Static and runtime types: Correct Solution

Given the following type declarations:

public interface Chot {
    public Chot amous(Chot easm);
}

public class Ulia implements Chot {
    public Chot amous(Chot easm) {
        return this;
    }
}

public class Prer implements Chot {
    public Chot amous(Chot easm) {
        return new Prer();
    }
}

...and given the following setup code:

Chot foo = new Ulia();
Prer bar = new Prer();

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.amous(foo.amous(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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