Document what the parser! body must contain
@@ -212,7 +212,10 @@ macro_rules! impl_token_parser {
/// integer[I](I) -> i32
/// where [I: Stream<Item = char>]
/// {
-/// many1(digit()).and_then(|s: String| s.parse())
+/// // The body must be a block body ( `{ <block body> }`) which ends with an expression
+/// // which evaluates to a parser
+/// let digits = many1(digit());
+/// digits.and_then(|s: String| s.parse())
/// }
/// }
///
