import BasicTypes
import HscTypes
import BuildTyCl
+import TcUnify
import TcRnMonad
import TcEnv
import TcTyDecls
import Class
import TyCon
import DataCon
+import Id
import Var
import VarSet
import Name
import ListSetOps
import Digraph
import DynFlags
+import FastString
import Data.List
import Control.Monad ( mplus )
tcTyAndClassDecls :: ModDetails -> [LTyClDecl Name]
-> TcM TcGblEnv -- Input env extended by types and classes
-- and their implicit Ids,DataCons
+-- Fails if there are any errors
+
tcTyAndClassDecls boot_details allDecls
- = do { -- Omit instances of type families; they are handled together
+ = checkNoErrs $ -- The code recovers internally, but if anything gave rise to
+ -- an error we'd better stop now, to avoid a cascade
+ do { -- Omit instances of type families; they are handled together
-- with the *heads* of class instances
; let decls = filter (not . isFamInstDecl . unLoc) allDecls
; checkCycleErrs decls
; mod <- getModule
; traceTc (text "tcTyAndCl" <+> ppr mod)
- ; (syn_tycons, alg_tyclss) <- fixM (\ ~(rec_syn_tycons, rec_alg_tyclss) ->
+ ; (syn_tycons, alg_tyclss) <- fixM (\ ~(_rec_syn_tycons, rec_alg_tyclss) ->
do { let { -- Seperate ordinary synonyms from all other type and
-- class declarations and add all associated type
-- declarations from type classes. The latter is
; tcExtendGlobalEnv syn_tycons $ do
-- Type-check the data types and classes
- { alg_tyclss <- mappM tc_decl kc_alg_decls
+ { alg_tyclss <- mapM tc_decl kc_alg_decls
; return (syn_tycons, concat alg_tyclss)
}}})
-- Finished with knot-tying now
-- Perform the validity check
{ traceTc (text "ready for validity check")
- ; mappM_ (addLocM checkValidTyCl) decls
+ ; mapM_ (addLocM checkValidTyCl) decls
; traceTc (text "done")
-- Add the implicit things;
= (name, AClass cl)
mk_thing (L _ decl, ~(ATyCon tc))
= (tcdName decl, ATyCon tc)
+#if __GLASGOW_HASKELL__ < 605
+-- Old GHCs don't understand that ~... matches anything
+ mk_thing _ = panic "mkGlobalThings: Can't happen"
+#endif
\end{code}
tcFamInstDecl :: LTyClDecl Name -> TcM (Maybe TyThing) -- Nothing if error
tcFamInstDecl (L loc decl)
= -- Prime error recovery, set source location
- recoverM (returnM Nothing) $
+ recoverM (return Nothing) $
setSrcSpan loc $
tcAddDeclCtxt decl $
- do { -- type families require -ftype-families and can't be in an
+ do { -- type families require -XTypeFamilies and can't be in an
-- hs-boot file
- ; gla_exts <- doptM Opt_TypeFamilies
+ ; type_families <- doptM Opt_TypeFamilies
; is_boot <- tcIsHsBoot -- Are we compiling an hs-boot file?
- ; checkTc gla_exts $ badFamInstDecl (tcdLName decl)
+ ; checkTc type_families $ badFamInstDecl (tcdLName decl)
; checkTc (not is_boot) $ badBootFamInstDeclErr
- -- perform kind and type checking
- ; tcFamInstDecl1 decl
+ -- Perform kind and type checking
+ ; tc <- tcFamInstDecl1 decl
+ ; checkValidTyCon tc -- Remember to check validity;
+ -- no recursion to worry about here
+ ; return (Just (ATyCon tc))
}
-tcFamInstDecl1 :: TyClDecl Name -> TcM (Maybe TyThing) -- Nothing if error
+tcFamInstDecl1 :: TyClDecl Name -> TcM TyCon
-- "type instance"
tcFamInstDecl1 (decl@TySynonym {tcdLName = L loc tc_name})
; -- (1) kind check the right-hand side of the type equation
; k_rhs <- kcCheckHsType (tcdSynRhs decl) resKind
+ -- we need the exact same number of type parameters as the family
+ -- declaration
+ ; let famArity = tyConArity family
+ ; checkTc (length k_typats == famArity) $
+ wrongNumberOfParmsErr famArity
+
-- (2) type check type equation
; tcTyVarBndrs k_tvs $ \t_tvs -> do { -- turn kinded into proper tyvars
- ; t_typats <- mappM tcHsKindedType k_typats
+ ; t_typats <- mapM tcHsKindedType k_typats
; t_rhs <- tcHsKindedType k_rhs
- -- (3) check that
- -- - left-hand side contains no type family applications
- -- (vanilla synonyms are fine, though)
- ; mappM_ checkTyFamFreeness t_typats
-
- -- - the right-hand side is a tau type
- ; unless (isTauTy t_rhs) $
- addErr (polyTyErr t_rhs)
+ -- (3) check the well-formedness of the instance
+ ; checkValidTypeInst t_typats t_rhs
-- (4) construct representation tycon
; rep_tc_name <- newFamInstTyConName tc_name loc
- ; tycon <- buildSynTyCon rep_tc_name t_tvs (SynonymTyCon t_rhs)
- (Just (family, t_typats))
-
- ; return $ Just (ATyCon tycon)
+ ; buildSynTyCon rep_tc_name t_tvs (SynonymTyCon t_rhs)
+ (Just (family, t_typats))
}}
-- "newtype instance" and "data instance"
k_cons = tcdCons k_decl
-- result kind must be '*' (otherwise, we have too few patterns)
- ; checkTc (isLiftedTypeKind resKind) $ tooFewParmsErr tc_name
+ ; checkTc (isLiftedTypeKind resKind) $ tooFewParmsErr (tyConArity family)
-- (2) type check indexed data type declaration
; tcTyVarBndrs k_tvs $ \t_tvs -> do { -- turn kinded into proper tyvars
; unbox_strict <- doptM Opt_UnboxStrictFields
-- kind check the type indexes and the context
- ; t_typats <- mappM tcHsKindedType k_typats
+ ; t_typats <- mapM tcHsKindedType k_typats
; stupid_theta <- tcHsKindedContext k_ctxt
-- (3) Check that
-- - left-hand side contains no type family applications
- -- (vanilla synonyms are fine, though)
- ; mappM_ checkTyFamFreeness t_typats
+ -- (vanilla synonyms are fine, though, and we checked for
+ -- foralls earlier)
+ ; mapM_ checkTyFamFreeness t_typats
-- - we don't use GADT syntax for indexed types
; checkTc h98_syntax (badGadtIdxTyDecl tc_name)
-- (4) construct representation tycon
; rep_tc_name <- newFamInstTyConName tc_name loc
- ; tycon <- fixM (\ tycon -> do
- { data_cons <- mappM (addLocM (tcConDecl unbox_strict tycon t_tvs))
+ ; let ex_ok = True -- Existentials ok for type families!
+ ; fixM (\ tycon -> do
+ { data_cons <- mapM (addLocM (tcConDecl unbox_strict ex_ok tycon t_tvs))
k_cons
; tc_rhs <-
case new_or_data of
DataType -> return (mkDataTyConRhs data_cons)
- NewType -> ASSERT( isSingleton data_cons )
+ NewType -> ASSERT( not (null data_cons) )
mkNewTyConRhs rep_tc_name tycon (head data_cons)
; buildAlgTyCon rep_tc_name t_tvs stupid_theta tc_rhs Recursive
False h98_syntax (Just (family, t_typats))
-- dependency. (2) They are always valid loop breakers as
-- they involve a coercion.
})
-
- -- construct result
- ; return $ Just (ATyCon tycon)
}}
where
h98_syntax = case cons of -- All constructors have same shape
L _ (ConDecl { con_res = ResTyGADT _ }) : _ -> False
- other -> True
-
--- Check that a type index does not contain any type family applications
---
--- * Earlier phases have already checked that there are no foralls in the
--- type; we also cannot have PredTys and NoteTys are being skipped by using
--- the core view.
---
-checkTyFamFreeness :: Type -> TcM ()
-checkTyFamFreeness ty | Just (tycon, tys) <- splitTyConApp_maybe ty
- = if isSynTyCon tycon
- then addErr $ tyFamAppInIndexErr ty
- else mappM_ checkTyFamFreeness tys
- -- splitTyConApp_maybe uses the core view; hence,
- -- any synonym tycon must be a family tycon
-
- | Just (ty1, ty2) <- splitAppTy_maybe ty
- = checkTyFamFreeness ty1 >> checkTyFamFreeness ty2
-
- | otherwise -- only vars remaining
- = return ()
+ _ -> True
+tcFamInstDecl1 d = pprPanic "tcFamInstDecl1" (ppr d)
-- Kind checking of indexed types
-- -
-- type functions can have a higher-kinded result
; let resultKind = mkArrowKinds (drop (length hs_typats) kinds) resKind
- ; typats <- TcRnMonad.zipWithM kcCheckHsType hs_typats kinds
+ ; typats <- zipWithM kcCheckHsType hs_typats kinds
; thing_inside tvs typats resultKind family
}
where
initial kind environment. (This is handled by `allDecls').
\begin{code}
+kcTyClDecls :: [LTyClDecl Name] -> [Located (TyClDecl Name)]
+ -> TcM ([LTyClDecl Name], [Located (TyClDecl Name)])
kcTyClDecls syn_decls alg_decls
= do { -- First extend the kind env with each data type, class, and
-- indexed type, mapping them to a type variable
let initialKindDecls = concat [allDecls decl | L _ decl <- alg_decls]
- ; alg_kinds <- mappM getInitialKind initialKindDecls
+ ; alg_kinds <- mapM getInitialKind initialKindDecls
; tcExtendKindEnv alg_kinds $ do
-- Now kind-check the type synonyms, in dependency order
-- returning kind-annotated decls; we don't kind-check
-- instances of indexed types yet, but leave this to
-- `tcInstDecls1'
- { kc_alg_decls <- mappM (wrapLocM kcTyClDecl)
+ { kc_alg_decls <- mapM (wrapLocM kcTyClDecl)
(filter (not . isFamInstDecl . unLoc) alg_decls)
; return (kc_syn_decls, kc_alg_decls) }}}
mk_res_kind (TyData { tcdKindSig = Just kind }) = return kind
-- On GADT-style declarations we allow a kind signature
-- data T :: *->* where { ... }
- mk_res_kind other = return liftedTypeKind
+ mk_res_kind _ = return liftedTypeKind
----------------
kcSynDecl :: SCC (LTyClDecl Name)
-> TcM (LTyClDecl Name, -- Kind-annotated decls
(Name,TcKind)) -- Kind bindings
-kcSynDecl (AcyclicSCC ldecl@(L loc decl))
+kcSynDecl (AcyclicSCC (L loc decl))
= tcAddDeclCtxt decl $
kcHsTyVars (tcdTyVars decl) (\ k_tvs ->
do { traceTc (text "kcd1" <+> ppr (unLoc (tcdLName decl)) <+> brackets (ppr (tcdTyVars decl))
= do { recSynErr decls; failM } -- Fail here to avoid error cascade
-- of out-of-scope tycons
+kindedTyVarKind :: LHsTyVarBndr Name -> Kind
kindedTyVarKind (L _ (KindedTyVar _ k)) = k
+kindedTyVarKind x = pprPanic "kindedTyVarKind" (ppr x)
------------------------------------------------------------------------
kcTyClDecl :: TyClDecl Name -> TcM (TyClDecl Name)
kcTyClDeclBody decl $
kcDataDecl decl
-kcTyClDecl decl@(TyFamily {tcdKind = kind})
- = kcTyClDeclBody decl $ \ tvs' ->
- return (decl {tcdTyVars = tvs',
- tcdKind = kind `mplus` Just liftedTypeKind})
- -- default result kind is '*'
+kcTyClDecl decl@(TyFamily {})
+ = kcFamilyDecl [] decl -- the empty list signals a toplevel decl
kcTyClDecl decl@(ClassDecl {tcdCtxt = ctxt, tcdSigs = sigs, tcdATs = ats})
= kcTyClDeclBody decl $ \ tvs' ->
- do { is_boot <- tcIsHsBoot
- ; ctxt' <- kcHsContext ctxt
- ; ats' <- mappM (wrapLocM kcTyClDecl) ats
- ; sigs' <- mappM (wrapLocM kc_sig ) sigs
+ do { ctxt' <- kcHsContext ctxt
+ ; ats' <- mapM (wrapLocM (kcFamilyDecl tvs')) ats
+ ; sigs' <- mapM (wrapLocM kc_sig) sigs
; return (decl {tcdTyVars = tvs', tcdCtxt = ctxt', tcdSigs = sigs',
tcdATs = ats'}) }
where
kcTyClDecl decl@(ForeignType {})
= return decl
+kcTyClDecl (TySynonym {}) = panic "kcTyClDecl TySynonym"
+
kcTyClDeclBody :: TyClDecl Name
-> ([LHsTyVarBndr Name] -> TcM a)
-> TcM a
kcTyClDeclBody decl thing_inside
= tcAddDeclCtxt decl $
do { tc_ty_thing <- tcLookupLocated (tcdLName decl)
- ; let tc_kind = case tc_ty_thing of { AThing k -> k }
+ ; let tc_kind = case tc_ty_thing of
+ AThing k -> k
+ _ -> pprPanic "kcTyClDeclBody" (ppr tc_ty_thing)
(kinds, _) = splitKindFunTys tc_kind
hs_tvs = tcdTyVars decl
kinded_tvs = ASSERT( length kinds >= length hs_tvs )
kcDataDecl decl@(TyData {tcdND = new_or_data, tcdCtxt = ctxt, tcdCons = cons})
tvs
= do { ctxt' <- kcHsContext ctxt
- ; cons' <- mappM (wrapLocM kc_con_decl) cons
+ ; cons' <- mapM (wrapLocM kc_con_decl) cons
; return (decl {tcdTyVars = tvs, tcdCtxt = ctxt', tcdCons = cons'}) }
where
-- doc comments are typechecked to Nothing here
return (ConDecl name expl ex_tvs' ex_ctxt' details' res' Nothing)
kc_con_details (PrefixCon btys)
- = do { btys' <- mappM kc_larg_ty btys ; return (PrefixCon btys') }
+ = do { btys' <- mapM kc_larg_ty btys
+ ; return (PrefixCon btys') }
kc_con_details (InfixCon bty1 bty2)
- = do { bty1' <- kc_larg_ty bty1; bty2' <- kc_larg_ty bty2; return (InfixCon bty1' bty2') }
+ = do { bty1' <- kc_larg_ty bty1
+ ; bty2' <- kc_larg_ty bty2
+ ; return (InfixCon bty1' bty2') }
kc_con_details (RecCon fields)
- = do { fields' <- mappM kc_field fields; return (RecCon fields') }
+ = do { fields' <- mapM kc_field fields
+ ; return (RecCon fields') }
kc_field (ConDeclField fld bty d) = do { bty' <- kc_larg_ty bty
; return (ConDeclField fld bty' d) }
-- Can't allow an unlifted type for newtypes, because we're effectively
-- going to remove the constructor while coercing it to a lifted type.
-- And newtypes can't be bang'd
+kcDataDecl d _ = pprPanic "kcDataDecl" (ppr d)
+
+-- Kind check a family declaration or type family default declaration.
+--
+kcFamilyDecl :: [LHsTyVarBndr Name] -- tyvars of enclosing class decl if any
+ -> TyClDecl Name -> TcM (TyClDecl Name)
+kcFamilyDecl classTvs decl@(TyFamily {tcdKind = kind})
+ = kcTyClDeclBody decl $ \tvs' ->
+ do { mapM_ unifyClassParmKinds tvs'
+ ; return (decl {tcdTyVars = tvs',
+ tcdKind = kind `mplus` Just liftedTypeKind})
+ -- default result kind is '*'
+ }
+ where
+ unifyClassParmKinds (L _ (KindedTyVar n k))
+ | Just classParmKind <- lookup n classTyKinds = unifyKind k classParmKind
+ | otherwise = return ()
+ unifyClassParmKinds x = pprPanic "kcFamilyDecl/unifyClassParmKinds" (ppr x)
+ classTyKinds = [(n, k) | L _ (KindedTyVar n k) <- classTvs]
+kcFamilyDecl _ (TySynonym {}) -- type family defaults
+ = panic "TcTyClsDecls.kcFamilyDecl: not implemented yet"
+kcFamilyDecl _ d = pprPanic "kcFamilyDecl" (ppr d)
\end{code}
; return (syn_tc : syn_tcs) }
-- "type"
+tcSynDecl :: TyClDecl Name -> TcM TyThing
tcSynDecl
(TySynonym {tcdLName = L _ tc_name, tcdTyVars = tvs, tcdSynRhs = rhs_ty})
= tcTyVarBndrs tvs $ \ tvs' -> do
; tycon <- buildSynTyCon tc_name tvs' (SynonymTyCon rhs_ty') Nothing
; return (ATyCon tycon)
}
+tcSynDecl d = pprPanic "tcSynDecl" (ppr d)
--------------------
tcTyClDecl :: (Name -> RecFlag) -> TyClDecl Name -> TcM [TyThing]
= tcAddDeclCtxt decl (tcTyClDecl1 calc_isrec decl)
-- "type family" declarations
+tcTyClDecl1 :: (Name -> RecFlag) -> TyClDecl Name -> TcM [TyThing]
tcTyClDecl1 _calc_isrec
(TyFamily {tcdFlavour = TypeFamily,
tcdLName = L _ tc_name, tcdTyVars = tvs, tcdKind = Just kind})
{ traceTc (text "type family: " <+> ppr tc_name)
; idx_tys <- doptM Opt_TypeFamilies
- -- Check that we don't use families without -ftype-families
+ -- Check that we don't use families without -XTypeFamilies
; checkTc idx_tys $ badFamInstDecl tc_name
; tycon <- buildSynTyCon tc_name tvs' (OpenSynTyCon kind Nothing) Nothing
; return [ATyCon tycon]
}
- -- "newtype family" or "data family" declaration
+ -- "data family" declaration
tcTyClDecl1 _calc_isrec
(TyFamily {tcdFlavour = DataFamily,
tcdLName = L _ tc_name, tcdTyVars = tvs, tcdKind = mb_kind})
; idx_tys <- doptM Opt_TypeFamilies
- -- Check that we don't use families without -ftype-families
+ -- Check that we don't use families without -XTypeFamilies
; checkTc idx_tys $ badFamInstDecl tc_name
; tycon <- buildAlgTyCon tc_name final_tvs []
}
-- "newtype" and "data"
+ -- NB: not used for newtype/data instances (whether associated or not)
tcTyClDecl1 calc_isrec
(TyData {tcdND = new_or_data, tcdCtxt = ctxt, tcdTyVars = tvs,
tcdLName = L _ tc_name, tcdKindSig = mb_ksig, tcdCons = cons})
; stupid_theta <- tcHsKindedContext ctxt
; want_generic <- doptM Opt_Generics
; unbox_strict <- doptM Opt_UnboxStrictFields
- ; gla_exts <- doptM Opt_GlasgowExts
; empty_data_decls <- doptM Opt_EmptyDataDecls
; kind_signatures <- doptM Opt_KindSignatures
+ ; existential_ok <- doptM Opt_ExistentialQuantification
; gadt_ok <- doptM Opt_GADTs
; is_boot <- tcIsHsBoot -- Are we compiling an hs-boot file?
+ ; let ex_ok = existential_ok || gadt_ok -- Data cons can have existential context
-- Check that we don't use GADT syntax in H98 world
; checkTc (gadt_ok || h98_syntax) (badGadtDecl tc_name)
-- Check that the stupid theta is empty for a GADT-style declaration
; checkTc (null stupid_theta || h98_syntax) (badStupidTheta tc_name)
+ -- Check that a newtype has exactly one constructor
+ -- Do this before checking for empty data decls, so that
+ -- we don't suggest -XEmptyDataDecls for newtypes
+ ; checkTc (new_or_data == DataType || isSingleton cons)
+ (newtypeConError tc_name (length cons))
+
-- Check that there's at least one condecl,
-- or else we're reading an hs-boot file, or -XEmptyDataDecls
; checkTc (not (null cons) || empty_data_decls || is_boot)
(emptyConDeclsErr tc_name)
- -- Check that a newtype has exactly one constructor
- ; checkTc (new_or_data == DataType || isSingleton cons)
- (newtypeConError tc_name (length cons))
-
; tycon <- fixM (\ tycon -> do
- { data_cons <- mappM (addLocM (tcConDecl unbox_strict tycon final_tvs))
+ { data_cons <- mapM (addLocM (tcConDecl unbox_strict ex_ok tycon final_tvs))
cons
; tc_rhs <-
if null cons && is_boot -- In a hs-boot file, empty cons means
else case new_or_data of
DataType -> return (mkDataTyConRhs data_cons)
NewType ->
- ASSERT( isSingleton data_cons )
+ ASSERT( not (null data_cons) )
mkNewTyConRhs tc_name tycon (head data_cons)
; buildAlgTyCon tc_name final_tvs stupid_theta tc_rhs is_rec
(want_generic && canDoGenerics data_cons) h98_syntax Nothing
is_rec = calc_isrec tc_name
h98_syntax = case cons of -- All constructors have same shape
L _ (ConDecl { con_res = ResTyGADT _ }) : _ -> False
- other -> True
+ _ -> True
tcTyClDecl1 calc_isrec
(ClassDecl {tcdLName = L _ class_name, tcdTyVars = tvs,
tcdFDs = fundeps, tcdSigs = sigs, tcdATs = ats} )
= tcTyVarBndrs tvs $ \ tvs' -> do
{ ctxt' <- tcHsKindedContext ctxt
- ; fds' <- mappM (addLocM tc_fundep) fundeps
- ; atss <- mappM (addLocM (tcTyClDecl1 (const Recursive))) ats
+ ; fds' <- mapM (addLocM tc_fundep) fundeps
+ ; atss <- mapM (addLocM (tcTyClDecl1 (const Recursive))) ats
+ -- NB: 'ats' only contains "type family" and "data family"
+ -- declarations as well as type family defaults
; let ats' = zipWith setTyThingPoss atss (map (tcdTyVars . unLoc) ats)
; sig_stuff <- tcClassSigs class_name sigs meths
; clas <- fixM (\ clas ->
tycon_name = tyConName (classTyCon clas)
tc_isrec = calc_isrec tycon_name
in
- buildClass class_name tvs' ctxt' fds' ats'
+ buildClass False {- Must include unfoldings for selectors -}
+ class_name tvs' ctxt' fds' ats'
sig_stuff tc_isrec)
; return (AClass clas : ats')
-- NB: Order is important due to the call to `mkGlobalThings' when
-- tying the the type and class declaration type checking knot.
}
where
- tc_fundep (tvs1, tvs2) = do { tvs1' <- mappM tcLookupTyVar tvs1 ;
- ; tvs2' <- mappM tcLookupTyVar tvs2 ;
+ tc_fundep (tvs1, tvs2) = do { tvs1' <- mapM tcLookupTyVar tvs1 ;
+ ; tvs2' <- mapM tcLookupTyVar tvs2 ;
; return (tvs1', tvs2') }
-- For each AT argument compute the position of the corresponding class
ATyCon (setTyConArgPoss tycon poss)
setTyThingPoss _ _ = panic "TcTyClsDecls.setTyThingPoss"
-tcTyClDecl1 calc_isrec
+tcTyClDecl1 _
(ForeignType {tcdLName = L _ tc_name, tcdExtName = tc_ext_name})
- = returnM [ATyCon (mkForeignTyCon tc_name tc_ext_name liftedTypeKind 0)]
+ = return [ATyCon (mkForeignTyCon tc_name tc_ext_name liftedTypeKind 0)]
+
+tcTyClDecl1 _ d = pprPanic "tcTyClDecl1" (ppr d)
-----------------------------------
tcConDecl :: Bool -- True <=> -funbox-strict_fields
+ -> Bool -- True <=> -XExistentialQuantificaton or -XGADTs
-> TyCon -> [TyVar]
-> ConDecl Name
-> TcM DataCon
-tcConDecl unbox_strict tycon tc_tvs -- Data types
+tcConDecl unbox_strict existential_ok tycon tc_tvs -- Data types
(ConDecl name _ tvs ctxt details res_ty _)
- = tcTyVarBndrs tvs $ \ tvs' -> do
+ = addErrCtxt (dataConCtxt name) $
+ tcTyVarBndrs tvs $ \ tvs' -> do
{ ctxt' <- tcHsKindedContext ctxt
+ ; checkTc (existential_ok || (null tvs && null (unLoc ctxt)))
+ (badExistential name)
; (univ_tvs, ex_tvs, eq_preds, data_tc) <- tcResultType tycon tc_tvs tvs' res_ty
; let
-- Tiresome: tidy the tyvar binders, since tc_tvs and tvs' may have the same OccNames
tc_datacon is_infix field_lbls btys
= do { let bangs = map getBangStrictness btys
- ; arg_tys <- mappM tcHsBangType btys
+ ; arg_tys <- mapM tcHsBangType btys
; buildDataCon (unLoc name) is_infix
(argStrictness unbox_strict bangs arg_tys)
(map unLoc field_lbls)
where
-- choose_univs uses the res_ty itself if it's a type variable
-- and hasn't already been used; otherwise it uses one of the tc_tvs
- choose_univs used tc_tvs []
+ choose_univs _ tc_tvs []
= ASSERT( null tc_tvs ) []
choose_univs used (tc_tv:tc_tvs) (res_ty:res_tys)
| Just tv <- tcGetTyVar_maybe res_ty, not (tv `elem` used)
-- interface files and general confusion. So rename
-- the tc_tvs, since they are not used yet (no
-- consequential renaming needed)
+ choose_univs _ _ _ = panic "tcResultType/choose_univs"
init_occ_env = initTidyOccEnv (map getOccName dc_tvs)
(_, tidy_tc_tvs) = mapAccumL tidy_one init_occ_env tc_tvs
tidy_one env tv = (env', setTyVarName tv (tidyNameOcc name occ'))
HsStrict | unbox_strict_fields
&& can_unbox arg_ty -> MarkedUnboxed
HsUnbox | can_unbox arg_ty -> MarkedUnboxed
- other -> MarkedStrict
+ _ -> MarkedStrict
where
-- we can unbox if the type is a chain of newtypes with a product tycon
-- at the end
| null cls_cycles
= return ()
| otherwise
- = do { mappM_ recClsErr cls_cycles
+ = do { mapM_ recClsErr cls_cycles
; failM } -- Give up now, because later checkValidTyCl
-- will loop if the synonym is recursive
where
; case thing of
ATyCon tc -> checkValidTyCon tc
AClass cl -> checkValidClass cl
+ _ -> panic "checkValidTyCl"
; traceTc (text "Done validity of" <+> ppr thing)
}
OpenSynTyCon _ _ -> return ()
SynonymTyCon ty -> checkValidType syn_ctxt ty
| otherwise
- = -- Check the context on the data decl
- checkValidTheta (DataTyCtxt name) (tyConStupidTheta tc) `thenM_`
+ = do -- Check the context on the data decl
+ checkValidTheta (DataTyCtxt name) (tyConStupidTheta tc)
-- Check arg types of data constructors
- mappM_ (checkValidDataCon tc) data_cons `thenM_`
+ mapM_ (checkValidDataCon tc) data_cons
-- Check that fields with the same name share a type
- mappM_ check_fields groups
+ mapM_ check_fields groups
where
syn_ctxt = TySynCtxt name
-- result type against other candidates' types BOTH WAYS ROUND.
-- If they magically agrees, take the substitution and
-- apply them to the latter ones, and see if they match perfectly.
- check_fields fields@((label, con1) : other_fields)
+ check_fields ((label, con1) : other_fields)
-- These fields all have the same name, but are from
-- different constructors in the data type
= recoverM (return ()) $ mapM_ checkOne other_fields
(tvs2, _, _, res2) = dataConSig con2
ts2 = mkVarSet tvs2
fty2 = dataConFieldType con2 label
+ check_fields [] = panic "checkValidTyCon/check_fields []"
+checkFieldCompat :: Name -> DataCon -> DataCon -> TyVarSet
+ -> Type -> Type -> Type -> Type -> TcM ()
checkFieldCompat fld con1 con2 tvs1 res1 res2 fty1 fty2
= do { checkTc (isJust mb_subst1) (resultTypeMisMatch fld con1 con2)
; checkTc (isJust mb_subst2) (fieldTypeMisMatch fld con1 con2) }
addErrCtxt (dataConCtxt con) $
do { checkTc (dataConTyCon con == tc) (badDataConTyCon con)
; checkValidType ctxt (dataConUserType con)
- ; ifM (isNewTyCon tc) (checkNewDataCon con)
+ ; checkValidMonoType (dataConOrigResTy con)
+ -- Disallow MkT :: T (forall a. a->a)
+ -- Reason: it's really the argument of an equality constraint
+ ; when (isNewTyCon tc) (checkNewDataCon con)
}
where
ctxt = ConArgCtxt (dataConName con)
-- One argument
; checkTc (null eq_spec) (newtypePredError con)
-- Return type is (T a b c)
- ; checkTc (null ex_tvs && null theta) (newtypeExError con)
+ ; checkTc (null ex_tvs && null eq_theta && null dict_theta) (newtypeExError con)
-- No existentials
; checkTc (not (any isMarkedStrict (dataConStrictMarks con)))
(newtypeStrictError con)
-- No strictness
}
where
- (_univ_tvs, ex_tvs, eq_spec, theta, arg_tys, _res_ty) = dataConFullSig con
+ (_univ_tvs, ex_tvs, eq_spec, eq_theta, dict_theta, arg_tys, _res_ty) = dataConFullSig con
-------------------------------
checkValidClass :: Class -> TcM ()
checkValidClass cls
- = do { -- CHECK ARITY 1 FOR HASKELL 1.4
- gla_exts <- doptM Opt_GlasgowExts
+ = do { constrained_class_methods <- doptM Opt_ConstrainedClassMethods
; multi_param_type_classes <- doptM Opt_MultiParamTypeClasses
+ ; fundep_classes <- doptM Opt_FunctionalDependencies
-- Check that the class is unary, unless GlaExs
; checkTc (notNull tyvars) (nullaryClassErr cls)
; checkTc (multi_param_type_classes || unary) (classArityErr cls)
+ ; checkTc (fundep_classes || null fundeps) (classFunDepsErr cls)
-- Check the super-classes
; checkValidTheta (ClassSCCtxt (className cls)) theta
-- Check the class operations
- ; mappM_ (check_op gla_exts) op_stuff
+ ; mapM_ (check_op constrained_class_methods) op_stuff
-- Check that if the class has generic methods, then the
-- class has only one parameter. We can't do generic
; checkTc (unary || no_generics) (genericMultiParamErr cls)
}
where
- (tyvars, theta, _, op_stuff) = classBigSig cls
+ (tyvars, fundeps, theta, _, _, op_stuff) = classExtraBigSig cls
unary = isSingleton tyvars
no_generics = null [() | (_, GenDefMeth) <- op_stuff]
- check_op gla_exts (sel_id, dm)
+ check_op constrained_class_methods (sel_id, dm)
= addErrCtxt (classOpCtxt sel_id tau) $ do
{ checkValidTheta SigmaCtxt (tail theta)
-- The 'tail' removes the initial (C a) from the
-- class itself, leaving just the method type
+ ; traceTc (text "class op type" <+> ppr op_ty <+> ppr tau)
; checkValidType (FunSigCtxt op_name) tau
-- Check that the type mentions at least one of
op_ty = idType sel_id
(_,theta1,tau1) = tcSplitSigmaTy op_ty
(_,theta2,tau2) = tcSplitSigmaTy tau1
- (theta,tau) | gla_exts = (theta1 ++ theta2, tau2)
- | otherwise = (theta1, mkPhiTy (tail theta1) tau1)
+ (theta,tau) | constrained_class_methods = (theta1 ++ theta2, tau2)
+ | otherwise = (theta1, mkPhiTy (tail theta1) tau1)
-- Ugh! The function might have a type like
-- op :: forall a. C a => forall b. (Eq b, Eq a) => tau2
- -- With -fglasgow-exts, we want to allow this, even though the inner
+ -- With -XConstrainedClassMethods, we want to allow this, even though the inner
-- forall has an (Eq a) constraint. Whereas in general, each constraint
-- in the context of a for-all must mention at least one quantified
-- type variable. What a mess!
---------------------------------------------------------------------
+resultTypeMisMatch :: Name -> DataCon -> DataCon -> SDoc
resultTypeMisMatch field_name con1 con2
- = vcat [sep [ptext SLIT("Constructors") <+> ppr con1 <+> ptext SLIT("and") <+> ppr con2,
- ptext SLIT("have a common field") <+> quotes (ppr field_name) <> comma],
- nest 2 $ ptext SLIT("but have different result types")]
+ = vcat [sep [ptext (sLit "Constructors") <+> ppr con1 <+> ptext (sLit "and") <+> ppr con2,
+ ptext (sLit "have a common field") <+> quotes (ppr field_name) <> comma],
+ nest 2 $ ptext (sLit "but have different result types")]
+
+fieldTypeMisMatch :: Name -> DataCon -> DataCon -> SDoc
fieldTypeMisMatch field_name con1 con2
- = sep [ptext SLIT("Constructors") <+> ppr con1 <+> ptext SLIT("and") <+> ppr con2,
- ptext SLIT("give different types for field"), quotes (ppr field_name)]
+ = sep [ptext (sLit "Constructors") <+> ppr con1 <+> ptext (sLit "and") <+> ppr con2,
+ ptext (sLit "give different types for field"), quotes (ppr field_name)]
-dataConCtxt con = ptext SLIT("In the definition of data constructor") <+> quotes (ppr con)
+dataConCtxt :: Outputable a => a -> SDoc
+dataConCtxt con = ptext (sLit "In the definition of data constructor") <+> quotes (ppr con)
-classOpCtxt sel_id tau = sep [ptext SLIT("When checking the class method:"),
+classOpCtxt :: Var -> Type -> SDoc
+classOpCtxt sel_id tau = sep [ptext (sLit "When checking the class method:"),
nest 2 (ppr sel_id <+> dcolon <+> ppr tau)]
+nullaryClassErr :: Class -> SDoc
nullaryClassErr cls
- = ptext SLIT("No parameters for class") <+> quotes (ppr cls)
+ = ptext (sLit "No parameters for class") <+> quotes (ppr cls)
+classArityErr :: Class -> SDoc
classArityErr cls
- = vcat [ptext SLIT("Too many parameters for class") <+> quotes (ppr cls),
- parens (ptext SLIT("Use -XMultiParamTypeClasses to allow multi-parameter classes"))]
+ = vcat [ptext (sLit "Too many parameters for class") <+> quotes (ppr cls),
+ parens (ptext (sLit "Use -XMultiParamTypeClasses to allow multi-parameter classes"))]
+classFunDepsErr :: Class -> SDoc
+classFunDepsErr cls
+ = vcat [ptext (sLit "Fundeps in class") <+> quotes (ppr cls),
+ parens (ptext (sLit "Use -XFunctionalDependencies to allow fundeps"))]
+
+noClassTyVarErr :: Class -> Var -> SDoc
noClassTyVarErr clas op
- = sep [ptext SLIT("The class method") <+> quotes (ppr op),
- ptext SLIT("mentions none of the type variables of the class") <+>
+ = sep [ptext (sLit "The class method") <+> quotes (ppr op),
+ ptext (sLit "mentions none of the type variables of the class") <+>
ppr clas <+> hsep (map ppr (classTyVars clas))]
+genericMultiParamErr :: Class -> SDoc
genericMultiParamErr clas
- = ptext SLIT("The multi-parameter class") <+> quotes (ppr clas) <+>
- ptext SLIT("cannot have generic methods")
+ = ptext (sLit "The multi-parameter class") <+> quotes (ppr clas) <+>
+ ptext (sLit "cannot have generic methods")
+badGenericMethodType :: Name -> Kind -> SDoc
badGenericMethodType op op_ty
- = hang (ptext SLIT("Generic method type is too complex"))
+ = 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, lists, and tuples")])
+ ptext (sLit "You can only use type variables, arrows, lists, and tuples")])
+recSynErr :: [LTyClDecl Name] -> TcRn ()
recSynErr syn_decls
= setSrcSpan (getLoc (head sorted_decls)) $
- addErr (sep [ptext SLIT("Cycle in type synonym declarations:"),
+ addErr (sep [ptext (sLit "Cycle in type synonym declarations:"),
nest 2 (vcat (map ppr_decl sorted_decls))])
where
sorted_decls = sortLocated syn_decls
ppr_decl (L loc decl) = ppr loc <> colon <+> ppr decl
+recClsErr :: [Located (TyClDecl Name)] -> TcRn ()
recClsErr cls_decls
= setSrcSpan (getLoc (head sorted_decls)) $
- addErr (sep [ptext SLIT("Cycle in class declarations (via superclasses):"),
+ addErr (sep [ptext (sLit "Cycle in class declarations (via superclasses):"),
nest 2 (vcat (map ppr_decl sorted_decls))])
where
sorted_decls = sortLocated cls_decls
where
le (L l1 _) (L l2 _) = l1 <= l2
+badDataConTyCon :: DataCon -> SDoc
badDataConTyCon data_con
- = hang (ptext SLIT("Data constructor") <+> quotes (ppr data_con) <+>
- ptext SLIT("returns type") <+> quotes (ppr (dataConTyCon data_con)))
- 2 (ptext SLIT("instead of its parent type"))
+ = hang (ptext (sLit "Data constructor") <+> quotes (ppr data_con) <+>
+ ptext (sLit "returns type") <+> quotes (ppr (dataConTyCon data_con)))
+ 2 (ptext (sLit "instead of its parent type"))
+badGadtDecl :: Name -> SDoc
badGadtDecl tc_name
- = vcat [ ptext SLIT("Illegal generalised algebraic data declaration for") <+> quotes (ppr tc_name)
- , nest 2 (parens $ ptext SLIT("Use -X=GADT to allow GADTs")) ]
+ = vcat [ ptext (sLit "Illegal generalised algebraic data declaration for") <+> quotes (ppr tc_name)
+ , nest 2 (parens $ ptext (sLit "Use -XGADTs to allow GADTs")) ]
+
+badExistential :: Located Name -> SDoc
+badExistential con_name
+ = hang (ptext (sLit "Data constructor") <+> quotes (ppr con_name) <+>
+ ptext (sLit "has existential type variables, or a context"))
+ 2 (parens $ ptext (sLit "Use -XExistentialQuantification or -XGADTs to allow this"))
+badStupidTheta :: Name -> SDoc
badStupidTheta tc_name
- = ptext SLIT("A data type declared in GADT style cannot have a context:") <+> quotes (ppr tc_name)
+ = ptext (sLit "A data type declared in GADT style cannot have a context:") <+> quotes (ppr tc_name)
+newtypeConError :: Name -> Int -> SDoc
newtypeConError tycon n
- = sep [ptext SLIT("A newtype must have exactly one constructor,"),
- nest 2 $ ptext SLIT("but") <+> quotes (ppr tycon) <+> ptext SLIT("has") <+> speakN n ]
+ = sep [ptext (sLit "A newtype must have exactly one constructor,"),
+ nest 2 $ ptext (sLit "but") <+> quotes (ppr tycon) <+> ptext (sLit "has") <+> speakN n ]
+newtypeExError :: DataCon -> SDoc
newtypeExError con
- = sep [ptext SLIT("A newtype constructor cannot have an existential context,"),
- nest 2 $ ptext SLIT("but") <+> quotes (ppr con) <+> ptext SLIT("does")]
+ = sep [ptext (sLit "A newtype constructor cannot have an existential context,"),
+ nest 2 $ ptext (sLit "but") <+> quotes (ppr con) <+> ptext (sLit "does")]
+newtypeStrictError :: DataCon -> SDoc
newtypeStrictError con
- = sep [ptext SLIT("A newtype constructor cannot have a strictness annotation,"),
- nest 2 $ ptext SLIT("but") <+> quotes (ppr con) <+> ptext SLIT("does")]
+ = sep [ptext (sLit "A newtype constructor cannot have a strictness annotation,"),
+ nest 2 $ ptext (sLit "but") <+> quotes (ppr con) <+> ptext (sLit "does")]
+newtypePredError :: DataCon -> SDoc
newtypePredError con
- = sep [ptext SLIT("A newtype constructor must have a return type of form T a1 ... an"),
- nest 2 $ ptext SLIT("but") <+> quotes (ppr con) <+> ptext SLIT("does not")]
+ = sep [ptext (sLit "A newtype constructor must have a return type of form T a1 ... an"),
+ nest 2 $ ptext (sLit "but") <+> quotes (ppr con) <+> ptext (sLit "does not")]
+newtypeFieldErr :: DataCon -> Int -> SDoc
newtypeFieldErr con_name n_flds
- = sep [ptext SLIT("The constructor of a newtype must have exactly one field"),
- nest 2 $ ptext SLIT("but") <+> quotes (ppr con_name) <+> ptext SLIT("has") <+> speakN n_flds]
+ = sep [ptext (sLit "The constructor of a newtype must have exactly one field"),
+ nest 2 $ ptext (sLit "but") <+> quotes (ppr con_name) <+> ptext (sLit "has") <+> speakN n_flds]
+badSigTyDecl :: Name -> SDoc
badSigTyDecl tc_name
- = vcat [ ptext SLIT("Illegal kind signature") <+>
+ = vcat [ ptext (sLit "Illegal kind signature") <+>
quotes (ppr tc_name)
- , nest 2 (parens $ ptext SLIT("Use -XKindSignatures to allow kind signatures")) ]
+ , nest 2 (parens $ ptext (sLit "Use -XKindSignatures to allow kind signatures")) ]
+badFamInstDecl :: Outputable a => a -> SDoc
badFamInstDecl tc_name
- = vcat [ ptext SLIT("Illegal family instance for") <+>
+ = vcat [ ptext (sLit "Illegal family instance for") <+>
quotes (ppr tc_name)
- , nest 2 (parens $ ptext SLIT("Use -X=TypeFamilies to allow indexed type families")) ]
+ , nest 2 (parens $ ptext (sLit "Use -XTypeFamilies to allow indexed type families")) ]
+badGadtIdxTyDecl :: Name -> SDoc
badGadtIdxTyDecl tc_name
- = vcat [ ptext SLIT("Illegal generalised algebraic data declaration for") <+>
+ = vcat [ ptext (sLit "Illegal generalised algebraic data declaration for") <+>
quotes (ppr tc_name)
- , nest 2 (parens $ ptext SLIT("Family instances can not yet use GADT declarations")) ]
+ , nest 2 (parens $ ptext (sLit "Family instances can not yet use GADT declarations")) ]
+tooManyParmsErr :: Located Name -> SDoc
tooManyParmsErr tc_name
- = ptext SLIT("Family instance has too many parameters:") <+>
+ = ptext (sLit "Family instance has too many parameters:") <+>
quotes (ppr tc_name)
-tooFewParmsErr tc_name
- = ptext SLIT("Family instance has too few parameters:") <+>
- quotes (ppr tc_name)
+tooFewParmsErr :: Arity -> SDoc
+tooFewParmsErr arity
+ = ptext (sLit "Family instance has too few parameters; expected") <+>
+ ppr arity
+
+wrongNumberOfParmsErr :: Arity -> SDoc
+wrongNumberOfParmsErr exp_arity
+ = ptext (sLit "Number of parameters must match family declaration; expected")
+ <+> ppr exp_arity
+badBootFamInstDeclErr :: SDoc
badBootFamInstDeclErr =
- ptext SLIT("Illegal family instance in hs-boot file")
+ ptext (sLit "Illegal family instance in hs-boot file")
+wrongKindOfFamily :: TyCon -> SDoc
wrongKindOfFamily family =
- ptext SLIT("Wrong category of family instance; declaration was for a") <+>
+ ptext (sLit "Wrong category of family instance; declaration was for a") <+>
kindOfFamily
where
- kindOfFamily | isSynTyCon family = ptext SLIT("type synonym")
- | isAlgTyCon family = ptext SLIT("data type")
+ kindOfFamily | isSynTyCon family = ptext (sLit "type synonym")
+ | isAlgTyCon family = ptext (sLit "data type")
| otherwise = pprPanic "wrongKindOfFamily" (ppr family)
-polyTyErr ty
- = hang (ptext SLIT("Illegal polymorphic type in type instance") <> colon) 4 $
- ppr ty
-
-tyFamAppInIndexErr ty
- = hang (ptext SLIT("Illegal type family application in type instance") <>
- colon) 4 $
- ppr ty
-
+emptyConDeclsErr :: Name -> SDoc
emptyConDeclsErr tycon
- = sep [quotes (ppr tycon) <+> ptext SLIT("has no constructors"),
- nest 2 $ ptext SLIT("(-XEmptyDataDecls permits this)")]
+ = sep [quotes (ppr tycon) <+> ptext (sLit "has no constructors"),
+ nest 2 $ ptext (sLit "(-XEmptyDataDecls permits this)")]
\end{code}