Re: expanding nameref target?

[Mikael Magnusson <mikachu@gmail.com>]

On 2/28/23, Oliver Kiddle <opk@zsh.org> wrote:
> Bart Schaefer wrote:
>> In ksh emulation (and history disabled), I have this working:
>>
>> % typeset -n foo=bar
>> % echo ${!foo}
>> bar
>
> Supporting ${!foo} is useful for ksh (and bash) compatibility so that
> sounds good. There are also other forms such as ${!name[@]}.
>
>> However, that's pretty clumsy because of history expansion, so I'm
>> proposing the following for zsh native mode:
>>
>> % typeset -n foo=bar
>> % echo ${(?)foo}
>
> I would question whether it's really sufficiently useful to warrant
> that.

What about (PP)? There is some precedent for doubling a flag to
disable its effect. The downside is that (PP) already works and is
treated like (P) but...

> I'm inclined to suspect that anyone who thinks they need ${!foo}
> has probably missed the point of namerefs. Unless they are writing
> something that is meta in nature to begin with like the describe-params
> function that recently circulated on the -users list. ${!foo} may give
> you the name of a variable that is hidden by a local variable so you
> don't want to rely on it if you want your code to be robust.
>
> So my view is that I wouldn't bother expending one of the few remaining
> flag characters on it.
>
>> As an extension (more by accident than by design but possibly useful):
>>
>> % echo ${(?)options}
>> zsh/parameter
>
> Doesn't that lead to a conflict for a nameref defined in a module - do
> you get the module name or the target of the nameref?

Does a nameref defined in a module before the module is loaded
actually have a target yet?

-- 
Mikael Magnusson