X-Git-Url: http://git.megacz.com/?p=ghc-hetmet.git;a=blobdiff_plain;f=compiler%2Ftypes%2FGenerics.lhs;h=323da41d66a4b54cb24a6e6937e5b515b8b34898;hp=2adcc58832aced3e84cbd0b3330230e7aae8f92d;hb=c648345e3d82c0c40333bfd8ddea2633e21b08dc;hpb=a5673c5bcc20a9504c523c122112b935962dafe3

diff --git a/compiler/types/Generics.lhs b/compiler/types/Generics.lhs
index 2adcc58..323da41 100644
--- a/compiler/types/Generics.lhs
+++ b/compiler/types/Generics.lhs
@@ -22,10 +22,12 @@ import RdrName
 import BasicTypes
 import TysWiredIn
 import PrelNames
+
 -- For generation of representation types
 import TcEnv (tcLookupTyCon)
-import TcRnMonad (TcM, newUnique)
+import TcRnMonad
 import HscTypes
+import BuildTyCl
 
 import SrcLoc
 import Bag
@@ -52,11 +54,11 @@ canDoGenerics tycon
   =  mergeErrors (
           -- We do not support datatypes with context
               (if (not (null (tyConStupidTheta tycon)))
-                then (Just (ppr tycon <+> text "has a datatype context"))
+                then (Just (ppr tycon <+> text "must not have a datatype context"))
                 else Nothing)
           -- We don't like type families
             : (if (isFamilyTyCon tycon)
-                then (Just (ppr tycon <+> text "is a family instance"))
+                then (Just (ppr tycon <+> text "must not be a family instance"))
                 else Nothing)
           -- See comment below
             : (map bad_con (tyConDataCons tycon)))
@@ -66,9 +68,9 @@ canDoGenerics tycon
         -- it relies on instantiating *polymorphic* sum and product types
         -- at the argument types of the constructors
     bad_con dc = if (any bad_arg_type (dataConOrigArgTys dc))
-                  then (Just (ppr dc <+> text "has unlifted or polymorphic arguments"))
+                  then (Just (ppr dc <+> text "must not have unlifted or polymorphic arguments"))
                   else (if (not (isVanillaDataCon dc))
-                          then (Just (ppr dc <+> text "is not a vanilla data constructor"))
+                          then (Just (ppr dc <+> text "must be a vanilla data constructor"))
                           else Nothing)
 
 
@@ -81,7 +83,7 @@ canDoGenerics tycon
     mergeErrors []           = Nothing
     mergeErrors ((Just s):t) = case mergeErrors t of
                                  Nothing -> Just s
-                                 Just s' -> Just (s $$ s')
+                                 Just s' -> Just (s <> text ", and" $$ s')
     mergeErrors (Nothing :t) = mergeErrors t
 \end{code}
 
@@ -112,6 +114,37 @@ mkBindsRep tycon =
         (from_alts, to_alts) = mkSum (1 :: US) tycon datacons
         
 --------------------------------------------------------------------------------
+-- The type instance synonym and synonym
+--       type instance Rep (D a b) = Rep_D a b
+--       type Rep_D a b = ...representation type for D ...
+--------------------------------------------------------------------------------
+
+tc_mkRepTyCon :: TyCon           -- The type to generate representation for
+               -> MetaTyCons      -- Metadata datatypes to refer to
+               -> TcM TyCon       -- Generated representation0 type
+tc_mkRepTyCon tycon metaDts = 
+-- Consider the example input tycon `D`, where data D a b = D_ a
+  do { -- `rep0` = GHC.Generics.Rep (type family)
+       rep0 <- tcLookupTyCon repTyConName
+
+       -- `rep0Ty` = D1 ... (C1 ... (S1 ... (Rec0 a))) :: * -> *
+     ; rep0Ty <- tc_mkRepTy tycon metaDts
+    
+       -- `rep_name` is a name we generate for the synonym
+     ; rep_name <- newImplicitBinder (tyConName tycon) mkGenR
+     ; let -- `tyvars` = [a,b]
+           tyvars  = tyConTyVars tycon
+
+           -- rep0Ty has kind * -> *
+           rep_kind = liftedTypeKind `mkArrowKind` liftedTypeKind
+
+           -- `appT` = D a b
+           appT = [mkTyConApp tycon (mkTyVarTys tyvars)]
+
+     ; buildSynTyCon rep_name tyvars (SynonymTyCon rep0Ty) rep_kind
+                     NoParentTyCon (Just (rep0, appT)) }
+
+--------------------------------------------------------------------------------
 -- Type representation
 --------------------------------------------------------------------------------
 
@@ -173,41 +206,6 @@ tc_mkRepTy tycon metaDts =
         
     return (mkD tycon)
 
-tc_mkRepTyCon :: TyCon           -- The type to generate representation for
-               -> MetaTyCons      -- Metadata datatypes to refer to
-               -> TcM TyCon       -- Generated representation0 type
-tc_mkRepTyCon tycon metaDts = 
--- Consider the example input tycon `D`, where data D a b = D_ a
-  do
-    uniq1   <- newUnique
-    uniq2   <- newUnique
-    -- `rep0Ty` = D1 ... (C1 ... (S1 ... (Rec0 a))) :: * -> *
-    rep0Ty  <- tc_mkRepTy tycon metaDts
-    -- `rep0` = GHC.Generics.Rep (type family)
-    rep0    <- tcLookupTyCon repTyConName
-    
-    let modl    = nameModule  (tyConName tycon)
-        loc     = nameSrcSpan (tyConName tycon)
-        -- `repName` is a name we generate for the synonym
-        repName = mkExternalName uniq1 modl (mkGenR0 (nameOccName (tyConName tycon))) loc
-        -- `coName` is a name for the coercion
-        coName  = mkExternalName uniq2 modl (mkGenR0 (nameOccName (tyConName tycon))) loc
-        -- `tyvars` = [a,b]
-        tyvars  = tyConTyVars tycon
-        -- `appT` = D a b
-        appT    = [mkTyConApp tycon (mkTyVarTys tyvars)]
-        -- Result
-        res = mkSynTyCon repName
-                 -- rep0Ty has kind `kind of D` -> *
-                 (tyConKind tycon `mkArrowKind` liftedTypeKind)
-                 tyvars (SynonymTyCon rep0Ty)
-                 (FamInstTyCon rep0 appT
-                   (mkCoercionTyCon coName (tyConArity tycon)
-                     -- co : forall a b. Rep (D a b) ~ `rep0Ty` a b
-                     (CoAxiom tyvars (mkTyConApp rep0 appT) rep0Ty)))
-
-    return res
-
 --------------------------------------------------------------------------------
 -- Meta-information
 --------------------------------------------------------------------------------
@@ -220,7 +218,7 @@ data MetaTyCons = MetaTyCons { -- One meta datatype per dataype
                              , metaS :: [[TyCon]] }
                              
 instance Outputable MetaTyCons where
-  ppr (MetaTyCons d c s) = ppr d <+> ppr c <+> ppr s
+  ppr (MetaTyCons d c s) = ppr d $$ vcat (map ppr c) $$ vcat (map ppr (concat s))
                                    
 metaTyCons2TyCons :: MetaTyCons -> [TyCon]
 metaTyCons2TyCons (MetaTyCons d c s) = d : c ++ concat s