Rewrite the unsafe code dealing with unboxed primitives in RtClosureInspect

[ghc-hetmet.git] / compiler / types / FamInstEnv.lhs

diff --git a/compiler/types/FamInstEnv.lhs b/compiler/types/FamInstEnv.lhs
index 60b55d1..b8c82f8 100644 (file)
--- a/compiler/types/FamInstEnv.lhs
+++ b/compiler/types/FamInstEnv.lhs
@@ -51,7 +51,7 @@ data FamInst
 
                -- Used for "rough matching"; same idea as for class instances
            , fi_tcs   :: [Maybe Name]  -- Top of type args
 
                -- Used for "rough matching"; same idea as for class instances
            , fi_tcs   :: [Maybe Name]  -- Top of type args

-               -- INVARIANT: fi_tcs = roughMatchTcs is_tys
+               -- INVARIANT: fi_tcs = roughMatchTcs fi_tys

 
                -- Used for "proper matching"; ditto
            , fi_tvs   :: TyVarSet      -- Template tyvars for full match
 
                -- Used for "proper matching"; ditto
            , fi_tvs   :: TyVarSet      -- Template tyvars for full match

@@ -82,7 +82,7 @@ instance Outputable FamInst where
 pprFamInst :: FamInst -> SDoc
 pprFamInst famInst
   = hang (pprFamInstHdr famInst)
 pprFamInst :: FamInst -> SDoc
 pprFamInst famInst
   = hang (pprFamInstHdr famInst)

-       2 (ptext SLIT("--") <+> (pprDefnLoc (getSrcLoc famInst)))
+       2 (ptext SLIT("--") <+> (pprDefnLoc (getSrcSpan famInst)))

 
 pprFamInstHdr :: FamInst -> SDoc
 pprFamInstHdr (FamInst {fi_fam = fam, fi_tys = tys, fi_tycon = tycon})
 
 pprFamInstHdr :: FamInst -> SDoc
 pprFamInstHdr (FamInst {fi_fam = fam, fi_tys = tys, fi_tycon = tycon})

@@ -198,10 +198,24 @@ Multiple matches are only possible in case of type families (not data
 families), and then, it doesn't matter which match we choose (as the
 instances are guaranteed confluent).
 
 families), and then, it doesn't matter which match we choose (as the
 instances are guaranteed confluent).
 

+We return the matching family instances and the type instance at which it
+matches.  For example, if we lookup 'T [Int]' and have a family instance
+
+  data instance T [a] = ..
+
+desugared to
+
+  data :R42T a = ..
+  coe :Co:R42T a :: T [a] ~ :R42T a
+
+we return the matching instance '(FamInst{.., fi_tycon = :R42T}, Int)'.
+

 \begin{code}
 \begin{code}

+type FamInstMatch = (FamInst, [Type])           -- Matching type instance
+

 lookupFamInstEnv :: FamInstEnvs
                 -> TyCon -> [Type]             -- What we are looking for
 lookupFamInstEnv :: FamInstEnvs
                 -> TyCon -> [Type]             -- What we are looking for

-                -> [(TvSubst, FamInst)]        -- Successful matches
+                -> [FamInstMatch]              -- Successful matches

 lookupFamInstEnv (pkg_ie, home_ie) fam tys
   = home_matches ++ pkg_matches
   where
 lookupFamInstEnv (pkg_ie, home_ie) fam tys
   = home_matches ++ pkg_matches
   where

@@ -231,7 +245,7 @@ lookupFamInstEnv (pkg_ie, home_ie) fam tys
 
         -- Proper check
       | Just subst <- tcMatchTys tpl_tvs tpl_tys tys
 
         -- Proper check
       | Just subst <- tcMatchTys tpl_tvs tpl_tys tys

-      = (subst, item) : find rest
+      = (item, substTyVars subst (tyConTyVars tycon)) : find rest

 
         -- No match => try next
       | otherwise
 
         -- No match => try next
       | otherwise

@@ -250,7 +264,7 @@ indexed synonyms and we don't want to slow that down by needless unification.
 
 \begin{code}
 lookupFamInstEnvUnify :: (FamInstEnv, FamInstEnv) -> TyCon -> [Type]
 
 \begin{code}
 lookupFamInstEnvUnify :: (FamInstEnv, FamInstEnv) -> TyCon -> [Type]

-                     -> [(TvSubst, FamInst)]
+                     -> [(FamInstMatch)]

 lookupFamInstEnvUnify (pkg_ie, home_ie) fam tys
   = home_matches ++ pkg_matches
   where
 lookupFamInstEnvUnify (pkg_ie, home_ie) fam tys
   = home_matches ++ pkg_matches
   where

@@ -286,7 +300,9 @@ lookupFamInstEnvUnify (pkg_ie, home_ie) fam tys
                -- Unification will break badly if the variables overlap
                -- They shouldn't because we allocate separate uniques for them
         case tcUnifyTys bind_fn tpl_tys tys of
                -- Unification will break badly if the variables overlap
                -- They shouldn't because we allocate separate uniques for them
         case tcUnifyTys bind_fn tpl_tys tys of

-           Just subst -> (subst, item) : find rest
+           Just subst -> let rep_tys = substTyVars subst (tyConTyVars tycon)
+                          in
+                          (item, rep_tys) : find rest

            Nothing    -> find rest
 
 -- See explanation at @InstEnv.bind_fn@.
            Nothing    -> find rest
 
 -- See explanation at @InstEnv.bind_fn@.