So records are only immutable, it's a bold move and i like that.
For beginners we offer a simple model with immutable named tuples and mutable
List and Map, very like Python.
I still think we should restrict sealed to interface only (you can always
retrofit a class or an abstract class to add a
but can I compatibly turn a class type into a record type? It's
potentially a source-compatible change (make the state description
match the class's ctor), but binary-compatible?
Yes. You can transform
class Point {
final int x, y;
public Point(int x, int y) { this.x
