X-Git-Url: http://git.megacz.com/?p=ghc-hetmet.git;a=blobdiff_plain;f=compiler%2Ftypecheck%2FTcArrows.lhs;h=0055d6453feb9f0f60fe7f8a2f8aca2cfae322ac;hp=2316162c18a5b6193bfcf01846d1940a8b95a621;hb=6a05ec5ef5373f61b7f9f5bdc344483417fa801b;hpb=15cb792d18b1094e98c035dca6ecec5dad516056

diff --git a/compiler/typecheck/TcArrows.lhs b/compiler/typecheck/TcArrows.lhs
index 2316162..0055d64 100644
--- a/compiler/typecheck/TcArrows.lhs
+++ b/compiler/typecheck/TcArrows.lhs
@@ -1,9 +1,17 @@
 %
+% (c) The University of Glasgow 2006
 % (c) The GRASP/AQUA Project, Glasgow University, 1992-1998
 %
-\section{Typecheck arrow notation}
+Typecheck arrow notation
 
 \begin{code}
+{-# OPTIONS -w #-}
+-- 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
+
 module TcArrows ( tcProc ) where
 
 #include "HsVersions.h"
@@ -11,32 +19,29 @@ module TcArrows ( tcProc ) where
 import {-# SOURCE #-}	TcExpr( tcMonoExpr, tcInferRho )
 
 import HsSyn
-import TcHsSyn	(  mkHsDictLet )
-
-import TcMatches ( matchCtxt, tcStmts, tcMDoStmt, tcGuardStmt,
-		   TcMatchCtxt(..), tcMatchesCase )
-
-import TcType	( TcType, TcTauType, BoxyRhoType, mkFunTys, mkTyConApp,
-		  mkTyVarTy, mkAppTys, tcSplitTyConApp_maybe, tcEqType, 
-		  SkolemInfo(..) )
-import TcMType	( newFlexiTyVarTy, tcInstSkolTyVars, zonkTcType )
-import TcBinds	( tcLocalBinds )
-import TcSimplify ( tcSimplifyCheck )
-import TcGadt	( Refinement, emptyRefinement, refineResType )
-import TcPat	( tcLamPat, tcLamPats )
-import TcUnify	( checkSigTyVarsWrt, boxySplitAppTy )
+import TcHsSyn
+
+import TcMatches
+
+import TcType
+import TcMType
+import TcBinds
+import TcSimplify
+import TcGadt
+import TcPat
+import TcUnify
 import TcRnMonad
-import Inst	( tcSyntaxName )
-import Name	( Name )
-import TysWiredIn ( boolTy, pairTyCon )
+import Coercion
+import Inst
+import Name
+import TysWiredIn
 import VarSet 
-import TysPrim	( alphaTyVar )
-import Type	( Kind, mkArrowKinds, liftedTypeKind, openTypeKind, tyVarsOfTypes )
+import TysPrim
+import Type
 
-import SrcLoc	( Located(..), noLoc, unLoc )
+import SrcLoc
 import Outputable
-import Util	( lengthAtLeast )
-
+import Util
 \end{code}
 
 %************************************************************************
@@ -48,16 +53,18 @@ import Util	( lengthAtLeast )
 \begin{code}
 tcProc :: InPat Name -> LHsCmdTop Name		-- proc pat -> expr
        -> BoxyRhoType				-- Expected type of whole proc expression
-       -> TcM (OutPat TcId, LHsCmdTop TcId)
+       -> TcM (OutPat TcId, LHsCmdTop TcId, CoercionI)
 
 tcProc pat cmd exp_ty
   = newArrowScope $
-    do	{ (exp_ty1, res_ty) <- boxySplitAppTy exp_ty 
-	; (arr_ty, arg_ty)  <- boxySplitAppTy exp_ty1
+    do	{ ((exp_ty1, res_ty), coi) <- boxySplitAppTy exp_ty 
+	; ((arr_ty, arg_ty), coi1) <- boxySplitAppTy exp_ty1
 	; let cmd_env = CmdEnv { cmd_arr = arr_ty }
 	; (pat', cmd') <- tcLamPat pat arg_ty (emptyRefinement, res_ty) $
 			  tcCmdTop cmd_env cmd []
-	; return (pat', cmd') }
+        ; let res_coi = mkTransCoI coi (mkAppTyCoI exp_ty1 coi1 res_ty IdCo)
+	; return (pat', cmd', res_coi) 
+        }
 \end{code}
 
 
@@ -101,7 +108,7 @@ tcGuardedCmd :: CmdEnv -> LHsExpr Name -> CmdStack
 tcGuardedCmd env expr stk (reft, res_ty)
   = do	{ let (co, res_ty') = refineResType reft res_ty
     	; body <- tcCmd env expr (stk, res_ty')
-	; return (mkLHsCoerce co body) }
+	; return (mkLHsWrap co body) }
 
 tcCmd :: CmdEnv -> LHsExpr Name -> (CmdStack, TcTauType) -> TcM (LHsExpr TcId)
 	-- The main recursive function
@@ -199,7 +206,7 @@ tc_cmd env cmd@(HsLam (MatchGroup [L mtch_loc (match@(Match pats maybe_rhs_sig g
   where
     n_pats     = length pats
     stk'       = drop n_pats cmd_stk
-    match_ctxt = LambdaExpr 	-- Maybe KappaExpr?
+    match_ctxt = (LambdaExpr :: HsMatchContext Name)	-- Maybe KappaExpr?
     pg_ctxt    = PatGuard match_ctxt
 
     tc_grhss (GRHSs grhss binds) res_ty
@@ -241,7 +248,7 @@ tc_cmd env cmd@(HsArrForm expr fixity cmd_args) (cmd_stk, res_ty)
   = addErrCtxt (cmdCtxt cmd)	$
     do	{ cmds_w_tys <- zipWithM new_cmd_ty cmd_args [1..]
 	; span       <- getSrcSpanM
-	; [w_tv]     <- tcInstSkolTyVars (ArrowSkol span) [alphaTyVar]
+	; [w_tv]     <- tcInstSkolTyVars ArrowSkol [alphaTyVar]
 	; let w_ty = mkTyVarTy w_tv 	-- Just a convenient starting point
 
 		--  a ((w,t1) .. tn) t
@@ -254,7 +261,8 @@ tc_cmd env cmd@(HsArrForm expr fixity cmd_args) (cmd_stk, res_ty)
 
 		-- Check expr
 	; (expr', lie) <- escapeArrowScope (getLIE (tcMonoExpr expr e_ty))
-	; inst_binds <- tcSimplifyCheck sig_msg [w_tv] [] lie
+	; 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)
@@ -264,7 +272,7 @@ tc_cmd env cmd@(HsArrForm expr fixity cmd_args) (cmd_stk, res_ty)
 		-- the s1..sm and check each cmd
 	; cmds' <- mapM (tc_cmd w_tv) cmds_w_tys
 
-	; returnM (HsArrForm (noLoc $ HsCoerce (CoTyLam w_tv) 
+	; returnM (HsArrForm (noLoc $ HsWrap (WpTyLam w_tv) 
 					       (unLoc $ mkHsDictLet inst_binds expr')) 
 			     fixity cmds')
 	}
@@ -306,8 +314,6 @@ tc_cmd env cmd@(HsArrForm expr fixity cmd_args) (cmd_stk, res_ty)
 				    
 	    other -> (ty, [])
 
-    sig_msg  = ptext SLIT("expected type of a command form")
-
 -----------------------------------------------------------------
 --		Base case for illegal commands
 -- This is where expressions that aren't commands get rejected