On 02/04/2014 20:53, Alejandro Zamora Fonseca wrote:
(defmethod dup ((a string)) (concatenate 'string a a))(defmethod dup ((a integer)) (list a a))
1) From the standard Racket "swindle/tiny-clos" library, you can use the CLOS-like functions that you may already know from Common Lisp.
2) I have written a short library myself for this, and your code would look like this:
(def-multi dup) (add-multi dup (list string?) (lambda (a) (string-append a a))) (add-multi dup (list integer?) (lambda (a) (list a a))) (dup "Hello") => "HelloHello" (dup 10) => '(10 10) I can share it if you're interested, it's roughly 40 lines of code. -Patrick ____________________ Racket Users list: http://lists.racket-lang.org/users
