Macro nemo::handlers

macro_rules! handlers {
    (@final_entry $t:ty => $($rest:tt)*) => { ... };
    (@final_entry $t:ty) => { ... };
    (@nested_env $prev:ty, $cur:ty => $($rest:tt)*) => { ... };
    (@nested_env $prev:ty, $cur:ty) => { ... };
    (
        $protocol:ident ($($impl_bound:ty),*);
        $chan:ident($($environment:tt)*) => $b:block
    ) => { ... };
    (
        $protocol:ident ($($impl_bound:ty),*);
        $chan:ident($($environment:tt)*) => $b:block

        $($rest:tt)*
    ) => { ... };
}