function clone<Type>(o:Type) -> Type
Deep clone an object or fiber.
If code is built with
--enable-lazy-deep-clone (the default), this
initializes a lazy deep clone of the object or fiber, such that any other
objects or fibers reachable through it are only copied when necessary, and
may never be copied at all. If code is built with
--disable-lazy-deep-clone then all objects are copied immediately.
For objects used with a lazy deep clone, consider using recursive data structures such as List and Stack to maximise sharing and memory efficiency.