Add tuple sections as a new feature

[ghc-hetmet.git] / compiler / deSugar / DsMeta.hs

diff --git a/compiler/deSugar/DsMeta.hs b/compiler/deSugar/DsMeta.hs
index 2de2cae..411da40 100644 (file)
--- a/compiler/deSugar/DsMeta.hs
+++ b/compiler/deSugar/DsMeta.hs
@@ -13,14 +13,6 @@
 -- a Royal Pain (triggers other recompilation).
 -----------------------------------------------------------------------------
 
-{-# OPTIONS -fno-warn-unused-imports #-}
--- The above warning supression flag is a temporary kludge.
--- While working on this module you are encouraged to remove it and fix
--- any warnings in the module. See
---     http://hackage.haskell.org/trac/ghc/wiki/Commentary/CodingStyle#Warnings
--- for details
--- The kludge is only needed in this module because of trac #2267.
-
 module DsMeta( dsBracket, 
               templateHaskellNames, qTyConName, nameTyConName,
               liftName, liftStringName, expQTyConName, patQTyConName, decQTyConName, typeQTyConName,
@@ -33,7 +25,6 @@ module DsMeta( dsBracket,
 import {-# SOURCE #-}  DsExpr ( dsExpr )
 
 import MatchLit
-import DsUtils
 import DsMonad
 
 import qualified Language.Haskell.TH as TH
@@ -372,14 +363,14 @@ ds_msg = ptext (sLit "Cannot desugar this Template Haskell declaration:")
 -------------------------------------------------------
 
 repC :: LConDecl Name -> DsM (Core TH.ConQ)
-repC (L _ (ConDecl con _ [] (L _ []) details ResTyH98 _))
+repC (L _ (ConDecl { con_name = con, con_qvars = [], con_cxt = L _ []
+                  , con_details = details, con_res = ResTyH98 }))
   = do { con1 <- lookupLOcc con        -- See note [Binders and occurrences] 
        ; repConstr con1 details 
        }
-repC (L loc (ConDecl con expl tvs (L cloc ctxt) details ResTyH98 doc))
+repC (L loc con_decl@(ConDecl { con_qvars = tvs, con_cxt = L cloc ctxt, con_res = ResTyH98 }))
   = addTyVarBinds tvs $ \bndrs -> 
-      do { c' <- repC (L loc (ConDecl con expl [] (L cloc []) details 
-                                      ResTyH98 doc))
+      do { c' <- repC (L loc (con_decl { con_qvars = [], con_cxt = L cloc [] }))
          ; ctxt' <- repContext ctxt
          ; bndrs' <- coreList tyVarBndrTyConName bndrs
          ; rep2 forallCName [unC bndrs', unC ctxt', unC c']
@@ -721,8 +712,10 @@ repE e@(HsDo _ _ _ _) = notHandled "mdo and [: :]" (ppr e)
 repE (ExplicitList _ es) = do { xs <- repLEs es; repListExp xs }
 repE e@(ExplicitPArr _ _) = notHandled "Parallel arrays" (ppr e)
 repE e@(ExplicitTuple es boxed) 
-  | isBoxed boxed         = do { xs <- repLEs es; repTup xs }
-  | otherwise            = notHandled "Unboxed tuples" (ppr e)
+  | not (isBoxed boxed)        = notHandled "Unboxed tuples" (ppr e)
+  | not (all tupArgPresent es) = notHandled "Tuple sections" (ppr e)
+  | otherwise                  = do { xs <- repLEs [e | Present e <- es]; repTup xs }
+
 repE (RecordCon c _ flds)
  = do { x <- lookupLOcc c;
         fs <- repFields flds;