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

[Luc Teirlinck]

A summary and some amendments to my previous messages on abbrevs:

I actually might have overestimated the work involved in implementing
true inheritance.  True inheritance seems easier to implement than the
"bug fix" approach.  The bugs involved in copying are really bad and
need to be fixed reasonably soon, if we decide to retain any form of
copying or inheritance.  So there seem to be two choices:

1.  Get rid of copying altogether.

2.  Implement true inheritance.  

In case 2, implementing true inheritance and getting rid of the bugs
involved in copying is relatively urgent, since these bugs are really
bad.  I could implement true inheritance in Lisp, but it might be more
efficient to implement it in C.  Even though I know C, I am not
familiar enough with the Emacs C code to implement it.  Some form of
inheritance seems actually already to be implemented in C, since local
abbrev tables in a certain sense "inherit" from the global one, so
generalizing this might not be too bad.  True inheritance seems to
require less work than a mere bug fix, because the necessary changes
to prepare-abbrev-list-buffer are very minor in that case.  In the
case of a mere bug fix, they seem rather cumbersome to me.  The
changes to prepare-abbrev-list-buffer seem necessary to enable the
user to use M-x edit-abbrevs without having to do a lot of "research".

We should make a decision on this relatively quickly, as discussing
the technical details of other things such as a standard function to
define major modes is difficult if we do not know where we want to go
in terms of abbrev tables.

Sincerely,

Luc.