\etl_token_split:nN
\etl_token_split_keep_spaces:nN
\tl_show:e { \etl_token_split:nN { a~b~;~a~\empty;~d~;e~ } ; }
> {a b}{a \empty }{d}{e}.
aspell
.pws
\cs_set_eq:NN
\let