#include "HsVersions.h"
-import CmdLineOpts ( DynFlag(..), dopt )
+import CmdLineOpts ( DynFlag(..) )
import HsSyn ( HsDecl(..), InstDecl(..), TyClDecl(..), HsType(..),
- MonoBinds(..), HsExpr(..), HsLit(..), Sig(..),
- andMonoBindList, collectMonoBinders, isClassDecl
+ MonoBinds(..), HsExpr(..), HsLit(..), Sig(..), HsTyVarBndr(..),
+ andMonoBindList, collectMonoBinders,
+ isClassDecl, isIfaceInstDecl, toHsType
)
import RnHsSyn ( RenamedHsBinds, RenamedInstDecl, RenamedHsDecl,
RenamedMonoBinds, RenamedTyClDecl, RenamedHsType,
import TcBinds ( tcSpecSigs )
import TcClassDcl ( tcMethodBind, badMethodErr )
import TcMonad
-import TcType ( tcInstType )
-import Inst ( InstOrigin(..),
- newDicts, instToId,
+import TcMType ( tcInstSigType, checkValidTheta, checkValidInstHead, instTypeErr,
+ UserTypeCtxt(..), SourceTyCtxt(..) )
+import TcType ( mkClassPred, mkTyVarTy, mkTyVarTys, tcSplitForAllTys,
+ tcSplitSigmaTy, getClassPredTys, tcSplitPredTy_maybe,
+ TyVarDetails(..)
+ )
+import Inst ( InstOrigin(..), newDicts, instToId,
LIE, mkLIE, emptyLIE, plusLIE, plusLIEs )
import TcDeriv ( tcDeriving )
import TcEnv ( TcEnv, tcExtendGlobalValEnv,
- tcExtendTyVarEnvForMeths,
- tcAddImportedIdInfo, tcLookupClass,
+ tcExtendTyVarEnvForMeths, tcLookupId, tcLookupClass,
InstInfo(..), pprInstInfo, simpleInstInfoTyCon,
- simpleInstInfoTy, newDFunName, tcExtendTyVarEnv,
- isLocalThing,
+ simpleInstInfoTy, newDFunName
)
import InstEnv ( InstEnv, extendInstEnv )
-import TcMonoType ( tcTyVars, tcHsSigType, kcHsSigType, checkSigTyVars )
+import PprType ( pprClassPred )
+import TcMonoType ( tcHsTyVars, kcHsSigType, tcHsType, tcHsSigType )
+import TcUnify ( checkSigTyVars )
import TcSimplify ( tcSimplifyCheck )
import HscTypes ( HomeSymbolTable, DFunId,
ModDetails(..), PackageInstEnv, PersistentRenamerState
)
-
+import Subst ( substTy, substTheta )
import DataCon ( classDataCon )
-import Class ( Class, DefMeth(..), classBigSig )
+import Class ( Class, classBigSig )
import Var ( idName, idType )
import VarSet ( emptyVarSet )
-import Maybes ( maybeToBool )
-import MkId ( mkDictFunId )
+import Id ( setIdLocalExported )
+import MkId ( mkDictFunId, unsafeCoerceId, eRROR_ID )
import FunDeps ( checkInstFDs )
import Generics ( validGenericInstanceType )
import Module ( Module, foldModuleEnv )
import Name ( getSrcLoc )
-import NameSet ( emptyNameSet, mkNameSet, nameSetToList )
-import PrelInfo ( eRROR_ID )
-import PprType ( pprClassPred, pprPred )
-import TyCon ( TyCon, isSynTyCon )
-import Type ( splitDFunTy, isTyVarTy,
- splitTyConApp_maybe, splitDictTy,
- splitForAllTys,
- tyVarsOfTypes, mkClassPred, mkTyVarTy,
- isTyVarClassPred, inheritablePred
- )
+import NameSet ( unitNameSet, emptyNameSet, nameSetToList )
+import TyCon ( TyCon )
import Subst ( mkTopTyVarSubst, substTheta )
-import VarSet ( varSetElems )
-import TysWiredIn ( genericTyCons, isFFIArgumentTy, isFFIImportResultTy )
-import PrelNames ( cCallableClassKey, cReturnableClassKey, hasKey )
+import TysWiredIn ( genericTyCons )
import Name ( Name )
import SrcLoc ( SrcLoc )
-import VarSet ( varSetElems )
import Unique ( Uniquable(..) )
+import Util ( lengthExceeds, isSingleton )
import BasicTypes ( NewOrData(..), Fixity )
import ErrUtils ( dumpIfSet_dyn )
import ListSetOps ( Assoc, emptyAssoc, plusAssoc_C, mapAssoc,
- assocElts, extendAssoc_C,
- equivClassesByUniq, minusList
+ assocElts, extendAssoc_C, equivClassesByUniq, minusList
)
+import Maybe ( catMaybes )
import List ( partition )
import Outputable
\end{code}
inst_decls = [inst_decl | InstD inst_decl <- decls]
tycl_decls = [decl | TyClD decl <- decls]
clas_decls = filter isClassDecl tycl_decls
+ (imported_inst_ds, local_inst_ds) = partition isIfaceInstDecl inst_decls
in
-- (1) Do the ordinary instance declarations
- mapNF_Tc tcInstDecl1 inst_decls `thenNF_Tc` \ inst_infos ->
+ mapNF_Tc tcLocalInstDecl1 local_inst_ds `thenNF_Tc` \ local_inst_infos ->
+ mapNF_Tc tcImportedInstDecl1 imported_inst_ds `thenNF_Tc` \ imported_dfuns ->
-- (2) Instances from generic class declarations
getGenericInstances clas_decls `thenTc` \ generic_inst_info ->
-- e) generic instances inst_env4
-- The result of (b) replaces the cached InstEnv in the PCS
let
- (local_inst_info, imported_inst_info)
- = partition (isLocalThing this_mod . iDFunId) (concat inst_infos)
+ local_inst_info = catMaybes local_inst_infos
+ hst_dfuns = foldModuleEnv ((++) . md_insts) [] hst
+ in
+
+-- pprTrace "tcInstDecls" (vcat [ppr imported_dfuns, ppr hst_dfuns]) $
- imported_dfuns = map (tcAddImportedIdInfo unf_env . iDFunId)
- imported_inst_info
- hst_dfuns = foldModuleEnv ((++) . md_insts) [] hst
- in
addInstDFuns inst_env0 imported_dfuns `thenNF_Tc` \ inst_env1 ->
addInstDFuns inst_env1 hst_dfuns `thenNF_Tc` \ inst_env2 ->
addInstInfos inst_env2 local_inst_info `thenNF_Tc` \ inst_env3 ->
-- note that we only do derivings for things in this module;
-- we ignore deriving decls from interfaces!
-- This stuff computes a context for the derived instance decl, so it
- -- needs to know about all the instances possible; hecne inst_env4
+ -- needs to know about all the instances possible; hence inst_env4
tcDeriving prs this_mod inst_env4 get_fixity tycl_decls
`thenTc` \ (deriv_inst_info, deriv_binds) ->
addInstInfos inst_env4 deriv_inst_info `thenNF_Tc` \ final_inst_env ->
addInstInfos inst_env infos = addInstDFuns inst_env (map iDFunId infos)
addInstDFuns :: InstEnv -> [DFunId] -> NF_TcM InstEnv
-addInstDFuns dfuns infos
- = getDOptsTc `thenTc` \ dflags ->
+addInstDFuns inst_env dfuns
+ = getDOptsTc `thenNF_Tc` \ dflags ->
let
- (inst_env', errs) = extendInstEnv dflags dfuns infos
+ (inst_env', errs) = extendInstEnv dflags inst_env dfuns
in
addErrsTc errs `thenNF_Tc_`
+ traceTc (text "Adding instances:" <+> vcat (map pp dfuns)) `thenTc_`
returnTc inst_env'
+ where
+ pp dfun = ppr dfun <+> dcolon <+> ppr (idType dfun)
\end{code}
\begin{code}
-tcInstDecl1 :: RenamedInstDecl -> NF_TcM [InstInfo]
--- Deal with a single instance declaration
-tcInstDecl1 decl@(InstDecl poly_ty binds uprags maybe_dfun_name src_loc)
- = -- Prime error recovery, set source location
- recoverNF_Tc (returnNF_Tc []) $
- tcAddSrcLoc src_loc $
-
+tcImportedInstDecl1 :: RenamedInstDecl -> NF_TcM DFunId
+ -- An interface-file instance declaration
+ -- Should be in scope by now, because we should
+ -- have sucked in its interface-file definition
+ -- So it will be replete with its unfolding etc
+tcImportedInstDecl1 decl@(InstDecl poly_ty binds uprags (Just dfun_name) src_loc)
+ = tcLookupId dfun_name
+
+
+tcLocalInstDecl1 :: RenamedInstDecl
+ -> NF_TcM (Maybe InstInfo) -- Nothing if there was an error
+ -- A source-file instance declaration
-- Type-check all the stuff before the "where"
- tcAddErrCtxt (instDeclCtxt poly_ty) (
- tcHsSigType poly_ty
- ) `thenTc` \ poly_ty' ->
- let
- (tyvars, theta, clas, inst_tys) = splitDFunTy poly_ty'
- in
-
- (case maybe_dfun_name of
- Nothing -> -- A source-file instance declaration
-
- -- Check for respectable instance type, and context
- -- but only do this for non-imported instance decls.
- -- Imported ones should have been checked already, and may indeed
- -- contain something illegal in normal Haskell, notably
- -- instance CCallable [Char]
- getDOptsTc `thenTc` \ dflags ->
- checkInstValidity dflags theta clas inst_tys `thenTc_`
-
- -- Make the dfun id and return it
- newDFunName clas inst_tys src_loc `thenNF_Tc` \ dfun_name ->
- returnNF_Tc (True, dfun_name)
-
- Just dfun_name -> -- An interface-file instance declaration
- -- Make the dfun id
- returnNF_Tc (False, dfun_name)
- ) `thenNF_Tc` \ (is_local, dfun_name) ->
+ --
+ -- We check for respectable instance type, and context
+ -- but only do this for non-imported instance decls.
+ -- Imported ones should have been checked already, and may indeed
+ -- contain something illegal in normal Haskell, notably
+ -- instance CCallable [Char]
+tcLocalInstDecl1 decl@(InstDecl poly_ty binds uprags Nothing src_loc)
+ = -- Prime error recovery, set source location
+ recoverNF_Tc (returnNF_Tc Nothing) $
+ tcAddSrcLoc src_loc $
+ tcAddErrCtxt (instDeclCtxt poly_ty) $
+ -- Typecheck the instance type itself. We can't use
+ -- tcHsSigType, because it's not a valid user type.
+ kcHsSigType poly_ty `thenTc_`
+ tcHsType poly_ty `thenTc` \ poly_ty' ->
let
- dfun_id = mkDictFunId dfun_name clas tyvars inst_tys theta
+ (tyvars, theta, tau) = tcSplitSigmaTy poly_ty'
in
- returnTc [InstInfo { iDFunId = dfun_id,
- iBinds = binds, iPrags = uprags }]
+ checkValidTheta InstThetaCtxt theta `thenTc_`
+ checkValidInstHead tau `thenTc` \ (clas,inst_tys) ->
+ checkTc (checkInstFDs theta clas inst_tys)
+ (instTypeErr (pprClassPred clas inst_tys) msg) `thenTc_`
+ newDFunName clas inst_tys src_loc `thenNF_Tc` \ dfun_name ->
+ returnTc (Just (InstInfo { iDFunId = mkDictFunId dfun_name clas tyvars inst_tys theta,
+ iBinds = binds, iPrags = uprags }))
+ where
+ msg = parens (ptext SLIT("the instance types do not agree with the functional dependencies of the class"))
\end{code}
if null gen_inst_info then
returnTc []
else
- getDOptsTc `thenTc` \ dflags ->
+ getDOptsTc `thenNF_Tc` \ dflags ->
ioToTc (dumpIfSet_dyn dflags Opt_D_dump_deriv "Generic instances"
(vcat (map pprInstInfo gen_inst_info)))
`thenNF_Tc_`
| null groups
= returnTc [] -- The comon case: no generic default methods
- | otherwise -- A local class decl with generic default methods
+ | otherwise -- A source class decl with generic default methods
= recoverNF_Tc (returnNF_Tc []) $
tcAddDeclCtxt decl $
tcLookupClass class_name `thenTc` \ clas ->
tc_inst_infos = [(simpleInstInfoTyCon i, i) | i <- inst_infos]
bad_groups = [group | group <- equivClassesByUniq get_uniq tc_inst_infos,
- length group > 1]
+ group `lengthExceeds` 1]
get_uniq (tc,_) = getUnique tc
in
mapTc (addErrTc . dupGenericInsts) bad_groups `thenTc_`
-- For example: instance (C a, C b) => C (a+b) where { binds }
= -- Extract the universally quantified type variables
- tcTyVars (nameSetToList (extractHsTyVars hs_ty))
- (kcHsSigType hs_ty) `thenTc` \ tyvars ->
- tcExtendTyVarEnv tyvars $
+ let
+ sig_tvs = map UserTyVar (nameSetToList (extractHsTyVars hs_ty))
+ in
+ tcHsTyVars sig_tvs (kcHsSigType hs_ty) $ \ tyvars ->
-- Type-check the instance type, and check its form
- tcHsSigType hs_ty `thenTc` \ inst_ty ->
+ tcHsSigType GenPatCtxt hs_ty `thenTc` \ inst_ty ->
checkTc (validGenericInstanceType inst_ty)
(badGenericInstanceType binds) `thenTc_`
newDFunName clas [inst_ty] loc `thenNF_Tc` \ dfun_name ->
let
inst_theta = [mkClassPred clas [mkTyVarTy tv] | tv <- tyvars]
- inst_tys = [inst_ty]
- dfun_id = mkDictFunId dfun_name clas tyvars inst_tys inst_theta
+ dfun_id = mkDictFunId dfun_name clas tyvars [inst_ty] inst_theta
in
- returnTc (InstInfo { iDFunId = dfun_id,
- iBinds = binds, iPrags = [] })
+ returnTc (InstInfo { iDFunId = dfun_id, iBinds = binds, iPrags = [] })
\end{code}
\begin{code}
-tcInstDecl2 :: InstInfo -> NF_TcM (LIE, TcMonoBinds)
--- tcInstDecl2 is called *only* on InstInfos
+tcInstDecl2 :: InstInfo -> TcM (LIE, TcMonoBinds)
+
+tcInstDecl2 (NewTypeDerived { iDFunId = dfun_id })
+ = tcInstSigType InstTv (idType dfun_id) `thenNF_Tc` \ (inst_tyvars', dfun_theta', inst_head') ->
+ newDicts InstanceDeclOrigin dfun_theta' `thenNF_Tc` \ rep_dicts ->
+ let
+ rep_dict_id = ASSERT( isSingleton rep_dicts )
+ instToId (head rep_dicts) -- Derived newtypes have just one dict arg
+
+ body = TyLam inst_tyvars' $
+ DictLam [rep_dict_id] $
+ (HsVar unsafeCoerceId `TyApp` [idType rep_dict_id, inst_head'])
+ `HsApp`
+ (HsVar rep_dict_id)
+ -- You might wonder why we have the 'coerce'. It's because the
+ -- type equality mechanism isn't clever enough; see comments with Type.eqType.
+ -- So Lint complains if we don't have this.
+ in
+ returnTc (emptyLIE, VarMonoBind dfun_id body)
-tcInstDecl2 (InstInfo { iDFunId = dfun_id,
- iBinds = monobinds, iPrags = uprags })
+tcInstDecl2 (InstInfo { iDFunId = dfun_id, iBinds = monobinds, iPrags = uprags })
= -- Prime error recovery
- recoverNF_Tc (returnNF_Tc (emptyLIE, EmptyMonoBinds)) $
- tcAddSrcLoc (getSrcLoc dfun_id) $
+ recoverNF_Tc (returnNF_Tc (emptyLIE, EmptyMonoBinds)) $
+ tcAddSrcLoc (getSrcLoc dfun_id) $
+ tcAddErrCtxt (instDeclCtxt (toHsType (idType dfun_id))) $
-- Instantiate the instance decl with tc-style type variables
- tcInstType (idType dfun_id) `thenNF_Tc` \ (inst_tyvars', dfun_theta', dict_ty') ->
+ tcInstSigType InstTv (idType dfun_id) `thenNF_Tc` \ (inst_tyvars', dfun_theta', inst_head') ->
let
- (clas, inst_tys') = splitDictTy dict_ty'
- origin = InstanceDeclOrigin
-
+ Just pred = tcSplitPredTy_maybe inst_head'
+ (clas, inst_tys') = getClassPredTys pred
(class_tyvars, sc_theta, _, op_items) = classBigSig clas
- dm_ids = [dm_id | (_, DefMeth dm_id) <- op_items]
sel_names = [idName sel_id | (sel_id, _) <- op_items]
-- Instantiate the super-class context with inst_tys
sc_theta' = substTheta (mkTopTyVarSubst class_tyvars inst_tys') sc_theta
-- Find any definitions in monobinds that aren't from the class
- bad_bndrs = collectMonoBinders monobinds `minusList` sel_names
-
- -- The type variable from the dict fun actually scope
- -- over the bindings. They were gotten from
- -- the original instance declaration
- (inst_tyvars, _) = splitForAllTys (idType dfun_id)
+ bad_bndrs = collectMonoBinders monobinds `minusList` sel_names
+ (inst_tyvars, _) = tcSplitForAllTys (idType dfun_id)
+ origin = InstanceDeclOrigin
in
-- Check that all the method bindings come from this class
mapTc (addErrTc . badMethodErr clas) bad_bndrs `thenNF_Tc_`
newDicts origin [mkClassPred clas inst_tys'] `thenNF_Tc` \ [this_dict] ->
tcExtendTyVarEnvForMeths inst_tyvars inst_tyvars' (
- tcExtendGlobalValEnv dm_ids (
- -- Default-method Ids may be mentioned in synthesised RHSs
+ -- The type variable from the dict fun actually scope
+ -- over the bindings. They were gotten from
+ -- the original instance declaration
+
+ -- Default-method Ids may be mentioned in synthesised RHSs,
+ -- but they'll already be in the environment.
mapAndUnzip3Tc (tcMethodBind clas origin inst_tyvars' inst_tys'
dfun_theta'
monobinds uprags True)
op_items
- )) `thenTc` \ (method_binds_s, insts_needed_s, meth_insts) ->
+ ) `thenTc` \ (method_binds_s, insts_needed_s, meth_insts) ->
-- Deal with SPECIALISE instance pragmas by making them
-- look like SPECIALISE pragmas for the dfun
-- Create the result bindings
let
+ local_dfun_id = setIdLocalExported dfun_id
+ -- Reason for setIdLocalExported: see notes with MkId.mkDictFunId
+
dict_constr = classDataCon clas
scs_and_meths = map instToId (sc_dicts ++ meth_insts)
this_dict_id = instToId this_dict
- inlines = mkNameSet [idName dfun_id | InlineInstSig _ _ <- uprags]
+ inlines | null dfun_arg_dicts = emptyNameSet
+ | otherwise = unitNameSet (idName dfun_id)
+ -- Always inline the dfun; this is an experimental decision
+ -- because it makes a big performance difference sometimes.
+ -- Often it means we can do the method selection, and then
+ -- inline the method as well. Marcin's idea; see comments below.
+ --
+ -- BUT: don't inline it if it's a constant dictionary;
+ -- we'll get all the benefit without inlining, and we get
+ -- a **lot** of code duplication if we inline it
dict_rhs
| null scs_and_meths
= AbsBinds
zonked_inst_tyvars
(map instToId dfun_arg_dicts)
- [(inst_tyvars', dfun_id, this_dict_id)]
+ [(inst_tyvars', local_dfun_id, this_dict_id)]
inlines
(lie_binds1 `AndMonoBinds`
lie_binds2 `AndMonoBinds`
main_bind `AndMonoBinds` prag_binds)
\end{code}
-
-%************************************************************************
-%* *
-\subsection{Checking for a decent instance type}
-%* *
-%************************************************************************
-
-@scrutiniseInstanceHead@ checks the type {\em and} its syntactic constraints:
-it must normally look like: @instance Foo (Tycon a b c ...) ...@
-
-The exceptions to this syntactic checking: (1)~if the @GlasgowExts@
-flag is on, or (2)~the instance is imported (they must have been
-compiled elsewhere). In these cases, we let them go through anyway.
-
-We can also have instances for functions: @instance Foo (a -> b) ...@.
-
-\begin{code}
-checkInstValidity dflags theta clas inst_tys
- | null errs = returnTc ()
- | otherwise = addErrsTc errs `thenNF_Tc_` failTc
- where
- errs = checkInstHead dflags theta clas inst_tys ++
- [err | pred <- theta, err <- checkInstConstraint dflags pred]
-
-checkInstConstraint dflags pred
- -- Checks whether a predicate is legal in the
- -- context of an instance declaration
- | ok = []
- | otherwise = [instConstraintErr pred]
- where
- ok = inheritablePred pred &&
- (isTyVarClassPred pred || arbitrary_preds_ok)
-
- arbitrary_preds_ok = dopt Opt_AllowUndecidableInstances dflags
-
-
-checkInstHead dflags theta clas inst_taus
- | -- CCALL CHECK
- -- A user declaration of a CCallable/CReturnable instance
- -- must be for a "boxed primitive" type.
- (clas `hasKey` cCallableClassKey
- && not (ccallable_type dflags first_inst_tau))
- ||
- (clas `hasKey` cReturnableClassKey
- && not (creturnable_type first_inst_tau))
- = [nonBoxedPrimCCallErr clas first_inst_tau]
-
- -- If GlasgowExts then check at least one isn't a type variable
- | dopt Opt_GlasgowExts dflags
- = -- GlasgowExts case
- check_tyvars dflags clas inst_taus ++ check_fundeps dflags theta clas inst_taus
-
- -- WITH HASKELL 1.4, MUST HAVE C (T a b c)
- | not (length inst_taus == 1 &&
- maybeToBool maybe_tycon_app && -- Yes, there's a type constuctor
- not (isSynTyCon tycon) && -- ...but not a synonym
- all isTyVarTy arg_tys && -- Applied to type variables
- length (varSetElems (tyVarsOfTypes arg_tys)) == length arg_tys
- -- This last condition checks that all the type variables are distinct
- )
- = [instTypeErr clas inst_taus
- (text "the instance type must be of form (T a b c)" $$
- text "where T is not a synonym, and a,b,c are distinct type variables")]
-
- | otherwise
- = []
-
- where
- (first_inst_tau : _) = inst_taus
-
- -- Stuff for algebraic or -> type
- maybe_tycon_app = splitTyConApp_maybe first_inst_tau
- Just (tycon, arg_tys) = maybe_tycon_app
-
- ccallable_type dflags ty = isFFIArgumentTy dflags False {- Not safe call -} ty
- creturnable_type ty = isFFIImportResultTy dflags ty
-
-check_tyvars dflags clas inst_taus
- -- Check that at least one isn't a type variable
- -- unless -fallow-undecideable-instances
- | dopt Opt_AllowUndecidableInstances dflags = []
- | not (all isTyVarTy inst_taus) = []
- | otherwise = [the_err]
- where
- the_err = instTypeErr clas inst_taus msg
- msg = ptext SLIT("There must be at least one non-type-variable in the instance head")
-
-check_fundeps dflags theta clas inst_taus
- | checkInstFDs theta clas inst_taus = []
- | otherwise = [the_err]
- where
- the_err = instTypeErr clas inst_taus msg
- msg = ptext SLIT("the instance types do not agree with the functional dependencies of the class")
-\end{code}
+ ------------------------------
+ Inlining dfuns unconditionally
+ ------------------------------
+
+The code above unconditionally inlines dict funs. Here's why.
+Consider this program:
+
+ test :: Int -> Int -> Bool
+ test x y = (x,y) == (y,x) || test y x
+ -- Recursive to avoid making it inline.
+
+This needs the (Eq (Int,Int)) instance. If we inline that dfun
+the code we end up with is good:
+
+ Test.$wtest =
+ \r -> case ==# [ww ww1] of wild {
+ PrelBase.False -> Test.$wtest ww1 ww;
+ PrelBase.True ->
+ case ==# [ww1 ww] of wild1 {
+ PrelBase.False -> Test.$wtest ww1 ww;
+ PrelBase.True -> PrelBase.True [];
+ };
+ };
+ Test.test = \r [w w1]
+ case w of w2 {
+ PrelBase.I# ww ->
+ case w1 of w3 { PrelBase.I# ww1 -> Test.$wtest ww ww1; };
+ };
+
+If we don't inline the dfun, the code is not nearly as good:
+
+ (==) = case PrelTup.$fEq(,) PrelBase.$fEqInt PrelBase.$fEqInt of tpl {
+ PrelBase.:DEq tpl1 tpl2 -> tpl2;
+ };
+
+ Test.$wtest =
+ \r [ww ww1]
+ let { y = PrelBase.I#! [ww1]; } in
+ let { x = PrelBase.I#! [ww]; } in
+ let { sat_slx = PrelTup.(,)! [y x]; } in
+ let { sat_sly = PrelTup.(,)! [x y];
+ } in
+ case == sat_sly sat_slx of wild {
+ PrelBase.False -> Test.$wtest ww1 ww;
+ PrelBase.True -> PrelBase.True [];
+ };
+
+ Test.test =
+ \r [w w1]
+ case w of w2 {
+ PrelBase.I# ww ->
+ case w1 of w3 { PrelBase.I# ww1 -> Test.$wtest ww ww1; };
+ };
+
+Why doesn't GHC inline $fEq? Because it looks big:
+
+ PrelTup.zdfEqZ1T{-rcX-}
+ = \ @ a{-reT-} :: * @ b{-reS-} :: *
+ zddEq{-rf6-} _Ks :: {PrelBase.Eq{-23-} a{-reT-}}
+ zddEq1{-rf7-} _Ks :: {PrelBase.Eq{-23-} b{-reS-}} ->
+ let {
+ zeze{-rf0-} _Kl :: (b{-reS-} -> b{-reS-} -> PrelBase.Bool{-3c-})
+ zeze{-rf0-} = PrelBase.zeze{-01L-}@ b{-reS-} zddEq1{-rf7-} } in
+ let {
+ zeze1{-rf3-} _Kl :: (a{-reT-} -> a{-reT-} -> PrelBase.Bool{-3c-})
+ zeze1{-rf3-} = PrelBase.zeze{-01L-} @ a{-reT-} zddEq{-rf6-} } in
+ let {
+ zeze2{-reN-} :: ((a{-reT-}, b{-reS-}) -> (a{-reT-}, b{-reS-})-> PrelBase.Bool{-3c-})
+ zeze2{-reN-} = \ ds{-rf5-} _Ks :: (a{-reT-}, b{-reS-})
+ ds1{-rf4-} _Ks :: (a{-reT-}, b{-reS-}) ->
+ case ds{-rf5-}
+ of wild{-reW-} _Kd { (a1{-rf2-} _Ks, a2{-reZ-} _Ks) ->
+ case ds1{-rf4-}
+ of wild1{-reX-} _Kd { (b1{-rf1-} _Ks, b2{-reY-} _Ks) ->
+ PrelBase.zaza{-r4e-}
+ (zeze1{-rf3-} a1{-rf2-} b1{-rf1-})
+ (zeze{-rf0-} a2{-reZ-} b2{-reY-})
+ }
+ } } in
+ let {
+ a1{-reR-} :: ((a{-reT-}, b{-reS-})-> (a{-reT-}, b{-reS-})-> PrelBase.Bool{-3c-})
+ a1{-reR-} = \ a2{-reV-} _Ks :: (a{-reT-}, b{-reS-})
+ b1{-reU-} _Ks :: (a{-reT-}, b{-reS-}) ->
+ PrelBase.not{-r6I-} (zeze2{-reN-} a2{-reV-} b1{-reU-})
+ } in
+ PrelBase.zdwZCDEq{-r8J-} @ (a{-reT-}, b{-reS-}) a1{-reR-} zeze2{-reN-})
+
+and it's not as bad as it seems, because it's further dramatically
+simplified: only zeze2 is extracted and its body is simplified.
%************************************************************************
\end{code}
\begin{code}
-instConstraintErr pred
- = hang (ptext SLIT("Illegal constraint") <+>
- quotes (pprPred pred) <+>
- ptext SLIT("in instance context"))
- 4 (ptext SLIT("(Instance contexts must constrain only type variables)"))
-
badGenericInstanceType binds
= vcat [ptext SLIT("Illegal type pattern in the generic bindings"),
nest 4 (ppr binds)]
missingGenericInstances missing
= ptext SLIT("Missing type patterns for") <+> pprQuotedList missing
-
-
dupGenericInsts tc_inst_infos
= vcat [ptext SLIT("More than one type pattern for a single generic type constructor:"),
nest 4 (vcat (map ppr_inst_ty tc_inst_infos)),
where
ppr_inst_ty (tc,inst) = ppr (simpleInstInfoTy inst)
-instTypeErr clas tys msg
- = sep [ptext SLIT("Illegal instance declaration for") <+>
- quotes (pprClassPred clas tys),
- nest 4 (parens msg)
- ]
-
-nonBoxedPrimCCallErr clas inst_ty
- = hang (ptext SLIT("Unacceptable instance type for ccall-ish class"))
- 4 (pprClassPred clas [inst_ty])
-
methodCtxt = ptext SLIT("When checking the methods of an instance declaration")
superClassCtxt = ptext SLIT("When checking the super-classes of an instance declaration")
\end{code}
projects / ghc-hetmet.git / blobdiff