Re: Sparse key maps garbage?

[Lennart Borgman (gmail)]

Stefan Monnier wrote:
>> If you do
> 
>>  (defvar my-sparse-map (make-sparse-keymap))
>>  (define-key my-sparse-map [f4] nil)
> 
>> then there will be an entry with f4 in my-sparse-keymap. I do not think
>> that is used for anything. Is it? Should it be there?
> 
> Actually, IIRC it's (been) used at some places to create a place holder
> in the keymap which is later on replaced with the actual binding.
> But I do wonder why you care,

I was looking a bit at how to undefine a key, for example at
local-unset-key. So what I really wondered was how do you undefine a
key? Is there a standard way to do that?

> PS: Some other issues have to do with the delicate treatment of nil
> bindings w.r.t inheritance: a nil binding will hide any other binding in
> the parent(s).
>