bug#70392: 29.3; null info page is unclear

[Eli Zaretskii <eliz@gnu.org>]

> From: Tom DL <tom_dl@hotmail.com>
> Date: Mon, 15 Apr 2024 07:28:59 +0000
> 
> …as a matter of clarity we use null when object is considered a list and
> not when it is considered a truth value…
> 
> But my understanding is that we also use null when object is considered
> a non-boolean value. E.g. if `foo` could be `red` `green` or `nil` then
> `foo` is neither a list nor a truth value. The info page made me think I
> should use `not` rather than `null`, but upon further research, it looks
> like `null` is fine for checking for `nil` when `nil` isn't used to
> represent falsity.

'null' is fine here, but the manual describes this in a section about
lists, so that's why it contrasts between lists and booleans.

> I would suggested rewording the info page to read as so:
> 
> …as a matter of clarity we use null when object is considered a list or
> other non-boolean value. We use not when object is considered a boolean
> value…
> 
> It may also be helpful to change the section on `not` in "Constructs for
> Combining Conditions":
> 
> …we recommend using the name null if you are testing for an empty list
> or other non-boolean nil.

Thanks, I clarified the wording in these two cases, and I'm therefore
closing this bug.