Nice to @Share?

[Peter Levart]

On Tuesday 23 February 2010 14:43:32 David.Moss at ubs.com wrote:
> > By the way, I am very happy with final (or implicit final).
> > When I code and find that I need a non-final local variable,
> > I first try to rewrite the code to avoid to use non-final
> > before trying to use a mutable object.
> 
> Where des this leave closures?
> 
> i.e.: what would we need to make the following code do what it is meant to:
> 
> public class C {
>     public #int() getSequenceGenerator(int start, int increment) {
>         return #int() {
>             int ret = start;
>             start += increment;
>             return ret;
>         };
>     }
> }
> 
> 

Well, there is a workarround if you want to capture arbitrary state by copy and still not have to define any extra classes or stash each wariable in it's own wrapper:

public class C {
    public #int() getSequenceGenerator(final int start, final int increment) {
        return new Object() {
            int seq = start;
            final #int() fn = #() {
                try { return seq; } finally { seq+=increment; }
            }
        }.fn;
    }
}

The benefit being that it is obvious what code does...

Peter