and hence
could be of no help here.  A similar behavior could be implemented in
Lisp using pre-abbrev-expand-hook, but I believe that would definitely
be less efficient.

Essentially, the above behavior is true inheritance, my previous
proposal is a bug fix mimicking true inheritance perfectly, but with
the drawback of the same abbrev definition occurring in multiple
abbrev tables.  (This drawback is present in the current situation
too.)

Sincerely,

Luc.