Merge pull request #1 from kl0tl/roles-declarations

Add roles declarations to forbid unsafe coercions

Author: paluh

src/Data/Enum.purs

@@ -162,6 +162,8 @@ toEnumWithDefaults low high x = case toEnum x of
 -- | A type for the size of finite enumerations.
 newtype Cardinality a = Cardinality Int
 
+type role Cardinality representational
+
 derive instance newtypeCardinality :: Newtype (Cardinality a) _
 derive newtype instance eqCardinality :: Eq (Cardinality a)
 derive newtype instance ordCardinality :: Ord (Cardinality a)