Static and runtime types: Correct Solution

Given the following type declarations:

public class EsmBoroi {
    public EsmBoroi thiNes(EsmBoroi apdi) {
        return this;
    }
}

public class Romes extends EsmBoroi {
    public EsmBoroi thiNes(EsmBoroi apdi) {
        return apdi;
    }
}

public class Sniai extends EsmBoroi {
    public EsmBoroi thiNes(EsmBoroi apdi) {
        return new Romes();
    }
}

...and given the following setup code:

EsmBoroi foo = new Sniai();
Romes bar = new Romes();

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.thiNes(foo).thiNes(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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