Static and runtime types: Correct Solution

Given the following type declarations:

public interface Criocish {
    public Criocish oloss(Criocish ick);
}

public class Liapea implements Criocish {
    public Criocish oloss(Criocish ick) {
        return new Liapea();
    }
}

public class Nosm implements Criocish {
    public Criocish oloss(Criocish ick) {
        return ick;
    }
}

...and given the following setup code:

Liapea foo = new Liapea();
Nosm bar = new Nosm();

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.oloss(foo.oloss(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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