X-Git-Url: http://git.megacz.com/?a=blobdiff_plain;f=compiler%2FbasicTypes%2FDataCon.lhs;h=0558daeff2aa9cd388670b144ee3c39de01fa485;hb=432b9c9322181a3644083e3c19b7e240d90659e7;hp=d8fdfb55aeaea09ecbc125d014a99b681cafed1a;hpb=9ffadf219cbc4f8ec57264786df936a3cee88aec;p=ghc-hetmet.git

diff --git a/compiler/basicTypes/DataCon.lhs b/compiler/basicTypes/DataCon.lhs
index d8fdfb5..0558dae 100644
--- a/compiler/basicTypes/DataCon.lhs
+++ b/compiler/basicTypes/DataCon.lhs
@@ -15,9 +15,11 @@ module DataCon (
 	
 	-- ** Type deconstruction
 	dataConRepType, dataConSig, dataConFullSig,
-	dataConName, dataConIdentity, dataConTag, dataConTyCon, dataConUserType,
+	dataConName, dataConIdentity, dataConTag, dataConTyCon, 
+        dataConOrigTyCon, dataConUserType,
 	dataConUnivTyVars, dataConExTyVars, dataConAllTyVars, 
-	dataConEqSpec, eqSpecPreds, dataConEqTheta, dataConDictTheta, dataConStupidTheta, 
+	dataConEqSpec, eqSpecPreds, dataConEqTheta, dataConDictTheta,
+	dataConStupidTheta,  
 	dataConInstArgTys, dataConOrigArgTys, dataConOrigResTy,
 	dataConInstOrigArgTys, dataConRepArgTys, 
 	dataConFieldLabels, dataConFieldType,
@@ -96,12 +98,12 @@ Note [Data Constructor Naming]
 ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
 Each data constructor C has two, and possibly up to four, Names associated with it:
 
-			     OccName	Name space	Name of
-  ---------------------------------------------------------------------------
-  * The "data con itself" 	C	DataName	DataCon
-  * The "worker data con"	C	VarName		Id (the worker)
-  * The "wrapper data con"	\$WC	VarName		Id (the wrapper)
-  * The "newtype coercion"      :CoT    TcClsName	TyCon
+		   OccName   Name space	  Name of   Notes
+ ---------------------------------------------------------------------------
+ The "data con itself" 	 C     DataName	  DataCon   In dom( GlobalRdrEnv )
+ The "worker data con"	 C     VarName	  Id        The worker
+ The "wrapper data con"	 $WC   VarName	  Id        The wrapper
+ The "newtype coercion"  :CoT  TcClsName  TyCon
  
 EVERY data constructor (incl for newtypes) has the former two (the
 data con itself, and its worker.  But only some data constructors have a
@@ -269,8 +271,9 @@ data DataCon
 		--	 syntax, provided its type looks like the above.
 		--       The declaration format is held in the TyCon (algTcGadtSyntax)
 
-	dcUnivTyVars :: [TyVar],	-- Universally-quantified type vars 
+	dcUnivTyVars :: [TyVar],	-- Universally-quantified type vars [a,b,c]
 					-- INVARIANT: length matches arity of the dcRepTyCon
+					---           result type of (rep) data con is exactly (T a b c)
 
 	dcExTyVars   :: [TyVar],	-- Existentially-quantified type vars 
 		-- In general, the dcUnivTyVars are NOT NECESSARILY THE SAME AS THE TYVARS
@@ -563,6 +566,14 @@ dataConTag  = dcTag
 dataConTyCon :: DataCon -> TyCon
 dataConTyCon = dcRepTyCon
 
+-- | The original type constructor used in the definition of this data
+-- constructor.  In case of a data family instance, that will be the family
+-- type constructor.
+dataConOrigTyCon :: DataCon -> TyCon
+dataConOrigTyCon dc 
+  | Just (tc, _) <- tyConFamInst_maybe (dcRepTyCon dc) = tc
+  | otherwise                                          = dcRepTyCon dc
+
 -- | The representation type of the data constructor, i.e. the sort
 -- type that will represent values of this type at runtime
 dataConRepType :: DataCon -> Type