On Wed, Nov 22, 2017 at 10:40 PM, Quentin Liu
Hi Patrik,
The reason for the requirement of “Eq a” in your `sortListOfLists` is that you are calling myOrderFunc which carries the signature “Eq a”. If you remove the `Eq` declaration in `myOrderFunc` the compiler then would not complain about the absence of `Eq` in `sortListOfLists`. For a detailed explanation you could reference chapter 6 of Real World Haskell.
Thanks a lot for the reference. I'll make sure to read that chapter soon.
Yes, you could pass the function a list of strings as well. A string is just a list of Chars. The type signature `a` does not restrict the range of types you could pass to the function.
That seem strange to me. Wouldn't that mean that i could write the declaration of myOrderFunc as `myOrderFunc :: a -> a -> Ordering` as well? GHCI give me an error on this though so obviously it's wrong. I just don't see why. Why cannot a represent [b]? // Patrik