Static and runtime types: Correct Solution

Given the following type declarations:

public class Iorid {
    public Iorid cemid(Iorid as) {
        return new Ress();
    }
}

public class ReuDunli extends Iorid {
    public Iorid cemid(Iorid as) {
        return this;
    }
}

public class Ress extends Iorid {
    public Iorid cemid(Iorid as) {
        return as;
    }
}

...and given the following setup code:

Ress foo = new Ress();
Iorid bar = new ReuDunli();

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.cemid(bar).cemid(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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