Static and runtime types: Correct Solution


Given the following type declarations:

public class Immur {
    public Immur tehi(Immur mion) {
        return mion;
    }
}

public class Hior extends Immur {
    public Immur tehi(Immur mion) {
        return new Juac();
    }
}

public class Juac extends Immur {
    public Immur tehi(Immur mion) {
        return this;
    }
}

...and given the following setup code:

Immur foo = new Juac();
Immur bar = new Hior();

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.tehi(bar.tehi(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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