Hi,
I was looking at some of my old patches and stumbled upon this one
which implements mksh' ${|func;} substitution. The old thread went
over a complex (x) flag choice as a expected candidate for such use
case, however I've now thought that something is better than nothing
and that implementing simpler ${!func;} doesn't block us from adding a
more advanced x-flag in the future. Also, the simplicity of this
substitution is a plus for it, opposed to x-flag complexity (think of
existing e flag, whose's use is fairly complex).

So I thought that I send the patch again upon cleaning conflicts, for
consideration. Or should we revive the advanced x-flag?

To recall - the ${|func;} substitution runs function "func" and
substitutes (returned string in…) $REPLY after it has completed,
without (!) doing forks, which is a performance and functionality
benefit over currently available equivalent: $(func;print -rn --
$REPLY). Original thread:
https://zsh.org/mla/workers/2019/msg00768.html

-- 
Best regards,
Sebastian Gniazdowski