1 {-# OPTIONS -fglasgow-exts #-}
3 -- !!! Error messages with scoped type variables
9 unionSetB :: Eq a => Set a -> Set a -> Set a
10 unionSetB (s1 :: Set a) s2 = unionSets s1 s2
12 unionSets :: Eq a => Set a -> Set a -> Set a
16 {- In GHC 4.04 this gave the terrible message:
18 None of the type variable(s) in the constraint `Eq a'
19 appears in the type `Set a -> Set a -> Set a'
20 In the type signature for `unionSets'