Person.j

@import <foundation>
@implementation Person : CPObject
{
    CPString name;
}
+ (id)personWithName:(CPString)aName
{
    return [[self alloc] initWithName:aName];
}
- (id)initWithName:(CPString)aName
{
    self = [super init];
    name = aName;
    return self;
}
- (void)setName:(CPString)aName
{
    name = aName;
}
- (CPString)name
{
    return name;
}
@end

// Reversing Category for CPString
@implementation CPString (Reversing)
- (CPString)reverse
{
    var reversedString = "",
        index = [self length];
    while(index--)
        reversedString += [self characterAtIndex:index];       
    return reversedString;
}
@end

var john = [Person personWithName:"John"];
alert([john name]);
[john setName:"Ralph"];
alert("John changed his name to "+[john name]+" which is "+[[john name] reverse]+" backwards.");