Static and runtime types: Correct Solution

Given the following type declarations:

public interface Neant {
    public Neant miress(Neant shis);
}

public class Bopeir implements Neant {
    public Neant miress(Neant shis) {
        return this;
    }
}

public class PidWroomass implements Neant {
    public Neant miress(Neant shis) {
        return new PidWroomass();
    }
}

...and given the following setup code:

Neant foo = new Bopeir();
PidWroomass bar = new PidWroomass();

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.miress(foo.miress(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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