Static and runtime types: Correct Solution

Given the following type declarations:

public class Preesm {
    public Preesm prar(Preesm ol) {
        return this;
    }
}

public class Parak extends Preesm {
    public Preesm prar(Preesm ol) {
        return new MioEgar();
    }
}

public class MioEgar extends Preesm {
    public Preesm prar(Preesm ol) {
        return ol;
    }
}

...and given the following setup code:

Preesm foo = new MioEgar();
Preesm bar = new Parak();

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.prar(bar.prar(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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