On Wed, Nov 19, 2008 at 4:16 PM, Mark Volkmann <[EMAIL PROTECTED]> wrote: > > I'm reading an excellent article on functional programming at > http://www.defmacro.org/ramblings/fp.html. Toward the end there is a > section on pattern matching. They give the following example which > uses a fictional, Java-like syntax. Can Clojure do something like this > where the fib function is overloaded using "patterns" instead of > arity? > > int fib(0) { return 1; } > > int fib(1) { return 1; } > > int fib(int n) { > return fib(n - 2) + fib(n - 1); > }
I don't believe Clojure supports this, no, though it has been brought up before and I seem to recall somebody working on something. However, this example can implemented using multimethods: user=> (defmulti fib int) #'user/fib user=> (defmethod fib 0 [_] 1) #<MultiFn [EMAIL PROTECTED]> user=> (defmethod fib 1 [_] 1) #<MultiFn [EMAIL PROTECTED]> user=> (defmethod fib :default [n] (+ (fib (- n 2)) (fib (- n 1)))) #<MultiFn [EMAIL PROTECTED]> user=> (map fib (range 10)) (1 1 2 3 5 8 13 21 34 55) --~--~---------~--~----~------------~-------~--~----~ You received this message because you are subscribed to the Google Groups "Clojure" group. To post to this group, send email to clojure@googlegroups.com To unsubscribe from this group, send email to [EMAIL PROTECTED] For more options, visit this group at http://groups.google.com/group/clojure?hl=en -~----------~----~----~----~------~----~------~--~---
