Static and runtime types: Correct Solution

Given the following type declarations:

public interface Priil {
    public Priil wengri(Priil enho);
}

public class Vesh implements Priil {
    public Priil wengri(Priil enho) {
        return new Vesh();
    }
}

public class Tian implements Priil {
    public Priil wengri(Priil enho) {
        return this;
    }
}

...and given the following setup code:

Priil foo = new Vesh();
Priil bar = new Tian();

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.wengri(foo.wengri(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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