Typechecker performance fixes and flatten skolem bugfixing

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

diff --git a/compiler/typecheck/TcType.lhs b/compiler/typecheck/TcType.lhs
index dcc51ef..b49dbff 100644 (file)
--- a/compiler/typecheck/TcType.lhs
+++ b/compiler/typecheck/TcType.lhs
@@ -274,17 +274,18 @@ TcBinds.tcInstSig, and its use_skols parameter.
 data TcTyVarDetails
   = SkolemTv SkolemInfo          -- A skolem constant
 
-  | FlatSkol TcType      -- The "skolem" obtained by flattening during
-                         -- constraint simplification
+  | FlatSkol TcType      
+           -- The "skolem" obtained by flattening during
+          -- constraint simplification
     
-                          -- In comments we will use the notation alpha[flat = ty]
-                          -- to represent a flattening skolem variable alpha
-                          -- identified with type ty.
-
+           -- In comments we will use the notation alpha[flat = ty]
+           -- to represent a flattening skolem variable alpha
+           -- identified with type ty.
+          
   | MetaTv MetaInfo (IORef MetaDetails)
 
 data MetaDetails
-  = Flexi      -- Flexi type variables unify to become Indirects  
+  = Flexi  -- Flexi type variables unify to become Indirects  
   | Indirect TcType
 
 data MetaInfo 
@@ -405,7 +406,7 @@ kind_var_occ = mkOccName tvName "k"
 pprTcTyVarDetails :: TcTyVarDetails -> SDoc
 -- For debugging
 pprTcTyVarDetails (SkolemTv _)         = ptext (sLit "sk")
-pprTcTyVarDetails (FlatSkol _)         = ptext (sLit "fsk")
+pprTcTyVarDetails (FlatSkol {})        = ptext (sLit "fsk")
 pprTcTyVarDetails (MetaTv TauTv _)     = ptext (sLit "tau")
 pprTcTyVarDetails (MetaTv (SigTv _) _) = ptext (sLit "sig")
 
@@ -431,7 +432,7 @@ pprSkolTvBinding tv
     quotes (ppr tv) <+> ppr_details (tcTyVarDetails tv)
   where
     ppr_details (SkolemTv info)      = ppr_skol info
-    ppr_details (FlatSkol _)        = ptext (sLit "is a flattening type variable")
+    ppr_details (FlatSkol {})       = ptext (sLit "is a flattening type variable")
     ppr_details (MetaTv TauTv _)     = ptext (sLit "is a meta type variable")
     ppr_details (MetaTv (SigTv n) _) = ptext (sLit "is bound by the type signature for") <+> quotes (ppr n)