Static and runtime types: Correct Solution

Given the following type declarations:

public class Hionka {
    public Hionka froda(Hionka ga) {
        return this;
    }
}

public class DioFene extends Hionka {
    public Hionka froda(Hionka ga) {
        return ga;
    }
}

public class Vung extends Hionka {
    public Hionka froda(Hionka ga) {
        return new Vung();
    }
}

...and given the following setup code:

DioFene foo = new DioFene();
Vung bar = new Vung();

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.froda(foo).froda(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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