Static and runtime types: Correct Solution

Given the following type declarations:

public class HosDerna {
    public HosDerna micvod(HosDerna cla) {
        return new Decsan();
    }
}

public class Decsan extends HosDerna {
    public HosDerna micvod(HosDerna cla) {
        return this;
    }
}

public class Nephen extends HosDerna {
    public HosDerna micvod(HosDerna cla) {
        return cla;
    }
}

...and given the following setup code:

Decsan foo = new Decsan();
HosDerna bar = new Nephen();

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.micvod(foo).micvod(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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