You can use substitute-command-keys, e.g.,
;; => "C-g"
though if there are multiple key bindings, it returns only one of them (the "first" one), for example,
;; => "C-x ("
see also it's docstring and (elisp) Keys in Documentation.
You can use func-arity added in 26.1. C-h f func-arity:
func-arity is a built-in function in `C source code'.
Return minimum and maximum number of args allowed for FUNCTION.
FUNCTION must be a function of some kind.
The returned value is a cons
cell (MIN . MAX).
MIN is the minimum number of args.
MAX is the
You might want to have the documentation display immediately when you type C-h f on a command (that is, without having to press <RET>), while keeping the original behaviour of being able to type the function name when you're anywhere else.
That is not so trivial to do, because function-at-point is very greedy. Telling it to display its first ...
I'm familiar with C-c and with C-h, but I can't figure out what the @ means.
It's the literal character @ for which your keyboard should have a key (or key sequence). On my keyboard @ is Shift+2.
So just type Ctrl+C and then type @
Conceptually it's no different to being told to type C-c a (for example).
@ doesn't mean anything, by itself, beside representing the @ key on your keyboard.
The key sequence C-c @ C-h is bound to command hs-hide-block in hs-minor-mode, that is, in keymap hs-minor-mode-map.
In that key sequence, C-c is a prefix key, which means it's bound to a keymap.
In that keymap, @ is a prefix key, which means it's bound to a keymap.
In that ...