[project @ 2001-01-29 08:42:54 by simonpj]

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

diff --git a/ghc/compiler/typecheck/TcRules.lhs b/ghc/compiler/typecheck/TcRules.lhs
index 16fb692..ca6dab6 100644 (file)
--- a/ghc/compiler/typecheck/TcRules.lhs
+++ b/ghc/compiler/typecheck/TcRules.lhs
@@ -4,64 +4,68 @@
 \section[TcRules]{Typechecking transformation rules}
 
 \begin{code}
-module TcRules ( tcRules ) where
+module TcRules ( tcIfaceRules, tcSourceRules ) where
 
 #include "HsVersions.h"
 
-import HsSyn           ( HsDecl(..), RuleDecl(..), RuleBndr(..) )
+import HsSyn           ( RuleDecl(..), RuleBndr(..) )
 import CoreSyn         ( CoreRule(..) )
-import RnHsSyn         ( RenamedHsDecl, RenamedRuleDecl )
+import RnHsSyn         ( RenamedRuleDecl )
 import HscTypes                ( PackageRuleBase )
 import TcHsSyn         ( TypecheckedRuleDecl, mkHsLet )
 import TcMonad
-import TcSimplify      ( tcSimplifyToDicts, tcSimplifyAndCheck )
-import TcType          ( zonkTcTypes, zonkTcTyVarToTyVar, newTyVarTy )
+import TcSimplify      ( tcSimplifyToDicts, tcSimplifyInferCheck )
+import TcType          ( zonkTcTyVarToTyVar, newTyVarTy )
 import TcIfaceSig      ( tcCoreExpr, tcCoreLamBndrs, tcVar )
 import TcMonoType      ( kcHsSigType, tcHsSigType, tcTyVars, checkSigTyVars )
 import TcExpr          ( tcExpr )
-import TcEnv           ( tcExtendLocalValEnv, tcExtendTyVarEnv )
+import TcEnv           ( tcExtendLocalValEnv, tcExtendTyVarEnv, isLocalThing )
 import Rules           ( extendRuleBase )
-import Inst            ( LIE, emptyLIE, plusLIEs, instToId )
-import Id              ( idType, idName, mkVanillaId )
-import Name            ( nameModule )
+import Inst            ( LIE, plusLIEs, instToId )
+import Id              ( idName, mkVanillaId )
 import Module          ( Module )
 import VarSet
-import Type            ( tyVarsOfTypes, openTypeKind )
-import Bag             ( bagToList )
+import Type            ( tyVarsOfType, openTypeKind )
 import List            ( partition )
 import Outputable
 \end{code}
 
 \begin{code}
-tcRules :: PackageRuleBase -> Module -> [RenamedHsDecl] 
-       -> TcM (PackageRuleBase, LIE, [TypecheckedRuleDecl])
-tcRules pkg_rule_base mod decls 
-  = mapAndUnzipTc tcRule [rule | RuleD rule <- decls]  `thenTc` \ (lies, new_rules) ->
+tcIfaceRules :: PackageRuleBase -> Module -> [RenamedRuleDecl] 
+            -> TcM (PackageRuleBase, [TypecheckedRuleDecl])
+tcIfaceRules pkg_rule_base mod decls 
+  = mapTc tcIfaceRule decls            `thenTc` \ new_rules ->
     let
        (local_rules, imported_rules) = partition is_local new_rules
        new_rule_base = foldl add pkg_rule_base imported_rules
     in
-    returnTc (new_rule_base, plusLIEs lies, local_rules)
+    returnTc (new_rule_base, local_rules)
   where
     add rule_base (IfaceRuleOut id rule) = extendRuleBase rule_base (id, rule)
 
        -- When relinking this module from its interface-file decls
        -- we'll have IfaceRules that are in fact local to this module
-    is_local (IfaceRuleOut n _) = mod == nameModule (idName n)
+    is_local (IfaceRuleOut n _) = isLocalThing mod n
     is_local other             = True
 
-tcRule :: RenamedRuleDecl -> TcM (LIE, TypecheckedRuleDecl)
+tcIfaceRule :: RenamedRuleDecl -> TcM TypecheckedRuleDecl
   -- No zonking necessary!
-tcRule (IfaceRule name vars fun args rhs src_loc)
+tcIfaceRule (IfaceRule name vars fun args rhs src_loc)
   = tcAddSrcLoc src_loc                $
     tcAddErrCtxt (ruleCtxt name)       $
     tcVar fun                          `thenTc` \ fun' ->
     tcCoreLamBndrs vars                        $ \ vars' ->
     mapTc tcCoreExpr args              `thenTc` \ args' ->
     tcCoreExpr rhs                     `thenTc` \ rhs' ->
-    returnTc (emptyLIE, IfaceRuleOut fun' (Rule name vars' args' rhs'))
+    returnTc (IfaceRuleOut fun' (Rule name vars' args' rhs'))
 
-tcRule (HsRule name sig_tvs vars lhs rhs src_loc)
+
+tcSourceRules :: [RenamedRuleDecl] -> TcM (LIE, [TypecheckedRuleDecl])
+tcSourceRules decls
+  = mapAndUnzipTc tcSourceRule decls   `thenTc` \ (lies, decls') ->
+    returnTc (plusLIEs lies, decls')
+
+tcSourceRule (HsRule name sig_tvs vars lhs rhs src_loc)
   = tcAddSrcLoc src_loc                                $
     tcAddErrCtxt (ruleCtxt name)                       $
     newTyVarTy openTypeKind                            `thenNF_Tc` \ rule_ty ->
@@ -82,12 +86,12 @@ tcRule (HsRule name sig_tvs vars lhs rhs src_loc)
     )                                          `thenTc` \ (sig_tyvars, ids, lhs', rhs', lhs_lie, rhs_lie) ->
 
                -- Check that LHS has no overloading at all
-    tcSimplifyToDicts lhs_lie                          `thenTc` \ (lhs_dicts, lhs_binds) ->
-    checkSigTyVars sig_tyvars emptyVarSet              `thenTc_`
+    tcSimplifyToDicts lhs_lie                  `thenTc` \ (lhs_dicts, lhs_binds) ->
+    checkSigTyVars sig_tyvars emptyVarSet      `thenTc_`
 
        -- Gather the template variables and tyvars
     let
-       tpl_ids = map instToId (bagToList lhs_dicts) ++ ids
+       tpl_ids = map instToId lhs_dicts ++ ids
 
        -- IMPORTANT!  We *quantify* over any dicts that appear in the LHS
        -- Reason: 
@@ -101,16 +105,13 @@ tcRule (HsRule name sig_tvs vars lhs rhs src_loc)
        --         See the 'lhs_dicts' in tcSimplifyAndCheck for the RHS
     in
 
-       -- Gather type variables to quantify over
-       -- and turn them into real TyVars (just as in TcBinds.tcBindWithSigs)
-    zonkTcTypes (rule_ty : map idType tpl_ids)                         `thenNF_Tc` \ zonked_tys ->
-    mapTc zonkTcTyVarToTyVar (varSetElems (tyVarsOfTypes zonked_tys))  `thenTc` \ tvs ->
-
        -- RHS can be a bit more lenient.  In particular,
        -- we let constant dictionaries etc float outwards
-    tcSimplifyAndCheck (text "tcRule") (mkVarSet tvs)
-                      lhs_dicts rhs_lie                `thenTc` \ (lie', rhs_binds) ->
+    tcSimplifyInferCheck (text "tcRule")
+                        (varSetElems (tyVarsOfType rule_ty))
+                        lhs_dicts rhs_lie      `thenTc` \ (forall_tvs', lie', rhs_binds) ->
 
+    mapTc zonkTcTyVarToTyVar forall_tvs'               `thenTc` \ tvs ->
     returnTc (lie', HsRule     name tvs
                                (map RuleBndr tpl_ids)  -- yuk
                                (mkHsLet lhs_binds lhs')