Detailed Java Generics

[jsc59]

I have a very detailed/complicated java generics question. Consider
the following code

public abstract class AEdge {
ANode fr, to;
}

public abstract class ANode { }

public class CEdge extends AEdge { }

public class CNode extends ANode { }

public class MyEdgeDatabase<N extends ANode, E extends AEdge> {
Set<E> edges;

public abstract class ForEachEdgeFrom {
public ForEachEdgeFrom(N n) {
for(E e : edges) if (e.fr == n) run(e);
}
public abstract void run(E e);
}
}


public class Test {
MyEdgeDatabase<CNode, CEdge> edgeDB
= new MyEdgeDatabase<CNode, CEdge>();
CNode n = new CNode();

public void doIt() {
edgeDB.new ForEachEdgeFrom(n){
public void run(CEdge e) {
System.out.println(e);
}
};
}
}

The doIt() method will not compile. It gives the following error:

"No enclosing instance of type MyEdgeDatabase<N,E> is accessible. Must
qualify the allocation with an enclosing instance of type
MyEdgeDatabase<N,E> (e.g. x.new A() where x is an instance of
MyEdgeDatabase<N,E>)."


What does this mean and how to I fix it? Please don't suggest other
ways of iterating through edges in MyEdgeDatabase (we have reason to do
it this way).

 

[Oliver Wong]

I have a very detailed/complicated java generics question.

Crosspost, don't multipost:
http://www.cs.tut.fi/~jkorpela/usenet/xpost.html

A thread is already forming in another newsgroup.

- Oliver

 

[EJP]

Crosspost, don't multipost:

A thread is already forming in another newsgroup.

Where?

BTW the original code compiles for me.

 

[Hendrik Maryns]

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EJP schreef:

Where?

c.l.j.help

- --
Hendrik Maryns

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