X-Git-Url: http://git.megacz.com/?a=blobdiff_plain;f=compiler%2Ftypecheck%2FTcRules.lhs;h=50ad098e1e08ade12e1a674e3f40c044cc39b398;hb=79011516105291b58324ce71a87f6bb26a131090;hp=ef8e388f8706eb1b4ff0e8988a50532d6bdc4afc;hpb=ab22f4e6456820c1b5169d75f5975a94e61f54ce;p=ghc-hetmet.git diff --git a/compiler/typecheck/TcRules.lhs b/compiler/typecheck/TcRules.lhs index ef8e388..50ad098 100644 --- a/compiler/typecheck/TcRules.lhs +++ b/compiler/typecheck/TcRules.lhs @@ -6,6 +6,13 @@ TcRules: Typechecking transformation rules \begin{code} +{-# OPTIONS -w #-} +-- The above warning supression flag is a temporary kludge. +-- While working on this module you are encouraged to remove it and fix +-- any warnings in the module. See +-- http://hackage.haskell.org/trac/ghc/wiki/Commentary/CodingStyle#Warnings +-- for details + module TcRules ( tcRules ) where #include "HsVersions.h" @@ -23,29 +30,29 @@ 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 @@ -72,20 +79,19 @@ 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) @@ -100,7 +106,7 @@ 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