Static and runtime types: Correct Solution

Given the following type declarations:

public class Gonin {
    public Gonin lecjoc(Gonin on) {
        return this;
    }
}

public class Douhuss extends Gonin {
    public Gonin lecjoc(Gonin on) {
        return on;
    }
}

public class Siac extends Gonin {
    public Gonin lecjoc(Gonin on) {
        return new Siac();
    }
}

...and given the following setup code:

Gonin foo = new Douhuss();
Siac bar = new Siac();

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.lecjoc(foo.lecjoc(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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