[project @ 2000-10-31 12:07:43 by simonpj]

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

diff --git a/ghc/compiler/types/PprType.lhs b/ghc/compiler/types/PprType.lhs
index 24294ba..637ea1f 100644 (file)
--- a/ghc/compiler/types/PprType.lhs
+++ b/ghc/compiler/types/PprType.lhs
@@ -25,26 +25,22 @@ import Type         ( PredType(..), ThetaType,
                          splitPredTy_maybe,
                          splitForAllTys, splitSigmaTy, splitRhoTy,
                          isDictTy, splitTyConApp_maybe, splitFunTy_maybe,
-                          splitUsForAllTys
+                          splitUsForAllTys, predRepTy
                        )
-import Var             ( TyVar, tyVarKind,
-                         tyVarName, setTyVarName
-                       )
-import VarEnv
+import Var             ( TyVar, tyVarKind )
 import TyCon           ( TyCon, isPrimTyCon, isTupleTyCon, isUnboxedTupleTyCon, 
                          maybeTyConSingleCon, isEnumerationTyCon, 
-                         tyConArity, tyConUnique
+                         tyConArity
                        )
-import Class           ( Class, className )
+import Class           ( Class )
 
 -- others:
 import Maybes          ( maybeToBool )
-import Name            ( getOccString, NamedThing(..) )
+import Name            ( getOccString, getOccName )
 import Outputable
 import PprEnv
 import Unique          ( Uniquable(..) )
-import Unique          -- quite a few *Keys
-import Util
+import PrelNames               -- quite a few *Keys
 \end{code}
 
 %************************************************************************
@@ -69,16 +65,20 @@ pprParendKind = pprParendType
 
 pprPred :: PredType -> SDoc
 pprPred (Class clas tys) = pprConstraint clas tys
-pprPred (IParam n ty)    = ppr n <+> ppr ty
+pprPred (IParam n ty)    = hsep [ptext SLIT("?") <> ppr n,
+                                ptext SLIT("::"), ppr ty]
 
 pprConstraint :: Class -> [Type] -> SDoc
-pprConstraint clas tys = ppr clas <+> hsep (map (pprParendType) tys)
+pprConstraint clas tys = ppr clas <+> hsep (map pprParendType tys)
 
 pprTheta :: ThetaType -> SDoc
 pprTheta theta = parens (hsep (punctuate comma (map pprPred theta)))
 
 instance Outputable Type where
     ppr ty = pprType ty
+
+instance Outputable PredType where
+    ppr = pprPred
 \end{code}
 
 
@@ -116,16 +116,15 @@ ppr_ty env ctxt_prec (TyVarTy tyvar)
 
 ppr_ty env ctxt_prec ty@(TyConApp tycon tys)
        -- KIND CASE; it's of the form (Type x)
-  | tycon_uniq == typeConKey && n_tys == 1
+  | tycon `hasKey` typeConKey && n_tys == 1
   =    -- For kinds, print (Type x) as just x if x is a 
        --      type constructor (must be Boxed, Unboxed, AnyBox)
        -- Otherwise print as (Type x)
     case ty1 of
-       TyConApp bx [] -> ppr bx
+       TyConApp bx [] -> ppr (getOccName bx)   -- Always unqualified
        other          -> maybeParen ctxt_prec tYCON_PREC 
                                     (sep [ppr tycon, nest 4 tys_w_spaces])
                       
-       
        -- TUPLE CASE (boxed and unboxed)
   |  isTupleTyCon tycon
   && length tys == tyConArity tycon    -- no magic if partially applied
@@ -136,7 +135,7 @@ ppr_ty env ctxt_prec ty@(TyConApp tycon tys)
   = parens (char '#' <+> tys_w_commas <+> char '#')
 
        -- LIST CASE
-  | tycon_uniq == listTyConKey && n_tys == 1
+  | tycon `hasKey` listTyConKey && n_tys == 1
   = brackets (ppr_ty env tOP_PREC ty1)
 
        -- DICTIONARY CASE, prints {C a}
@@ -154,7 +153,6 @@ ppr_ty env ctxt_prec ty@(TyConApp tycon tys)
   = maybeParen ctxt_prec tYCON_PREC (sep [ppr tycon, nest 4 tys_w_spaces])
 
   where
-    tycon_uniq = tyConUnique tycon
     n_tys      = length tys
     (ty1:_)    = tys
     Just pred  = maybe_pred
@@ -167,30 +165,20 @@ ppr_ty env ctxt_prec ty@(TyConApp tycon tys)
 ppr_ty env ctxt_prec ty@(ForAllTy _ _)
   = getPprStyle $ \ sty -> 
     maybeParen ctxt_prec fUN_PREC $
-    if ifaceStyle sty then
-       sep [ ptext SLIT("__forall") <+> brackets pp_tyvars <+> ptext SLIT("=>"), 
-            ppr_ty env tOP_PREC rho
-          ]
-    else
-       -- The type checker occasionally prints a type in an error message,
-       -- and it had better come out looking like a user type
-       sep [ ptext SLIT("forall") <+> pp_tyvars <> ptext SLIT("."), 
-            ppr_theta theta,
-            ppr_ty env tOP_PREC tau
-          ]
-  where                
+    sep [ ptext SLIT("forall") <+> pp_tyvars <> ptext SLIT("."), 
+         ppr_theta theta,
+         ppr_ty env tOP_PREC tau
+    ]
+ where         
     (tyvars, rho) = splitForAllTys ty  -- don't treat theta specially any more (KSW 1999-04)
     (theta, tau)  = splitRhoTy rho
     
     pp_tyvars = hsep (map (pBndr env LambdaBind) tyvars)
     
     ppr_theta []       = empty
-    ppr_theta theta     = parens (hsep (punctuate comma (map ppr_pred theta))) 
+    ppr_theta theta     = parens (hsep (punctuate comma (map (ppr_pred env) theta))) 
                          <+> ptext SLIT("=>")
 
-    ppr_pred (Class clas tys) = ppr clas <+> hsep (map (ppr_ty env tYCON_PREC) tys)
-    ppr_pred (IParam n ty)    = hsep [char '?' <> ppr n, text "::",
-                                     ppr_ty env tYCON_PREC ty]
 
 ppr_ty env ctxt_prec (FunTy ty1 ty2)
   = maybeParen ctxt_prec fUN_PREC (sep (ppr_ty env fUN_PREC ty1 : pp_rest ty2))
@@ -224,25 +212,16 @@ ppr_ty env ctxt_prec (NoteTy (UsgNote u) ty)
   = maybeParen ctxt_prec tYCON_PREC $
     ptext SLIT("__u") <+> ppr u <+> ppr_ty env tYCON_PREC ty
 
-ppr_ty env ctxt_prec (NoteTy (IPNote nm) ty)
-  = braces (ppr_pred env (IParam nm ty))
-
-ppr_theta env []    = empty
-ppr_theta env theta = braces (hsep (punctuate comma (map (ppr_pred env) theta)))
+ppr_ty env ctxt_prec (PredTy p) = braces (ppr_pred env p)
 
 ppr_pred env (Class clas tys) = ppr clas <+>
                                hsep (map (ppr_ty env tYCON_PREC) tys)
 ppr_pred env (IParam n ty)    = hsep [char '?' <> ppr n, text "::",
                                      ppr_ty env tYCON_PREC ty]
-
-{-
-ppr_dict env ctxt (clas, tys) = ppr clas <+> 
-                               hsep (map (ppr_ty env tYCON_PREC) tys)
--}
 \end{code}
 
 \begin{code}
-pprTyEnv = initPprEnv b b (Just ppr) b (Just (\site -> pprTyVarBndr)) b
+pprTyEnv = initPprEnv b (Just ppr) b (Just (\site -> pprTyVarBndr)) b
   where
     b = panic "PprType:init_ppr_env"
 \end{code}
@@ -267,7 +246,7 @@ and when in debug mode.
 \begin{code}
 pprTyVarBndr tyvar
   = getPprStyle $ \ sty ->
-    if (ifaceStyle sty || debugStyle sty) && kind /= boxedTypeKind then
+    if (ifaceStyle sty  && kind /= boxedTypeKind) || debugStyle sty then
         hsep [ppr tyvar, dcolon, pprParendKind kind]
                -- See comments with ppDcolon in PprCore.lhs
     else
@@ -301,6 +280,7 @@ getTyDescription ty
       NoteTy (FTVNote _) ty  -> getTyDescription ty
       NoteTy (SynNote ty1) _ -> getTyDescription ty1
       NoteTy (UsgNote _) ty  -> getTyDescription ty
+      PredTy p              -> getTyDescription (predRepTy p)
       ForAllTy _ ty    -> getTyDescription ty
     }
   where