On 25 June 2013 12:47, Nicolas Cellier <nicolas.cellier.aka.n...@gmail.com> wrote: > But in some cases, you will end up with an object that is more than one > thing: > - a Number > - an Integer > - a Fraction > For example 0 shall answer yes to these 3. > So ^foo == #specialName just does not work, or you end up with caseOf: >
err, why? if you define it like: Number>>is: symbol ^ symbol == #number 0 is: #number => true 0.0 is: #number => true 0/1 is: #number => true ? It is actually up to implementor how to his own classes should process #is: message. The only invariant (which imo best one), that Object should always answer false to #is: message no matter what parameter you passed, to avoid any ambiguous cases and keep things simple and easy to remember. That means, that unless you override this method in own class, its instances will always answer false to #is: message. And when you override it, you are free to define it the way you like... MyClass>>is: foo ^ foo class == self class or MyClass>>is: foo ^ foo class name == self class name or MyClass>>is: foo ^ foo isKindOf: MyClass (no limits to imagination :) -- Best regards, Igor Stasenko.
