-emptyTypeEnv :: TypeEnv
-typeEnvElts :: TypeEnv -> [TyThing]
-typeEnvClasses :: TypeEnv -> [Class]
-typeEnvTyCons :: TypeEnv -> [TyCon]
-typeEnvIds :: TypeEnv -> [Id]
-lookupTypeEnv :: TypeEnv -> Name -> Maybe TyThing
-
-emptyTypeEnv = emptyNameEnv
-typeEnvElts env = nameEnvElts env
-typeEnvClasses env = [cl | AClass cl <- typeEnvElts env]
-typeEnvTyCons env = [tc | ATyCon tc <- typeEnvElts env]
-typeEnvIds env = [id | AnId id <- typeEnvElts env]
+emptyTypeEnv :: TypeEnv
+typeEnvElts :: TypeEnv -> [TyThing]
+typeEnvClasses :: TypeEnv -> [Class]
+typeEnvTyCons :: TypeEnv -> [TyCon]
+typeEnvIds :: TypeEnv -> [Id]
+typeEnvDataCons :: TypeEnv -> [DataCon]
+lookupTypeEnv :: TypeEnv -> Name -> Maybe TyThing
+
+emptyTypeEnv = emptyNameEnv
+typeEnvElts env = nameEnvElts env
+typeEnvClasses env = [cl | AClass cl <- typeEnvElts env]
+typeEnvTyCons env = [tc | ATyCon tc <- typeEnvElts env]
+typeEnvIds env = [id | AnId id <- typeEnvElts env]
+typeEnvDataCons env = [dc | ADataCon dc <- typeEnvElts env]