hitesh wrote: > I'm working on some opengl code in clojure and I want to specify a > vertex. However, instead of passing in the three arguments it wants, > I want to specify a single vector of 3 elements. How can I do this? > > Here's what it would normally look like (gl represents the current > opengl drawing context object): > > (.glVertex3f gl 1.0 3.7 0.0) > > > Here's what I want to write: > > (let [ point [1.0 3.7 0.0] ] > (.glVertex3f gl point)) > > > I've tried playing around with apply. > > (apply .glVertex3f gl point) > > But it generates an error: no matching method glVertex3f for class > com.sun.opengl.impl.GLImpl. > > I'm not sure what this concept is called, but here's some code in > other languages that demonstrates it. > > Here's the equivalent concept in Haskell > > foo :: (Show a) => a -> a -> IO () > foo a b = mapM_ print [a, b] > > *Main> uncurry foo (1,2) > 1 > 2 > > > Or in Ruby > > def foo(a,b) > puts a > puts b > end > > x = [1,2] > > foo *x > 1 > 2 > > > Any ideas? > > Thanks, > Hitesh So it works with functions defined in Clojure:
Clojure user=> (defn foo [a b c] (list a b c)) #'user/foo user=> (foo [1 2 3]) java.lang.IllegalArgumentException: Wrong number of args passed to: user$foo (NO_SOURCE_FILE:0) user=> (apply foo [1 2 3]) (1 2 3) user=> (defn bar [[a b c]] (foo a b c)) #'user/bar user=> (bar [1 2 3]) (1 2 3) Using apply you can use anything that can be a sequence (it either implements or it can return something that implements ISeq). Otherwise you could wrap it with a function like bar, which uses destructuring to decompose the vector and call foo explicitly. I think the problem you are having has to do with wanting to apply arguments to a function inside a doto, the java interop stuff. From what I can tell you won't be able to do it currently. In ruby the foo(*args) syntax is called the splat operator, but I don't know if that's universal. Later, Jeff --~--~---------~--~----~------------~-------~--~----~ 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 -~----------~----~----~----~------~----~------~--~---
