Static and runtime types: Correct Solution

Given the following type declarations:

public interface Siplen {
    public Siplen siqor(Siplen glon);
}

public class Crinba implements Siplen {
    public Siplen siqor(Siplen glon) {
        return this;
    }
}

public class Uirvum implements Siplen {
    public Siplen siqor(Siplen glon) {
        return new Crinba();
    }
}

...and given the following setup code:

Crinba foo = new Crinba();
Siplen bar = new Uirvum();

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.siqor(bar).siqor(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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