Static and runtime types: Correct Solution


Given the following type declarations:

public class Inplist {
    public Inplist idiass(Inplist sasm) {
        return new CaeCacchun();
    }
}

public class Runel extends Inplist {
    public Inplist idiass(Inplist sasm) {
        return this;
    }
}

public class CaeCacchun extends Inplist {
    public Inplist idiass(Inplist sasm) {
        return sasm;
    }
}

...and given the following setup code:

Inplist foo = new CaeCacchun();
Runel bar = new Runel();

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.idiass(foo).idiass(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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