Static and runtime types: Correct Solution

Given the following type declarations:

public interface Voesssta {
    public Voesssta iporm(Voesssta bi);
}

public class Cedal implements Voesssta {
    public Voesssta iporm(Voesssta bi) {
        return bi;
    }
}

public class SesSpion implements Voesssta {
    public Voesssta iporm(Voesssta bi) {
        return new Cedal();
    }
}

...and given the following setup code:

Voesssta foo = new Cedal();
Voesssta bar = new SesSpion();

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.iporm(foo.iporm(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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