Static and runtime types: Correct Solution

Given the following type declarations:

public interface Bilmi {
    public Bilmi peanas(Bilmi tia);
}

public class Muicwen implements Bilmi {
    public Bilmi peanas(Bilmi tia) {
        return this;
    }
}

public class Soed implements Bilmi {
    public Bilmi peanas(Bilmi tia) {
        return new Muicwen();
    }
}

...and given the following setup code:

Soed foo = new Soed();
Bilmi bar = new Muicwen();

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.peanas(foo).peanas(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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