[Haskell-cafe] Pathological overloaded function

[Simon Yarde]

Could anyone chip in with examples of a pathological overloaded functions in relation to the GHC Guide 6.2:

> Overloaded functions are not your friend:
> Haskell's overloading (using type classes) is elegant, neat, etc., etc., but it is death to performance if left to linger in an inner loop. How can you squash it?
> 
> Give explicit type signatures:
> Signatures are the basic trick; putting them on exported, top-level functions is good software-engineering practice, anyway. (Tip: using -fwarn-missing-signatures can help enforce good signature-practice).

http://lambda.haskell.org/platform/doc/current/ghc-doc/users_guide/faster.html

Best Regards, Simon