Re: turn-on-*-mode

[Kevin Rodgers]

Kim F. Storm wrote:
> Lennart Borgman <address@hidden> writes:
>
> > Sam Steingold wrote:
> > > > * Richard Stallman <address@hidden> [2006-05-16 00:28:34 -0400]:
> > > >
> > > >     What is the policy on the turn-on-*-mode and turn-off-*-mode functions?
> > > >     Which modes get it and which don't?
> > > >
> > > > We don't need to have a general policy.
>
> We could have a general policy to _discurage_ having such functions!

We do: neither define-minor-mode nor define-global-minor-mode define
turn-on-MODE-mode and turn-off-MODE-mode functions, or even provide
an option to do so.

> > > OK, so if I want turn-on-flyspell-mode, do I just add it?
>
> You are free to add whatever you like to your own .emacs file :-)
>
> > I think that even if Richard says that we do not need a general policy
> > there are some advantages (and some drawbacks too of course) with
> > having similar structures. The main advantage in my opinion is
> > usability. Similar structures reduces unnecessary complexity. It is
> > therefore more easy to remember for a user if things works in a
> > similar way.
> >
> > At least I want people using this software to be able to do things
> > easily. That way I hope they are doing more of the things I like.
>
> There are only three "turn-on-" and on "turn-off-" functions defined
> in my Emacs with my normal .emacs.  Loading more packages may define
> more of them, but I really don't want more of them, as this is still
> an inconsistent interactive interface!  And for non-interactive use,
> doing (*-mode 1) and (*-mode -1) is the preferred interface.

The reason the turn-on-*-mode and turn-off-*-mode functions exist in the
first place is that the (*-mode 1) and (*-mode -1) calls have to be 
wrapped in a function definition (either a lambda form or a user-defined
function) in order to be added to a hook.

I think the turn-on-*-mode and turn-off-*-mode functions should be
provided for all local minor modes to provide a simpler idiom for that.
Global minor modes aren't used that way, are they?

> There are also a number of "toggle-" functions, which IMO is a much
> better interface (just one function, with a simple common prefix).
>
> 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.

There was a long discussion recently about how to programmatically
determine the minor-mode functions and/or variables, partly for the
purpose of presenting them to the user...

> It might even toggle any boolean variable given a C-u prefix...

I had such a command in my .emacs many years ago, but never used it
much.  `M-x toggle-truncate-lines' is a lot more convenient than
`M-x set-variable RET truncate-lines RET ... RET' though!

> .. after the release!

I hope I live to see it!

--
Kevin