In Haskell lazy values are just thunks. So a Lisp-style cons can have a tail that's just a thunk, and when you need to coerce it to a non-thunk value, it just

In Haskell lazy values are just thunks. So a Lisp-style cons can have a tail that's just a thunk, and when you need to coerce it to a non-thunk value, it just happens and presto, you have the next cons. That's a list! A lazy list.