Re: PROPOSAL: Repurpose one key and reserve it for third-party packages

[Robin Tarsiger <rtt@dasyatidae.com>]

Gregory Heytings wrote:
> Option 1. C-z, with a single exception: "C-z C-z" would be bound to "suspend-frame"
> 
> Option 2. C-z and M-z, with two exceptions: "C-z C-z" would be bound to "suspend-frame", and "M-z M-z" to
> "zap-to-char"
> 
> Option 3. C-o, with a single exception: "C-o C-o" would be bound to "open-line"
> 
> Option 4. C-o and M-o, with two exceptions: "C-o C-o" would be bound to "open-line", and "M-o M-o" to
> "facemenu-keymap"

In my own init code, I use f8 as a prefix key for a bunch of custom bindings,
including for global Calc, SLIME, and Org commands. This seems similar in general
nature to the desired use for third-party packages, and I notice that f5--f8 are
all available in vanilla Emacs. That would obviously be less disruptive than
repurposing an existing key, but I don't know how reachable those keys are in
everyone's configurations.

For those who use them, M-z and C-o are frequent in normal editing. C-z potentially
less so, but I don't really know that---I would expect it to be more redundant in
GUI Emacs where there is usually a window manager gesture for iconify/deiconify,
but in TTY Emacs it's a necessity; but C-x C-z also exists and indeed parallels
C-x C-c better than C-z currently does. ("Preserve the normal behavior of control
keys" is already out the window from C-c being a prefix, though of course that
doesn't obviate the "users may need to retrain" difficulty with any of these.)

I don't find M-o very useful currently because most modes don't preserve faces
meaningfully, and it's already a prefix key, but that idea feels really weird for
some reason.

I _kind of_ like this general idea because the current situation is getting kind of
hazardous. _But_ if any of these do happen, make sure the symbol for the sub-keymap
is exposed so the user can move the whole thing somewhere else from init code.

-RTT