test_withexpand.tex

%! TEX program = lualatex
\documentclass{article}
\usepackage{prettytok}
\ExplSyntaxOn \prettyinit: \ExplSyntaxOff
\usepackage{imperative}
\AutoGenerateVariants
\errorcontextlines=100
\begin{document}

\ExplSyntaxOn
\makeatletter

\debug_putnextwithexpand {
	\in@ {\foo} {\cslist}
} {
	\expandat \cslist
	\expandat \foo
}


\debug_putnextwithexpand {
	\in@{ ! \csname foo * \endcsname}{ ^ \csname cslist\endcsname}
} {
	\expandatlabel !
	\expandatlabel !
	\onlabel * \expandatlabel ^
	\onlabel * \expandatlabel ^
}

\debug_putnextwithexpand {
	\uppercase { \foo }
} {
	\after \uppercase \expandat \foo
}

\ExplSyntaxOff
\makeatother

\end{document}