Re: Clarifying the C-c letter guideline

[Matt Armstrong]

chad <yandros@gmail.com> writes:

> On Sun, Feb 14, 2021 at 4:14 AM Philip Kaludercic <philipk@posteo.net>
> wrote:
>
>> > • Don’t define ‘C-c LETTER’ as a key in Lisp programs.  Sequences
>> >   consisting of ‘C-c’ and a letter (either upper or lower case) are
>> >   reserved for users; they are the *only* sequences reserved for
>> >   users, so do not block them.
>>
>> There seems to be some uncertainty in how this should be
>> interpreted. Does this mean that...
>>
>> - No package/library/third-party code may ever bind a command or map to
>>   C-c LETTER, under any circumstances (in the letter of the law).
>>
>> - A package/library/third-party code may bind a command or a map to C-c
>>   LETTER, if the user is explicitly asked and he or she gives
>>   permission (in the spirit of the law).
>>
>
> IIRC, the intent was roughly "anyone interested in binding key inside Emacs
> should assume that individual users may have arbitrary bindings to anything
> inside C-c", with the strong implication that they cannot "safely"
> establish any common or conventional binding inside that space. (I don't
> recall if the original intent was restricted to C-c [alpha], C-c
> [alphanum], or C-c [any-single].
>
> If my memory from ~30 years ago is correct, this didn't outlaw a local
> group from making packages that used C-c bindings, with the understanding
> that a given lab or research group would manage conflicts within themselves
> as needed. Of course, in those times a given elisp "package" was likely to
> be distributed  uuencoded via email, ftp, or usenet, with changes noted in
> RCS or SCCS headers, so "distribution" wasn't the same sort of concern.

Neat bit of history Chat.

I will say that I have successfully convinced non-Emacs packages to move
their default bindings off C-c <letter> based on this writeup. Most were
happy to do so once I pointed them to the docs.