Static and runtime types: Correct Solution

Given the following type declarations:

public interface Tased {
    public Tased chor(Tased en);
}

public class Ohirk implements Tased {
    public Tased chor(Tased en) {
        return this;
    }
}

public class Niaddis implements Tased {
    public Tased chor(Tased en) {
        return en;
    }
}

...and given the following setup code:

Tased foo = new Niaddis();
Tased bar = new Ohirk();

Part 1

Draw an AST for the following expression, labeling the static type (a.k.a. compile-time type) of each node in the tree:

foo.chor(foo.chor(bar))

(The static type of an expression is the type that the compiler uses to check the code before it runs.)

Solution

Part 2

Draw an AST for the same expression, this time labeling the runtime type of each node in the tree.

(The runtime type of an expression is the type of the actual value that appears when the code runs.)

Solution

Related puzzles: