Re: [chuck-users] Functional Chuck?

8 Jun 2008

      Okay that's really interesting.  I thought about doing this last
night, but I found it kind of frustrating.  I'll see what I can do
with this combo of functors and judicious use of function overloading
and see what I can come up with.

Thanks!

-Mike

PS: Here's the really simple example with functors:

class Function {
    fun int fn( int n ) {
        return n + 3;
    }
}

fun int[] mapInt( Function fn, int list[] ) {
    int results[list.cap()];
    for( 0 => int i; i < list.cap(); i++ ) {
        fn.fn( list[i] ) => results[i];
    }
    return results;
}

[1, 2, 3, 4, 5] @=> int input[];

Function add3;

mapInt( add3, input ) @=> int output[];

<<< output[2] >>>;  // prints 6

On Sun, Jun 8, 2008 at 4:38 PM, Michael Heuer  wrote:
...
On Sun, Jun 8, 2008 at 3:33 PM, Michael Heuer  wrote:
...
mike clemow wrote:
...
Hey folks,
Anyone else really wish that Chuck supported higher order functions???
check it out.  This doesn't work, but i'd love for it to work:
// a function that returns an int
fun int fn( int n ) {
   return n + 3;
}
// a function that takes a function and an array of ints
// and returns an array of ints which correspond to the action
// of that function on each int in the original array
fun int[] mapInt( function fn, int list[] ) {
   int results[list.cap()];
   for( 0 => int i; i < list.cap(); i++ ) {
       fn( list[i] ) => results[i];
   }
   return results;
}
[1, 2, 3, 4, 5] @=> input;
Add3 add3;
mapInt( add3, input ) => int output[];
<<< output[2] >>>;  // should print 6
--
I just wish that functions could take other functions as parameters
and return functions as their return value.  I think that would make
sense.  Functions, I find are more powerful than classes in Chuck.
Also, why is "function" a keyword?
cheers,
mike
Hello Mike,
You can do this with functors, small classes that are functions.
There is a thread on the forum with some example code, but it is
basically just
class Function
{
 fun int doIt(int n) { ... }
}
fun void int[] mapInt(Function f, int list[]) { ... }
michael
Said thread
http://electro-music.com/forum/topic-23546.html
michael
_______________________________________________
chuck-users mailing list
chuck-users@lists.cs.princeton.edu
https://lists.cs.princeton.edu/mailman/listinfo/chuck-users
-- 
http://semiotech.org
http://deadlylittlepills.com/michael