Macro nom::tap[−][src]

macro_rules! tap {
    ($i : expr, $name : ident : $submac : ident! ($($args : tt) *) => $e : expr) => { ... };
    ($i : expr, $name : ident : $f : expr => $e : expr) => { ... };
}

Expand description

tap!(name: I -> IResult<I,O> => { block }) => I -> IResult<I, O> allows access to the parser’s result without affecting it

 named!(ptag, tap!(res: tag!( "abcd" ) => { println!("recognized {}", str::from_utf8(res).unwrap()) } ) );

 let r = ptag(&b"abcdefgh"[..]);
 assert_eq!(r, Ok((&b"efgh"[..], &b"abcd"[..])));