Function gobble::reader::keyword

pub fn keyword<P: Parser<V>, V>(p: P) -> KeyWord<P, V>

 use gobble::*;
 assert_eq!(keyword("let").parse_s("let"), Ok("let"));
 assert_eq!(keyword("let").parse_s("let "), Ok("let"));
 assert_eq!(keyword("let").parse_s("let*"), Ok("let"));
 assert!(keyword("let").parse_s("letl").is_err());