// This work is Copyright(c) 2008 John Miller.  All rights reserved.
/*
 * @test
 * @summary Test use of closures for computing statistics
 * Closures are to be included in the next version of JSIM.         
 * This code was tested using Neal Gafter's prototype that
 * supports the BGGA closure proposal.
 * http://www.javac.info/closures.tar.gz  (updated 2008-04-14)
 * @author John Miller
 */

import static java.lang.System.*;
import static java.lang.Math.*;

public class StatsClosure
{
    static void stats (double [] v, { double => double } f)
    {
        for (double x : v)  f.invoke (x);

    } // stats  
  
    public static void main (String [] args)
    {
        @Shared double y;
        double [] data = { 20.0, 10.0, 30.0, 50.0, 40.0 };
        double    size = (double) data.length;
        
        y = 0.0;
        stats (data, { double x => y += x });
        out.println ("mean\t = " + y / size );

        y = 0.0;
        stats (data, { double x => y += x * x });
        out.println ("stddev\t = " + sqrt (y / (size - 1.0)));

        y = Double.MAX_VALUE;
        stats (data, { double x => y = x < y ? x : y });
        out.println ("min\t = " + y);

        y = Double.MIN_VALUE;
        stats (data, { double x => y = x > y ? x : y });
        out.println ("max\t = " + y);

    } // main

} // StatsClosure class