From fb2771f8d4228535353f7161c63d5ad0055e9df7 Mon Sep 17 00:00:00 2001 From: Twan van Laarhoven Date: Thu, 17 Jan 2008 20:53:07 +0000 Subject: [PATCH] Monadify typecheck/TcRules: use do, return and standard monad functions --- compiler/typecheck/TcRules.lhs | 33 ++++++++++++++++----------------- 1 file changed, 16 insertions(+), 17 deletions(-) diff --git a/compiler/typecheck/TcRules.lhs b/compiler/typecheck/TcRules.lhs index 2909910..a0774fe 100644 --- a/compiler/typecheck/TcRules.lhs +++ b/compiler/typecheck/TcRules.lhs @@ -34,25 +34,24 @@ import Outputable \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 @@ -79,18 +78,18 @@ 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 - getInstLoc (SigOrigin (RuleSkol name)) `thenM` \ loc -> - tcSimplifyInferCheck loc - forall_tvs - lhs_dicts rhs_lie `thenM` \ (forall_tvs1, rhs_binds) -> + loc <- getInstLoc (SigOrigin (RuleSkol name)) + (forall_tvs1, rhs_binds) <- tcSimplifyInferCheck loc + forall_tvs + lhs_dicts rhs_lie - returnM (HsRule name act + return (HsRule name act (map (RuleBndr . noLoc) (forall_tvs1 ++ tpl_ids)) -- yuk (mkHsDictLet lhs_binds lhs') fv_lhs (mkHsDictLet rhs_binds rhs') fv_rhs) -- 1.7.10.4