Add a type synonym for FamInstEnvs

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

diff --git a/compiler/types/Coercion.lhs b/compiler/types/Coercion.lhs
index ca1b1a6..e17d0b0 100644 (file)
--- a/compiler/types/Coercion.lhs
+++ b/compiler/types/Coercion.lhs
@@ -1,5 +1,8 @@
+%
+% (c) The University of Glasgow 2006
+%

 
 

- Module for type coercions, as in System FC.
+Module for type coercions, as in System FC.

 
 Coercions are represented as types, and their kinds tell what types the 
 coercion works on. 
 
 Coercions are represented as types, and their kinds tell what types the 
 coercion works on. 

@@ -34,29 +37,18 @@ module Coercion (
 #include "HsVersions.h"
 
 import TypeRep
 #include "HsVersions.h"
 
 import TypeRep

-import Type      ( Type, Kind, PredType, substTyWith, mkAppTy, mkForAllTy,
-                    mkFunTy, splitAppTy_maybe, splitForAllTy_maybe, coreView,
-                    kindView, mkTyConApp, isCoercionKind, isEqPred, mkAppTys,
-                    coreEqType, splitAppTys, isTyVarTy, splitTyConApp_maybe
-                  )
-import TyCon      ( TyCon, tyConArity, mkCoercionTyCon, isClosedNewTyCon,
-                    newTyConRhs, newTyConCo_maybe, 
-                    isCoercionTyCon, isCoercionTyCon_maybe )
-import Var       ( Var, TyVar, isTyVar, tyVarKind )
-import Name       ( BuiltInSyntax(..), Name, mkWiredInName, tcName )
-import OccName    ( mkOccNameFS )
-import PrelNames  ( symCoercionTyConKey, 
-                    transCoercionTyConKey, leftCoercionTyConKey,
-                    rightCoercionTyConKey, instCoercionTyConKey, 
-                    unsafeCoercionTyConKey, gHC_PRIM
-                  )
-import Util       ( lengthIs, snocView )
-import Unique     ( hasKey )
-import BasicTypes ( Arity )
+import Type
+import TyCon
+import Var
+import Name
+import OccName
+import PrelNames
+import Util
+import Unique
+import BasicTypes

 import Outputable
 
 
 import Outputable
 
 

-

 ------------------------------
 decomposeCo :: Arity -> Coercion -> [Coercion]
 -- (decomposeCo 3 c) = [right (left (left c)), right (left c), right c]
 ------------------------------
 decomposeCo :: Arity -> Coercion -> [Coercion]
 -- (decomposeCo 3 c) = [right (left (left c)), right (left c), right c]

@@ -99,9 +91,6 @@ splitCoercionKind_maybe co | Just co' <- kindView co = splitCoercionKind_maybe c
 splitCoercionKind_maybe (PredTy (EqPred ty1 ty2)) = Just (ty1, ty2)
 splitCoercionKind_maybe other = Nothing
 
 splitCoercionKind_maybe (PredTy (EqPred ty1 ty2)) = Just (ty1, ty2)
 splitCoercionKind_maybe other = Nothing
 

-isCoVar :: Var -> Bool
-isCoVar tv = isTyVar tv && isCoercionKind (tyVarKind tv)
-

 type Coercion     = Type
 type CoercionKind = Kind       -- A CoercionKind is always of form (ty1 :=: ty2)
 
 type Coercion     = Type
 type CoercionKind = Kind       -- A CoercionKind is always of form (ty1 :=: ty2)