Static and runtime types: Correct Solution

Given the following type declarations:

public class Scraccisk {
    public Scraccisk uthClobas(Scraccisk meep) {
        return new NenPlia();
    }
}

public class NenPlia extends Scraccisk {
    public Scraccisk uthClobas(Scraccisk meep) {
        return this;
    }
}

public class IdiUdol extends Scraccisk {
    public Scraccisk uthClobas(Scraccisk meep) {
        return meep;
    }
}

...and given the following setup code:

IdiUdol foo = new IdiUdol();
Scraccisk bar = new NenPlia();

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.uthClobas(foo.uthClobas(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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