Trim unused imports detected by new unused-import code

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

diff --git a/compiler/types/Coercion.lhs b/compiler/types/Coercion.lhs
index eda45a3..b49b356 100644 (file)
--- a/compiler/types/Coercion.lhs
+++ b/compiler/types/Coercion.lhs
@@ -31,8 +31,8 @@ module Coercion (
        mkCoercion,
         mkSymCoercion, mkTransCoercion,
         mkLeftCoercion, mkRightCoercion, mkRightCoercions,
-       mkInstCoercion, mkAppCoercion,
-        mkForAllCoercion, mkFunCoercion, mkInstsCoercion, mkUnsafeCoercion,
+       mkInstCoercion, mkAppCoercion, mkTyConCoercion, mkFunCoercion,
+        mkForAllCoercion, mkInstsCoercion, mkUnsafeCoercion,
         mkNewTypeCoercion, mkFamInstCoercion, mkAppsCoercion,
 
         splitNewTypeRepCo_maybe, instNewTyCon_maybe, decomposeCo,
@@ -63,10 +63,8 @@ import TyCon
 import Class
 import Var
 import Name
-import OccName
 import PrelNames
 import Util
-import Unique
 import BasicTypes
 import Outputable
 import FastString
@@ -200,36 +198,40 @@ mkCoercion :: TyCon -> [Type] -> Coercion
 mkCoercion coCon args = ASSERT( tyConArity coCon == length args ) 
                         TyConApp coCon args
 
--- | Apply a 'Coercion' to another 'Coercion', which is presumably a 'Coercion' constructor of some
--- kind
+-- | Apply a 'Coercion' to another 'Coercion', which is presumably a
+-- 'Coercion' constructor of some kind
 mkAppCoercion :: Coercion -> Coercion -> Coercion
-mkAppCoercion    co1 co2 = mkAppTy co1 co2
+mkAppCoercion co1 co2 = mkAppTy co1 co2
 
 -- | Applies multiple 'Coercion's to another 'Coercion', from left to right.
 -- See also 'mkAppCoercion'
 mkAppsCoercion :: Coercion -> [Coercion] -> Coercion
-mkAppsCoercion   co1 tys = foldl mkAppTy co1 tys
+mkAppsCoercion co1 tys = foldl mkAppTy co1 tys
+
+-- | Apply a type constructor to a list of coercions.
+mkTyConCoercion :: TyCon -> [Coercion] -> Coercion
+mkTyConCoercion con cos = mkTyConApp con cos
+
+-- | Make a function 'Coercion' between two other 'Coercion's
+mkFunCoercion :: Coercion -> Coercion -> Coercion
+mkFunCoercion co1 co2 = mkFunTy co1 co2
 
 -- | Make a 'Coercion' which binds a variable within an inner 'Coercion'
 mkForAllCoercion :: Var -> Coercion -> Coercion
 -- note that a TyVar should be used here, not a CoVar (nor a TcTyVar)
 mkForAllCoercion tv  co  = ASSERT ( isTyVar tv ) mkForAllTy tv co
 
--- | Make a function 'Coercion' between two other 'Coercion's
-mkFunCoercion :: Coercion -> Coercion -> Coercion
-mkFunCoercion    co1 co2 = mkFunTy co1 co2
-
 
 -------------------------------
 
 mkSymCoercion :: Coercion -> Coercion
--- ^ Create a symmetric version of the given 'Coercion' that asserts equality between
--- the same types but in the other "direction", so a kind of @t1 ~ t2@ becomes the
--- kind @t2 ~ t1@.
+-- ^ Create a symmetric version of the given 'Coercion' that asserts equality
+-- between the same types but in the other "direction", so a kind of @t1 ~ t2@ 
+-- becomes the kind @t2 ~ t1@.
 --
--- This function attempts to simplify the generated 'Coercion' by removing redundant applications
--- of @sym@. This is done by pushing this new @sym@ down into the 'Coercion' and exploiting the fact that 
--- @sym (sym co) = co@.
+-- This function attempts to simplify the generated 'Coercion' by removing 
+-- redundant applications of @sym@. This is done by pushing this new @sym@ 
+-- down into the 'Coercion' and exploiting the fact that @sym (sym co) = co@.
 mkSymCoercion co      
   | Just co' <- coreView co = mkSymCoercion co'