True, the particular use case where this really shines is large datasets where typical usage is to read a tiny part of it. Also there is no reason you couldn't

True, the particular use case where this really shines is large datasets where typical usage is to read a tiny part of it. Also there is no reason you couldn't write an rx parser that creates normal mutable objects. It could even be a hybrid one that is lazy parsed till you want to turn it mutable and then does a normal parse to normal objects after that point.