X-Git-Url: http://git.megacz.com/?p=ghc-hetmet.git;a=blobdiff_plain;f=compiler%2Ftypecheck%2FTcArrows.lhs;h=227c6ce923abded27256a736230495ac740d7553;hp=9fede384a7d2108d15ac65a1a9f9f53c4c8e1821;hb=b10d7d079ec9c3fc22d4700fe484dd297bddb805;hpb=d436c70d43fb905c63220040168295e473f4b90a

diff --git a/compiler/typecheck/TcArrows.lhs b/compiler/typecheck/TcArrows.lhs
index 9fede38..227c6ce 100644
--- a/compiler/typecheck/TcArrows.lhs
+++ b/compiler/typecheck/TcArrows.lhs
@@ -10,14 +10,10 @@ module TcArrows ( tcProc ) where
 import {-# SOURCE #-}	TcExpr( tcMonoExpr, tcInferRho )
 
 import HsSyn
-import TcHsSyn
-
 import TcMatches
-
 import TcType
 import TcMType
 import TcBinds
-import TcSimplify
 import TcPat
 import TcUnify
 import TcRnMonad
@@ -44,19 +40,18 @@ import Control.Monad
 
 \begin{code}
 tcProc :: InPat Name -> LHsCmdTop Name		-- proc pat -> expr
-       -> BoxyRhoType				-- Expected type of whole proc expression
+       -> TcRhoType				-- Expected type of whole proc expression
        -> TcM (OutPat TcId, LHsCmdTop TcId, CoercionI)
 
 tcProc pat cmd exp_ty
   = newArrowScope $
-    do	{ ((exp_ty1, res_ty), coi) <- boxySplitAppTy exp_ty 
-	; ((arr_ty, arg_ty), coi1) <- boxySplitAppTy exp_ty1
+    do	{ (coi, (exp_ty1, res_ty)) <- matchExpectedAppTy exp_ty 
+	; (coi1, (arr_ty, arg_ty)) <- matchExpectedAppTy exp_ty1
 	; let cmd_env = CmdEnv { cmd_arr = arr_ty }
-	; (pat', cmd') <- tcPat ProcExpr pat arg_ty res_ty $
-			  tcCmdTop cmd_env cmd []
-        ; let res_coi = mkTransCoI coi (mkAppTyCoI exp_ty1 coi1 res_ty IdCo)
-	; return (pat', cmd', res_coi) 
-        }
+	; (pat', cmd') <- tcPat ProcExpr pat arg_ty $
+			  tcCmdTop cmd_env cmd [] res_ty
+        ; let res_coi = mkTransCoI coi (mkAppTyCoI coi1 (IdCo res_ty))
+	; return (pat', cmd', res_coi) }
 \end{code}
 
 
@@ -185,9 +180,9 @@ tc_cmd env cmd@(HsLam (MatchGroup [L mtch_loc (match@(Match pats _maybe_rhs_sig
 		  (kappaUnderflow cmd)
 
 		-- Check the patterns, and the GRHSs inside
-	; (pats', grhss') <- setSrcSpan mtch_loc			$
-			     tcPats LambdaExpr pats cmd_stk res_ty	$
-			     tc_grhss grhss
+	; (pats', grhss') <- setSrcSpan mtch_loc		$
+			     tcPats LambdaExpr pats cmd_stk	$
+			     tc_grhss grhss res_ty
 
 	; let match' = L mtch_loc (Match pats' Nothing grhss')
 	; return (HsLam (MatchGroup [match'] res_ty))
@@ -214,11 +209,10 @@ tc_cmd env cmd@(HsLam (MatchGroup [L mtch_loc (match@(Match pats _maybe_rhs_sig
 
 tc_cmd env cmd@(HsDo do_or_lc stmts body _ty) (cmd_stk, res_ty)
   = do 	{ checkTc (null cmd_stk) (nonEmptyCmdStkErr cmd)
-	; (stmts', body') <- tcStmts do_or_lc tc_stmt stmts res_ty $
+	; (stmts', body') <- tcStmts do_or_lc (tcMDoStmt tc_rhs) stmts res_ty $
 			     tcGuardedCmd env body []
 	; return (HsDo do_or_lc stmts' body' res_ty) }
   where
-    tc_stmt = tcMDoStmt tc_rhs
     tc_rhs rhs = do { ty <- newFlexiTyVarTy liftedTypeKind
 		    ; rhs' <- tcCmd env rhs ([], ty)
 		    ; return (rhs', ty) }
@@ -249,22 +243,15 @@ tc_cmd env cmd@(HsArrForm expr fixity cmd_args) (cmd_stk, res_ty)
 			      e_res_ty
 
 		-- Check expr
-	; (expr', lie) <- escapeArrowScope (getLIE (tcMonoExpr expr e_ty))
-	; loc <- getInstLoc (SigOrigin ArrowSkol)
-	; inst_binds <- tcSimplifyCheck loc [w_tv] [] lie
-
-		-- Check that the polymorphic variable hasn't been unified with anything
-		-- and is not free in res_ty or the cmd_stk  (i.e.  t, t1..tn)
-	; checkSigTyVarsWrt (tyVarsOfTypes (res_ty:cmd_stk)) [w_tv] 
+	; (inst_binds, expr') <- checkConstraints ArrowSkol [w_tv] [] $
+                                 escapeArrowScope (tcMonoExpr expr e_ty)
 
 		-- OK, now we are in a position to unscramble 
 		-- the s1..sm and check each cmd
 	; cmds' <- mapM (tc_cmd w_tv) cmds_w_tys
 
-	; return (HsArrForm (noLoc $ HsWrap (WpTyLam w_tv) 
-					       (unLoc $ mkHsDictLet inst_binds expr')) 
-			     fixity cmds')
-	}
+        ; let wrap = WpTyLam w_tv <.> mkWpLet inst_binds
+	; return (HsArrForm (mkLHsWrap wrap expr') fixity cmds') }
   where
  	-- Make the types	
 	--	b, ((e,s1) .. sm), s
@@ -294,14 +281,13 @@ tc_cmd env cmd@(HsArrForm expr fixity cmd_args) (cmd_stk, res_ty)
 
     unscramble :: TcType -> (TcType, [TcType])
     -- unscramble ((w,s1) .. sn)	=  (w, [s1..sn])
-    unscramble ty
+    unscramble ty = unscramble' ty []
+
+    unscramble' ty ss
        = case tcSplitTyConApp_maybe ty of
 	    Just (tc, [t,s]) | tc == pairTyCon 
-	       ->  let 
-		      (w,ss) = unscramble t  
-		   in (w, s:ss)
-				    
-	    _ -> (ty, [])
+	       ->  unscramble' t (s:ss)
+	    _ -> (ty, ss)
 
 -----------------------------------------------------------------
 --		Base case for illegal commands
@@ -342,15 +328,15 @@ cmdCtxt cmd = ptext (sLit "In the command:") <+> ppr cmd
 nonEmptyCmdStkErr :: HsExpr Name -> SDoc
 nonEmptyCmdStkErr cmd
   = hang (ptext (sLit "Non-empty command stack at command:"))
-	 4 (ppr cmd)
+       2 (ppr cmd)
 
 kappaUnderflow :: HsExpr Name -> SDoc
 kappaUnderflow cmd
   = hang (ptext (sLit "Command stack underflow at command:"))
-	 4 (ppr cmd)
+       2 (ppr cmd)
 
 badFormFun :: Int -> TcType -> SDoc
 badFormFun i tup_ty'
  = hang (ptext (sLit "The type of the") <+> speakNth i <+> ptext (sLit "argument of a command form has the wrong shape"))
-	4 (ptext (sLit "Argument type:") <+> ppr tup_ty')
+      2 (ptext (sLit "Argument type:") <+> ppr tup_ty')
 \end{code}