Joel via ntg-context schrieb am 21.12.2021 um 18:51:
[...]
\define[3]\ifisempty{%
\setbox0=\hbox{#1\unskip}%
\ifdim\wd0=0pt
#2%
\else
#3%
\fi
}%
No need for your own command because ConTeXt already provides
\doifemptyelse which does the same thing.
Wolfgang
