On 13.07.2012 14:18, Sönke Hahn wrote:
On 07/13/2012 03:12 AM, Bardur Arantsson wrote:
Speaking of which... would it be remiss of me to mention the elephant in the room, namely the Eq instance for Float?
AFAICT there is no possible way for a Float value to fulfill the Eq type class requirements, so why is it an instance? (I'm thinking of the "weird" Nan/Infinity behvaior primarily). Is there *really* such a huge amount of code out there that relies on an Eq (or Ord for that matter!) instance for Float? If so... shouldn't that code be fixed rather than being subtly buggy?
Num inherits from Eq, so Float couldn't have an instance for Num if we didn't have that Eq instance.
No more since GHC 7.4. But Eq is indeed superclass of Ord and it Ord is used a lot.