[project @ 1997-07-26 03:40:25 by sof]

moved TcIdBndr and TcIdOcc to here from TcHsSyn

diff --git a/ghc/compiler/typecheck/TcType.lhs b/ghc/compiler/typecheck/TcType.lhs
index b6c2362..0af7c44 100644 (file)
--- a/ghc/compiler/typecheck/TcType.lhs
+++ b/ghc/compiler/typecheck/TcType.lhs
@@ -2,15 +2,15 @@
 #include "HsVersions.h"
 
 module TcType (
-
+  SYN_IE(TcIdBndr), TcIdOcc(..),
+       
+  -----------------------------------------
   SYN_IE(TcTyVar),
+  SYN_IE(TcTyVarSet),
   newTcTyVar,
   newTyVarTy,  -- Kind -> NF_TcM s (TcType s)
   newTyVarTys, -- Int -> Kind -> NF_TcM s [TcType s]
 
-
-  SYN_IE(TcTyVarSet),
-
   -----------------------------------------
   SYN_IE(TcType), TcMaybe(..),
   SYN_IE(TcTauType), SYN_IE(TcThetaType), SYN_IE(TcRhoType),
@@ -48,11 +48,12 @@ import TyVar        ( SYN_IE(TyVar), GenTyVar(..), SYN_IE(TyVarSet), SYN_IE(GenTyVarSet
                  nullTyVarEnv, mkTyVarEnv,
                  tyVarSetToList
                )
+import PprType ( GenType, GenTyVar )   -- Instances only
 
 -- others:
 import Class   ( GenClass, SYN_IE(Class) )
 import TyCon   ( isFunTyCon )
-import Id      ( idType, SYN_IE(Id) )
+import Id      ( idType, GenId, SYN_IE(Id) )
 import Kind    ( Kind )
 import TcKind  ( TcKind )
 import TcMonad
@@ -61,9 +62,11 @@ import Usage ( SYN_IE(Usage), GenUsage, SYN_IE(UVar), duffUsage )
 import TysPrim         ( voidTy )
 
 IMP_Ubiq()
+import Name            ( NamedThing(..) )
 import Unique          ( Unique )
 import UniqFM          ( UniqFM )
 import Maybes          ( assocMaybe )
+import Outputable      ( Outputable(..) )
 import Util            ( zipEqual, nOfThem, panic{-, pprPanic, pprTrace ToDo:rm-} )
 \end{code}
 
@@ -73,6 +76,26 @@ Data types
 ~~~~~~~~~~
 
 \begin{code}
+type TcIdBndr s = GenId  (TcType s)    -- Binders are all TcTypes
+data TcIdOcc  s = TcId   (TcIdBndr s)  -- Bindees may be either
+               | RealId Id
+
+instance Eq (TcIdOcc s) where
+  (TcId id1)   == (TcId id2)   = id1 == id2
+  (RealId id1) == (RealId id2) = id1 == id2
+  _           == _            = False
+
+instance Outputable (TcIdOcc s) where
+  ppr sty (TcId id)   = ppr sty id
+  ppr sty (RealId id) = ppr sty id
+
+instance NamedThing (TcIdOcc s) where
+  getName (TcId id)   = getName id
+  getName (RealId id) = getName id
+\end{code}
+
+
+\begin{code}
 type TcType s = GenType (TcTyVar s) UVar       -- Used during typechecker
        -- Invariant on ForAllTy in TcTypes:
        --      forall a. T
@@ -383,7 +406,7 @@ zonkTcTyVar :: TcTyVar s -> NF_TcM s (TcType s)
 zonkTcTyVar tyvar 
   = tcReadTyVar tyvar          `thenNF_Tc` \ maybe_ty ->
     case maybe_ty of
-       BoundTo ty@(TyVarTy tyvar') -> returnNF_Tc ty
+       BoundTo ty@(TyVarTy tyvar') -> returnNF_Tc ty           -- tcReadTyVar never returns a bound tyvar
        BoundTo other               -> zonkTcType other
        other                       -> returnNF_Tc (TyVarTy tyvar)