X-Git-Url: http://git.megacz.com/?p=ghc-hetmet.git;a=blobdiff_plain;f=compiler%2Ftypecheck%2FTcArrows.lhs;h=0055d6453feb9f0f60fe7f8a2f8aca2cfae322ac;hp=57cb48c9e24b71b9be141d7de113a2b9f7ab4b7e;hb=6a05ec5ef5373f61b7f9f5bdc344483417fa801b;hpb=49c98d143c382a1341e1046f5ca00819a25691ba

diff --git a/compiler/typecheck/TcArrows.lhs b/compiler/typecheck/TcArrows.lhs
index 57cb48c..0055d64 100644
--- a/compiler/typecheck/TcArrows.lhs
+++ b/compiler/typecheck/TcArrows.lhs
@@ -5,6 +5,13 @@
 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"
@@ -24,6 +31,7 @@ import TcGadt
 import TcPat
 import TcUnify
 import TcRnMonad
+import Coercion
 import Inst
 import Name
 import TysWiredIn
@@ -45,16 +53,18 @@ import Util
 \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}
 
 
@@ -196,7 +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
@@ -238,7 +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
@@ -251,7 +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)
@@ -303,8 +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