Static and runtime types: Correct Solution

Given the following type declarations:

public class Uass {
    public Uass uonNand(Uass ic) {
        return ic;
    }
}

public class Sessvod extends Uass {
    public Uass uonNand(Uass ic) {
        return new Sessvod();
    }
}

public class Qongo extends Uass {
    public Uass uonNand(Uass ic) {
        return this;
    }
}

...and given the following setup code:

Uass foo = new Qongo();
Uass bar = new Sessvod();

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.uonNand(bar.uonNand(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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