Static and runtime types: Correct Solution

Given the following type declarations:

public class Proat {
    public Proat dumess(Proat el) {
        return this;
    }
}

public class Cegneb extends Proat {
    public Proat dumess(Proat el) {
        return new Solnal();
    }
}

public class Solnal extends Proat {
    public Proat dumess(Proat el) {
        return el;
    }
}

...and given the following setup code:

Proat foo = new Cegneb();
Proat bar = new Solnal();

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.dumess(bar).dumess(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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