module TcInstDcls (
tcInstDecls1,
- tcInstDecls2,
- processInstBinds
+ tcInstDecls2
) where
-import Ubiq
+IMP_Ubiq()
-import HsSyn ( InstDecl(..), FixityDecl, Sig(..),
- SpecInstSig(..), HsBinds(..), Bind(..),
- MonoBinds(..), GRHSsAndBinds, Match,
+import HsSyn ( HsDecl(..), InstDecl(..), TyDecl, ClassDecl, DefaultDecl,
+ FixityDecl, IfaceSig, Sig(..),
+ SpecInstSig(..), HsBinds(..),
+ MonoBinds(..), GRHSsAndBinds(..), GRHS(..), Match,
InPat(..), OutPat(..), HsExpr(..), HsLit(..),
- Stmt, Qual, ArithSeqInfo, Fake,
- PolyType(..), MonoType )
-import RnHsSyn ( RenamedHsBinds(..), RenamedMonoBinds(..),
- RenamedInstDecl(..), RenamedFixityDecl(..),
- RenamedSig(..), RenamedSpecInstSig(..),
- RnName(..){-incl instance Outputable-}
+ Stmt, DoOrListComp, ArithSeqInfo, Fake, Fixity,
+ HsType(..), HsTyVar,
+ SYN_IE(RecFlag), recursive, nonRecursive, collectMonoBinders,
+ andMonoBinds
)
-import TcHsSyn ( TcIdOcc(..), TcHsBinds(..),
- TcMonoBinds(..), TcExpr(..), tcIdType,
+import RnHsSyn ( SYN_IE(RenamedHsBinds), SYN_IE(RenamedMonoBinds),
+ SYN_IE(RenamedInstDecl), SYN_IE(RenamedFixityDecl), SYN_IE(RenamedHsExpr),
+ SYN_IE(RenamedSig), SYN_IE(RenamedSpecInstSig), SYN_IE(RenamedHsDecl)
+ )
+import TcHsSyn ( SYN_IE(TcHsBinds),
+ SYN_IE(TcMonoBinds), SYN_IE(TcExpr), tcIdType,
mkHsTyLam, mkHsTyApp,
mkHsDictLam, mkHsDictApp )
-
-import TcMonad hiding ( rnMtoTcM )
-import GenSpecEtc ( checkSigTyVars )
-import Inst ( Inst, InstOrigin(..), InstanceMapper(..),
- newDicts, newMethod, LIE(..), emptyLIE, plusLIE )
import TcBinds ( tcPragmaSigs )
+import TcClassDcl ( tcMethodBind )
+import TcMonad
+import RnMonad ( SYN_IE(RnNameSupply) )
+import Inst ( Inst, InstOrigin(..), SYN_IE(InstanceMapper),
+ instToId, newDicts, newMethod, SYN_IE(LIE), emptyLIE, plusLIE )
+import PragmaInfo ( PragmaInfo(..) )
import TcDeriv ( tcDeriving )
-import TcEnv ( tcLookupClass, tcTyVarScope, newLocalId )
+import TcEnv ( tcLookupClass, newLocalId, tcExtendGlobalTyVars, tcGetGlobalTyVars,
+ tcExtendGlobalValEnv, tcAddImportedIdInfo
+ )
+import SpecEnv ( SpecEnv )
import TcGRHSs ( tcGRHSsAndBinds )
import TcInstUtil ( InstInfo(..), mkInstanceRelatedIds, buildInstanceEnvs )
import TcKind ( TcKind, unifyKind )
import TcMatches ( tcMatchesFun )
-import TcMonoType ( tcContext, tcMonoTypeKind )
-import TcSimplify ( tcSimplifyAndCheck, tcSimplifyThetas )
-import TcType ( TcType(..), TcTyVar(..),
- tcInstSigTyVars, tcInstType, tcInstTheta
+import TcMonoType ( tcTyVarScope, tcContext, tcHsTypeKind )
+import TcSimplify ( tcSimplifyAndCheck )
+import TcType ( TcIdOcc(..), SYN_IE(TcIdBndr), SYN_IE(TcType), SYN_IE(TcTyVar), SYN_IE(TcTyVarSet),
+ tcInstSigTyVars, tcInstType, tcInstSigTcType,
+ tcInstTheta, tcInstTcType, tcInstSigType
)
-import Unify ( unifyTauTy )
+import Unify ( unifyTauTy, unifyTauTyLists )
import Bag ( emptyBag, unitBag, unionBags, unionManyBags,
- concatBag, foldBag, bagToList )
-import CmdLineOpts ( opt_GlasgowExts, opt_CompilingPrelude,
- opt_OmitDefaultInstanceMethods,
- opt_SpecialiseOverloaded )
-import Class ( GenClass, GenClassOp,
- isCcallishClass, classBigSig,
- classOps, classOpLocalType,
- classOpTagByString
+ concatBag, foldBag, bagToList, listToBag,
+ Bag )
+import CmdLineOpts ( opt_GlasgowExts, opt_OmitDefaultInstanceMethods,
+ opt_PprUserLength, opt_SpecialiseOverloaded
+ )
+import Class ( GenClass,
+ classBigSig,
+ classDefaultMethodId, SYN_IE(Class)
)
-import Id ( GenId, idType, isDefaultMethodId_maybe )
+import Id ( GenId, idType, replacePragmaInfo,
+ isNullaryDataCon, dataConArgTys, SYN_IE(Id) )
import ListSetOps ( minusList )
-import Maybes ( maybeToBool, expectJust )
-import Name ( getLocalName, origName, nameOf, Name{--O only-} )
-import PrelVals ( nO_EXPLICIT_METHOD_ERROR_ID )
-import PrelMods ( pRELUDE )
-import PprType ( GenType, GenTyVar, GenClass, GenClassOp, TyCon,
+import Maybes ( maybeToBool, expectJust, seqMaybe, catMaybes )
+import Name ( nameOccName, getSrcLoc, mkLocalName,
+ 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 Outputable
+import SrcLoc ( SrcLoc, noSrcLoc )
import Pretty
-import RnUtils ( RnEnv(..) )
-import TyCon ( isSynTyCon, derivedFor )
-import Type ( GenType(..), ThetaType(..), mkTyVarTys,
- splitSigmaTy, splitAppTy, isTyVarTy, matchTy, mkSigmaTy,
- getTyCon_maybe, maybeBoxedPrimType
+import TyCon ( isSynTyCon, isDataTyCon, derivedClasses )
+import Type ( GenType(..), SYN_IE(ThetaType), mkTyVarTys, isPrimType,
+ splitSigmaTy, splitAppTys, isTyVarTy, matchTy, mkSigmaTy,
+ getTyCon_maybe, maybeAppTyCon, SYN_IE(Type), getTyVar,
+ maybeBoxedPrimType, maybeAppDataTyCon, splitRhoTy, eqTy
)
-import TyVar ( GenTyVar, mkTyVarSet )
+import TyVar ( GenTyVar, SYN_IE(GenTyVarSet), tyVarSetToList,
+ mkTyVarSet, unionTyVarSets, SYN_IE(TyVar) )
+import TysPrim ( byteArrayPrimTyCon, mutableByteArrayPrimTyCon )
import TysWiredIn ( stringTy )
-import Unique ( Unique )
-import Util ( zipEqual, panic )
+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 :: Bag RenamedInstDecl
- -> [RenamedSpecInstSig]
+tcInstDecls1 :: TcEnv s -- Contains IdInfo for dfun ids
+ -> [RenamedHsDecl]
-> Module -- module name for deriving
- -> RnEnv -- for renaming derivings
- -> [RenamedFixityDecl] -- fixities for deriving
+ -> RnNameSupply -- for renaming derivings
-> TcM s (Bag InstInfo,
RenamedHsBinds,
- PprStyle -> Pretty)
+ PprStyle -> Doc)
-tcInstDecls1 inst_decls specinst_sigs mod_name rn_env fixities
+tcInstDecls1 unf_env decls mod_name rn_name_supply
= -- Do the ordinary instance declarations
- mapBagNF_Tc (tcInstDecl1 mod_name) inst_decls
- `thenNF_Tc` \ inst_info_bags ->
+ mapNF_Tc (tcInstDecl1 unf_env mod_name)
+ [inst_decl | InstD inst_decl <- decls] `thenNF_Tc` \ inst_info_bags ->
let
- decl_inst_info = concatBag inst_info_bags
+ decl_inst_info = unionManyBags inst_info_bags
in
-- Handle "derived" instances; note that we only do derivings
-- for things in this module; we ignore deriving decls from
-- interfaces! We pass fixities, because they may be used
-- in deriving Read and Show.
- tcDeriving mod_name rn_env decl_inst_info fixities
+ tcDeriving mod_name rn_name_supply decl_inst_info
`thenTc` \ (deriv_inst_info, deriv_binds, ddump_deriv) ->
let
- inst_info = deriv_inst_info `unionBags` decl_inst_info
- in
-{- LATER
- -- Handle specialise instance pragmas
- tcSpecInstSigs inst_info specinst_sigs
- `thenTc` \ spec_inst_info ->
--}
- let
- spec_inst_info = emptyBag -- For now
-
- full_inst_info = inst_info `unionBags` spec_inst_info
+ full_inst_info = deriv_inst_info `unionBags` decl_inst_info
in
returnTc (full_inst_info, deriv_binds, ddump_deriv)
-tcInstDecl1 :: FAST_STRING -> RenamedInstDecl -> NF_TcM s (Bag InstInfo)
+tcInstDecl1 :: TcEnv s -> Module -> RenamedInstDecl -> NF_TcM s (Bag InstInfo)
-tcInstDecl1 mod_name
- (InstDecl class_name
- poly_ty@(HsForAllTy tyvar_names context inst_ty)
- binds
- from_here inst_mod uprags pragmas 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 $
-- Look things up
- tcLookupClass class_name `thenNF_Tc` \ (clas_kind, clas) ->
+ tcLookupClass class_name `thenTc` \ (clas_kind, clas) ->
- let
- de_rn (RnName n) = n
- in
-- Typecheck the context and instance type
- tcTyVarScope (map de_rn tyvar_names) (\ tyvars ->
+ tcTyVarScope tyvar_names (\ tyvars ->
tcContext context `thenTc` \ theta ->
- tcMonoTypeKind inst_ty `thenTc` \ (tau_kind, tau) ->
+ tcHsTypeKind inst_ty `thenTc` \ (tau_kind, tau) ->
unifyKind clas_kind tau_kind `thenTc_`
returnTc (tyvars, theta, tau)
) `thenTc` \ (inst_tyvars, inst_theta, inst_tau) ->
-- Check for respectable instance type
- scrutiniseInstanceType from_here clas inst_tau
+ scrutiniseInstanceType dfun_name clas inst_tau
`thenTc` \ (inst_tycon,arg_tys) ->
- -- Deal with the case where we are deriving
- -- and importing the same instance
- if (not from_here && (clas `derivedFor` inst_tycon)
- && all isTyVarTy arg_tys)
- then
- if not opt_CompilingPrelude && maybeToBool inst_mod &&
- mod_name == expectJust "inst_mod" inst_mod
- then
- -- Imported instance came from this module;
- -- discard and derive fresh instance
- returnTc emptyBag
- else
- -- Imported instance declared in another module;
- -- report duplicate instance error
- failTc (derivingWhenInstanceImportedErr inst_mod clas inst_tycon)
- else
-
-- Make the dfun id and constant-method ids
- mkInstanceRelatedIds from_here src_loc inst_mod pragmas
- clas inst_tyvars inst_tau inst_theta uprags
- `thenTc` \ (dfun_id, dfun_theta, const_meth_ids) ->
-
+ 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 const_meth_ids
- binds from_here inst_mod src_loc uprags))
+ dfun_theta final_dfun_id
+ binds src_loc uprags))
+ where
+ (tyvar_names, context, dict_ty) = case poly_ty of
+ HsForAllTy tvs cxt dict_ty -> (tvs, cxt, dict_ty)
+ other -> ([], [], poly_ty)
+ (class_name, inst_ty) = case dict_ty of
+ MonoDictTy cls ty -> (cls,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 _ _ _ _ _ _ _ _ False{-import-} _ _ _)
- = returnNF_Tc (emptyLIE, EmptyBinds)
+tcInstDecl2 :: InstInfo -> NF_TcM s (LIE s, TcMonoBinds s)
tcInstDecl2 (InstInfo clas inst_tyvars inst_ty
inst_decl_theta dfun_theta
- dfun_id const_meth_ids monobinds
- True{-here-} inst_mod locn uprags)
+ 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 = newMethodId sel_id inst_ty' origin locn
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) ->
-
- -- Collect available Insts
- let
- avail_insts -- These insts are in scope; quite a few, eh?
- = unionManyBags (this_dict : dfun_arg_dicts : meth_insts_s)
+ -- 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) ->
- mk_method_expr
- = if opt_OmitDefaultInstanceMethods then
- makeInstanceDeclNoDefaultExpr origin meth_ids defm_ids inst_ty' clas inst_mod
- else
- makeInstanceDeclDefaultMethodExpr origin meth_ids defm_ids inst_ty' this_dict_id
- in
- processInstBinds clas mk_method_expr inst_tyvars' avail_insts meth_ids monobinds
- `thenTc` \ (insts_needed, method_mbinds) ->
+ -- Check the method bindings
let
- -- Create the dict and method binds
- dict_bind
- = VarMonoBind this_dict_id (Dictionary sc_dict_ids meth_ids)
-
- dict_and_method_binds
- = dict_bind `AndMonoBinds` method_mbinds
-
inst_tyvars_set' = mkTyVarSet inst_tyvars'
+ 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' (
+ tcExtendGlobalValEnv (catMaybes defm_ids) $
+ -- Default-method Ids may be mentioned in synthesised RHSs
+ mapAndUnzip3Tc (tcInstMethodBind clas inst_ty' monobinds)
+ (op_sel_ids `zip` defm_ids)
+ ) `thenTc` \ (method_binds_s, insts_needed_s, meth_lies_w_ids) ->
+
-- 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)
- : (meth_ids `zip` map RealId const_meth_ids))
- -- NB: const_meth_ids will often be empty
- 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}
-
-@mkMethodId@ manufactures an id for a local method.
-It's rather turgid stuff, because there are two cases:
-
- (a) For methods with no local polymorphism, we can make an Inst of the
- class-op selector function and a corresp InstId;
- which is good because then other methods which call
- this one will do so directly.
-
- (b) For methods with local polymorphism, we can't do this. For example,
-
- class Foo a where
- op :: (Num b) => a -> b -> a
-
- Here the type of the class-op-selector is
-
- forall a b. (Foo a, Num b) => a -> b -> a
-
- The locally defined method at (say) type Float will have type
-
- forall b. (Num b) => Float -> b -> Float
-
- and the one is not an instance of the other.
-
- So for these we just make a local (non-Inst) id with a suitable type.
-
-How disgusting.
-
-\begin{code}
-newMethodId sel_id inst_ty origin loc
- = let (sel_tyvars,sel_theta,sel_tau) = splitSigmaTy (idType sel_id)
- (_:meth_theta) = sel_theta -- The local theta is all except the
- -- first element of the context
- in
- case sel_tyvars of
- -- Ah! a selector for a class op with no local polymorphism
- -- Build an Inst for this
- [clas_tyvar] -> newMethod origin (RealId sel_id) [inst_ty]
-
- -- Ho! a selector for a class op with local polymorphism.
- -- Just make a suitably typed local id for this
- (clas_tyvar:local_tyvars) ->
- tcInstType [(clas_tyvar,inst_ty)]
- (mkSigmaTy local_tyvars meth_theta sel_tau)
- `thenNF_Tc` \ method_ty ->
- newLocalId (getLocalName sel_id) method_ty `thenNF_Tc` \ meth_id ->
- returnNF_Tc (emptyLIE, meth_id)
-\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
- :: InstOrigin s
- -> [TcIdOcc s]
- -> [Id]
- -> TcType s
- -> TcIdOcc s
- -> Int
- -> NF_TcM s (TcExpr s)
-
-makeInstanceDeclDefaultMethodExpr origin meth_ids defm_ids inst_ty this_dict tag
- = newDicts origin op_theta `thenNF_Tc` \ (op_lie,op_dicts) ->
-
- -- def_op_id = /\ op_tyvars -> \ op_dicts ->
- -- defm_id inst_ty op_tyvars this_dict op_dicts
- returnNF_Tc (
- mkHsTyLam op_tyvars (
- mkHsDictLam op_dicts (
- mkHsDictApp (mkHsTyApp (HsVar (RealId defm_id))
- (inst_ty : mkTyVarTys op_tyvars))
- (this_dict : op_dicts)
- )))
- where
- idx = tag - 1
- meth_id = meth_ids !! idx
- defm_id = defm_ids !! idx
- (op_tyvars, op_theta, op_tau) = splitSigmaTy (tcIdType meth_id)
-
-makeInstanceDeclNoDefaultExpr
- :: InstOrigin s
- -> [TcIdOcc s]
- -> [Id]
- -> TcType s
- -> Class
- -> Maybe Module
- -> Int
- -> NF_TcM s (TcExpr s)
-
-makeInstanceDeclNoDefaultExpr origin meth_ids defm_ids inst_ty clas inst_mod tag
- = newDicts origin op_theta `thenNF_Tc` \ (op_lie, op_dicts) ->
-
- -- Produce a warning if the default instance method
- -- has been omitted when one exists in the class
- warnTc (not err_defm_ok)
- (omitDefaultMethodWarn clas_op clas_name inst_ty)
- `thenNF_Tc_`
- returnNF_Tc (mkHsTyLam op_tyvars (
- mkHsDictLam op_dicts (
- HsApp (mkHsTyApp (HsVar (RealId nO_EXPLICIT_METHOD_ERROR_ID)) [op_tau])
- (HsLitOut (HsString (_PK_ error_msg)) stringTy))))
- where
- idx = tag - 1
- meth_id = meth_ids !! idx
- clas_op = (classOps clas) !! idx
- defm_id = defm_ids !! idx
- (op_tyvars,op_theta,op_tau) = splitSigmaTy (tcIdType meth_id)
-
- Just (_, _, err_defm_ok) = isDefaultMethodId_maybe defm_id
-
- mod_str = case inst_mod of { Nothing -> pRELUDE; Just m -> m }
-
- error_msg = _UNPK_ mod_str ++ "." ++ _UNPK_ clas_name ++ "."
- ++ (ppShow 80 (ppr PprForUser inst_ty)) ++ "."
- ++ (ppShow 80 (ppr PprForUser clas_op)) ++ "\""
-
- clas_name = nameOf (origName clas)
+ returnTc (const_lie `plusLIE` spec_lie,
+ main_bind `AndMonoBinds` spec_binds)
\end{code}
%* *
%************************************************************************
-@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
+tcInstMethodBind
:: Class
- -> (Int -> NF_TcM s (TcExpr s)) -- Function to make default method
- -> [TcTyVar s] -- Tyvars for this instance decl
- -> 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 inst_tyvars avail_insts method_ids monobinds
- =
- -- Process the explicitly-given method bindings
- processInstBinds1 clas inst_tyvars 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))
+
+tcInstMethodBind clas inst_ty meth_binds (sel_id, maybe_dm_id)
+ = tcGetSrcLoc `thenNF_Tc` \ loc ->
+ tcGetUnique `thenNF_Tc` \ uniq ->
let
- unmentioned_tags = [1.. length method_ids] `minusList` tags
+ meth_occ = getOccName sel_id
+ default_meth_name = mkLocalName uniq meth_occ loc
+ maybe_meth_bind = find meth_occ meth_binds
+ the_meth_bind = case maybe_meth_bind of
+ Just stuff -> stuff
+ Nothing -> mk_default_bind default_meth_name
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_`
+
+ -- Typecheck the method binding
+ tcMethodBind clas origin inst_ty sel_id the_meth_bind
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
- -> [TcTyVar s] -- Tyvars for this instance decl
- -> 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 inst_tyvars avail_insts method_ids EmptyMonoBinds
- = returnTc ([], emptyLIE, EmptyMonoBinds)
-
-processInstBinds1 clas inst_tyvars avail_insts method_ids (AndMonoBinds mb1 mb2)
- = processInstBinds1 clas inst_tyvars avail_insts method_ids mb1
- `thenTc` \ (op_tags1,dicts1,method_binds1) ->
- processInstBinds1 clas inst_tyvars 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}
+ find occ EmptyMonoBinds = Nothing
+ find occ (AndMonoBinds b1 b2) = find occ b1 `seqMaybe` find occ b2
-\begin{code}
-processInstBinds1 clas inst_tyvars 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)
+ find occ b@(FunMonoBind op_name _ _ _) | nameOccName op_name == occ = Just b
+ | otherwise = Nothing
+ find occ b@(PatMonoBind (VarPatIn op_name) _ _) | nameOccName op_name == occ = Just b
+ | otherwise = Nothing
+ find occ other = panic "Urk! Bad instance method binding"
- occ = getLocalName op
- origin = InstanceDeclOrigin
- in
- tcAddSrcLoc locn $
- -- Make a method id for the method
- let
- tag = classOpTagByString clas occ
- method_id = method_ids !! (tag-1)
- in
+ mk_default_bind local_meth_name
+ = PatMonoBind (VarPatIn local_meth_name)
+ (GRHSsAndBindsIn [OtherwiseGRHS default_expr noSrcLoc] EmptyBinds)
+ noSrcLoc
- -- The "method" might be a RealId, when processInstBinds is used by
- -- TcClassDcls:buildDefaultMethodBinds to make default-method bindings
- (case method_id of
- TcId id -> returnNF_Tc (idType id)
- RealId id -> tcInstType [] (idType id)
- ) `thenNF_Tc` \ method_ty ->
- let
- (method_tyvars, method_theta, method_tau) = splitSigmaTy method_ty
- 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.
-
- newLocalId occ method_tau `thenNF_Tc` \ local_id ->
- newLocalId occ method_ty `thenNF_Tc` \ copy_id ->
- let
- inst_method_tyvars = inst_tyvars ++ method_tyvars
- in
- -- Typecheck the method
- tcMethodBind local_id method_tau mbind `thenTc` \ (mbind', lieIop) ->
-
- -- Check the overloading part of the signature.
- -- 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.
- tcAddErrCtxt (methodSigCtxt op method_ty) (
- tcSimplifyAndCheck
- (mkTyVarSet inst_method_tyvars)
- (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
- [(local_id, copy_id)]
- dict_binds
- (NonRecBind mbind'))
- (HsVar 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}
clas = lookupCE ce class_name -- Renamer ensures this can't fail
-- Make some new type variables, named as in the specialised instance type
- ty_names = extractMonoTyNames ???is_tyvarish_name??? ty
+ ty_names = extractHsTyNames ???is_tyvarish_name??? ty
(tmpl_e,inst_tmpls,inst_tmpl_tys) = mkTVE ty_names
in
babyTcMtoTcM (tcInstanceType ce tce tmpl_e True src_loc ty)
copyTyVars inst_tmpls `thenNF_Tc` \ (tv_e, inst_tvs, inst_tv_tys) ->
let
Just (InstInfo _ unspec_tyvars unspec_inst_ty unspec_theta
- _ _ _ binds True{-from here-} mod _ uprag) = maybe_unspec_inst
+ _ _ binds _ uprag) = maybe_unspec_inst
subst = case matchTy unspec_inst_ty inst_ty of
Just subst -> subst
tv_tmpl_map = zipEqual "tcSpecInstSig" inst_tv_tys inst_tmpl_tys
tv_to_tmpl tv = assoc "tcSpecInstSig" tv_tmpl_map tv
in
- mkInstanceRelatedIds e True{-from here-} src_loc mod NoInstancePragmas
+ mkInstanceRelatedIds
clas inst_tmpls inst_ty simpl_theta uprag
- `thenTc` \ (dfun_id, dfun_theta, const_meth_ids) ->
+ `thenNF_Tc` \ (dfun_id, dfun_theta, const_meth_ids) ->
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 ppStr "=>",
+ (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 [ppStr " derived from:",
- if null unspec_theta then ppNil else ppr PprDebug unspec_theta,
- if null unspec_theta then ppNil else ppStr "=>",
+ 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 (unitBag (InstInfo clas inst_tmpls inst_ty simpl_theta
- dfun_theta dfun_id const_meth_ids
- binds True{-from here-} mod src_loc uprag))
+ dfun_theta dfun_id
+ binds src_loc uprag))
)))
We can also have instances for functions: @instance Foo (a -> b) ...@.
\begin{code}
-scrutiniseInstanceType from_here clas inst_tau
+scrutiniseInstanceType dfun_name clas inst_tau
-- TYCON CHECK
| not (maybeToBool inst_tycon_maybe) || isSynTyCon inst_tycon
= failTc (instTypeErr inst_tau)
-- IMPORTED INSTANCES ARE OK (but see tcInstDecl1)
- | from_here
+ | not (isLocallyDefined dfun_name)
= returnTc (inst_tycon,arg_tys)
-- TYVARS CHECK
- | not (all isTyVarTy arg_tys ||
- not from_here ||
- 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)
| -- CCALL CHECK
-- A user declaration of a CCallable/CReturnable instance
-- must be for a "boxed primitive" type.
- isCcallishClass clas
- && not opt_CompilingPrelude -- which allows anything
- && maybeToBool (maybeBoxedPrimType inst_tau)
+ (uniqueOf clas == cCallableClassKey && not (ccallable_type inst_tau)) ||
+ (uniqueOf clas == cReturnableClassKey && not (creturnable_type inst_tau))
= failTc (nonBoxedPrimCCallErr clas inst_tau)
| otherwise
= returnTc (inst_tycon,arg_tys)
where
- (possible_tycon, arg_tys) = splitAppTy inst_tau
+ (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.
+
+ccallable_type ty = isPrimType ty || -- Allow CCallable Int# etc
+ maybeToBool (maybeBoxedPrimType ty) || -- Ditto Int etc
+ ty `eqTy` stringTy ||
+ byte_arr_thing
+ where
+ byte_arr_thing = case maybeAppDataTyCon ty of
+ Just (tycon, ty_args, [data_con]) | isDataTyCon tycon ->
+ length data_con_arg_tys == 2 &&
+ maybeToBool maybe_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
+ maybe_arg2_tycon = maybeAppTyCon data_con_arg_ty2
+ Just (arg2_tycon,_) = maybe_arg2_tycon
+
+ other -> False
+
+creturnable_type ty = maybeToBool (maybeBoxedPrimType ty) ||
+ -- Or, a data type with a single nullary constructor
+ case (maybeAppDataTyCon ty) of
+ Just (tycon, tys_applied, [data_con])
+ -> isNullaryDataCon data_con
+ other -> False
\end{code}
\begin{code}
instTypeErr ty sty
= case ty of
- SynTy tc _ _ -> ppBesides [ppStr "The type synonym `", ppr sty tc, rest_of_msg]
- TyVarTy tv -> ppBesides [ppStr "The type variable `", ppr sty tv, rest_of_msg]
- other -> ppBesides [ppStr "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 = ppStr "' 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 [ppStr "Deriving class `", ppr sty clas, ppStr "' type `", ppr sty tycon, ppStr "'"])
- 4 (ppStr "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 [ppStr "Deriving class `", ppr sty clas, ppStr "' type `", ppr sty tycon, ppStr "'"])
- 4 (ppBesides [ppStr "when an instance declared in module `", pp_mod, ppStr "' has been imported"])
- where
- pp_mod = case inst_mod of
- Nothing -> ppPStr SLIT("the standard Prelude")
- Just m -> ppBesides [ppStr "module `", ppPStr m, ppStr "'"]
+derivingWhenInstanceExistsErr clas tycon sty
+ = hang (hsep [ptext SLIT("Deriving class"),
+ ppr sty clas,
+ ptext SLIT("type"), ppr sty tycon])
+ 4 (ptext SLIT("when an explicit instance exists"))
nonBoxedPrimCCallErr clas inst_ty sty
- = ppHang (ppStr "Instance isn't for a `boxed-primitive' type")
- 4 (ppBesides [ ppStr "class `", ppr sty clas, ppStr "' type `",
- ppr sty inst_ty, ppStr "'"])
+ = 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 [ppStr "Warning: Omitted default method for",
- ppr sty clas_op, ppStr "in instance",
- ppPStr 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
+ = 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 (ppStr "In a pattern binding:")
+ = hang (ptext SLIT("In a pattern binding:"))
4 (ppr sty pbind)
methodSigCtxt name ty sty
- = ppHang (ppBesides [ppStr "When matching the definition of class method `",
- ppr sty name, ppStr "' 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 (ppStr "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
- = ppStr "When checking superclass constraints on instance declaration"
-
+ = ptext SLIT("When checking superclass constraints of an instance declaration")
\end{code}
projects / ghc-hetmet.git / blobdiff