Re: Is this a bug in while-let or do I missunderstand it?

[Joost Kremers <joostkremers@fastmail.fm>]

On Mon, Nov 25 2024, Sean Whitton wrote:
> I realised though that we are missing one of the features of these
> macros: you can also just write a symbol in the list, and it means to
> proceed if that symbol is already bound to a true value.  E.g.
>
> (let ((foo t))
>   (when-let* ((hello "hello")
> 	      foo)
>     (message hello)))
>
> If in the first line you bind foo to nil instead, then 'message' is not
> called.  I can't remember where this is documented, but it is somewhere..

It's in the doc string of `if-let` (Emacs 29) or `if-let*` (Emacs 30).

> It would be good to have it in the manual too, if you would consider
> working on it.

I left it out because I figured it was just a special case of having just
the VALUEFORM, where VALUEFORM is a symbol, but I realise now that that's
not the case, because unlike VALUEFORM it's not wrapped in a set of
parentheses.

I'll find some time to add it.

-- 
Joost Kremers
Life has its moments