RE: turn-on-*-mode

[Drew Adams]

    We could even make a M-x toggle command which could toggle any mode
    (it should provide a list of known modes as completion choices).
    That would also be a good way to learn about new modes.

    It might even toggle any boolean variable given a C-u prefix...
    after the release!

I suggested such a generic toggle with completion a while back - see thread
"add generic toggle, turn on,and turn off commands to Options menu"
(2006-03-04 and 2006-04-21-24). This also proposed adding such a generic
toggle to the Options menu, since that menu cannot accomodate an unlimited
number of specific toggle items.

Richard's decision was this:

    I don't like the idea of a generic toggle menu item.
    I don't think that is a helpful UI.  I don't have time to
    discuss it, though.

Of course, the idea of a generic toggle command need not be coupled with the
suggestion to add it to the Options menu. If the idea of such a command (but
not menu item) is still open (Richard?), then please see the previous thread
for some suggestions about treating quasi-binary options, that is, options
that are essentially binary but whose non-nil value need not be t.

Toggling a mode generically (your suggestion) is not necessarily the same as
toggling a user option generically, and mode-variable values are not always
nil and non-nil. But in many cases the treatment of the two could be the
same or similar. In any case, any discussion of one should perhaps also
consider the other.

FATHOC (For after the release, of course.)