Static and runtime types: Correct Solution

Given the following type declarations:

public interface Mirn {
    public Mirn pidGriso(Mirn gao);
}

public class Chro implements Mirn {
    public Mirn pidGriso(Mirn gao) {
        return new Chro();
    }
}

public class Rolthi implements Mirn {
    public Mirn pidGriso(Mirn gao) {
        return gao;
    }
}

...and given the following setup code:

Mirn foo = new Rolthi();
Mirn bar = new Chro();

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.pidGriso(foo.pidGriso(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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