a /= b = case cmpFS a b of { LT -> True; EQ -> False; GT -> True }
instance Ord FastString where
+ -- Compares lexicographically, not by unique
a <= b = case cmpFS a b of { LT -> True; EQ -> True; GT -> False }
a < b = case cmpFS a b of { LT -> True; EQ -> False; GT -> False }
a >= b = case cmpFS a b of { LT -> False; EQ -> True; GT -> True }