Static and runtime types: Correct Solution

Given the following type declarations:

public class Sahen {
    public Sahen ewhem(Sahen fes) {
        return fes;
    }
}

public class Craul extends Sahen {
    public Sahen ewhem(Sahen fes) {
        return this;
    }
}

public class Ciat extends Sahen {
    public Sahen ewhem(Sahen fes) {
        return new Ciat();
    }
}

...and given the following setup code:

Sahen foo = new Ciat();
Sahen bar = new Craul();

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.ewhem(foo.ewhem(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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