Show Keys In Emacs Keymap Value

Did you know the command C-h m (describe-mode), which usually shows a description of the current major and minor modes, usually with their keymaps?

(substitute-command-keys "\\{foo-map}") is what describe-mode uses internally to generate the user-friendly description of the keymap foo-map.

If you’d like to have something closer to the keymap structure, the API is documented in “Classifying Events” in the Emacs Lisp manual. For example,
    (event-modifiers 33554445) ==> (shift control)
    (format "%c" (event-basic-type 33554445)) ==> "m"