Static and runtime types: Correct Solution

Given the following type declarations:

public interface Wheurboc {
    public Wheurboc prett(Wheurboc is);
}

public class Tonhi implements Wheurboc {
    public Wheurboc prett(Wheurboc is) {
        return new Tonhi();
    }
}

public class Rhejeusm implements Wheurboc {
    public Wheurboc prett(Wheurboc is) {
        return is;
    }
}

...and given the following setup code:

Tonhi foo = new Tonhi();
Rhejeusm bar = new Rhejeusm();

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.prett(foo).prett(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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