X-Git-Url: http://git.megacz.com/?a=blobdiff_plain;f=ghc%2Fcompiler%2Ftypecheck%2FTcExpr.lhs;h=c5d9e36c24012b900af6bd1f236a24f98468037e;hb=ca5a4a480d10d61e5b7a52eb4d556e8b8c33e69d;hp=6b2bec7a860b4a93e7221ef31c65926b9b2ed006;hpb=a77abe6a30ea2763cfa1c0ca83cdce9b7200ced2;p=ghc-hetmet.git

diff --git a/ghc/compiler/typecheck/TcExpr.lhs b/ghc/compiler/typecheck/TcExpr.lhs
index 6b2bec7..c5d9e36 100644
--- a/ghc/compiler/typecheck/TcExpr.lhs
+++ b/ghc/compiler/typecheck/TcExpr.lhs
@@ -24,7 +24,7 @@ import TcHsSyn		( TcExpr(..), TcQual(..), TcStmt(..),
 			  mkHsTyApp
 			)
 
-import TcMonad
+import TcMonad		hiding ( rnMtoTcM )
 import Inst		( Inst, InstOrigin(..), OverloadedLit(..),
 			  LIE(..), emptyLIE, plusLIE, plusLIEs, newOverloadedLit,
 			  newMethod, newMethodWithGivenTy, newDicts )
@@ -361,7 +361,7 @@ tcExpr (ExplicitTuple exprs)
 tcExpr (RecordCon (HsVar con) rbinds)
   = tcId con				`thenNF_Tc` \ (con_expr, con_lie, con_tau) ->
     let
-	(_, record_ty)       = splitFunTy con_tau
+	(_, record_ty) = splitFunTy con_tau
     in
 	-- Con is syntactically constrained to be a data constructor
     ASSERT( maybeToBool (maybeAppDataTyCon record_ty ) )
@@ -708,6 +708,12 @@ tcListComp expr (qual@(GeneratorQual pat rhs) : quals)
       tcAddErrCtxt (qualCtxt qual) (
         tcPat pat				`thenTc` \ (pat',  lie_pat,  pat_ty)  ->
         tcExpr rhs				`thenTc` \ (rhs', lie_rhs, rhs_ty) ->
+		-- NB: the environment has been extended with the new binders
+		-- which the rhs can't "see", but the renamer should have made
+		-- sure that everything is distinct by now, so there's no problem.
+		-- Putting the tcExpr before the newMonoIds messes up the nesting
+		-- of error contexts, so I didn't  bother
+
         unifyTauTy (mkListTy pat_ty) rhs_ty	`thenTc_`
 	returnTc (GeneratorQual pat' rhs', 
 		  lie_pat `plusLIE` lie_rhs)