New prefix

[Lars Magne Ingebrigtsen <larsi@ifi.uio.no>]

Ok; so I want to add a new prefix.  We already have the normal prefix
-- `C-u' and friends, but in some cases we need an additional prefix.

For instance, the `L' command(s) use the numerical prefix to say how
much to lower the score, and that works fine.  But there are
additional common modifications to the behavior of those commands that
would be nice to have.  For instance, if would be nice if I could tap
a prefix key to make the score command result with a score entry in
"all.SCORE" instead of the current score file.

The machanism has to be somewhat general.  I'm thinking along the
lines of `M-C-u b COMMAND' would give COMMAND the symbolic `b' prefix,
which COMMAND is fit to interpret is it chooses, just as the case is
with the numerical prefix.  I'll be adding a new macro to make these
easy to deal with, and things'll look somewhat like this:

(defun gnus-some-function (&optional arg syms)
  (gnus-interactive "P\nG")
  (let ((prefix-p (memq 'a syms)))
    ... ))

"G" would give a list of symbolic prefixes, and "g" would give one;
the first.

In the former case, the user could say `M-C-u a M-C-u b COMMAND'
to give COMMAND both the `a' and `b' prefixes.

Not all that many commands would need these symbolic prefixes, but a
few commands scream out for something like this.  For instance,
`M-C-u a S o m' to forward something with complete headers.

Reactions?  Good?  Bad?  Use some other prefix key?  What?

-- 
(domestic pets only, the antidote for overdose, milk.)
  larsi@ifi.uio.no * Lars Magne Ingebrigtsen