X-Git-Url: http://git.megacz.com/?a=blobdiff_plain;f=ghc%2Fcompiler%2Ftypecheck%2FTcRules.lhs;h=50175334e7bfc8a4e9ad9efc51cfd2545020b025;hb=ac10f8408520a30e8437496d320b8b86afda2e8f;hp=a87a66160c13ba401683d80118ec2dcb2a459334;hpb=d069cec2bd92d4156aeab80f7eb1f222a82e4103;p=ghc-hetmet.git diff --git a/ghc/compiler/typecheck/TcRules.lhs b/ghc/compiler/typecheck/TcRules.lhs index a87a661..5017533 100644 --- a/ghc/compiler/typecheck/TcRules.lhs +++ b/ghc/compiler/typecheck/TcRules.lhs @@ -4,91 +4,46 @@ \section[TcRules]{Typechecking transformation rules} \begin{code} -module TcRules ( tcIfaceRules, tcSourceRules ) where +module TcRules ( tcRules ) where #include "HsVersions.h" -import HsSyn ( RuleDecl(..), RuleBndr(..) ) -import CoreSyn ( CoreRule(..) ) -import RnHsSyn ( RenamedRuleDecl ) -import HscTypes ( PackageRuleBase ) -import TcHsSyn ( TypecheckedRuleDecl, mkHsLet ) -import TcMonad +import HsSyn ( RuleDecl(..), LRuleDecl, RuleBndr(..), mkHsDictLet ) +import TcRnMonad import TcSimplify ( tcSimplifyToDicts, tcSimplifyInferCheck ) -import TcMType ( newTyVarTy ) -import TcType ( tyVarsOfTypes, openTypeKind ) -import TcIfaceSig ( tcCoreExpr, tcCoreLamBndrs, tcVar ) -import TcMonoType ( kcHsSigTypes, tcHsSigType, tcScopedTyVars, checkSigTyVars ) -import TcExpr ( tcExpr ) -import TcEnv ( tcExtendLocalValEnv, tcExtendTyVarEnv, isLocalThing ) -import Rules ( extendRuleBase ) -import Inst ( LIE, plusLIEs, instToId ) -import Id ( idName, idType, mkLocalId ) -import Module ( Module ) -import VarSet -import List ( partition ) +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} -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, 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 _) = isLocalThing mod n - is_local other = True - -tcIfaceRule :: RenamedRuleDecl -> TcM TypecheckedRuleDecl - -- No zonking necessary! -tcIfaceRule rule@(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' -> - let - new_rule :: TypecheckedRuleDecl - new_rule = IfaceRuleOut fun' (Rule name vars' args' rhs') - in - returnTc new_rule +tcRules :: [LRuleDecl Name] -> TcM [LRuleDecl TcId] +tcRules decls = mappM (wrapLocM tcRule) decls -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 -> +tcRule :: RuleDecl Name -> TcM (RuleDecl TcId) +tcRule (HsRule name act vars lhs rhs) + = addErrCtxt (ruleCtxt name) $ + traceTc (ptext SLIT("---- Rule ------") + <+> ppr name) `thenM_` + newFlexiTyVarTy openTypeKind `thenM` \ rule_ty -> -- Deal with the tyvars mentioned in signatures - tcScopedTyVars sig_tvs (kcHsSigTypes sig_tys) ( - - -- Ditto forall'd variables - mapNF_Tc new_id vars `thenNF_Tc` \ ids -> - tcExtendLocalValEnv [(idName id, id) | id <- ids] $ - + tcRuleBndrs vars (\ ids -> -- Now LHS and RHS - tcExpr lhs rule_ty `thenTc` \ (lhs', lhs_lie) -> - tcExpr rhs rule_ty `thenTc` \ (rhs', rhs_lie) -> - - returnTc (ids, lhs', rhs', lhs_lie, rhs_lie) - ) `thenTc` \ (ids, lhs', rhs', lhs_lie, 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) -> -- Check that LHS has no overloading at all - tcSimplifyToDicts lhs_lie `thenTc` \ (lhs_dicts, lhs_binds) -> + getLIE (tcSimplifyToDicts lhs_lie) `thenM` \ (lhs_binds, lhs_dicts) -> -- Gather the template variables and tyvars let @@ -106,41 +61,54 @@ tcSourceRule (HsRule name sig_tvs 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)) -- - -- It's still conceivable that there may be type variables mentioned - -- in the LHS, but not in the type of the lhs, nor in the binders. - -- They'll get zapped to (), but that's over-constraining really. - -- Let's see if we get a problem. + -- We also need to get the free tyvars of the LHS; but we do that + -- 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 `thenTc` \ (forall_tvs1, lie', rhs_binds) -> - - returnTc (lie', HsRule name forall_tvs1 - (map RuleBndr tpl_ids) -- yuk - (mkHsLet lhs_binds lhs') - (mkHsLet rhs_binds rhs') - src_loc) + 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 + (mkHsDictLet lhs_binds lhs') + (mkHsDictLet rhs_binds rhs')) where - sig_tys = [t | RuleBndrSig _ t <- vars] - new_id (RuleBndr var) = newTyVarTy openTypeKind `thenNF_Tc` \ ty -> - returnNF_Tc (mkLocalId var ty) - new_id (RuleBndrSig var rn_ty) = tcHsSigType rn_ty `thenTc` \ ty -> - returnNF_Tc (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 (ptext name) + doubleQuotes (ftext name) \end{code}