X-Git-Url: http://git.megacz.com/?a=blobdiff_plain;f=compiler%2Ftypes%2FTyCon.lhs;h=eb0474bafe733eadb43939ee8d36b0f7b31dc38c;hb=c128930dc98c73e2459a4610539fee73ca941247;hp=f03fb8952ef8a7626f51695871e0b28cab11a53a;hpb=683ccf1854b2ffd2e703b120e39da8234d555075;p=ghc-hetmet.git

diff --git a/compiler/types/TyCon.lhs b/compiler/types/TyCon.lhs
index f03fb89..eb0474b 100644
--- a/compiler/types/TyCon.lhs
+++ b/compiler/types/TyCon.lhs
@@ -1,7 +1,9 @@
 %
+% (c) The University of Glasgow 2006
 % (c) The GRASP/AQUA Project, Glasgow University, 1992-1998
 %
-\section[TyCon]{The @TyCon@ datatype}
+
+The @TyCon@ datatype
 
 \begin{code}
 module TyCon(
@@ -10,7 +12,8 @@ module TyCon(
 	PrimRep(..),
 	tyConPrimRep,
 
-	AlgTyConRhs(..), visibleDataCons, AlgTyConParent(..),
+	AlgTyConRhs(..), visibleDataCons, 
+        AlgTyConParent(..), hasParent,
 	SynTyConRhs(..),
 
 	isFunTyCon, isUnLiftedTyCon, isProductTyCon, 
@@ -22,6 +25,7 @@ module TyCon(
 	isRecursiveTyCon, newTyConRep, newTyConRhs, newTyConCo_maybe,
 	isHiBootTyCon, isSuperKindTyCon,
         isCoercionTyCon_maybe, isCoercionTyCon,
+        isImplicitTyCon,
 
 	tcExpandTyCon_maybe, coreExpandTyCon_maybe,
 
@@ -64,13 +68,12 @@ module TyCon(
 import {-# SOURCE #-} TypeRep ( Kind, Type, PredType )
 import {-# SOURCE #-} DataCon ( DataCon, isVanillaDataCon )
 
-import Var   		( TyVar, Id )
-import Class		( Class )
-import BasicTypes	( Arity, RecFlag(..), Boxity(..), isBoxed )
-import Name		( Name, nameUnique, NamedThing(getName) )
-import PrelNames	( Unique, Uniquable(..) )
-import Maybe		( isJust )
-import Maybes		( orElse )
+import Var
+import Class
+import BasicTypes
+import Name
+import PrelNames
+import Maybes
 import Outputable
 import FastString
 \end{code}
@@ -169,7 +172,8 @@ data TyCon
 	tyConUnique   :: Unique,
 	tyConName     :: Name,
 	tyConKind     :: Kind,
-	tyConArity    :: Arity,
+	tyConArity    :: Arity,		-- SLPJ Oct06: I'm not sure what the significance
+					--	       of the arity of a primtycon is!
 
 	primTyConRep  :: PrimRep,
 			-- Many primitive tycons are unboxed, but some are
@@ -275,6 +279,10 @@ data AlgTyConParent = -- An ordinary type constructor has no parent.
 						-- the representation type
 						-- with the type instance
 
+hasParent :: AlgTyConParent -> Bool
+hasParent NoParentTyCon = False
+hasParent _other        = True
+
 data SynTyConRhs
   = OpenSynTyCon Kind	-- Type family: *result* kind given
   | SynonymTyCon Type   -- Mentioning head type vars.  Acts as a template for
@@ -537,8 +545,8 @@ isAlgTyCon (TupleTyCon {}) = True
 isAlgTyCon other 	   = False
 
 isDataTyCon :: TyCon -> Bool
--- isDataTyCon returns True for data types that are represented by
--- heap-allocated constructors.
+-- isDataTyCon returns True for data types that are definitely
+-- represented by heap-allocated constructors.
 -- These are srcutinised by Core-level @case@ expressions, and they
 -- get info tables allocated for them.
 --	True for all @data@ types
@@ -550,7 +558,7 @@ isDataTyCon tc@(AlgTyCon {algTcRhs = rhs})
 	DataTyCon {}  -> True
 	OpenNewTyCon  -> False
 	NewTyCon {}   -> False
-	AbstractTyCon -> pprPanic "isDataTyCon" (ppr tc)
+	AbstractTyCon -> False	-- We don't know, so return False
 isDataTyCon (TupleTyCon {tyConBoxed = boxity}) = isBoxed boxity
 isDataTyCon other = False
 
@@ -662,8 +670,16 @@ isCoercionTyCon_maybe (CoercionTyCon {tyConArity = ar, coKindFun = rule})
   = Just (ar, rule)
 isCoercionTyCon_maybe other = Nothing
 
+isCoercionTyCon :: TyCon -> Bool
 isCoercionTyCon (CoercionTyCon {}) = True
 isCoercionTyCon other              = False
+
+isImplicitTyCon :: TyCon -> Bool
+isImplicitTyCon SynTyCon{}                     = False
+isImplicitTyCon AlgTyCon{algTcParent = parent} = hasParent parent
+isImplicitTyCon other                          = True
+        -- catches: FunTyCon, TupleTyCon, PrimTyCon, 
+        -- CoercionTyCon, SuperKindTyCon
 \end{code}