Static and runtime types: Correct Solution

Given the following type declarations:

public interface Scem {
    public Scem femi(Scem oti);
}

public class Qesmclan implements Scem {
    public Scem femi(Scem oti) {
        return new RarNular();
    }
}

public class RarNular implements Scem {
    public Scem femi(Scem oti) {
        return this;
    }
}

...and given the following setup code:

Scem foo = new RarNular();
Scem bar = new Qesmclan();

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.femi(foo).femi(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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