Static and runtime types: Correct Solution

Given the following type declarations:

public interface Upriss {
    public Upriss nudo(Upriss is);
}

public class Irtspect implements Upriss {
    public Upriss nudo(Upriss is) {
        return is;
    }
}

public class Asscen implements Upriss {
    public Upriss nudo(Upriss is) {
        return this;
    }
}

...and given the following setup code:

Upriss foo = new Asscen();
Irtspect bar = new Irtspect();

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.nudo(bar).nudo(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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