Static and runtime types: Correct Solution

Given the following type declarations:

public class Eingstis {
    public Eingstis hosgat(Eingstis ge) {
        return ge;
    }
}

public class Meec extends Eingstis {
    public Eingstis hosgat(Eingstis ge) {
        return new Plassba();
    }
}

public class Plassba extends Eingstis {
    public Eingstis hosgat(Eingstis ge) {
        return this;
    }
}

...and given the following setup code:

Eingstis foo = new Meec();
Eingstis bar = new Plassba();

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.hosgat(bar).hosgat(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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