QSort question from yesterday still unsolved

[Paul E Johnson]

Concerning MA's question from yesterday, I've gotten a few follow up
emails, still have not figured it out.  I'd be inclined to look for
sorting tools native to Java, but since the Swarm QSort is there, I
wonder how to use it, like everybody else.

The QSort usage in java is not easy.  In Objective-C, QSort is a class
method, and I've looked at the example of the java usage of NSelect
(http://lark.cc.ukans.edu/~pauljohn/SwarmFaq/WorkingExampleCode/java/NSelectUsage.txt)
as an example of how a class method might be used in Java.  I guess that
the basics of the usage should be something like:
new QSortImpl().sortObjectsIn$using (aList, sel ); 

but the problem is that I was getting a lot of compiler messages about
the usage of an IVAR sel in a static context.

So I kept working on this test program to try to make the sel use
statics thing so I wouldn't get that complaint, and ended up with this
(ugly?) that does compile but gets a runtime error. I think the print
statements show that the selector and class are found, but the runtime
error is in the QSortImpl usage.  I tried at this for a while and I'm
ready to ask for anybody's insights.

import swarm.Globals; 
import swarm.simtools.NSelectImpl; 
import swarm.simtools.QSortImpl;
import swarm.simtools.QSort;
import swarm.Selector;
import java.util.List; 
import java.util.LinkedList;
import java.util.ListIterator; 
import java.lang.Integer;

public class TestQSort { 

    static void main (String args[]) { 
        Globals.env.initSwarm ("TestQSort", "address@hidden", "0.0",
args); 

        List aList = new LinkedList (); 
        List bList = new LinkedList (); 

        for (int i = 0; i < 100; i++) 
            aList.add (new Integer (i)); 

        Class myClass = getMyClass(); 
        Selector sel = getASelector(myClass,"comparison");

        new QSortImpl().sortObjectsIn$using (aList, sel ); 

        ListIterator index = bList.listIterator (); 
        while (index.hasNext ()) { 
            System.out.println (index.next ()); 
        } 
    }
    
    public int comparison (Integer a, Integer b ) {
        if (a.intValue() < b.intValue()) return -1;
        else if (a.intValue() > b.intValue()) return 1;
        else return 0;
    }

    static Selector getASelector(Class a, String s) {
        Selector newsel=null;
        try {
            newsel = new Selector (a,s,false);
            System.out.println("My selector is " + newsel + " \n");
        }
        catch (Exception e) {
            System.out.println("Failure");
        }
        return newsel;
    }

    static Class getMyClass(){
        Class aClass=null;
        try{
            aClass = Class.forName("TestQSort");
            System.out.println("My Class is " + aClass + " \n");
            
        }catch (Exception e){
            System.out.println("Failure2");
        }
        return aClass;
    }
}




-- 
Paul E. Johnson                       email: address@hidden
Dept. of Political Science            http://lark.cc.ukans.edu/~pauljohn
University of Kansas                  Office: (785) 864-9086
Lawrence, Kansas 66045                FAX: (785) 864-5700

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