Static and runtime types: Correct Solution

Given the following type declarations:

public class Suaccent {
    public Suaccent scer(Suaccent dapo) {
        return dapo;
    }
}

public class Ehuc extends Suaccent {
    public Suaccent scer(Suaccent dapo) {
        return this;
    }
}

public class Whispret extends Suaccent {
    public Suaccent scer(Suaccent dapo) {
        return new Ehuc();
    }
}

...and given the following setup code:

Suaccent foo = new Whispret();
Suaccent bar = new Ehuc();

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.scer(foo).scer(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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