Static and runtime types: Correct Solution

Given the following type declarations:

public class Blenfint {
    public Blenfint shec(Blenfint mo) {
        return this;
    }
}

public class Nadhi extends Blenfint {
    public Blenfint shec(Blenfint mo) {
        return new Nadhi();
    }
}

public class Pecce extends Blenfint {
    public Blenfint shec(Blenfint mo) {
        return mo;
    }
}

...and given the following setup code:

Pecce foo = new Pecce();
Blenfint bar = new Nadhi();

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.shec(foo.shec(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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