The only actual increase in difficulty from scannerless parsing is having to janitor whether a function will always slurp up whitespace before it finishes. Lin

The only actual increase in difficulty from scannerless parsing is having to janitor whether a function will always slurp up whitespace before it finishes. Linear-time is easy, questions of unique parse tree are irrelevant because the only ambiguity is who owns a piece of whitespace that gets discarded anyway.