final def orElseU[Err2 >: Err, In2 <: In, Result2](that: => Parser[Err2, In2, Result2]): Parser[Err2, In2, Result | Result2]
Assigns 'that' parser as a fallback of this. First this parser gets evaluated. In case it succeeds, the result is this parser's result. In case it fails, the result is 'that' parser's result.
Assigns 'that' parser as a fallback of this. First this parser gets evaluated. In case it succeeds, the result is this parser's result. In case it fails, the result is 'that' parser's result.
If auto-backtracking is on, this parser will backtrack before trying 'that' parser.