Static and runtime types: Correct Solution

Given the following type declarations:

public class Iric {
    public Iric ongbul(Iric vo) {
        return vo;
    }
}

public class Bontthint extends Iric {
    public Iric ongbul(Iric vo) {
        return new Bontthint();
    }
}

public class Spiesm extends Iric {
    public Iric ongbul(Iric vo) {
        return this;
    }
}

...and given the following setup code:

Bontthint foo = new Bontthint();
Iric bar = new Spiesm();

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.ongbul(foo.ongbul(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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