[project @ 2004-11-16 10:00:10 by simonmar]

[ghc-hetmet.git] / ghc / compiler / typecheck / TcRules.lhs

diff --git a/ghc/compiler/typecheck/TcRules.lhs b/ghc/compiler/typecheck/TcRules.lhs
index 0688922..d78003b 100644 (file)
--- a/ghc/compiler/typecheck/TcRules.lhs
+++ b/ghc/compiler/typecheck/TcRules.lhs
@@ -8,58 +8,37 @@ module TcRules ( tcRules ) where
 
 #include "HsVersions.h"
 
-import HsSyn           ( RuleDecl(..), RuleBndr(..), HsExpr(..), collectRuleBndrSigTys )
-import CoreSyn         ( CoreRule(..) )
-import RnHsSyn         ( RenamedRuleDecl )
-import TcHsSyn         ( TypecheckedRuleDecl, TcExpr, mkHsLet )
+import HsSyn           ( RuleDecl(..), LRuleDecl, RuleBndr(..), mkHsLet )
 import TcRnMonad
 import TcSimplify      ( tcSimplifyToDicts, tcSimplifyInferCheck )
-import TcMType         ( newTyVarTy )
-import TcType          ( TcTyVarSet, tyVarsOfTypes, tyVarsOfType, openTypeKind )
-import TcIfaceSig      ( tcCoreExpr, tcCoreLamBndrs, tcVar )
-import TcMonoType      ( tcHsSigType, UserTypeCtxt(..), tcAddScopedTyVars )
-import TcExpr          ( tcMonoExpr )
-import TcEnv           ( tcExtendLocalValEnv )
+import TcMType         ( newTyFlexiVarTy, zonkQuantifiedTyVar )
+import TcType          ( tyVarsOfTypes, openTypeKind )
+import TcHsType                ( UserTypeCtxt(..), tcHsPatSigType )
+import TcExpr          ( tcCheckRho )
+import TcEnv           ( tcExtendIdEnv, tcExtendTyVarEnv )
 import Inst            ( instToId )
 import Id              ( idType, mkLocalId )
-import VarSet
+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) $
-    tcVar 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 come this way
-  = tcVar fun                          `thenM` \ fun' ->
-    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 rhs)
+  = addErrCtxt (ruleCtxt name)                 $
+    traceTc (ptext SLIT("---- Rule ------")
+                <+> ppr name)                  `thenM_` 
+    newTyFlexiVarTy 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 (tcMonoExpr lhs rule_ty)         `thenM` \ (lhs', lhs_lie) ->
-       getLIE (tcMonoExpr rhs rule_ty)         `thenM` \ (rhs', rhs_lie) ->
-       
+       getLIE (tcCheckRho lhs rule_ty) `thenM` \ (lhs', lhs_lie) ->
+       getLIE (tcCheckRho rhs rule_ty) `thenM` \ (rhs', rhs_lie) ->
        returnM (ids, lhs', rhs', lhs_lie, rhs_lie)
     )                          `thenM` \ (ids, lhs', rhs', lhs_lie, rhs_lie) ->
 
@@ -100,17 +79,27 @@ 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
+                   (map (RuleBndr . noLoc) (forall_tvs2 ++ tpl_ids))   -- yuk
                    (mkHsLet lhs_binds lhs')
-                   (mkHsLet rhs_binds rhs')
-                   src_loc)
+                   (mkHsLet rhs_binds 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 <- newTyFlexiVarTy openTypeKind
+       ; let id = mkLocalId (unLoc var) ty
+       ; tcExtendIdEnv [id] $
+         tcRuleBndrs vars (\ids -> thing_inside (id:ids)) }
+tcRuleBndrs (RuleBndrSig var rn_ty : vars) thing_inside
+  = do { (tyvars, ty) <- tcHsPatSigType (RuleSigCtxt (unLoc var)) rn_ty
+       ; let id = mkLocalId (unLoc var) ty
+       ; tcExtendTyVarEnv tyvars $
+         tcExtendIdEnv [id] $
+         tcRuleBndrs vars (\ids -> thing_inside (id:ids)) }
 
 ruleCtxt name = ptext SLIT("When checking the transformation rule") <+> 
                doubleQuotes (ftext name)