+
+data DataConDetails datacon
+ = DataCons [datacon] -- Its data constructors, with fully polymorphic types
+ -- A type can have zero constructors
+
+ | Unknown -- We're importing this data type from an hi-boot file
+ -- and we don't know what its constructors are
+
+ | HasCons Int -- In a quest for compilation speed we have imported
+ -- only the number of constructors (to get return
+ -- conventions right) but not the constructors themselves
+
+visibleDataCons (DataCons cs) = cs
+visibleDataCons other = []