Static and runtime types: Correct Solution

Given the following type declarations:

public class Saspo {
    public Saspo asad(Saspo i) {
        return this;
    }
}

public class Este extends Saspo {
    public Saspo asad(Saspo i) {
        return i;
    }
}

public class Asos extends Saspo {
    public Saspo asad(Saspo i) {
        return new Asos();
    }
}

...and given the following setup code:

Este foo = new Este();
Saspo bar = new Asos();

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.asad(foo.asad(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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