X-Git-Url: http://git.megacz.com/?a=blobdiff_plain;f=ghc%2Fcompiler%2Ftypecheck%2FTcClassDcl.lhs;h=cdd2c7ec28f3d58dd6d49769b6e853c20452e7a7;hb=dd8235367cd61e6811eee42b78c6514e77428c7c;hp=cf01b509c11d01e3f36522d0ec494ecde39f98fc;hpb=6c936babdfb7f9c229b1d01be35728e2caf1d53d;p=ghc-hetmet.git diff --git a/ghc/compiler/typecheck/TcClassDcl.lhs b/ghc/compiler/typecheck/TcClassDcl.lhs index cf01b50..cdd2c7e 100644 --- a/ghc/compiler/typecheck/TcClassDcl.lhs +++ b/ghc/compiler/typecheck/TcClassDcl.lhs @@ -4,57 +4,57 @@ \section[TcClassDcl]{Typechecking class declarations} \begin{code} -module TcClassDcl ( tcClassDecl1, tcClassDecls2, +module TcClassDcl ( tcClassDecl1, checkValidClass, tcClassDecls2, tcMethodBind, badMethodErr ) where #include "HsVersions.h" import HsSyn ( TyClDecl(..), Sig(..), MonoBinds(..), - HsExpr(..), HsLit(..), HsType(..), HsPred(..), + HsExpr(..), HsLit(..), mkSimpleMatch, andMonoBinds, andMonoBindList, isClassOpSig, isPragSig, - getClassDeclSysNames, + getClassDeclSysNames, placeHolderType ) -import BasicTypes ( TopLevelFlag(..), RecFlag(..) ) +import BasicTypes ( TopLevelFlag(..), RecFlag(..), StrictnessMark(..) ) import RnHsSyn ( RenamedTyClDecl, RenamedClassOpSig, RenamedMonoBinds, - RenamedContext, RenamedSig, - maybeGenericMatch + RenamedSig, maybeGenericMatch ) import TcHsSyn ( TcMonoBinds ) import Inst ( Inst, InstOrigin(..), LIE, emptyLIE, plusLIE, plusLIEs, instToId, newDicts, newMethod ) -import TcEnv ( TcId, TcEnv, RecTcEnv, TyThingDetails(..), tcAddImportedIdInfo, +import TcEnv ( RecTcEnv, TyThingDetails(..), tcAddImportedIdInfo, tcLookupClass, tcExtendTyVarEnvForMeths, tcExtendGlobalTyVars, tcExtendLocalValEnv, tcExtendTyVarEnv ) import TcBinds ( tcBindWithSigs, tcSpecSigs ) -import TcMonoType ( tcHsRecType, tcRecClassContext, checkSigTyVars, checkAmbiguity, sigCtxt, mkTcSig ) +import TcMonoType ( tcHsType, tcHsTheta, checkSigTyVars, sigCtxt, mkTcSig ) import TcSimplify ( tcSimplifyCheck, bindInstsOfLocalFuns ) -import TcType ( TcType, TcTyVar, tcInstTyVars ) +import TcMType ( tcInstSigTyVars, checkValidTheta, checkValidType, SourceTyCtxt(..), UserTypeCtxt(..) ) +import TcType ( Type, TyVarDetails(..), TcType, TcThetaType, TcTyVar, + mkSigmaTy, mkTyVarTys, mkPredTys, mkClassPred, + tcIsTyVarTy, tcSplitTyConApp_maybe, tcSplitSigmaTy + ) import TcMonad import Generics ( mkGenericRhs, validGenericMethodType ) import PrelInfo ( nO_METHOD_BINDING_ERROR_ID ) -import Class ( classTyVars, classBigSig, classTyCon, +import Class ( classTyVars, classBigSig, classTyCon, className, Class, ClassOpItem, DefMeth (..) ) import MkId ( mkDictSelId, mkDataConId, mkDataConWrapId, mkDefaultMethodId ) -import DataCon ( mkDataCon, notMarkedStrict ) -import Id ( Id, idType, idName ) +import DataCon ( mkDataCon ) +import Id ( Id, idType, idName, setIdLocalExported ) import Module ( Module ) import Name ( Name, NamedThing(..) ) -import Name ( NameEnv, lookupNameEnv, emptyNameEnv, unitNameEnv, plusNameEnv, nameEnvElts ) +import NameEnv ( NameEnv, lookupNameEnv, emptyNameEnv, unitNameEnv, plusNameEnv ) import NameSet ( emptyNameSet ) import Outputable -import Type ( Type, ClassContext, mkTyVarTys, mkDictTys, mkClassPred, - splitTyConApp_maybe, isTyVarTy - ) import Var ( TyVar ) import VarSet ( mkVarSet, emptyVarSet ) import CmdLineOpts import ErrUtils ( dumpIfSet ) -import Util ( count ) +import Util ( count, isSingleton, lengthIs, equalLength ) import Maybes ( seqMaybe, maybeToBool ) \end{code} @@ -101,21 +101,13 @@ Death to "ExpandingDicts". \begin{code} -tcClassDecl1 :: RecFlag -> RecTcEnv -> RenamedTyClDecl -> TcM (Name, TyThingDetails) -tcClassDecl1 is_rec rec_env +tcClassDecl1 :: RecTcEnv -> RenamedTyClDecl -> TcM (Name, TyThingDetails) +tcClassDecl1 rec_env (ClassDecl {tcdCtxt = context, tcdName = class_name, tcdTyVars = tyvar_names, tcdFDs = fundeps, tcdSigs = class_sigs, tcdMeths = def_methods, tcdSysNames = sys_names, tcdLoc = src_loc}) - = -- CHECK ARITY 1 FOR HASKELL 1.4 - doptsTc Opt_GlasgowExts `thenTc` \ gla_ext_opt -> - let - gla_exts = gla_ext_opt || not (maybeToBool def_methods) - -- Accept extensions if gla_exts is on, - -- or if we're looking at an interface file decl - in -- (in which case def_methods = Nothing - - -- LOOK THINGS UP IN THE ENVIRONMENT + = -- LOOK THINGS UP IN THE ENVIRONMENT tcLookupClass class_name `thenTc` \ clas -> let tyvars = classTyVars clas @@ -125,34 +117,27 @@ tcClassDecl1 is_rec rec_env in tcExtendTyVarEnv tyvars $ - -- SOURCE-CODE CONSISTENCY CHECKS - (case def_methods of - Nothing -> -- Not source - returnTc Nothing - - Just dms -> -- Source so do error checks - checkTc (gla_exts || length tyvar_names == 1) - (classArityErr class_name) `thenTc_` - - checkDefaultBinds clas op_names dms `thenTc` \ dm_env -> - checkGenericClassIsUnary clas dm_env `thenTc_` - returnTc (Just dm_env) - ) `thenTc` \ mb_dm_env -> + checkDefaultBinds clas op_names def_methods `thenTc` \ mb_dm_env -> -- CHECK THE CONTEXT - tcSuperClasses is_rec gla_exts clas context sc_sel_names `thenTc` \ (sc_theta, sc_sel_ids) -> + -- The renamer has already checked that the context mentions + -- only the type variable of the class decl. + -- Context is already kind-checked + ASSERT( equalLength context sc_sel_names ) + tcHsTheta context `thenTc` \ sc_theta -> -- CHECK THE CLASS SIGNATURES, - mapTc (tcClassSig is_rec rec_env clas tyvars mb_dm_env) op_sigs `thenTc` \ sig_stuff -> + mapTc (tcClassSig rec_env clas tyvars mb_dm_env) op_sigs `thenTc` \ sig_stuff -> -- MAKE THE CLASS DETAILS let (op_tys, op_items) = unzip sig_stuff - sc_tys = mkDictTys sc_theta + sc_tys = mkPredTys sc_theta dict_component_tys = sc_tys ++ op_tys + sc_sel_ids = [mkDictSelId sc_name clas | sc_name <- sc_sel_names] dict_con = mkDataCon datacon_name - [notMarkedStrict | _ <- dict_component_tys] + [NotMarkedStrict | _ <- dict_component_tys] [{- No labelled fields -}] tyvars [{-No context-}] @@ -168,8 +153,8 @@ tcClassDecl1 is_rec rec_env \end{code} \begin{code} -checkDefaultBinds :: Class -> [Name] -> RenamedMonoBinds - -> TcM (NameEnv Bool) +checkDefaultBinds :: Class -> [Name] -> Maybe RenamedMonoBinds + -> TcM (Maybe (NameEnv Bool)) -- The returned environment says -- x not in env => no default method -- x -> True => generic default method @@ -182,78 +167,43 @@ checkDefaultBinds :: Class -> [Name] -> RenamedMonoBinds -- But do all this only for source binds -checkDefaultBinds clas ops EmptyMonoBinds = returnTc emptyNameEnv +checkDefaultBinds clas ops Nothing + = returnTc Nothing -checkDefaultBinds clas ops (AndMonoBinds b1 b2) - = checkDefaultBinds clas ops b1 `thenTc` \ dm_info1 -> - checkDefaultBinds clas ops b2 `thenTc` \ dm_info2 -> - returnTc (dm_info1 `plusNameEnv` dm_info2) +checkDefaultBinds clas ops (Just mbs) + = go mbs `thenTc` \ dm_env -> + returnTc (Just dm_env) + where + go EmptyMonoBinds = returnTc emptyNameEnv -checkDefaultBinds clas ops (FunMonoBind op _ matches loc) - = tcAddSrcLoc loc $ + go (AndMonoBinds b1 b2) + = go b1 `thenTc` \ dm_info1 -> + go b2 `thenTc` \ dm_info2 -> + returnTc (dm_info1 `plusNameEnv` dm_info2) + + go (FunMonoBind op _ matches loc) + = tcAddSrcLoc loc $ -- Check that the op is from this class - checkTc (op `elem` ops) (badMethodErr clas op) `thenTc_` + checkTc (op `elem` ops) (badMethodErr clas op) `thenTc_` -- Check that all the defns ar generic, or none are - checkTc (all_generic || none_generic) (mixedGenericErr op) `thenTc_` + checkTc (all_generic || none_generic) (mixedGenericErr op) `thenTc_` - returnTc (unitNameEnv op all_generic) - where - n_generic = count (maybeToBool . maybeGenericMatch) matches - none_generic = n_generic == 0 - all_generic = n_generic == length matches - -checkGenericClassIsUnary clas dm_env - = -- Check that if the class has generic methods, then the - -- class has only one parameter. We can't do generic - -- multi-parameter type classes! - checkTc (unary || no_generics) (genericMultiParamErr clas) - where - unary = length (classTyVars clas) == 1 - no_generics = not (or (nameEnvElts dm_env)) + returnTc (unitNameEnv op all_generic) + where + n_generic = count (maybeToBool . maybeGenericMatch) matches + none_generic = n_generic == 0 + all_generic = matches `lengthIs` n_generic \end{code} \begin{code} -tcSuperClasses :: RecFlag -> Bool -> Class - -> RenamedContext -- class context - -> [Name] -- Names for superclass selectors - -> TcM (ClassContext, -- the superclass context - [Id]) -- superclass selector Ids - -tcSuperClasses is_rec gla_exts clas context sc_sel_names - = -- Check the context. - -- The renamer has already checked that the context mentions - -- only the type variable of the class decl. - - -- For std Haskell check that the context constrains only tyvars - (if gla_exts then - returnTc () - else - mapTc_ check_constraint context - ) `thenTc_` - - -- Context is already kind-checked - tcRecClassContext is_rec context `thenTc` \ sc_theta -> - let - sc_sel_ids = [mkDictSelId sc_name clas | sc_name <- sc_sel_names] - in - -- Done - returnTc (sc_theta, sc_sel_ids) - - where - check_constraint sc@(HsPClass c tys) - = checkTc (all is_tyvar tys) (superClassErr clas sc) - - is_tyvar (HsTyVar _) = True - is_tyvar other = False - - -tcClassSig :: RecFlag -> RecTcEnv -- Knot tying only! +tcClassSig :: RecTcEnv -- Knot tying only! -> Class -- ...ditto... -> [TyVar] -- The class type variable, used for error check only - -> Maybe (NameEnv Bool) -- Info about default methods + -> Maybe (NameEnv Bool) -- Info about default methods; + -- Nothing => imported class defn with no method binds -> RenamedClassOpSig -> TcM (Type, -- Type of the method ClassOpItem) -- Selector Id, default-method Id, True if explicit default binding @@ -263,55 +213,79 @@ tcClassSig :: RecFlag -> RecTcEnv -- Knot tying only! -- so we distinguish them in checkDefaultBinds, and pass this knowledge in the -- Class.DefMeth data structure. -tcClassSig is_rec unf_env clas clas_tyvars maybe_dm_env +tcClassSig unf_env clas clas_tyvars maybe_dm_env (ClassOpSig op_name sig_dm op_ty src_loc) = tcAddSrcLoc src_loc $ -- Check the type signature. NB that the envt *already has* -- bindings for the type variables; see comments in TcTyAndClassDcls. + tcHsType op_ty `thenTc` \ local_ty -> - tcHsRecType is_rec op_ty `thenTc` \ local_ty -> - - -- Check for ambiguous class op types let theta = [mkClassPred clas (mkTyVarTys clas_tyvars)] - in - checkAmbiguity is_rec True clas_tyvars theta local_ty `thenTc` \ global_ty -> - -- The default method's type should really come from the - -- iface file, since it could be usage-generalised, but this - -- requires altering the mess of knots in TcModule and I'm - -- too scared to do that. Instead, I have disabled generalisation - -- of types of default methods (and dict funs) by annotating them - -- TyGenNever (in MkId). Ugh! KSW 1999-09. - let -- Build the selector id and default method id sel_id = mkDictSelId op_name clas - dm_id = mkDefaultMethodId dm_name clas global_ty DefMeth dm_name = sig_dm dm_info = case maybe_dm_env of - Nothing -> iface_dm_info + Nothing -> sig_dm Just dm_env -> mk_src_dm_info dm_env - iface_dm_info = case sig_dm of - NoDefMeth -> NoDefMeth - GenDefMeth -> GenDefMeth - DefMeth dm_name -> DefMeth (tcAddImportedIdInfo unf_env dm_id) - mk_src_dm_info dm_env = case lookupNameEnv dm_env op_name of Nothing -> NoDefMeth Just True -> GenDefMeth - Just False -> DefMeth dm_id + Just False -> DefMeth dm_name in - -- Check that for a generic method, the type of - -- the method is sufficiently simple - checkTc (dm_info /= GenDefMeth || validGenericMethodType local_ty) - (badGenericMethodType op_name op_ty) `thenTc_` - returnTc (local_ty, (sel_id, dm_info)) \end{code} +checkValidClass is called once the mutually-recursive knot has been +tied, so we can look at things freely. + +\begin{code} +checkValidClass :: Class -> TcM () +checkValidClass cls + = -- CHECK ARITY 1 FOR HASKELL 1.4 + doptsTc Opt_GlasgowExts `thenTc` \ gla_exts -> + + -- Check that the class is unary, unless GlaExs + checkTc (not (null tyvars)) (nullaryClassErr cls) `thenTc_` + checkTc (gla_exts || unary) (classArityErr cls) `thenTc_` + + -- Check the super-classes + checkValidTheta (ClassSCCtxt (className cls)) theta `thenTc_` + + -- Check the class operations + mapTc_ check_op op_stuff `thenTc_` + + -- Check that if the class has generic methods, then the + -- class has only one parameter. We can't do generic + -- multi-parameter type classes! + checkTc (unary || no_generics) (genericMultiParamErr cls) + + where + (tyvars, theta, _, op_stuff) = classBigSig cls + unary = isSingleton tyvars + no_generics = null [() | (_, GenDefMeth) <- op_stuff] + + check_op (sel_id, dm) + = checkValidTheta SigmaCtxt (tail theta) `thenTc_` + -- The 'tail' removes the initial (C a) from the + -- class itself, leaving just the method type + + checkValidType (FunSigCtxt op_name) tau `thenTc_` + + -- Check that for a generic method, the type of + -- the method is sufficiently simple + checkTc (dm /= GenDefMeth || validGenericMethodType op_ty) + (badGenericMethodType op_name op_ty) + where + op_name = idName sel_id + op_ty = idType sel_id + (_,theta,tau) = tcSplitSigmaTy op_ty +\end{code} + %************************************************************************ %* * @@ -378,18 +352,19 @@ The function @tcClassDecls2@ just arranges to apply @tcClassDecl2@ to each local class decl. \begin{code} -tcClassDecls2 :: Module -> [RenamedTyClDecl] -> NF_TcM (LIE, TcMonoBinds) +tcClassDecls2 :: Module -> [RenamedTyClDecl] -> NF_TcM (LIE, TcMonoBinds, [Id]) tcClassDecls2 this_mod decls = foldr combine - (returnNF_Tc (emptyLIE, EmptyMonoBinds)) + (returnNF_Tc (emptyLIE, EmptyMonoBinds, [])) [tcClassDecl2 cls_decl | cls_decl@(ClassDecl {tcdMeths = Just _}) <- decls] -- The 'Just' picks out source ClassDecls where - combine tc1 tc2 = tc1 `thenNF_Tc` \ (lie1, binds1) -> - tc2 `thenNF_Tc` \ (lie2, binds2) -> + combine tc1 tc2 = tc1 `thenNF_Tc` \ (lie1, binds1, ids1) -> + tc2 `thenNF_Tc` \ (lie2, binds2, ids2) -> returnNF_Tc (lie1 `plusLIE` lie2, - binds1 `AndMonoBinds` binds2) + binds1 `AndMonoBinds` binds2, + ids1 ++ ids2) \end{code} @tcClassDecl2@ generates bindings for polymorphic default methods @@ -397,12 +372,12 @@ tcClassDecls2 this_mod decls \begin{code} tcClassDecl2 :: RenamedTyClDecl -- The class declaration - -> NF_TcM (LIE, TcMonoBinds) + -> NF_TcM (LIE, TcMonoBinds, [Id]) tcClassDecl2 (ClassDecl {tcdName = class_name, tcdSigs = sigs, tcdMeths = Just default_binds, tcdLoc = src_loc}) = -- The 'Just' picks out source ClassDecls - recoverNF_Tc (returnNF_Tc (emptyLIE, EmptyMonoBinds)) $ + recoverNF_Tc (returnNF_Tc (emptyLIE, EmptyMonoBinds, [])) $ tcAddSrcLoc src_loc $ tcLookupClass class_name `thenNF_Tc` \ clas -> @@ -419,13 +394,13 @@ tcClassDecl2 (ClassDecl {tcdName = class_name, tcdSigs = sigs, prags = filter isPragSig sigs tc_dm = tcDefMeth clas tyvars default_binds prags in - mapAndUnzipTc tc_dm op_items `thenTc` \ (defm_binds, const_lies) -> + mapAndUnzip3Tc tc_dm op_items `thenTc` \ (defm_binds, const_lies, dm_ids_s) -> - returnTc (plusLIEs const_lies, andMonoBindList defm_binds) + returnTc (plusLIEs const_lies, andMonoBindList defm_binds, concat dm_ids_s) -tcDefMeth clas tyvars binds_in prags (_, NoDefMeth) = returnTc (EmptyMonoBinds, emptyLIE) -tcDefMeth clas tyvars binds_in prags (_, GenDefMeth) = returnTc (EmptyMonoBinds, emptyLIE) +tcDefMeth clas tyvars binds_in prags (_, NoDefMeth) = returnTc (EmptyMonoBinds, emptyLIE, []) +tcDefMeth clas tyvars binds_in prags (_, GenDefMeth) = returnTc (EmptyMonoBinds, emptyLIE, []) -- Generate code for polymorphic default methods only -- (Generic default methods have turned into instance decls by now.) -- This is incompatible with Hugs, which expects a polymorphic @@ -433,10 +408,22 @@ tcDefMeth clas tyvars binds_in prags (_, GenDefMeth) = returnTc (EmptyMonoBinds, -- the programmer supplied an explicit default decl for the class. -- (If necessary we can fix that, but we don't have a convenient Id to hand.) -tcDefMeth clas tyvars binds_in prags op_item@(_, DefMeth dm_id) - = tcInstTyVars tyvars `thenNF_Tc` \ (clas_tyvars, inst_tys, _) -> +tcDefMeth clas tyvars binds_in prags op_item@(sel_id, DefMeth dm_name) + = tcInstSigTyVars ClsTv tyvars `thenNF_Tc` \ clas_tyvars -> let - theta = [(mkClassPred clas inst_tys)] + dm_ty = idType sel_id -- Same as dict selector! + -- The default method's type should really come from the + -- iface file, since it could be usage-generalised, but this + -- requires altering the mess of knots in TcModule and I'm + -- too scared to do that. Instead, I have disabled generalisation + -- of types of default methods (and dict funs) by annotating them + -- TyGenNever (in MkId). Ugh! KSW 1999-09. + + inst_tys = mkTyVarTys clas_tyvars + theta = [mkClassPred clas inst_tys] + dm_id = mkDefaultMethodId dm_name dm_ty + local_dm_id = setIdLocalExported dm_id + -- Reason for setIdLocalExported: see notes with MkId.mkDictFunId in newDicts origin theta `thenNF_Tc` \ [this_dict] -> @@ -461,11 +448,11 @@ tcDefMeth clas tyvars binds_in prags op_item@(_, DefMeth dm_id) full_bind = AbsBinds clas_tyvars' [instToId this_dict] - [(clas_tyvars', dm_id, instToId local_dm_inst)] + [(clas_tyvars', local_dm_id, instToId local_dm_inst)] emptyNameSet -- No inlines (yet) (dict_binds `andMonoBinds` defm_bind) in - returnTc (full_bind, const_lie) + returnTc (full_bind, const_lie, [dm_id]) where origin = ClassDeclOrigin \end{code} @@ -519,7 +506,7 @@ tcMethodBind clas origin inst_tyvars inst_tys inst_theta Just user_bind -> returnTc user_bind Nothing -> mkDefMethRhs is_inst_decl clas inst_tys sel_id loc dm_info `thenTc` \ rhs -> returnTc (FunMonoBind meth_name False -- Not infix decl - [mkSimpleMatch [] rhs Nothing loc] loc) + [mkSimpleMatch [] rhs placeHolderType loc] loc) ) `thenTc` \ meth_bind -> -- Check the bindings; first add inst_tyvars to the envt -- so that we don't quantify over them in nested places @@ -527,7 +514,7 @@ tcMethodBind clas origin inst_tyvars inst_tys inst_theta tcExtendGlobalTyVars (mkVarSet inst_tyvars) (tcAddErrCtxt (methodCtxt sel_id) $ tcBindWithSigs NotTopLevel meth_bind - [sig_info] meth_prags NonRecursive + [sig_info] meth_prags NonRecursive ) `thenTc` \ (binds, insts, _) -> tcExtendLocalValEnv [(meth_name, meth_id)] @@ -555,16 +542,16 @@ tcMethodBind clas origin inst_tyvars inst_tys inst_theta -- The user didn't supply a method binding, -- so we have to make up a default binding -- The RHS of a default method depends on the default-method info -mkDefMethRhs is_inst_decl clas inst_tys sel_id loc (DefMeth dm_id) +mkDefMethRhs is_inst_decl clas inst_tys sel_id loc (DefMeth dm_name) = -- An polymorphic default method - returnTc (HsVar (idName dm_id)) + returnTc (HsVar dm_name) mkDefMethRhs is_inst_decl clas inst_tys sel_id loc NoDefMeth = -- No default method -- Warn only if -fwarn-missing-methods - doptsTc Opt_WarnMissingMethods `thenNF_Tc` \ warn -> + doptsTc Opt_WarnMissingMethods `thenNF_Tc` \ warn -> warnTc (is_inst_decl && warn) - (omittedMethodWarn sel_id clas) `thenNF_Tc_` + (omittedMethodWarn sel_id) `thenNF_Tc_` returnTc error_rhs where error_rhs = HsApp (HsVar (getName nO_METHOD_BINDING_ERROR_ID)) @@ -579,7 +566,7 @@ mkDefMethRhs is_inst_decl clas inst_tys sel_id loc GenDefMeth -- a type constructor applied to type arguments in the instance decl -- (checkTc, so False provokes the error) checkTc (not is_inst_decl || simple_inst) - (badGenericInstance sel_id clas) `thenTc_` + (badGenericInstance sel_id) `thenTc_` ioToTc (dumpIfSet opt_PprStyle_Debug "Generic RHS" stuff) `thenNF_Tc_` returnTc rhs @@ -597,9 +584,9 @@ mkDefMethRhs is_inst_decl clas inst_tys sel_id loc GenDefMeth clas_tyvar = head (classTyVars clas) Just tycon = maybe_tycon maybe_tycon = case inst_tys of - [ty] -> case splitTyConApp_maybe ty of - Just (tycon, arg_tys) | all isTyVarTy arg_tys -> Just tycon - other -> Nothing + [ty] -> case tcSplitTyConApp_maybe ty of + Just (tycon, arg_tys) | all tcIsTyVarTy arg_tys -> Just tycon + other -> Nothing other -> Nothing \end{code} @@ -618,10 +605,8 @@ find_bind sel_name meth_name other = Nothing -- Default case find_prags sel_name meth_name [] = [] find_prags sel_name meth_name (SpecSig name ty loc : prags) | name == sel_name = SpecSig meth_name ty loc : find_prags sel_name meth_name prags -find_prags sel_name meth_name (InlineSig name phase loc : prags) - | name == sel_name = InlineSig meth_name phase loc : find_prags sel_name meth_name prags -find_prags sel_name meth_name (NoInlineSig name phase loc : prags) - | name == sel_name = NoInlineSig meth_name phase loc : find_prags sel_name meth_name prags +find_prags sel_name meth_name (InlineSig sense name phase loc : prags) + | name == sel_name = InlineSig sense meth_name phase loc : find_prags sel_name meth_name prags find_prags sel_name meth_name (prag:prags) = find_prags sel_name meth_name prags \end{code} @@ -629,12 +614,12 @@ find_prags sel_name meth_name (prag:prags) = find_prags sel_name meth_name prags Contexts and errors ~~~~~~~~~~~~~~~~~~~ \begin{code} -classArityErr class_name - = ptext SLIT("Too many parameters for class") <+> quotes (ppr class_name) +nullaryClassErr cls + = ptext SLIT("No parameters for class") <+> quotes (ppr cls) -superClassErr clas sc - = ptext SLIT("Illegal superclass constraint") <+> quotes (ppr sc) - <+> ptext SLIT("in declaration for class") <+> quotes (ppr clas) +classArityErr cls + = vcat [ptext SLIT("Too many parameters for class") <+> quotes (ppr cls), + parens (ptext SLIT("Use -fglasgow-exts to allow multi-parameter classes"))] defltMethCtxt clas = ptext SLIT("When checking the default methods for class") <+> quotes (ppr clas) @@ -646,20 +631,18 @@ badMethodErr clas op = hsep [ptext SLIT("Class"), quotes (ppr clas), ptext SLIT("does not have a method"), quotes (ppr op)] -omittedMethodWarn sel_id clas - = sep [ptext SLIT("No explicit method nor default method for") <+> quotes (ppr sel_id), - ptext SLIT("in an instance declaration for") <+> quotes (ppr clas)] +omittedMethodWarn sel_id + = ptext SLIT("No explicit method nor default method for") <+> quotes (ppr sel_id) badGenericMethodType op op_ty = hang (ptext SLIT("Generic method type is too complex")) 4 (vcat [ppr op <+> dcolon <+> ppr op_ty, ptext SLIT("You can only use type variables, arrows, and tuples")]) -badGenericInstance sel_id clas +badGenericInstance sel_id = sep [ptext SLIT("Can't derive generic code for") <+> quotes (ppr sel_id), ptext SLIT("because the instance declaration is not for a simple type (T a b c)"), - ptext SLIT("(where T is a derivable type constructor)"), - ptext SLIT("in an instance declaration for") <+> quotes (ppr clas)] + ptext SLIT("(where T is a derivable type constructor)")] mixedGenericErr op = ptext SLIT("Can't mix generic and non-generic equations for class method") <+> quotes (ppr op)