Static and runtime types: Correct Solution

Given the following type declarations:

public interface IhaSkedse {
    public IhaSkedse ophBou(IhaSkedse gopo);
}

public class Schisa implements IhaSkedse {
    public IhaSkedse ophBou(IhaSkedse gopo) {
        return this;
    }
}

public class Ulchrism implements IhaSkedse {
    public IhaSkedse ophBou(IhaSkedse gopo) {
        return new Ulchrism();
    }
}

...and given the following setup code:

Ulchrism foo = new Ulchrism();
IhaSkedse bar = new Schisa();

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.ophBou(bar.ophBou(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

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