Re: Zsh's and ksh's bang (!) expansion flags have different meanings

[Mikael Magnusson <mikachu@xxxxxxxxx>]

On Sun, Jul 19, 2026 at 11:53 PM Bart Schaefer
<schaefer@xxxxxxxxxxxxxxxx> wrote:
>
> On Sun, Jul 19, 2026 at 10:24 AM Philippe Altherr
> <philippe.altherr@xxxxxxxxx> wrote:
> >
> > On Sun, Jul 19, 2026 at 6:36 PM Bart Schaefer <schaefer@xxxxxxxxxxxxxxxx> wrote:
> >>
> >> You're not noticing anything new, or rather the only thing new that you're noticing is that the (!) flag exists at all.
> >
> > I'm fully aware that the (!) flag is a part of named references, so not already present in any released version of Zsh.
>
> Well, yes.  The (sorry, unstated) point was that everything you said
> about (k) is long-standing and (hopefully?) derivable from
> documentation or FAQ.
>
> However, if someone wants to convert those tables of differences into
> a format that could be included in either the FAQ or the "Other
> Differences" section of the zsh/ksh93 module documentation, it would
> probably be quite useful.
>
> >>> In ksh, the (!) flag can be used to list the keys of arrays and associative arrays. In that regard, it's closer to Zsh's (k) flag than Zsh's (!) flag
>
> The (k) flag was originally intended to mimic ksh's ! name prefix (due
> to ! colliding with history).  The character "k" was chosen as a
> mnemonic for "like (k)sh".  I suppose, rather than introduce (!), I
> could have extended (k) for the named reference behavior, to preserve
> that similarity.  Could still try that if it seems a good idea.

I guess this would conflict with nameref-to-assoc, which currently
does what I would expect. (Unless I'm missing something).
% typeset -A a=( a 1 b 2 )
% typeset -n n=a
% echo ${n}
1 2
% echo ${(k)n}
a b

-- 
Mikael Magnusson