Static and runtime types: Correct Solution

Given the following type declarations:

public interface Stidrin {
    public Stidrin asvan(Stidrin pem);
}

public class Hiead implements Stidrin {
    public Stidrin asvan(Stidrin pem) {
        return pem;
    }
}

public class BreOha implements Stidrin {
    public Stidrin asvan(Stidrin pem) {
        return new Hiead();
    }
}

...and given the following setup code:

Stidrin foo = new Hiead();
BreOha bar = new BreOha();

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.asvan(bar.asvan(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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