Function tr 

pub fn tr<I, O, E, F>(
    tag: &'static str,
    name: &'static str,
    f: F,
) -> impl Fn(I) -> IResult<I, O, E>
where
    Input: From<I>,
    F: Fn(I) -> IResult<I, O, E>,
    I: Clone,
    O: Debug,
    E: Debug,

function tracer