[project @ 2003-10-30 16:01:49 by simonpj]

This commit does a long-overdue tidy-up

* Remove PprType (gets rid of one more bunch of hi-boot files)

* Put pretty-printing for types in TypeRep

* Make a specialised pretty-printer for Types, rather than
  converting to IfaceTypes and printing those

ghc/compiler/basicTypes/DataCon.hi-boot-5

 __interface DataCon 1 0 where
-__export DataCon DataCon isExistentialDataCon ;
+__export DataCon DataCon isExistentialDataCon dataConName ;
 1 data DataCon ;
 1 isExistentialDataCon :: DataCon -> PrelBase.Bool ;
+1 dataConName :: DataCon -> Name.Name ;

ghc/compiler/basicTypes/DataCon.hi-boot-6

 module DataCon where
 
 data DataCon
+dataConName :: DataCon -> Name.Name
 isExistentialDataCon :: DataCon -> GHC.Base.Bool

ghc/compiler/basicTypes/DataCon.lhs

@@ -25,12 +25,11 @@ module DataCon (
 #include "HsVersions.h"
 
 import {-# SOURCE #-} Subst( substTyWith )
-import {-# SOURCE #-} PprType( pprType )
 
 import Type		( Type, ThetaType, 
 			  mkForAllTys, mkFunTys, mkTyConApp,
 			  mkTyVarTys, splitTyConApp_maybe, 
-			  mkPredTys, isStrictPred
+			  mkPredTys, isStrictPred, pprType
 			)
 import TyCon		( TyCon, tyConDataCons, tyConDataCons, isProductTyCon,
 			  isTupleTyCon, isUnboxedTupleTyCon )

ghc/compiler/basicTypes/Name.lhs

@@ -311,13 +311,13 @@ pprName name@(Name {n_sort = sort, n_uniq = uniq, n_occ = occ})
 pprExternal sty name uniq mod occ mb_p is_wired
   | codeStyle sty        = ppr (moduleName mod) <> char '_' <> pprOccName occ
   | debugStyle sty       = sep [ppr (moduleName mod) <> dot <> pprOccName occ,
-				hsep [text "{-", 
-				      if is_wired then ptext SLIT("(w)") else empty,
-				      pprUnique uniq,
-				      case mb_p of
-					Nothing -> empty
-					Just n  -> brackets (ppr n),
-				      text "-}"]]
+				hsep [text "{-" 
+				     , if is_wired then ptext SLIT("(w)") else empty
+				     , pprUnique uniq
+-- (overkill)			     , case mb_p of
+--				 	 Nothing -> empty
+--					 Just n  -> brackets (ppr n)
+				     , text "-}"]]
   | unqualStyle sty name = pprOccName occ
   | otherwise		 = ppr (moduleName mod) <> dot <> pprOccName occ
 

ghc/compiler/codeGen/CgClosure.lhs

 %
 % (c) The GRASP/AQUA Project, Glasgow University, 1992-1998
 %
-% $Id: CgClosure.lhs,v 1.60 2003/05/14 09:13:53 simonmar Exp $
+% $Id: CgClosure.lhs,v 1.61 2003/10/30 16:01:52 simonpj Exp $
 %
 \section[CgClosure]{Code generation for closures}
 
@@ -39,7 +39,6 @@ import Name		( Name, isInternalName )
 import Module		( Module, pprModule )
 import ListSetOps	( minusList )
 import PrimRep		( PrimRep(..), getPrimRepSize )
-import PprType          ( showTypeCategory )
 import Util		( isIn, splitAtList )
 import CmdLineOpts	( opt_SccProfilingOn )
 import Outputable
@@ -47,6 +46,12 @@ import FastString
 
 import Name             ( nameOccName )
 import OccName          ( occNameFS )
+
+-- Turgid imports for showTypeCategory
+import PrelNames
+import TcType		( Type, isDictTy, tcSplitTyConApp_maybe, tcSplitFunTy_maybe )
+import TyCon		( isPrimTyCon, isTupleTyCon, isEnumerationTyCon, maybeTyConSingleCon )
+import Maybe
 \end{code}
 
 %********************************************************
@@ -674,3 +679,55 @@ chooseDynCostCentres ccs args fvs body
     in
     (use_cc, blame_cc)
 \end{code}
+
+
+\begin{code}
+showTypeCategory :: Type -> Char
+  {-
+	{C,I,F,D}   char, int, float, double
+	T	    tuple
+	S	    other single-constructor type
+	{c,i,f,d}   unboxed ditto
+	t	    *unpacked* tuple
+	s	    *unpacked" single-cons...
+
+	v	    void#
+	a	    primitive array
+
+	E	    enumeration type
+	+	    dictionary, unless it's a ...
+	L	    List
+	>	    function
+	M	    other (multi-constructor) data-con type
+	.	    other type
+	-	    reserved for others to mark as "uninteresting"
+    -}
+showTypeCategory ty
+  = if isDictTy ty
+    then '+'
+    else
+      case tcSplitTyConApp_maybe ty of
+	Nothing -> if isJust (tcSplitFunTy_maybe ty)
+		   then '>'
+		   else '.'
+
+	Just (tycon, _) ->
+          let utc = getUnique tycon in
+	  if	  utc == charDataConKey    then 'C'
+	  else if utc == intDataConKey     then 'I'
+	  else if utc == floatDataConKey   then 'F'
+	  else if utc == doubleDataConKey  then 'D'
+	  else if utc == smallIntegerDataConKey ||
+		  utc == largeIntegerDataConKey   then 'J'
+	  else if utc == charPrimTyConKey  then 'c'
+	  else if (utc == intPrimTyConKey || utc == wordPrimTyConKey
+		|| utc == addrPrimTyConKey)		   then 'i'
+	  else if utc  == floatPrimTyConKey		   then 'f'
+	  else if utc  == doublePrimTyConKey		   then 'd'
+	  else if isPrimTyCon tycon {- array, we hope -}   then 'A'	-- Bogus
+	  else if isEnumerationTyCon tycon		   then 'E'
+	  else if isTupleTyCon tycon			   then 'T'
+	  else if isJust (maybeTyConSingleCon tycon)       then 'S'
+	  else if utc == listTyConKey			   then 'L'
+	  else 'M' -- oh, well...
+\end{code}

ghc/compiler/codeGen/ClosureInfo.lhs

 %
 % (c) The GRASP/AQUA Project, Glasgow University, 1992-1998
 %
-% $Id: ClosureInfo.lhs,v 1.59 2003/10/09 11:58:46 simonpj Exp $
+% $Id: ClosureInfo.lhs,v 1.60 2003/10/30 16:01:52 simonpj Exp $
 %
 \section[ClosureInfo]{Data structures which describe closures}
 
@@ -72,14 +72,14 @@ import Id		( Id, idType, idArity, idName, idPrimRep )
 import DataCon		( DataCon, dataConTag, fIRST_TAG, dataConTyCon,
 			  isNullaryDataCon, dataConName
 			)
-import Name		( Name, nameUnique, getOccName, getName )
+import Name		( Name, nameUnique, getOccName, getName, getOccString )
 import OccName		( occNameUserString )
-import PprType		( getTyDescription )
 import PrimRep
 import SMRep		-- all of it
 import Type		( isUnLiftedType, Type, repType, splitTyConApp_maybe )
+import TcType		( tcSplitSigmaTy )
 import TyCon		( isFunTyCon )
-import BasicTypes	( TopLevelFlag(..), isNotTopLevel, isTopLevel )
+import BasicTypes	( TopLevelFlag(..), isNotTopLevel, isTopLevel, ipNameName )
 import Util		( mapAccumL, listLengthCmp, lengthIs )
 import FastString
 import Outputable
@@ -1056,6 +1056,27 @@ closureTypeDescr (ClosureInfo { closureType = ty })
   = getTyDescription ty
 closureTypeDescr (ConInfo { closureCon = data_con })
   = occNameUserString (getOccName (dataConTyCon data_con))
+
+getTyDescription :: Type -> String
+getTyDescription ty
+  = case (tcSplitSigmaTy ty) of { (_, _, tau_ty) ->
+    case tau_ty of
+      TyVarTy _	       	     -> "*"
+      AppTy fun _      	     -> getTyDescription fun
+      FunTy _ res      	     -> '-' : '>' : fun_result res
+      NewTcApp tycon _ 	     -> getOccString tycon
+      TyConApp tycon _ 	     -> getOccString tycon
+      NoteTy (FTVNote _) ty  -> getTyDescription ty
+      NoteTy (SynNote ty1) _ -> getTyDescription ty1
+      PredTy sty	     -> getPredTyDescription sty
+      ForAllTy _ ty          -> getTyDescription ty
+    }
+  where
+    fun_result (FunTy _ res) = '>' : fun_result res
+    fun_result other	     = getTyDescription other
+
+getPredTyDescription (ClassP cl tys) = getOccString cl
+getPredTyDescription (IParam ip ty)  = getOccString (ipNameName ip)
 \end{code}
 
 %************************************************************************

ghc/compiler/coreSyn/PprCore.lhs

@@ -27,7 +27,7 @@ import Id		( Id, idType, isDataConWorkId_maybe, idLBVarInfo, idArity,
 			  globalIdDetails, isGlobalId, isExportedId, 
 			  isSpecPragmaId, idNewDemandInfo
 			)
-import Var		( isTyVar )
+import Var		( TyVar, isTyVar, tyVarKind )
 import IdInfo		( IdInfo, megaSeqIdInfo, 
 			  arityInfo, ppArityInfo, 
 			  specInfo, pprNewStrictness,
@@ -40,7 +40,7 @@ import IdInfo		( IdInfo, megaSeqIdInfo,
 			)
 import DataCon		( dataConTyCon )
 import TyCon		( tupleTyConBoxity, isTupleTyCon )
-import PprType		( pprParendType, pprType, pprTyVarBndr )
+import Type		( pprParendType, pprType, pprParendKind )
 import BasicTypes	( tupleParens )
 import Util             ( lengthIs )
 import Outputable
@@ -294,6 +294,17 @@ pprTypedBinder binder
 	-- printing interfaces, because we get \ x::(a->b) y::(c->d) -> ...
 	--	[Jun 2002: interfaces are now binary, so this doesn't matter]
 
+pprTyVarBndr :: TyVar -> SDoc
+pprTyVarBndr tyvar
+  = getPprStyle $ \ sty ->
+    if debugStyle sty then
+        hsep [ppr tyvar, dcolon, pprParendKind kind]
+		-- See comments with ppDcolon in PprCore.lhs
+    else
+        ppr tyvar
+  where
+    kind = tyVarKind tyvar
+
 -- pprIdBndr does *not* print the type
 -- When printing any Id binder in debug mode, we print its inline pragma and one-shot-ness
 pprIdBndr id = ppr id <+> 

ghc/compiler/deSugar/DsCCall.lhs

@@ -178,7 +178,7 @@ unboxArg arg
   -- Data types with a single constructor, which has a single, primitive-typed arg
   -- This deals with Int, Float etc; also Ptr, ForeignPtr
   | is_product_type && data_con_arity == 1 
-  = ASSERT2(isUnLiftedType data_con_arg_ty1, crudePprType arg_ty)
+  = ASSERT2(isUnLiftedType data_con_arg_ty1, pprType arg_ty)
 			-- Typechecker ensures this
     newSysLocalDs arg_ty		`thenDs` \ case_bndr ->
     newSysLocalDs data_con_arg_ty1	`thenDs` \ prim_arg ->

ghc/compiler/ghci/ByteCodeGen.lhs

@@ -34,7 +34,7 @@ import DataCon		( DataCon, dataConTag, fIRST_TAG, dataConTyCon,
 import TyCon		( tyConFamilySize, isDataTyCon, tyConDataCons,
 			  isUnboxedTupleTyCon )
 import Class		( Class, classTyCon )
-import Type		( Type, repType, splitFunTys, dropForAlls )
+import Type		( Type, repType, splitFunTys, dropForAlls, pprType )
 import Util
 import DataCon		( dataConRepArity )
 import Var		( isTyVar )
@@ -48,7 +48,6 @@ import ErrUtils		( showPass, dumpIfSet_dyn )
 import Unique		( mkPseudoUnique3 )
 import FastString	( FastString(..), unpackFS )
 import Panic		( GhcException(..) )
-import PprType		( pprType )
 import SMRep		( arrWordsHdrSize, arrPtrsHdrSize, StgWord )
 import Bitmap		( intsToReverseBitmap, mkBitmap )
 import OrdList

ghc/compiler/hsSyn/HsExpr.lhs

@@ -17,8 +17,7 @@ import HsTypes		( HsType, PostTcType, SyntaxName, placeHolderType )
 import HsImpExp		( isOperator, pprHsVar )
 
 -- others:
-import PprType		( pprParendType )
-import Type		( Type )
+import Type		( Type, pprParendType )
 import Var		( TyVar, Id )
 import Name		( Name )
 import DataCon		( DataCon )

ghc/compiler/hsSyn/HsTypes.lhs

@@ -26,10 +26,9 @@ module HsTypes (
 #include "HsVersions.h"
 
 import TcType		( Type, Kind, liftedTypeKind, eqKind )
-import TypeRep		( Type )
+import Type		( {- instance Outputable Kind -}, pprParendKind, pprKind )
 import Name		( Name, mkInternalName )
 import OccName		( mkVarOcc )
-import PprType		( {- instance Outputable Kind -}, pprParendKind, pprKind )
 import BasicTypes	( IPName, Boxity, tupleParens )
 import PrelNames	( unboundKey )
 import SrcLoc		( noSrcLoc )

ghc/compiler/iface/IfaceType.lhs

@@ -27,7 +27,7 @@ module IfaceType (
 #include "HsVersions.h"
 
 import Type		( openTypeKind, liftedTypeKind, unliftedTypeKind,
-			  splitFunTy_maybe, eqKind )
+			  splitFunTy_maybe, eqKind, pprType )
 import TypeRep		( Type(..), TyNote(..), PredType(..), Kind, ThetaType )
 import TyCon		( TyCon, isTupleTyCon, tyConArity, tupleTyConBoxity )
 import Var		( isId, tyVarKind, idType )
@@ -38,10 +38,6 @@ import Module		( ModuleName )
 import BasicTypes	( IPName(..), Arity, Version, mapIPName, tupleParens, Boxity )
 import Outputable
 import FastString
-
-#ifdef DEBUG
-import TypeRep( crudePprType )
-#endif
 \end{code}
 
 	
@@ -342,7 +338,7 @@ toIfaceKind k
   | Just (arg,res) <- splitFunTy_maybe k 
   = IfaceFunKind (toIfaceKind arg) (toIfaceKind res)
 #ifdef DEBUG
-  | otherwise = pprTrace "toIfaceKind" (crudePprType k) IfaceOpenTypeKind
+  | otherwise = pprTrace "toIfaceKind" (pprType k) IfaceOpenTypeKind
 #endif
 
 ---------------------

ghc/compiler/iface/TcIface.lhs

@@ -22,7 +22,7 @@ import BuildTyCl	( buildSynTyCon, buildAlgTyCon, buildDataCon, buildClass )
 import TcRnMonad
 import Type		( Kind, openTypeKind, liftedTypeKind, 
 			  unliftedTypeKind, mkArrowKind, splitTyConApp, 
-			  mkTyVarTys, mkGenTyConApp, mkTyVarTys, ThetaType )
+			  mkTyVarTys, mkGenTyConApp, mkTyVarTys, ThetaType, pprClassPred )
 import TypeRep		( Type(..), PredType(..) )
 import TyCon		( TyCon, tyConName )
 import HscTypes		( ExternalPackageState(..), PackageInstEnv, PackageRuleBase,
@@ -32,7 +32,6 @@ import HscTypes		( ExternalPackageState(..), PackageInstEnv, PackageRuleBase,
 			  DeclPool, RulePool, Pool(..), Gated, addRuleToPool )
 import InstEnv		( extendInstEnv )
 import CoreSyn
-import PprType		( pprClassPred )
 import PprCore		( pprIdRules )
 import Rules		( extendRuleBaseList )
 import CoreUtils	( exprType )

ghc/compiler/ilxGen/IlxGen.lhs

@@ -16,7 +16,7 @@ import TyCon	( TyCon,  tyConPrimRep, isUnboxedTupleTyCon, tyConDataCons,
 		  tyConTyVars, isDataTyCon, isAlgTyCon, tyConArity
 		)
 import Type	( liftedTypeKind, openTypeKind, unliftedTypeKind,
-		  isUnLiftedType, isTyVarTy, mkTyVarTy, predTypeRep,
+		  isUnLiftedType, isTyVarTy, mkTyVarTy, predTypeRep, pprType,
 		  splitForAllTys, splitFunTys, applyTy, applyTys, eqKind, tyVarsOfTypes
 		)
 import TypeRep	( Type(..) )
@@ -43,7 +43,6 @@ import Outputable
 import Char		( ord )
 import List		( partition, elem, insertBy,any  )
 import UniqSet
-import PprType		( pprType )	-- Only called in debug messages
 
 import TysPrim  ( foreignObjPrimTyCon, weakPrimTyCon, byteArrayPrimTyCon, mutableByteArrayPrimTyCon )
 

ghc/compiler/typecheck/Inst.lhs

@@ -63,7 +63,8 @@ import TcType	( Type, TcType, TcThetaType, TcTyVarSet,
 		  isClassPred, isTyVarClassPred, isLinearPred, 
 		  getClassPredTys, getClassPredTys_maybe, mkPredName,
 		  isInheritablePred, isIPPred, matchTys,
-		  tidyType, tidyTypes, tidyFreeTyVars, tcSplitSigmaTy
+		  tidyType, tidyTypes, tidyFreeTyVars, tcSplitSigmaTy, 
+		  pprPred, pprParendType, pprThetaArrow, pprClassPred
 		)
 import HscTypes	( ExternalPackageState(..) )
 import CoreFVs	( idFreeTyVars )
@@ -72,7 +73,6 @@ import Id	( Id, idName, idType, mkUserLocal, mkSysLocal, mkLocalId, setIdUnique
 import PrelInfo	( isStandardClass, isNoDictClass )
 import Name	( Name, mkMethodOcc, getOccName, getSrcLoc, isHomePackageName, isInternalName )
 import NameSet	( addOneToNameSet )
-import PprType	( pprPred, pprParendType, pprThetaArrow, pprClassPred )	
 import Subst	( substTy, substTyWith, substTheta, mkTyVarSubst )
 import Literal	( inIntRange )
 import Var	( TyVar )

ghc/compiler/typecheck/TcClassDcl.lhs

@@ -14,7 +14,6 @@ module TcClassDcl ( tcClassSigs, tcClassDecl2,
 
 import HsSyn		( TyClDecl(..), Sig(..), MonoBinds(..), HsType(..), 
 			  HsExpr(..), HsLit(..), Pat(WildPat), HsTyVarBndr(..),
-			  HsExplicitForAll(..),
 			  mkSimpleMatch, andMonoBinds, andMonoBindList, 
 			  isPragSig, placeHolderType, mkExplicitHsForAllTy
 			)
@@ -29,7 +28,8 @@ import TcHsSyn		( TcMonoBinds )
 
 import Inst		( Inst, InstOrigin(..), instToId, newDicts, newMethod )
 import TcEnv		( tcLookupClass, tcExtendLocalValEnv2, tcExtendTyVarEnv2,
-			  InstInfo(..), pprInstInfo, simpleInstInfoTyCon, simpleInstInfoTy,
+			  InstInfo(..), pprInstInfoDetails,
+			  simpleInstInfoTyCon, simpleInstInfoTy,
 			  InstBindings(..), newDFunName
 			)
 import TcBinds		( tcMonoBinds, tcSpecSigs )
@@ -535,29 +535,28 @@ mkDefMethRhs origin clas inst_tys sel_id loc NoDefMeth
     wild_pats	 = [WildPat placeHolderType | ty <- arg_tys]
 
 mkDefMethRhs origin clas inst_tys sel_id loc GenDefMeth 
-  =  	-- A generic default method
-	-- If the method is defined generically, we can only do the job if the
+  = 	-- A generic default method
+    	-- If the method is defined generically, we can only do the job if the
 	-- instance declaration is for a single-parameter type class with
 	-- a type constructor applied to type arguments in the instance decl
 	-- 	(checkTc, so False provokes the error)
-     ASSERT( isInstDecl origin )	-- We never get here from a class decl
-
-     checkTc (isJust maybe_tycon)
-	     (badGenericInstance sel_id (notSimple inst_tys))		`thenM_`
-     checkTc (tyConHasGenerics tycon)
-	     (badGenericInstance sel_id (notGeneric tycon))		`thenM_`
-
-     ioToTcRn (dumpIfSet opt_PprStyle_Debug "Generic RHS" stuff)	`thenM_`
-
-	-- Rename it before returning it
-     rnExpr rhs			`thenM` \ (rn_rhs, _) ->
-     returnM rn_rhs
+    ASSERT( isInstDecl origin )	-- We never get here from a class decl
+    do	{ checkTc (isJust maybe_tycon)
+	 	  (badGenericInstance sel_id (notSimple inst_tys))
+	; checkTc (tyConHasGenerics tycon)
+	   	  (badGenericInstance sel_id (notGeneric tycon))
+
+	; dflags <- getDOpts
+	; ioToTcRn (dumpIfSet_dyn dflags Opt_D_dump_deriv "Filling in method body" 
+		   (vcat [ppr clas <+> ppr inst_tys,
+			  nest 2 (ppr sel_id <+> equals <+> ppr rhs)]))
+
+		-- Rename it before returning it
+	; (rn_rhs, _) <- rnExpr rhs
+	; returnM rn_rhs }
   where
     rhs = mkGenericRhs sel_id clas_tyvar tycon
 
-    stuff = vcat [ppr clas <+> ppr inst_tys,
-		  nest 4 (ppr sel_id <+> equals <+> ppr rhs)]
-
 	  -- The tycon is only used in the generic case, and in that
 	  -- case we require that the instance decl is for a single-parameter
 	  -- type class with type variable arguments:
@@ -629,7 +628,7 @@ getGenericInstances class_decls
 	-- Otherwise print it out
 	{ dflags <- getDOpts
 	; ioToTcRn (dumpIfSet_dyn dflags Opt_D_dump_deriv "Generic instances" 
-	 	   (vcat (map pprInstInfo gen_inst_info)))	
+	 	   (vcat (map pprInstInfoDetails gen_inst_info)))	
 	; returnM gen_inst_info }}
 
 get_generics decl@(ClassDecl {tcdName = class_name, tcdMeths = def_methods, tcdLoc = loc})
@@ -670,7 +669,6 @@ get_generics decl@(ClassDecl {tcdName = class_name, tcdMeths = def_methods, tcdL
     checkTc (null missing) (missingGenericInstances missing)	`thenM_`
 
     returnM inst_infos
-
   where
     generic_binds :: [(HsType Name, RenamedMonoBinds)]
     generic_binds = getGenericBinds def_methods

ghc/compiler/typecheck/TcDeriv.lhs

@@ -232,11 +232,7 @@ tcDeriving tycl_decls
   where
     ddump_deriving :: [InstInfo] -> RenamedHsBinds -> SDoc
     ddump_deriving inst_infos extra_binds
-      = vcat (map ppr_info inst_infos) $$ ppr extra_binds
-
-    ppr_info inst_info = pprInstInfo inst_info $$ 
-			 nest 4 (pprInstInfoDetails inst_info)
-	-- pprInstInfo doesn't print much: only the type
+      = vcat (map pprInstInfoDetails inst_infos) $$ ppr extra_binds
 
 -----------------------------------------
 deriveOrdinaryStuff []	-- Short cut

ghc/compiler/typecheck/TcEnv.lhs

@@ -572,8 +572,10 @@ data InstBindings
 
 pprInstInfo info = vcat [ptext SLIT("InstInfo:") <+> ppr (idType (iDFunId info))]
 
-pprInstInfoDetails (InstInfo { iBinds = VanillaInst b _ }) = ppr b
-pprInstInfoDetails (InstInfo { iBinds = NewTypeDerived _}) = text "Derived from the representation type"
+pprInstInfoDetails info = pprInstInfo info $$ nest 2 (details (iBinds info))
+  where
+    details (VanillaInst b _)  = ppr b
+    details (NewTypeDerived _) = text "Derived from the representation type"
 
 simpleInstInfoTy :: InstInfo -> Type
 simpleInstInfoTy info = case tcSplitDFunTy (idType (iDFunId info)) of

ghc/compiler/typecheck/TcHsType.lhs

@@ -43,9 +43,8 @@ import TcType		( Type, PredType(..), ThetaType, TyVarDetails(..),
 		 	  mkForAllTys, mkFunTys, tcEqType, isPredTy,
 			  mkSigmaTy, mkPredTy, mkGenTyConApp, mkTyConApp, mkAppTys, 
 			  liftedTypeKind, unliftedTypeKind, eqKind,
-			  tcSplitFunTy_maybe, tcSplitForAllTys, tcSplitSigmaTy
-			)
-import PprType		( pprKind, pprThetaArrow )
+			  tcSplitFunTy_maybe, tcSplitForAllTys, tcSplitSigmaTy, 
+			  pprKind, pprThetaArrow )
 import qualified Type	( splitFunTys )
 import Inst		( Inst, InstOrigin(..), newMethod, instToId )
 

ghc/compiler/typecheck/TcInstDcls.lhs

@@ -23,8 +23,7 @@ import TcMType		( tcInstType, checkValidTheta, checkValidInstHead, instTypeErr,
 			  checkAmbiguity, SourceTyCtxt(..) )
 import TcType		( mkClassPred, tcSplitForAllTys, tyVarsOfType,
 			  tcSplitSigmaTy, getClassPredTys, tcSplitPredTy_maybe, mkTyVarTys,
-			  TyVarDetails(..), tcSplitDFunTy
-			)
+			  TyVarDetails(..), tcSplitDFunTy, pprClassPred )
 import Inst		( InstOrigin(..), tcInstClassOp, newDicts, instToId, 
 			  showLIE, tcExtendLocalInstEnv )
 import TcDeriv		( tcDeriving )
@@ -32,7 +31,6 @@ import TcEnv		( tcExtendGlobalValEnv, tcExtendTyVarEnv2,
  			  InstInfo(..), InstBindings(..), 
 			  newDFunName, tcExtendLocalValEnv
 			)
-import PprType		( pprClassPred )
 import TcHsType		( kcHsSigType, tcHsKindedType )
 import TcUnify		( checkSigTyVars )
 import TcSimplify	( tcSimplifyCheck, tcSimplifyTop )