X-Git-Url: http://git.megacz.com/?a=blobdiff_plain;f=compiler%2Ftypecheck%2FTcPat.lhs;h=8c73fa9708cfa736517929799a95fc38a3e818d6;hb=f04dead93a15af1cb818172f207b8a81d2c81298;hp=82ac5e3596a53c1558c6800ed3f58f2b7b09a5fd;hpb=d95190caa3e09b33bca8544051043954ebd89c73;p=ghc-hetmet.git

diff --git a/compiler/typecheck/TcPat.lhs b/compiler/typecheck/TcPat.lhs
index 82ac5e3..8c73fa9 100644
--- a/compiler/typecheck/TcPat.lhs
+++ b/compiler/typecheck/TcPat.lhs
@@ -30,7 +30,6 @@ import VarSet
 import TcUnify
 import TcHsType
 import TysWiredIn
-import Type
 import Coercion
 import StaticFlags
 import TyCon
@@ -41,10 +40,9 @@ import DynFlags	( DynFlag( Opt_GADTs ) )
 import SrcLoc
 import ErrUtils
 import Util
-import Maybes
 import Outputable
 import FastString
-import Monad
+import Control.Monad
 \end{code}
 
 
@@ -181,7 +179,7 @@ tcPatBndr :: PatState -> Name -> BoxySigmaType -> TcM TcId
 tcPatBndr (PS { pat_ctxt = LetPat lookup_sig }) bndr_name pat_ty
   | Just mono_ty <- lookup_sig bndr_name
   = do	{ mono_name <- newLocalName bndr_name
-	; boxyUnify mono_ty pat_ty
+	; _ <- boxyUnify mono_ty pat_ty
 	; return (Id.mkLocalId mono_name mono_ty) }
 
   | otherwise
@@ -238,7 +236,7 @@ unBoxArgType ty pp_this
 		return ty'
 	  else do 	-- OpenTypeKind, so constrain it
 	{ ty2 <- newFlexiTyVarTy argTypeKind
-	; unifyType ty' ty2
+	; _ <- unifyType ty' ty2
 	; return ty' }}
   where
     msg = pp_this <+> ptext (sLit "cannot be bound to an unboxed tuple")
@@ -365,12 +363,15 @@ tc_pat pstate lpat@(LazyPat pat) pat_ty thing_inside
 	-- getLIE/extendLIEs: see Note [Hopping the LIE in lazy patterns]
 
 	-- Check no existentials
-	; if (null pat_tvs) then return ()
-	  else lazyPatErr lpat pat_tvs
+	; unless (null pat_tvs) $ lazyPatErr lpat pat_tvs
+
+	-- Check there are no unlifted types under the lazy pattern
+	; when (any (isUnLiftedType . idType) $ collectPatBinders pat') $
+               lazyUnliftedPatErr lpat
 
 	-- Check that the pattern has a lifted type
 	; pat_tv <- newBoxyTyVar liftedTypeKind
-	; boxyUnify pat_ty (mkTyVarTy pat_tv)
+	; _ <- boxyUnify pat_ty (mkTyVarTy pat_tv)
 
 	; return (LazyPat pat', [], res) }
 
@@ -627,7 +628,7 @@ tcConPat pstate con_span data_con tycon pat_ty arg_pats thing_inside
                                                    unwrap_ty res_pat
 
 	  -- Add the stupid theta
-	; addDataConStupidTheta data_con ctxt_res_tys
+	; setSrcSpan con_span $ addDataConStupidTheta data_con ctxt_res_tys
 
 	; ex_tvs' <- tcInstSkolTyVars skol_info ex_tvs	
                      -- Get location from monad, not from ex_tvs
@@ -1040,6 +1041,12 @@ lazyPatErr _ tvs
     hang (ptext (sLit "A lazy (~) pattern cannot match existential or GADT data constructors"))
        2 (vcat (map pprSkolTvBinding tvs))
 
+lazyUnliftedPatErr :: OutputableBndr name => Pat name -> TcM ()
+lazyUnliftedPatErr pat
+  = failWithTc $
+    hang (ptext (sLit "A lazy (~) pattern cannot contain unlifted types"))
+       2 (ppr pat)
+
 nonRigidMatch :: PatCtxt -> DataCon -> SDoc
 nonRigidMatch ctxt con
   =  hang (ptext (sLit "GADT pattern match in non-rigid context for") <+> quotes (ppr con))