Big fan of that approach as well, but there's no reason why you can't do it in Java. Records and streams are your friends. It's actually rather straightforward

Big fan of that approach as well, but there's no reason why you can't do it in Java. Records and streams are your friends. It's actually rather straightforward to start from a neat, functional pipeline and then do whatever at the edge. Of course you can't have the pure/impure distinction enforced, but nothing that isn't a purely functional language is going to give you that. The only really dumb limitation is that you can't have freestanding functions, but that's aesthetics more than substance.