X-Git-Url: http://git.megacz.com/?p=ghc-hetmet.git;a=blobdiff_plain;f=compiler%2Ftypecheck%2FTcRules.lhs;h=a95251d1b40627c24aa6660f3068ecadae519ac6;hp=c7e951f343fa17a9d0e3de1bc9ae6fb87a9f2fca;hb=432b9c9322181a3644083e3c19b7e240d90659e7;hpb=5a8a219c131b56c75dbb3110da3ab5ae3715ff66

diff --git a/compiler/typecheck/TcRules.lhs b/compiler/typecheck/TcRules.lhs
index c7e951f..a95251d 100644
--- a/compiler/typecheck/TcRules.lhs
+++ b/compiler/typecheck/TcRules.lhs
@@ -1,49 +1,49 @@
 %
+% (c) The University of Glasgow 2006
 % (c) The AQUA Project, Glasgow University, 1993-1998
 %
-\section[TcRules]{Typechecking transformation rules}
+
+TcRules: Typechecking transformation rules
 
 \begin{code}
 module TcRules ( tcRules ) where
 
-#include "HsVersions.h"
-
-import HsSyn		( RuleDecl(..), LRuleDecl, RuleBndr(..), mkHsDictLet )
+import HsSyn
 import TcRnMonad
-import TcSimplify	( tcSimplifyRuleLhs, tcSimplifyInferCheck )
-import TcMType		( newFlexiTyVarTy, zonkQuantifiedTyVar, tcSkolSigTyVars )
-import TcType		( tyVarsOfTypes, openTypeKind, SkolemInfo(..), substTyWith, mkTyVarTys )
-import TcHsType		( UserTypeCtxt(..), tcHsPatSigType )
-import TcExpr		( tcMonoExpr )
-import TcEnv		( tcExtendIdEnv, tcExtendTyVarEnv )
-import Inst		( instToId )
-import Id		( idType, mkLocalId )
-import Name		( Name )
-import SrcLoc		( noLoc, unLoc )
+import TcSimplify
+import TcMType
+import TcType
+import TcHsType
+import TcExpr
+import TcEnv
+import Inst
+import Id
+import Name
+import SrcLoc
 import Outputable
+import FastString
 \end{code}
 
 \begin{code}
 tcRules :: [LRuleDecl Name] -> TcM [LRuleDecl TcId]
-tcRules decls = mappM (wrapLocM tcRule) decls
+tcRules decls = mapM (wrapLocM tcRule) decls
 
 tcRule :: RuleDecl Name -> TcM (RuleDecl TcId)
 tcRule (HsRule name act vars lhs fv_lhs rhs fv_rhs)
-  = addErrCtxt (ruleCtxt name)			$
-    traceTc (ptext SLIT("---- Rule ------")
-		 <+> ppr name)			`thenM_` 
-    newFlexiTyVarTy openTypeKind		`thenM` \ rule_ty ->
+  = addErrCtxt (ruleCtxt name)			$ do
+    traceTc (ptext (sLit "---- Rule ------") <+> ppr name)
+    rule_ty <- newFlexiTyVarTy openTypeKind
 
 	-- Deal with the tyvars mentioned in signatures
-    tcRuleBndrs vars (\ ids ->
+    (ids, lhs', rhs', lhs_lie, rhs_lie) <-
+      tcRuleBndrs vars $ \ ids -> do
 		-- Now LHS and RHS
-	getLIE (tcMonoExpr lhs rule_ty)	`thenM` \ (lhs', lhs_lie) ->
-	getLIE (tcMonoExpr rhs rule_ty)	`thenM` \ (rhs', rhs_lie) ->
-	returnM (ids, lhs', rhs', lhs_lie, rhs_lie)
-    )				`thenM` \ (ids, lhs', rhs', lhs_lie, rhs_lie) ->
+        (lhs', lhs_lie) <- getLIE (tcMonoExpr lhs rule_ty)
+        (rhs', rhs_lie) <- getLIE (tcMonoExpr rhs rule_ty)
+        return (ids, lhs', rhs', lhs_lie, rhs_lie)
 
 		-- Check that LHS has no overloading at all
-    tcSimplifyRuleLhs lhs_lie	`thenM` \ (lhs_dicts, lhs_binds) ->
+    (lhs_dicts, lhs_binds) <- tcSimplifyRuleLhs lhs_lie
 
 	-- Gather the template variables and tyvars
     let
@@ -70,24 +70,23 @@ tcRule (HsRule name act vars lhs fv_lhs rhs fv_rhs)
 	-- during zonking (see TcHsSyn.zonkRule)
 	--
 	forall_tvs = tyVarsOfTypes (rule_ty : map idType tpl_ids)
-    in
+
 	-- RHS can be a bit more lenient.  In particular,
 	-- we let constant dictionaries etc float outwards
 	--
 	-- NB: tcSimplifyInferCheck zonks the forall_tvs, and 
 	--     knocks out any that are constrained by the environment
-    tcSimplifyInferCheck (text "tcRule")
-			 forall_tvs
-			 lhs_dicts rhs_lie	`thenM` \ (forall_tvs1, rhs_binds) ->
-    mappM zonkQuantifiedTyVar forall_tvs1 	`thenM` \ forall_tvs2 ->
-	-- This zonk is exactly the same as the one in TcBinds.tcBindWithSigs
-
-    returnM (HsRule name act
-		    (map (RuleBndr . noLoc) (forall_tvs2 ++ tpl_ids))	-- yuk
+    loc <- getInstLoc (SigOrigin (RuleSkol name))
+    (forall_tvs1, rhs_binds) <- tcSimplifyInferCheck loc
+                                        forall_tvs
+                                        lhs_dicts rhs_lie
+
+    return (HsRule name act
+		    (map (RuleBndr . noLoc) (forall_tvs1 ++ tpl_ids))	-- yuk
 		    (mkHsDictLet lhs_binds lhs') fv_lhs
 		    (mkHsDictLet rhs_binds rhs') fv_rhs)
 
-
+tcRuleBndrs :: [RuleBndr Name] -> ([Id] -> TcM a) -> TcM a
 tcRuleBndrs [] thing_inside = thing_inside []
 tcRuleBndrs (RuleBndr var : vars) thing_inside
   = do 	{ ty <- newFlexiTyVarTy openTypeKind
@@ -98,7 +97,7 @@ tcRuleBndrs (RuleBndrSig var rn_ty : vars) thing_inside
 --  e.g 	x :: a->a
 --  The tyvar 'a' is brought into scope first, just as if you'd written
 --		a::*, x :: a->a
-  = do	{ let ctxt = RuleSigCtxt (unLoc var)
+  = do	{ let ctxt = FunSigCtxt (unLoc var)
 	; (tyvars, ty) <- tcHsPatSigType ctxt rn_ty
 	; let skol_tvs = tcSkolSigTyVars (SigSkol ctxt) tyvars
 	      id_ty = substTyWith tyvars (mkTyVarTys skol_tvs) ty
@@ -107,7 +106,8 @@ tcRuleBndrs (RuleBndrSig var rn_ty : vars) thing_inside
 	  tcExtendIdEnv [id] $
 	  tcRuleBndrs vars (\ids -> thing_inside (id:ids)) }
 
-ruleCtxt name = ptext SLIT("When checking the transformation rule") <+> 
+ruleCtxt :: FastString -> SDoc
+ruleCtxt name = ptext (sLit "When checking the transformation rule") <+> 
 		doubleQuotes (ftext name)
 \end{code}