selectFarthestJoined<R> function
Reports the parser failure farthest down in the input string, joining error messages at the same position.
Implementation
Failure<R> selectFarthestJoined<R>(Failure<R> first, Failure<R> second) =>
first.position > second.position
? first
: first.position < second.position
? second
: first.failure<R>('${first.message} OR ${second.message}');