tree_automata
macro_rules! automaton_items { ( $aut:ident $f:tt ( $( $sub:expr ),* ) -> $q:tt, $( $token:tt )* ) => { ... }; ( $aut:ident $f:tt -> $q:tt, $( $token:tt )* ) => { ... }; ( $aut:ident finals $($q:tt)* ) => { ... }; }