This seems rudimentary, but I can't figure it out. `struct-copy` requires you to specify the id of the struct type, like so:
(define copied-struct (struct-copy struct-type-id instance-of-struct)) The docs for struct-copy say "subtypes can be copied as if they were supertypes, but the result is an instance of the supertype". [1] OK, but suppose I want the opposite behavior: I want to make a struct-copying function that accepts instances of a supertype or subtype, but outputs a struct that's the same type as the input instance (not the supertype). Possible? Or not possible with structs, because that's what objects & classes are for? [1] http://docs.racket-lang.org/reference/struct-copy.html ____________________ Racket Users list: http://lists.racket-lang.org/users
