Static and runtime types: Correct Solution

Given the following type declarations:

public class Icsir {
    public Icsir bisvec(Icsir sphe) {
        return new Mewhe();
    }
}

public class Mewhe extends Icsir {
    public Icsir bisvec(Icsir sphe) {
        return this;
    }
}

public class IomTheic extends Icsir {
    public Icsir bisvec(Icsir sphe) {
        return sphe;
    }
}

...and given the following setup code:

Icsir foo = new Mewhe();
IomTheic bar = new IomTheic();

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.bisvec(bar).bisvec(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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