X-Git-Url: http://git.megacz.com/?a=blobdiff_plain;f=ghc%2Fcompiler%2Ftypecheck%2FTcRules.lhs;h=b14c2c94499f7feef61035c2168846aa47d04352;hb=50bc39808cd5b483a048a4d387f937963bd0e00f;hp=0367f69689c6a6bc3d64ad5be843fdeddb6ebbb0;hpb=05afb7485eea44d6410139f8a20c94b6f66c46f2;p=ghc-hetmet.git

diff --git a/ghc/compiler/typecheck/TcRules.lhs b/ghc/compiler/typecheck/TcRules.lhs
index 0367f69..b14c2c9 100644
--- a/ghc/compiler/typecheck/TcRules.lhs
+++ b/ghc/compiler/typecheck/TcRules.lhs
@@ -8,64 +8,37 @@ module TcRules ( tcRules ) where
 
 #include "HsVersions.h"
 
-import HsSyn		( RuleDecl(..), RuleBndr(..), collectRuleBndrSigTys )
-import CoreSyn		( CoreRule(..) )
-import RnHsSyn		( RenamedRuleDecl )
-import TcHsSyn		( TypecheckedRuleDecl, mkHsLet )
+import HsSyn		( RuleDecl(..), LRuleDecl, RuleBndr(..), mkHsDictLet )
 import TcRnMonad
 import TcSimplify	( tcSimplifyToDicts, tcSimplifyInferCheck )
-import TcMType		( newTyVarTy )
-import TcType		( tyVarsOfTypes, openTypeKind )
-import TcIfaceSig	( tcCoreExpr, tcCoreLamBndrs )
-import TcMonoType	( tcHsSigType, UserTypeCtxt(..), tcAddScopedTyVars )
-import TcExpr		( tcCheckRho )
-import TcEnv		( tcExtendLocalValEnv, tcLookupGlobalId, tcLookupId )
+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 Outputable
 \end{code}
 
 \begin{code}
-tcRules :: [RenamedRuleDecl] -> TcM [TypecheckedRuleDecl]
-tcRules decls = mappM tcRule decls
-
-tcRule :: RenamedRuleDecl -> TcM TypecheckedRuleDecl
-tcRule (IfaceRule name act vars fun args rhs src_loc)
-  = addSrcLoc src_loc 		$
-    addErrCtxt (ruleCtxt name)	$
-    tcLookupGlobalId fun		`thenM` \ fun' ->
-    tcCoreLamBndrs vars			$ \ vars' ->
-    mappM tcCoreExpr args		`thenM` \ args' ->
-    tcCoreExpr rhs			`thenM` \ rhs' ->
-    returnM (IfaceRuleOut fun' (Rule name act vars' args' rhs'))
-
-tcRule (IfaceRuleOut fun rule)	-- Built-in rules, and only built-in rules, 
-				-- come this way.  Usually IfaceRuleOut is only
-				-- used for the *output* of the type checker
-  = tcLookupId fun		`thenM` \ fun' ->
-	-- NB: tcLookupId, not tcLookupGlobalId
-	-- Reason: when compiling GHC.Base, where eqString is defined,
-	--	   we'll get the builtin rule for eqString, but eqString
-	--	   will be in the *local* type environment.
-	-- Seems like a bit of a hack
-    returnM (IfaceRuleOut fun' rule)   
-
-tcRule (HsRule name act vars lhs rhs src_loc)
-  = addSrcLoc src_loc 				$
-    addErrCtxt (ruleCtxt name)			$
-    newTyVarTy openTypeKind				`thenM` \ rule_ty ->
+tcRules :: [LRuleDecl Name] -> TcM [LRuleDecl TcId]
+tcRules decls = mappM (wrapLocM tcRule) decls
 
-	-- Deal with the tyvars mentioned in signatures
-    tcAddScopedTyVars (collectRuleBndrSigTys vars) (
+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 ->
 
-		-- Ditto forall'd variables
-	mappM new_id vars			`thenM` \ ids ->
-	tcExtendLocalValEnv ids			$
-	
+	-- Deal with the tyvars mentioned in signatures
+    tcRuleBndrs vars (\ ids ->
 		-- Now LHS and RHS
-	getLIE (tcCheckRho lhs rule_ty)	`thenM` \ (lhs', lhs_lie) ->
-	getLIE (tcCheckRho rhs rule_ty)	`thenM` \ (rhs', rhs_lie) ->
-	
+	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) ->
 
@@ -88,7 +61,7 @@ tcRule (HsRule name act vars lhs rhs src_loc)
 	--	   See the 'lhs_dicts' in tcSimplifyAndCheck for the RHS
 
 	-- We initially quantify over any tyvars free in *either* the rule
-	-- *or* the bound variables.  The latter is important.  Consider
+	--  *or* the bound variables.  The latter is important.  Consider
 	--	ss (x,(y,z)) = (x,z)
 	--	RULE:  forall v. fst (ss v) = fst v
 	-- The type of the rhs of the rule is just a, but v::(a,(b,c))
@@ -106,17 +79,33 @@ tcRule (HsRule name act vars lhs rhs src_loc)
     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 (forall_tvs1 ++ tpl_ids))	-- yuk
-		    (mkHsLet lhs_binds lhs')
-		    (mkHsLet rhs_binds rhs')
-		    src_loc)
+		    (map (RuleBndr . noLoc) (forall_tvs2 ++ tpl_ids))	-- yuk
+		    (mkHsDictLet lhs_binds lhs') fv_lhs
+		    (mkHsDictLet rhs_binds rhs') fv_rhs)
   where
-    new_id (RuleBndr var) 	   = newTyVarTy openTypeKind			`thenM` \ ty ->
-		          	     returnM (mkLocalId var ty)
-    new_id (RuleBndrSig var rn_ty) = tcHsSigType (RuleSigCtxt var) rn_ty	`thenM` \ ty ->
-				     returnM (mkLocalId var ty)
+
+tcRuleBndrs [] thing_inside = thing_inside []
+tcRuleBndrs (RuleBndr var : vars) thing_inside
+  = do 	{ ty <- newFlexiTyVarTy openTypeKind
+	; let id = mkLocalId (unLoc var) ty
+	; tcExtendIdEnv [id] $
+	  tcRuleBndrs vars (\ids -> thing_inside (id:ids)) }
+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)
+	; (tyvars, ty) <- tcHsPatSigType ctxt rn_ty
+	; let skol_tvs = tcSkolSigTyVars (SigSkol ctxt) tyvars
+	      id_ty = substTyWith tyvars (mkTyVarTys skol_tvs) ty
+	      id = mkLocalId (unLoc var) id_ty
+	; tcExtendTyVarEnv skol_tvs $
+	  tcExtendIdEnv [id] $
+	  tcRuleBndrs vars (\ids -> thing_inside (id:ids)) }
 
 ruleCtxt name = ptext SLIT("When checking the transformation rule") <+> 
 		doubleQuotes (ftext name)