Re: local-ity of undef parameter

[Florian Weimer <fw@...>]

* spir:

> Thank you very much, this is exactly what I was wondering.
> (Actually, I find there is a bit of ambiguity around the sense of
> 'nil', or maybe I haven't it right yet. I would like a value that
> means *only* 'undef' or 'unkown in reachable scope',

But isn't this what nil means?  You shouldn't use it for any other
purpose (like poking holes into array-like tables, which seems to be
the most common misuse of nil).