Tidy up the treatment of newtypes, refactor, and fix Trac #736

[ghc-hetmet.git] / compiler / coreSyn / CoreUtils.lhs

diff --git a/compiler/coreSyn/CoreUtils.lhs b/compiler/coreSyn/CoreUtils.lhs
index d08a6c9..cb6770e 100644 (file)
--- a/compiler/coreSyn/CoreUtils.lhs
+++ b/compiler/coreSyn/CoreUtils.lhs
@@ -8,7 +8,7 @@ Utility functions on @Core@ syntax
 \begin{code}
 module CoreUtils (
        -- Construction
-       mkInlineMe, mkSCC, mkCoerce, 
+       mkInlineMe, mkSCC, mkCoerce, mkCoerceI,
        bindNonRec, needsCaseBinding,
        mkIfThenElse, mkAltExpr, mkPiType, mkPiTypes,
 
@@ -194,6 +194,10 @@ mkInlineMe e          = Note InlineMe e
 
 
 \begin{code}
+mkCoerceI :: CoercionI -> CoreExpr -> CoreExpr
+mkCoerceI IdCo e = e
+mkCoerceI (ACo co) e = mkCoerce co e
+
 mkCoerce :: Coercion -> CoreExpr -> CoreExpr
 mkCoerce co (Cast expr co2)
   = ASSERT(let { (from_ty, _to_ty) = coercionKind co; 
@@ -1159,8 +1163,8 @@ eta_expand n us expr ty
                --      coerce T (\x::[T] -> (coerce ([T]->Int) e) x)
 
        case splitNewTypeRepCo_maybe ty of {
-         Just(ty1,co) -> 
-              mkCoerce (mkSymCoercion co) (eta_expand n us (mkCoerce co expr) ty1) ;
+         Just(ty1,co) -> mkCoerce (mkSymCoercion co) 
+                                  (eta_expand n us (mkCoerce co expr) ty1) ;
          Nothing  -> 
 
        -- We have an expression of arity > 0, but its type isn't a function