[Haskell-beginners] Real world example of Typeclasses > Interfaces

[Ozgur Akgun]

On 4 September 2010 18:04, Alec Benzer <alecbenzer at gmail.com> wrote:

> What I mean is, if you had a function: something n =
> [1..n], and your type was a -> [a], a needs to be declared as (Num a,
> Enum a), even though this is sort of redundant, since you can't really
> have a number that isn't also enumerable.
>

Well, you can actually have a Num that isn't Enum.

ghci> :info Num
class (Eq a, Show a) => Num a where
  (+) :: a -> a -> a
  (*) :: a -> a -> a
  (-) :: a -> a -> a
  negate :: a -> a
  abs :: a -> a
  signum :: a -> a
  fromInteger :: Integer -> a


-- 
Ozgur Akgun
-------------- next part --------------
An HTML attachment was scrubbed...
URL: http://www.haskell.org/pipermail/beginners/attachments/20100904/fb52ced4/attachment.html