Hi, I am a newbie but I think that what you are proposing can be simulated in haskell. It is like subclassing in OOP. You can create a new type that is an extension of the older one. Unlike OOP overloading, you will need to create a new function that can work on the new type.
data SomeObject = SomeInt Int | SomeString String | _
will become: data SomeObject = SomeInt Int | SomeString String
...later...
data SomeObject |= SomeReal Double
will become: data SomeObject2 = SO SomeObject | SomeReal Double
same :: SomeObject -> SomeObject -> Bool same (SomeInt a) (SomeInt b) = a == b same (SomeString a) (SomeString b) = a == b same _ _ = False
...later...
same (SomeReal a) (SomeReal b) = a == b
will become: same :: SomeObject -> SomeObject -> Bool same (SomeInt a) (SomeInt b) = a == b same (SomeString a) (SomeString b) = a == b ...later... same2 :: SomeObject2 -> SomeObject2 -> Bool same2 (SomeReal a) (SomeReal b) = a == b same2 x y = same x y tell me if I am wrong. thanks. Mansour Al-Mutairi :) _________________________________________________________________ Get your FREE download of MSN Explorer at http://explorer.msn.com/intl.asp