import Inst ( Inst, InstOrigin(..), LIE, emptyLIE, plusLIE, plusLIEs,
instToId, newDicts, newMethod )
-import TcEnv ( RecTcEnv, TyThingDetails(..), tcAddImportedIdInfo,
+import TcEnv ( RecTcEnv, TyThingDetails(..),
tcLookupClass, tcExtendTyVarEnvForMeths, tcExtendGlobalTyVars,
tcExtendLocalValEnv, tcExtendTyVarEnv
)
import TcBinds ( tcBindWithSigs, tcSpecSigs )
-import TcMonoType ( tcHsType, tcHsTheta, checkSigTyVars, sigCtxt, mkTcSig )
+import TcMonoType ( tcHsType, tcHsTheta, mkTcSig )
import TcSimplify ( tcSimplifyCheck, bindInstsOfLocalFuns )
-import TcMType ( tcInstTyVars, checkValidTheta, checkValidType, SourceTyCtxt(..), UserTypeCtxt(..) )
-import TcType ( Type, mkSigmaTy, mkTyVarTys, mkPredTys, mkClassPred,
+import TcUnify ( checkSigTyVars, sigCtxt )
+import TcMType ( tcInstSigTyVars, checkValidTheta, checkValidType, SourceTyCtxt(..), UserTypeCtxt(..) )
+import TcType ( Type, TyVarDetails(..), TcType, TcThetaType, TcTyVar,
+ mkTyVarTys, mkPredTys, mkClassPred,
tcIsTyVarTy, tcSplitTyConApp_maybe, tcSplitSigmaTy
)
import TcMonad
Class, ClassOpItem, DefMeth (..) )
import MkId ( mkDictSelId, mkDataConId, mkDataConWrapId, mkDefaultMethodId )
import DataCon ( mkDataCon )
-import Id ( idType, idName )
+import Id ( Id, idType, idName, setIdLocalExported )
import Module ( Module )
import Name ( Name, NamedThing(..) )
import NameEnv ( NameEnv, lookupNameEnv, emptyNameEnv, unitNameEnv, plusNameEnv )
import VarSet ( mkVarSet, emptyVarSet )
import CmdLineOpts
import ErrUtils ( dumpIfSet )
-import Util ( count )
+import Util ( count, isSingleton, lengthIs, equalLength )
import Maybes ( seqMaybe, maybeToBool )
\end{code}
-- The renamer has already checked that the context mentions
-- only the type variable of the class decl.
-- Context is already kind-checked
- ASSERT( length context == length sc_sel_names )
+ ASSERT( equalLength context sc_sel_names )
tcHsTheta context `thenTc` \ sc_theta ->
-- CHECK THE CLASS SIGNATURES,
where
n_generic = count (maybeToBool . maybeGenericMatch) matches
none_generic = n_generic == 0
- all_generic = n_generic == length matches
+ all_generic = matches `lengthIs` n_generic
\end{code}
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
let
theta = [mkClassPred clas (mkTyVarTys clas_tyvars)]
- global_ty = mkSigmaTy clas_tyvars theta local_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.
-- Build the selector id and default method id
sel_id = mkDictSelId op_name clas
- dm_id = mkDefaultMethodId dm_name 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
returnTc (local_ty, (sel_id, dm_info))
\end{code}
doptsTc Opt_GlasgowExts `thenTc` \ gla_exts ->
-- Check that the class is unary, unless GlaExs
- checkTc (arity > 0) (nullaryClassErr cls) `thenTc_`
+ checkTc (not (null tyvars)) (nullaryClassErr cls) `thenTc_`
checkTc (gla_exts || unary) (classArityErr cls) `thenTc_`
-- Check the super-classes
checkTc (unary || no_generics) (genericMultiParamErr cls)
where
- (tyvars, theta, sel_ids, op_stuff) = classBigSig cls
- arity = length tyvars
- unary = arity == 1
+ (tyvars, theta, _, op_stuff) = classBigSig cls
+ unary = isSingleton tyvars
no_generics = null [() | (_, GenDefMeth) <- op_stuff]
check_op (sel_id, dm)
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
\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 ->
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
-- 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] ->
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}
let
meth_id = instToId meth
meth_name = idName meth_id
- sig_msg = ptext SLIT("When checking the expected type for class method") <+> ppr sel_id
meth_prags = find_prags (idName sel_id) meth_name prags
in
mkTcSig meth_id loc `thenNF_Tc` \ sig_info ->
-- We do this for each method independently to localise error messages
-- ...and this is why the call to tcExtendGlobalTyVars must be here
-- rather than in the caller
- tcAddErrCtxtM (sigCtxt sig_msg inst_tyvars inst_theta (idType meth_id)) $
+ tcAddErrCtxt (ptext SLIT("When checking the type of class method")
+ <+> quotes (ppr sel_id)) $
+ tcAddErrCtxtM (sigCtxt inst_tyvars inst_theta (idType meth_id)) $
checkSigTyVars inst_tyvars emptyVarSet `thenTc_`
returnTc (binds `AndMonoBinds` prag_binds1 `AndMonoBinds` prag_binds2,
-- 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
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}