[bongo-devel] Emacs 21

[Daniel Jensen]

I experimented with loading and running Bongo in Emacs 21. (And had
fun reading "Antinews" in the manuals.) There are a lot of problems
that need to be resolved, but I believe these are mostly details. It
should be possible to make a good Bongo backport with a little work.

I have outlined what appears to be the most urgent tasks. Without
fixing these, Bongo will not load. Most probably there are also other
issues that will come clear, if we go ahead and target Emacs 21.

Customize: No `custom-reevaluate-setting' or `customize-mark-as-set'.
Needs workaround.

Moving: Functions `move-beginning-of-line', `move-end-of-line' and
`line-move-invisible-p' do not exist. Potentially needs a lot of
debugging invisibility and so on.

Fringe: No fringe bitmaps. Bongo should silently accept this.

Keymaps: I found a few errors, but I haven't had a close look.

Other missing functions: `run-mode-hooks', `define-global-minor-mode',
`define-obsolete-function-alias', `define-obsolete-variable-alias',
'char-displayable-p', 'time-subtract', `read-directory-name'. Most of
which are not hard to replace, I think.

Regexps: Rx is a little different in Emacs 21, don't know exactly how.

Wrong number of arguments: `next-line', `previous-line',
`face-foreground', `defalias'. Pretty easy to fix.