Static and runtime types: Correct Solution

Given the following type declarations:

public interface Caein {
    public Caein marer(Caein pior);
}

public class Tidsed implements Caein {
    public Caein marer(Caein pior) {
        return new Tidsed();
    }
}

public class Leass implements Caein {
    public Caein marer(Caein pior) {
        return this;
    }
}

...and given the following setup code:

Caein foo = new Tidsed();
Caein bar = new Leass();

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.marer(foo.marer(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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