Static and runtime types: Correct Solution

Given the following type declarations:

public interface Raus {
    public Raus fler(Raus dosi);
}

public class Nahe implements Raus {
    public Raus fler(Raus dosi) {
        return this;
    }
}

public class Snen implements Raus {
    public Raus fler(Raus dosi) {
        return dosi;
    }
}

...and given the following setup code:

Raus foo = new Nahe();
Raus bar = new Snen();

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.fler(bar.fler(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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