rebase to ghc main repo

[ghc-hetmet.git] / compiler / typecheck / TcRnTypes.lhs

diff --git a/compiler/typecheck/TcRnTypes.lhs b/compiler/typecheck/TcRnTypes.lhs
index eee07e8..ada8180 100644 (file)
--- a/compiler/typecheck/TcRnTypes.lhs
+++ b/compiler/typecheck/TcRnTypes.lhs
@@ -260,9 +260,10 @@ data TcGblEnv
        tcg_warns     :: Warnings,          -- ...Warnings and deprecations
        tcg_anns      :: [Annotation],      -- ...Annotations
        tcg_insts     :: [Instance],        -- ...Instances
-       tcg_fam_insts :: [FamInst],         -- ...Family instances
-       tcg_rules     :: [LRuleDecl Id],    -- ...Rules
-       tcg_fords     :: [LForeignDecl Id], -- ...Foreign import & exports
+        tcg_fam_insts :: [FamInst],         -- ...Family instances
+        tcg_rules     :: [LRuleDecl Id],    -- ...Rules
+        tcg_fords     :: [LForeignDecl Id], -- ...Foreign import & exports
+        tcg_vects     :: [LVectDecl Id],    -- ...Vectorisation declarations
 
        tcg_doc_hdr   :: Maybe LHsDocString, -- ^ Maybe Haddock header docs
         tcg_hpc       :: AnyHpcUsage,        -- ^ @True@ if any part of the
@@ -718,10 +719,10 @@ andWC (WC { wc_flat = f1, wc_impl = i1, wc_insol = n1 })
        , wc_insol = n1 `unionBags` n2 }
 
 addFlats :: WantedConstraints -> Bag WantedEvVar -> WantedConstraints
-addFlats wc wevs = wc { wc_flat = wevs `unionBags` wc_flat wc }
+addFlats wc wevs = wc { wc_flat = wc_flat wc `unionBags` wevs }
 
 addImplics :: WantedConstraints -> Bag Implication -> WantedConstraints
-addImplics wc implic = wc { wc_impl = implic `unionBags` wc_impl wc }
+addImplics wc implic = wc { wc_impl = wc_impl wc `unionBags` implic }
 
 instance Outputable WantedConstraints where
   ppr (WC {wc_flat = f, wc_impl = i, wc_insol = n})
@@ -887,11 +888,12 @@ wantedToFlavored (EvVarX v wl) = EvVarX v (Wanted wl)
 
 keepWanted :: Bag FlavoredEvVar -> Bag WantedEvVar
 keepWanted flevs
-  = foldlBag keep_wanted emptyBag flevs
+  = foldrBag keep_wanted emptyBag flevs
+    -- Important: use fold*r*Bag to preserve the order of the evidence variables.
   where
-    keep_wanted :: Bag WantedEvVar -> FlavoredEvVar -> Bag WantedEvVar
-    keep_wanted r (EvVarX ev (Wanted wloc)) = consBag (EvVarX ev wloc) r
-    keep_wanted r _ = r
+    keep_wanted :: FlavoredEvVar -> Bag WantedEvVar -> Bag WantedEvVar
+    keep_wanted (EvVarX ev (Wanted wloc)) r = consBag (EvVarX ev wloc) r
+    keep_wanted _                         r = r
 \end{code}
 
 
@@ -939,10 +941,9 @@ data CtFlavor
 -- superclasses. 
 
 instance Outputable CtFlavor where
-  ppr (Given _)    = ptext (sLit "[Given]")
-  ppr (Wanted _)   = ptext (sLit "[Wanted]")
-  ppr (Derived {}) = ptext (sLit "[Derived]") 
-
+  ppr (Given {})   = ptext (sLit "[G]")
+  ppr (Wanted {})  = ptext (sLit "[W]")
+  ppr (Derived {}) = ptext (sLit "[D]") 
 pprFlavorArising :: CtFlavor -> SDoc
 pprFlavorArising (Derived wl )  = pprArisingAt wl
 pprFlavorArising (Wanted  wl)   = pprArisingAt wl