module TcInstDcls (
tcInstDecls1,
tcInstDecls2,
- processInstBinds
+ tcMethodBind
) where
import HsSyn ( HsDecl(..), InstDecl(..), TyDecl, ClassDecl, DefaultDecl,
FixityDecl, IfaceSig, Sig(..),
- SpecInstSig(..), HsBinds(..), Bind(..),
- MonoBinds(..), GRHSsAndBinds, Match,
+ SpecInstSig(..), HsBinds(..),
+ MonoBinds(..), GRHSsAndBinds(..), GRHS(..), Match,
InPat(..), OutPat(..), HsExpr(..), HsLit(..),
Stmt, DoOrListComp, ArithSeqInfo, Fake, Fixity,
- HsType(..), HsTyVar )
+ HsType(..), HsTyVar,
+ SYN_IE(RecFlag), recursive, nonRecursive, collectMonoBinders,
+ andMonoBinds
+ )
import RnHsSyn ( SYN_IE(RenamedHsBinds), SYN_IE(RenamedMonoBinds),
- SYN_IE(RenamedInstDecl), SYN_IE(RenamedFixityDecl),
+ SYN_IE(RenamedInstDecl), SYN_IE(RenamedFixityDecl), SYN_IE(RenamedHsExpr),
SYN_IE(RenamedSig), SYN_IE(RenamedSpecInstSig), SYN_IE(RenamedHsDecl)
)
-import TcHsSyn ( TcIdOcc(..), SYN_IE(TcHsBinds),
+import TcHsSyn ( TcIdOcc(..), SYN_IE(TcIdBndr), SYN_IE(TcHsBinds),
SYN_IE(TcMonoBinds), SYN_IE(TcExpr), tcIdType,
mkHsTyLam, mkHsTyApp,
mkHsDictLam, mkHsDictApp )
-
+import TcBinds ( tcBindWithSigs, tcPragmaSigs, TcSigInfo(..), checkSigTyVars )
import TcMonad
import RnMonad ( SYN_IE(RnNameSupply) )
import Inst ( Inst, InstOrigin(..), SYN_IE(InstanceMapper),
- newDicts, newMethod, SYN_IE(LIE), emptyLIE, plusLIE )
-import TcBinds ( tcPragmaSigs, checkSigTyVars )
+ instToId, newDicts, newMethod, SYN_IE(LIE), emptyLIE, plusLIE )
+import PragmaInfo ( PragmaInfo(..) )
import TcDeriv ( tcDeriving )
-import TcEnv ( tcLookupClass, newLocalId, tcExtendGlobalTyVars )
+import TcEnv ( tcLookupClass, newLocalId, tcExtendGlobalTyVars, tcGetGlobalTyVars,
+ tcExtendGlobalValEnv, tcAddImportedIdInfo
+ )
import SpecEnv ( SpecEnv )
import TcGRHSs ( tcGRHSsAndBinds )
import TcInstUtil ( InstInfo(..), mkInstanceRelatedIds, buildInstanceEnvs )
import TcMonoType ( tcTyVarScope, tcContext, tcHsTypeKind )
import TcSimplify ( tcSimplifyAndCheck )
import TcType ( SYN_IE(TcType), SYN_IE(TcTyVar), SYN_IE(TcTyVarSet),
- tcInstSigTyVars, tcInstType, tcInstTheta, tcInstTcType
+ tcInstSigTyVars, tcInstType, tcInstSigTcType,
+ tcInstTheta, tcInstTcType, tcInstSigType
)
import Unify ( unifyTauTy, unifyTauTyLists )
import Bag ( emptyBag, unitBag, unionBags, unionManyBags,
- concatBag, foldBag, bagToList )
+ concatBag, foldBag, bagToList, listToBag,
+ Bag )
import CmdLineOpts ( opt_GlasgowExts, opt_CompilingGhcInternals,
- opt_OmitDefaultInstanceMethods,
+ opt_OmitDefaultInstanceMethods, opt_PprUserLength,
opt_SpecialiseOverloaded
)
-import Class ( GenClass, GenClassOp,
- classBigSig, classOps, classOpLocalType,
- classOpTagByOccName_maybe
+import Class ( GenClass,
+ classBigSig,
+ classDefaultMethodId, SYN_IE(Class)
)
-import Id ( GenId, idType, isDefaultMethodId_maybe, isNullaryDataCon, dataConArgTys )
-import PrelInfo ( isCcallishClass )
+import Id ( GenId, idType, replacePragmaInfo,
+ isNullaryDataCon, dataConArgTys, SYN_IE(Id) )
import ListSetOps ( minusList )
-import Maybes ( maybeToBool, expectJust )
-import Name ( getOccString, occNameString, moduleString, isLocallyDefined, OccName, Name{--O only-} )
-import PrelVals ( nO_EXPLICIT_METHOD_ERROR_ID )
-import PprType ( GenType, GenTyVar, GenClass, GenClassOp, TyCon,
+import Maybes ( maybeToBool, expectJust, seqMaybe, catMaybes )
+import Name ( nameOccName, getOccString, occNameString, moduleString, getSrcLoc,
+ isLocallyDefined, OccName, Name{--O only-}, SYN_IE(Module),
+ NamedThing(..)
+ )
+import PrelVals ( nO_EXPLICIT_METHOD_ERROR_ID, nO_DEFAULT_METHOD_ERROR_ID )
+import PprType ( GenType, GenTyVar, GenClass, TyCon,
pprParendGenType
)
-import PprStyle
-import SrcLoc ( SrcLoc )
+import Outputable
+import SrcLoc ( SrcLoc, noSrcLoc )
import Pretty
-import TyCon ( isSynTyCon, derivedFor )
+import TyCon ( isSynTyCon, isDataTyCon, derivedClasses )
import Type ( GenType(..), SYN_IE(ThetaType), mkTyVarTys, isPrimType,
splitSigmaTy, splitAppTys, isTyVarTy, matchTy, mkSigmaTy,
- getTyCon_maybe, maybeAppTyCon,
+ getTyCon_maybe, maybeAppTyCon, SYN_IE(Type), getTyVar,
maybeBoxedPrimType, maybeAppDataTyCon, splitRhoTy, eqTy
)
-import TyVar ( GenTyVar, SYN_IE(GenTyVarSet), mkTyVarSet, unionTyVarSets )
+import TyVar ( GenTyVar, SYN_IE(GenTyVarSet), tyVarSetToList,
+ mkTyVarSet, unionTyVarSets, SYN_IE(TyVar) )
import TysPrim ( byteArrayPrimTyCon, mutableByteArrayPrimTyCon )
import TysWiredIn ( stringTy )
-import Unique ( Unique, cCallableClassKey, cReturnableClassKey )
-import Util ( zipEqual, panic, pprPanic, pprTrace )
+import Unique ( Unique, cCallableClassKey, cReturnableClassKey, Uniquable(..) )
+import Util ( zipEqual, panic, pprPanic, pprTrace, removeDups, Ord3(..)
+#if __GLASGOW_HASKELL__ < 202
+ , trace
+#endif
+ )
\end{code}
Typechecking instance declarations is done in two passes. The first
\end{enumerate}
\begin{code}
-tcInstDecls1 :: [RenamedHsDecl]
+tcInstDecls1 :: TcEnv s -- Contains IdInfo for dfun ids
+ -> [RenamedHsDecl]
-> Module -- module name for deriving
-> RnNameSupply -- for renaming derivings
-> TcM s (Bag InstInfo,
RenamedHsBinds,
- PprStyle -> Pretty)
+ PprStyle -> Doc)
-tcInstDecls1 decls mod_name rn_name_supply
+tcInstDecls1 unf_env decls mod_name rn_name_supply
= -- Do the ordinary instance declarations
- mapNF_Tc (tcInstDecl1 mod_name)
+ mapNF_Tc (tcInstDecl1 unf_env mod_name)
[inst_decl | InstD inst_decl <- decls] `thenNF_Tc` \ inst_info_bags ->
let
decl_inst_info = unionManyBags inst_info_bags
returnTc (full_inst_info, deriv_binds, ddump_deriv)
-tcInstDecl1 :: Module -> RenamedInstDecl -> NF_TcM s (Bag InstInfo)
+tcInstDecl1 :: TcEnv s -> Module -> RenamedInstDecl -> NF_TcM s (Bag InstInfo)
-tcInstDecl1 mod_name (InstDecl poly_ty binds uprags (Just dfun_name) src_loc)
+tcInstDecl1 unf_env mod_name (InstDecl poly_ty binds uprags (Just dfun_name) src_loc)
= -- Prime error recovery, set source location
recoverNF_Tc (returnNF_Tc emptyBag) $
tcAddSrcLoc src_loc $
`thenTc` \ (inst_tycon,arg_tys) ->
-- Make the dfun id and constant-method ids
- mkInstanceRelatedIds dfun_name
- clas inst_tyvars inst_tau inst_theta
- `thenNF_Tc` \ (dfun_id, dfun_theta) ->
-
+ let
+ (dfun_id, dfun_theta) = mkInstanceRelatedIds dfun_name
+ clas inst_tyvars inst_tau inst_theta
+ -- Add info from interface file
+ final_dfun_id = tcAddImportedIdInfo unf_env dfun_id
+ in
returnTc (unitBag (InstInfo clas inst_tyvars inst_tau inst_theta
- dfun_theta dfun_id
+ dfun_theta final_dfun_id
binds src_loc uprags))
where
(tyvar_names, context, dict_ty) = case poly_ty of
other -> ([], [], poly_ty)
(class_name, inst_ty) = case dict_ty of
MonoDictTy cls ty -> (cls,ty)
- other -> pprPanic "Malformed intance decl" (ppr PprDebug poly_ty)
+ other -> pprPanic "Malformed instance decl" (ppr PprDebug poly_ty)
\end{code}
\begin{code}
tcInstDecls2 :: Bag InstInfo
- -> NF_TcM s (LIE s, TcHsBinds s)
+ -> NF_TcM s (LIE s, TcMonoBinds s)
tcInstDecls2 inst_decls
- = foldBag combine tcInstDecl2 (returnNF_Tc (emptyLIE, EmptyBinds)) inst_decls
+ = foldBag combine tcInstDecl2 (returnNF_Tc (emptyLIE, EmptyMonoBinds)) inst_decls
where
combine tc1 tc2 = tc1 `thenNF_Tc` \ (lie1, binds1) ->
tc2 `thenNF_Tc` \ (lie2, binds2) ->
returnNF_Tc (lie1 `plusLIE` lie2,
- binds1 `ThenBinds` binds2)
+ binds1 `AndMonoBinds` binds2)
\end{code}
First comes the easy case of a non-local instance decl.
\begin{code}
-tcInstDecl2 :: InstInfo
- -> NF_TcM s (LIE s, TcHsBinds s)
+tcInstDecl2 :: InstInfo -> NF_TcM s (LIE s, TcMonoBinds s)
tcInstDecl2 (InstInfo clas inst_tyvars inst_ty
inst_decl_theta dfun_theta
dfun_id monobinds
locn uprags)
| not (isLocallyDefined dfun_id)
+ = returnNF_Tc (emptyLIE, EmptyMonoBinds)
+
+{-
+ -- I deleted this "optimisation" because when importing these
+ -- instance decls the renamer would look for the dfun bindings and they weren't there.
+ -- This would be fixable, but it seems simpler just to produce a tiny void binding instead,
+ -- even though it's never used.
+
+ -- This case deals with CCallable etc, which don't need any bindings
+ | isNoDictClass clas
= returnNF_Tc (emptyLIE, EmptyBinds)
+-}
| otherwise
= -- Prime error recovery
- recoverNF_Tc (returnNF_Tc (emptyLIE, EmptyBinds)) $
- tcAddSrcLoc locn $
+ recoverNF_Tc (returnNF_Tc (emptyLIE, EmptyMonoBinds)) $
+ tcAddSrcLoc locn $
-- Get the class signature
tcInstSigTyVars inst_tyvars `thenNF_Tc` \ (inst_tyvars', _, tenv) ->
let
+ origin = InstanceDeclOrigin
(class_tyvar,
super_classes, sc_sel_ids,
- class_ops, op_sel_ids, defm_ids) = classBigSig clas
+ op_sel_ids, defm_ids) = classBigSig clas
in
tcInstType tenv inst_ty `thenNF_Tc` \ inst_ty' ->
tcInstTheta tenv dfun_theta `thenNF_Tc` \ dfun_theta' ->
tcInstTheta tenv inst_decl_theta `thenNF_Tc` \ inst_decl_theta' ->
let
sc_theta' = super_classes `zip` repeat inst_ty'
- origin = InstanceDeclOrigin
- mk_method sel_id = newMethod origin (RealId sel_id) [inst_ty']
in
-- Create dictionary Ids from the specified instance contexts.
newDicts origin sc_theta' `thenNF_Tc` \ (sc_dicts, sc_dict_ids) ->
newDicts origin inst_decl_theta' `thenNF_Tc` \ (inst_decl_dicts, _) ->
newDicts origin [(clas,inst_ty')] `thenNF_Tc` \ (this_dict, [this_dict_id]) ->
- -- Create method variables
- mapAndUnzipNF_Tc mk_method op_sel_ids `thenNF_Tc` \ (meth_insts_s, meth_ids) ->
+ -- Now process any INLINE or SPECIALIZE pragmas for the methods
+ -- ...[NB May 97; all ignored except INLINE]
+ tcPragmaSigs uprags `thenTc` \ (prag_fn, spec_binds, spec_lie) ->
- -- Collect available Insts
+ -- Check the method bindings
let
inst_tyvars_set' = mkTyVarSet inst_tyvars'
-
- avail_insts -- These insts are in scope; quite a few, eh?
- = unionManyBags (this_dict : dfun_arg_dicts : meth_insts_s)
-
- mk_method_expr
- = makeInstanceDeclDefaultMethodExpr locn clas meth_ids defm_ids inst_ty' this_dict_id
+ check_from_this_class (bndr, loc)
+ | nameOccName bndr `elem` sel_names = returnTc ()
+ | otherwise = recoverTc (returnTc ()) $
+ tcAddSrcLoc loc $
+ failTc (instBndrErr bndr clas)
+ sel_names = map getOccName op_sel_ids
in
+ mapTc check_from_this_class (bagToList (collectMonoBinders monobinds)) `thenTc_`
tcExtendGlobalTyVars inst_tyvars_set' (
- processInstBinds clas mk_method_expr avail_insts meth_ids monobinds
- ) `thenTc` \ (insts_needed, method_mbinds) ->
- let
- -- Create the dict and method binds
- dict_bind
- = VarMonoBind this_dict_id (Dictionary sc_dict_ids meth_ids)
+ tcExtendGlobalValEnv (catMaybes defm_ids) $
+ -- Default-method Ids may be mentioned in synthesised RHSs
+ mapAndUnzip3Tc (tcMethodBind clas inst_ty' monobinds)
+ (op_sel_ids `zip` defm_ids)
+ ) `thenTc` \ (method_binds_s, insts_needed_s, meth_lies_w_ids) ->
- dict_and_method_binds
- = dict_bind `AndMonoBinds` method_mbinds
-
- in
-- Check the overloading constraints of the methods and superclasses
- tcAddErrCtxt (bindSigCtxt meth_ids) (
- tcSimplifyAndCheck
+ let
+ (meth_lies, meth_ids) = unzip meth_lies_w_ids
+ avail_insts -- These insts are in scope; quite a few, eh?
+ = this_dict `plusLIE` dfun_arg_dicts `plusLIE` unionManyBags meth_lies
+ in
+ tcAddErrCtxt bindSigCtxt (
+ tcSimplifyAndCheck
inst_tyvars_set' -- Local tyvars
avail_insts
- (sc_dicts `unionBags` insts_needed) -- Need to get defns for all these
+ (sc_dicts `unionBags`
+ unionManyBags insts_needed_s) -- Need to get defns for all these
) `thenTc` \ (const_lie, super_binds) ->
-- Check that we *could* construct the superclass dictionaries,
-- the check ensures that the caller will never have a problem building
-- them.
tcAddErrCtxt superClassSigCtxt (
- tcSimplifyAndCheck
+ tcSimplifyAndCheck
inst_tyvars_set' -- Local tyvars
inst_decl_dicts -- The instance dictionaries available
sc_dicts -- The superclass dicationaries reqd
-- Ignore the result; we're only doing
-- this to make sure it can be done.
- -- Now process any SPECIALIZE pragmas for the methods
- let
- spec_sigs = [ s | s@(SpecSig _ _ _ _) <- uprags ]
- in
- tcPragmaSigs spec_sigs `thenTc` \ (_, spec_binds, spec_lie) ->
+ -- Create the result bindings
let
- -- Complete the binding group, adding any spec_binds
- inst_binds
+ dict_bind = VarMonoBind this_dict_id (Dictionary sc_dict_ids meth_ids)
+ method_binds = andMonoBinds method_binds_s
+
+ main_bind
= AbsBinds
inst_tyvars'
dfun_arg_dicts_ids
- [(this_dict_id, RealId dfun_id)]
- super_binds
- (RecBind dict_and_method_binds)
-
- `ThenBinds`
- spec_binds
+ [(inst_tyvars', RealId dfun_id, this_dict_id)]
+ (super_binds `AndMonoBinds`
+ method_binds `AndMonoBinds`
+ dict_bind)
in
-
- returnTc (const_lie `plusLIE` spec_lie, inst_binds)
-\end{code}
-
-The next function makes a default method which calls the global default method, at
-the appropriate instance type.
-
-See the notes under default decls in TcClassDcl.lhs.
-
-\begin{code}
-makeInstanceDeclDefaultMethodExpr
- :: SrcLoc
- -> Class
- -> [TcIdOcc s]
- -> [Id]
- -> TcType s
- -> TcIdOcc s
- -> Int
- -> NF_TcM s (TcExpr s)
-
-makeInstanceDeclDefaultMethodExpr src_loc clas meth_ids defm_ids inst_ty this_dict tag
- | not defm_is_err -- Not sure that the default method is just error message
- = -- def_op_id = defm_id inst_ty this_dict
- returnNF_Tc (mkHsDictApp (mkHsTyApp (HsVar (RealId defm_id)) [inst_ty]) [this_dict])
-
- | otherwise -- There's definitely no default decl in the class,
- -- so we produce a warning, and a better run=time error message too
- = warnTc True (omitDefaultMethodWarn clas_op clas_name inst_ty)
- `thenNF_Tc_`
-
- returnNF_Tc (HsApp (mkHsTyApp (HsVar (RealId nO_EXPLICIT_METHOD_ERROR_ID)) [tcIdType meth_id])
- (HsLitOut (HsString (_PK_ error_msg)) stringTy))
- where
- idx = tag - 1
- meth_id = meth_ids !! idx
- defm_id = defm_ids !! idx
-
- Just (_, _, defm_is_err) = isDefaultMethodId_maybe defm_id
-
- error_msg = ppShow 80 (ppSep [ppr PprForUser clas_op, ppPStr SLIT("at"), ppr PprForUser src_loc])
-
- clas_op = (classOps clas) !! idx
- clas_name = getOccString clas
+ returnTc (const_lie `plusLIE` spec_lie,
+ main_bind `AndMonoBinds` spec_binds)
\end{code}
-
%************************************************************************
%* *
\subsection{Processing each method}
%* *
%************************************************************************
-@processInstBinds@ returns a @MonoBinds@ which binds
-all the method ids (which are passed in). It is used
- - both for instance decls,
- - and to compile the default-method declarations in a class decl.
-
-Any method ids which don't have a binding have a suitable default
-binding created for them. The actual right-hand side used is
-created using a function which is passed in, because the right thing to
-do differs between instance and class decls.
-
\begin{code}
-processInstBinds
+tcMethodBind
:: Class
- -> (Int -> NF_TcM s (TcExpr s)) -- Function to make default method
- -> LIE s -- available Insts
- -> [TcIdOcc s] -- Local method ids in tag order
- -- (instance tyvars are free in their types)
- -> RenamedMonoBinds
- -> TcM s (LIE s, -- These are required
- TcMonoBinds s)
-
-processInstBinds clas mk_default_method_rhs avail_insts method_ids monobinds
- =
- -- Process the explicitly-given method bindings
- processInstBinds1 clas avail_insts method_ids monobinds
- `thenTc` \ (tags, insts_needed_in_methods, method_binds) ->
-
- -- Find the methods not handled, and make default method bindings for them.
+ -> TcType s -- Instance type
+ -> RenamedMonoBinds -- Method binding
+ -> (Id, Maybe Id) -- Selector id and default-method id
+ -> TcM s (TcMonoBinds s, LIE s, (LIE s, TcIdOcc s))
+
+tcMethodBind clas inst_ty meth_binds (sel_id, maybe_dm_id)
+ = newMethod origin (RealId sel_id) [inst_ty] `thenNF_Tc` \ meth@(_, TcId local_meth_id) ->
+ tcInstSigTcType (idType local_meth_id) `thenNF_Tc` \ (tyvars', rho_ty') ->
let
- unmentioned_tags = [1.. length method_ids] `minusList` tags
+ meth_name = getName local_meth_id
+
+ maybe_meth_bind = go (getOccName sel_id) meth_binds
+ (bndr_name, op_bind) = case maybe_meth_bind of
+ Just stuff -> stuff
+ Nothing -> (meth_name, mk_default_bind meth_name)
+
+ (theta', tau') = splitRhoTy rho_ty'
+ sig_info = TySigInfo bndr_name local_meth_id tyvars' theta' tau' noSrcLoc
in
- mapNF_Tc mk_default_method unmentioned_tags
- `thenNF_Tc` \ default_bind_list ->
- returnTc (insts_needed_in_methods,
- foldr AndMonoBinds method_binds default_bind_list)
+ -- Warn if no method binding
+ warnTc (not (maybeToBool maybe_meth_bind) && not (maybeToBool maybe_dm_id))
+ (omittedMethodWarn sel_id clas) `thenNF_Tc_`
+
+ tcBindWithSigs [bndr_name] op_bind [sig_info]
+ nonRecursive (\_ -> NoPragmaInfo) `thenTc` \ (binds, insts, _) ->
+
+ returnTc (binds, insts, meth)
where
- -- From a tag construct us the passed-in function to construct
- -- the binding for the default method
- mk_default_method tag = mk_default_method_rhs tag `thenNF_Tc` \ rhs ->
- returnNF_Tc (VarMonoBind (method_ids !! (tag-1)) rhs)
-\end{code}
+ origin = InstanceDeclOrigin -- Poor
-\begin{code}
-processInstBinds1
- :: Class
- -> LIE s -- available Insts
- -> [TcIdOcc s] -- Local method ids in tag order (instance tyvars are free),
- -> RenamedMonoBinds
- -> TcM s ([Int], -- Class-op tags accounted for
- LIE s, -- These are required
- TcMonoBinds s)
-
-processInstBinds1 clas avail_insts method_ids EmptyMonoBinds
- = returnTc ([], emptyLIE, EmptyMonoBinds)
-
-processInstBinds1 clas avail_insts method_ids (AndMonoBinds mb1 mb2)
- = processInstBinds1 clas avail_insts method_ids mb1
- `thenTc` \ (op_tags1,dicts1,method_binds1) ->
- processInstBinds1 clas avail_insts method_ids mb2
- `thenTc` \ (op_tags2,dicts2,method_binds2) ->
- returnTc (op_tags1 ++ op_tags2,
- dicts1 `unionBags` dicts2,
- AndMonoBinds method_binds1 method_binds2)
-\end{code}
+ go occ EmptyMonoBinds = Nothing
+ go occ (AndMonoBinds b1 b2) = go occ b1 `seqMaybe` go occ b2
-\begin{code}
-processInstBinds1 clas avail_insts method_ids mbind
- =
- -- Find what class op is being defined here. The complication is
- -- that we could have a PatMonoBind or a FunMonoBind. If the
- -- former, it should only bind a single variable, or else we're in
- -- trouble (I'm not sure what the static semantics of methods
- -- defined in a pattern binding with multiple patterns is!)
- -- Renamer has reduced us to these two cases.
- let
- (op,locn) = case mbind of
- FunMonoBind op _ _ locn -> (op, locn)
- PatMonoBind (VarPatIn op) _ locn -> (op, locn)
+ go occ b@(FunMonoBind op_name _ _ locn) | nameOccName op_name == occ = Just (op_name, b)
+ | otherwise = Nothing
+ go occ b@(PatMonoBind (VarPatIn op_name) _ locn) | nameOccName op_name == occ = Just (op_name, b)
+ | otherwise = Nothing
+ go occ other = panic "Urk! Bad instance method binding"
- occ = getOccName op
- origin = InstanceDeclOrigin
- in
- tcAddSrcLoc locn $
- -- Make a method id for the method
- let
- maybe_tag = classOpTagByOccName_maybe clas occ
- (Just tag) = maybe_tag
- method_id = method_ids !! (tag-1)
- method_ty = tcIdType method_id
- in
- -- check that the method mentioned is actually in the class:
- checkMaybeTc maybe_tag (instMethodNotInClassErr occ clas) `thenTc_`
+ mk_default_bind local_meth_name
+ = PatMonoBind (VarPatIn local_meth_name)
+ (GRHSsAndBindsIn [OtherwiseGRHS default_expr noSrcLoc] EmptyBinds)
+ noSrcLoc
- tcInstTcType method_ty `thenNF_Tc` \ (method_tyvars, method_rho) ->
- let
- (method_theta, method_tau) = splitRhoTy method_rho
- in
- newDicts origin method_theta `thenNF_Tc` \ (method_dicts,method_dict_ids) ->
-
- case (method_tyvars, method_dict_ids) of
-
- ([],[]) -> -- The simple case; no local polymorphism or overloading in the method
-
- -- Type check the method itself
- tcMethodBind method_id method_tau mbind `thenTc` \ (mbind', lieIop) ->
- returnTc ([tag], lieIop, mbind')
-
- other -> -- It's a locally-polymorphic and/or overloaded method; UGH!
-
- -- Make a new id for (a) the local, non-overloaded method
- -- and (b) the locally-overloaded method
- -- The latter is needed just so we can return an AbsBinds wrapped
- -- up inside a MonoBinds.
-
-
- -- Make the method_tyvars into signature tyvars so they
- -- won't get unified with anything.
- tcInstSigTyVars method_tyvars `thenNF_Tc` \ (sig_tyvars, sig_tyvar_tys, _) ->
- unifyTauTyLists sig_tyvar_tys (mkTyVarTys method_tyvars) `thenTc_`
-
- newLocalId occ method_tau `thenNF_Tc` \ local_id ->
- newLocalId occ method_ty `thenNF_Tc` \ copy_id ->
- let
- tc_local_id = TcId local_id
- tc_copy_id = TcId copy_id
- sig_tyvar_set = mkTyVarSet sig_tyvars
- in
- -- Typecheck the method
- tcMethodBind tc_local_id method_tau mbind `thenTc` \ (mbind', lieIop) ->
-
- -- Check the overloading part of the signature.
-
- -- =========== POSSIBLE BUT NOT DONE =================
- -- Simplify everything fully, even though some
- -- constraints could "really" be left to the next
- -- level out. The case which forces this is
- --
- -- class Foo a where { op :: Bar a => a -> a }
- --
- -- Here we must simplify constraints on "a" to catch all
- -- the Bar-ish things.
-
- -- We don't do this because it's currently illegal Haskell (not sure why),
- -- and because the local type of the method would have a context at
- -- the front with no for-all, which confuses the hell out of everything!
- -- ====================================================
-
- tcAddErrCtxt (methodSigCtxt op method_ty) (
- checkSigTyVars
- sig_tyvars method_tau `thenTc_`
-
- tcSimplifyAndCheck
- sig_tyvar_set
- (method_dicts `plusLIE` avail_insts)
- lieIop
- ) `thenTc` \ (f_dicts, dict_binds) ->
-
-
- returnTc ([tag],
- f_dicts,
- VarMonoBind method_id
- (HsLet
- (AbsBinds
- method_tyvars
- method_dict_ids
- [(tc_local_id, tc_copy_id)]
- dict_binds
- (NonRecBind mbind'))
- (HsVar tc_copy_id)))
-\end{code}
+ default_expr = case maybe_dm_id of
+ Just dm_id -> HsVar (getName dm_id) -- There's a default method
+ Nothing -> error_expr -- No default method
-\begin{code}
-tcMethodBind :: TcIdOcc s -> TcType s -> RenamedMonoBinds
- -> TcM s (TcMonoBinds s, LIE s)
-
-tcMethodBind meth_id meth_ty (FunMonoBind name inf matches locn)
- = tcMatchesFun name meth_ty matches `thenTc` \ (rhs', lie) ->
- returnTc (FunMonoBind meth_id inf rhs' locn, lie)
-
-tcMethodBind meth_id meth_ty pbind@(PatMonoBind pat grhss_and_binds locn)
- -- pat is sure to be a (VarPatIn op)
- = tcAddErrCtxt (patMonoBindsCtxt pbind) $
- tcGRHSsAndBinds grhss_and_binds `thenTc` \ (grhss_and_binds', lie, rhs_ty) ->
- unifyTauTy meth_ty rhs_ty `thenTc_`
- returnTc (PatMonoBind (VarPat meth_id) grhss_and_binds' locn, lie)
+ error_expr = HsApp (HsVar (getName nO_DEFAULT_METHOD_ERROR_ID))
+ (HsLit (HsString (_PK_ error_msg)))
+
+ error_msg = show (hcat [ppr (PprForUser opt_PprUserLength) (getSrcLoc sel_id), text "|",
+ ppr (PprForUser opt_PprUserLength) sel_id
+ ])
\end{code}
+
%************************************************************************
%* *
\subsection{Type-checking specialise instance pragmas}
getSwitchCheckerTc `thenNF_Tc` \ sw_chkr ->
(if sw_chkr SpecialiseTrace then
pprTrace "Specialised Instance: "
- (ppAboves [ppCat [if null simpl_theta then ppNil else ppr PprDebug simpl_theta,
- if null simpl_theta then ppNil else ppPStr SLIT("=>"),
+ (vcat [hsep [if null simpl_theta then empty else ppr PprDebug simpl_theta,
+ if null simpl_theta then empty else ptext SLIT("=>"),
ppr PprDebug clas,
pprParendGenType PprDebug inst_ty],
- ppCat [ppPStr SLIT(" derived from:"),
- if null unspec_theta then ppNil else ppr PprDebug unspec_theta,
- if null unspec_theta then ppNil else ppPStr SLIT("=>"),
+ hsep [ptext SLIT(" derived from:"),
+ if null unspec_theta then empty else ppr PprDebug unspec_theta,
+ if null unspec_theta then empty else ptext SLIT("=>"),
ppr PprDebug clas,
pprParendGenType PprDebug unspec_inst_ty]])
else id) (
= returnTc (inst_tycon,arg_tys)
-- TYVARS CHECK
- | not (all isTyVarTy arg_tys ||
- opt_GlasgowExts)
+ | not (opt_GlasgowExts ||
+ (all isTyVarTy arg_tys && null tyvar_dups)
+ )
= failTc (instTypeErr inst_tau)
-- DERIVING CHECK
-- for something that we are also planning to `derive'
-- Though we can have an explicit instance which is more
-- specific than the derived instance
- | clas `derivedFor` inst_tycon
+ | clas `elem` (derivedClasses inst_tycon)
&& all isTyVarTy arg_tys
= failTc (derivingWhenInstanceExistsErr clas inst_tycon)
(possible_tycon, arg_tys) = splitAppTys inst_tau
inst_tycon_maybe = getTyCon_maybe possible_tycon
inst_tycon = expectJust "tcInstDecls1:inst_tycon" inst_tycon_maybe
+ (_, tyvar_dups) = removeDups cmp (map (getTyVar "tcInstDecls1:getTyVarTy") arg_tys)
-- These conditions come directly from what the DsCCall is capable of.
-- Totally grotesque. Green card should solve this.
byte_arr_thing
where
byte_arr_thing = case maybeAppDataTyCon ty of
- Just (tycon, ty_args, [data_con]) ->
--- pprTrace "cc1" (ppSep [ppr PprDebug tycon, ppr PprDebug data_con,
--- ppSep (map (ppr PprDebug) data_con_arg_tys)])(
+ Just (tycon, ty_args, [data_con]) | isDataTyCon tycon ->
length data_con_arg_tys == 2 &&
maybeToBool maybe_arg2_tycon &&
--- pprTrace "cc2" (ppSep [ppr PprDebug arg2_tycon]) (
(arg2_tycon == byteArrayPrimTyCon ||
arg2_tycon == mutableByteArrayPrimTyCon)
--- ))
where
data_con_arg_tys = dataConArgTys data_con ty_args
(data_con_arg_ty1 : data_con_arg_ty2 : _) = data_con_arg_tys
instTypeErr ty sty
= case ty of
- SynTy tc _ _ -> ppBesides [ppPStr SLIT("The type synonym `"), ppr sty tc, rest_of_msg]
- TyVarTy tv -> ppBesides [ppPStr SLIT("The type variable `"), ppr sty tv, rest_of_msg]
- other -> ppBesides [ppPStr SLIT("The type `"), ppr sty ty, rest_of_msg]
+ SynTy tc _ _ -> hsep [ptext SLIT("The type synonym"), ppr sty tc, rest_of_msg]
+ TyVarTy tv -> hsep [ptext SLIT("The type variable"), ppr sty tv, rest_of_msg]
+ other -> sep [ptext SLIT("The type"), nest 4 (ppr sty ty), rest_of_msg]
where
- rest_of_msg = ppPStr SLIT("' cannot be used as an instance type.")
+ rest_of_msg = ptext SLIT("cannot be used as an instance type")
-derivingWhenInstanceExistsErr clas tycon sty
- = ppHang (ppBesides [ppPStr SLIT("Deriving class `"),
- ppr sty clas,
- ppPStr SLIT("' type `"), ppr sty tycon, ppChar '\''])
- 4 (ppPStr SLIT("when an explicit instance exists"))
+instBndrErr bndr clas sty
+ = hsep [ptext SLIT("Class"), ppr sty clas, ptext SLIT("does not have a method"), ppr sty bndr]
-derivingWhenInstanceImportedErr inst_mod clas tycon sty
- = ppHang (ppBesides [ppPStr SLIT("Deriving class `"),
+derivingWhenInstanceExistsErr clas tycon sty
+ = hang (hsep [ptext SLIT("Deriving class"),
ppr sty clas,
- ppPStr SLIT("' type `"), ppr sty tycon, ppChar '\''])
- 4 (ppBesides [ppPStr SLIT("when an instance declared in module `"),
- pp_mod, ppPStr SLIT("' has been imported")])
- where
- pp_mod = ppBesides [ppPStr SLIT("module `"), ppPStr inst_mod, ppChar '\'']
+ ptext SLIT("type"), ppr sty tycon])
+ 4 (ptext SLIT("when an explicit instance exists"))
nonBoxedPrimCCallErr clas inst_ty sty
- = ppHang (ppPStr SLIT("Unacceptable instance type for ccall-ish class"))
- 4 (ppBesides [ ppPStr SLIT("class `"), ppr sty clas, ppPStr SLIT("' type `"),
- ppr sty inst_ty, ppChar '\''])
+ = hang (ptext SLIT("Unacceptable instance type for ccall-ish class"))
+ 4 (hsep [ ptext SLIT("class"), ppr sty clas, ptext SLIT("type"),
+ ppr sty inst_ty])
-omitDefaultMethodWarn clas_op clas_name inst_ty sty
- = ppCat [ppPStr SLIT("Warning: Omitted default method for"),
- ppr sty clas_op, ppPStr SLIT("in instance"),
- ppStr clas_name, pprParendGenType sty inst_ty]
+omittedMethodWarn sel_id clas sty
+ = sep [ptext SLIT("No explicit method nor default method for") <+> ppr sty sel_id,
+ ptext SLIT("in an instance declaration for") <+> ppr sty clas]
instMethodNotInClassErr occ clas sty
- = ppHang (ppPStr SLIT("Instance mentions a method not in the class"))
- 4 (ppBesides [ppPStr SLIT("class `"), ppr sty clas, ppPStr SLIT("' method `"),
- ppr sty occ, ppChar '\''])
+ = hang (ptext SLIT("Instance mentions a method not in the class"))
+ 4 (hsep [ptext SLIT("class"), ppr sty clas, ptext SLIT("method"),
+ ppr sty occ])
patMonoBindsCtxt pbind sty
- = ppHang (ppPStr SLIT("In a pattern binding:"))
+ = hang (ptext SLIT("In a pattern binding:"))
4 (ppr sty pbind)
methodSigCtxt name ty sty
- = ppHang (ppBesides [ppPStr SLIT("When matching the definition of class method `"),
- ppr sty name, ppPStr SLIT("' to its signature :") ])
+ = hang (hsep [ptext SLIT("When matching the definition of class method"),
+ ppr sty name, ptext SLIT("to its signature :") ])
4 (ppr sty ty)
-bindSigCtxt method_ids sty
- = ppHang (ppPStr SLIT("When checking type signatures for: "))
- 4 (ppInterleave (ppStr ", ") (map (ppr sty) method_ids))
+bindSigCtxt sty
+ = ptext SLIT("When checking methods of an instance declaration")
superClassSigCtxt sty
- = ppPStr SLIT("When checking superclass constraints on instance declaration")
-
+ = ptext SLIT("When checking superclass constraints of an instance declaration")
\end{code}
projects / ghc-hetmet.git / blobdiff