mkDictSelId,
mkDataConIds,
- mkRecordSelId,
mkPrimOpId, mkFCallId, mkTickBoxOpId, mkBreakPointOpId,
mkReboxingAlt, wrapNewTypeBody, unwrapNewTypeBody,
unsafeCoerceId, realWorldPrimId, voidArgId, nullAddrId, seqId,
lazyId, lazyIdUnfolding, lazyIdKey,
- mkRuntimeErrorApp,
+ mkRuntimeErrorApp, mkImpossibleExpr,
rEC_CON_ERROR_ID, iRREFUT_PAT_ERROR_ID, rUNTIME_ERROR_ID,
nON_EXHAUSTIVE_GUARDS_ERROR_ID, nO_METHOD_BINDING_ERROR_ID,
- pAT_ERROR_ID, eRROR_ID,
+ pAT_ERROR_ID, eRROR_ID, rEC_SEL_ERROR_ID,
unsafeCoerceName
) where
import TysPrim
import TysWiredIn
import PrelRules
-import Unify
import Type
import TypeRep
import Coercion
import TcType
-import CoreUtils
+import CoreUtils ( exprType, mkCoerce )
import CoreUnfold
import Literal
import TyCon
import ForeignCall
import DataCon
import Id
-import Var ( Var, TyVar, mkCoVar)
+import Var ( Var, TyVar, mkCoVar, mkExportedLocalVar )
import IdInfo
import NewDemand
-import DmdAnal
import CoreSyn
import Unique
import Maybes
nO_METHOD_BINDING_ERROR_ID,
pAT_ERROR_ID,
rEC_CON_ERROR_ID,
+ rEC_SEL_ERROR_ID,
lazyId
] ++ ghcPrimIds
representation and family type. It is accessible from :R123Map via
tyConFamilyCoercion_maybe and has kind
- Co123Map a b v :: {Map (a, b) v :=: :R123Map a b v}
+ Co123Map a b v :: {Map (a, b) v ~ :R123Map a b v}
The wrapper and worker of MapPair get the types
nt_work_info = noCafIdInfo -- The NoCaf-ness is set by noCafIdInfo
`setArityInfo` 1 -- Arity 1
`setUnfoldingInfo` newtype_unf
- newtype_unf = -- The assertion below is no longer correct:
- -- there may be a dict theta rather than a singleton orig_arg_ty
- -- ASSERT( isVanillaDataCon data_con &&
- -- isSingleton orig_arg_tys )
- --
- -- No existentials on a newtype, but it can have a context
- -- e.g. newtype Eq a => T a = MkT (...)
+ id_arg1 = mkTemplateLocal 1 (head orig_arg_tys)
+ newtype_unf = ASSERT2( isVanillaDataCon data_con &&
+ isSingleton orig_arg_tys, ppr data_con )
+ -- Note [Newtype datacons]
mkCompulsoryUnfolding $
mkLams wrap_tvs $ Lam id_arg1 $
- wrapNewTypeBody tycon res_ty_args
- (Var id_arg1)
+ wrapNewTypeBody tycon res_ty_args (Var id_arg1)
- id_arg1 = mkTemplateLocal 1
- (if null orig_arg_tys
- then ASSERT(not (null $ dataConDictTheta data_con)) mkPredTy $ head (dataConDictTheta data_con)
- else head orig_arg_tys
- )
----------- Wrapper --------------
-- We used to include the stupid theta in the wrapper's args
-- ...(let w = C x in ...(w p q)...)...
-- we want to see that w is strict in its two arguments
- wrap_unf = mkTopUnfolding $ Note InlineMe $
- mkLams wrap_tvs $
- mkLams eq_args $
- mkLams dict_args $ mkLams id_args $
- foldr mk_case con_app
- (zip (dict_args ++ id_args) all_strict_marks)
- i3 []
+ wrap_unf = mkImplicitUnfolding $ Note InlineMe $
+ mkLams wrap_tvs $
+ mkLams eq_args $
+ mkLams dict_args $ mkLams id_args $
+ foldr mk_case con_app
+ (zip (dict_args ++ id_args) all_strict_marks)
+ i3 []
con_app _ rep_ids = wrapFamInstBody tycon res_ty_args $
Var wrk_id `mkTyApps` res_ty_args
n = length tys
\end{code}
+Note [Newtype datacons]
+~~~~~~~~~~~~~~~~~~~~~~~
+The "data constructor" for a newtype should always be vanilla. At one
+point this wasn't true, because the newtype arising from
+ class C a => D a
+looked like
+ newtype T:D a = D:D (C a)
+so the data constructor for T:C had a single argument, namely the
+predicate (C a). But now we treat that as an ordinary argument, not
+part of the theta-type, so all is well.
+
%************************************************************************
%* *
-\subsection{Record selectors}
+\subsection{Dictionary selectors}
%* *
%************************************************************************
-We're going to build a record selector unfolding that looks like this:
-
- data T a b c = T1 { ..., op :: a, ...}
- | T2 { ..., op :: a, ...}
- | T3
-
- sel = /\ a b c -> \ d -> case d of
- T1 ... x ... -> x
- T2 ... x ... -> x
- other -> error "..."
-
-Similarly for newtypes
-
- newtype N a = MkN { unN :: a->a }
-
- unN :: N a -> a -> a
- unN n = coerce (a->a) n
-
-We need to take a little care if the field has a polymorphic type:
-
- data R = R { f :: forall a. a->a }
-
-Then we want
-
- f :: forall a. R -> a -> a
- f = /\ a \ r = case r of
- R f -> f a
+Selecting a field for a dictionary. If there is just one field, then
+there's nothing to do.
-(not f :: R -> forall a. a->a, which gives the type inference mechanism
-problems at call sites)
+Dictionary selectors may get nested forall-types. Thus:
-Similarly for (recursive) newtypes
+ class Foo a where
+ op :: forall b. Ord b => a -> b -> b
- newtype N = MkN { unN :: forall a. a->a }
+Then the top-level type for op is
- unN :: forall b. N -> b -> b
- unN = /\b -> \n:N -> (coerce (forall a. a->a) n)
+ op :: forall a. Foo a =>
+ forall b. Ord b =>
+ a -> b -> b
+This is unlike ordinary record selectors, which have all the for-alls
+at the outside. When dealing with classes it's very convenient to
+recover the original type signature from the class op selector.
-Note [Naughty record selectors]
-~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
-A "naughty" field is one for which we can't define a record
-selector, because an existential type variable would escape. For example:
- data T = forall a. MkT { x,y::a }
-We obviously can't define
- x (MkT v _) = v
-Nevertheless we *do* put a RecordSelId into the type environment
-so that if the user tries to use 'x' as a selector we can bleat
-helpfully, rather than saying unhelpfully that 'x' is not in scope.
-Hence the sel_naughty flag, to identify record selectors that don't really exist.
+\begin{code}
+mkDictSelId :: Bool -- True <=> don't include the unfolding
+ -- Little point on imports without -O, because the
+ -- dictionary itself won't be visible
+ -> Name -> Class -> Id
+mkDictSelId no_unf name clas
+ = mkGlobalId (ClassOpId clas) name sel_ty info
+ where
+ sel_ty = mkForAllTys tyvars (mkFunTy (idType dict_id) (idType the_arg_id))
+ -- We can't just say (exprType rhs), because that would give a type
+ -- C a -> C a
+ -- for a single-op class (after all, the selector is the identity)
+ -- But it's type must expose the representation of the dictionary
+ -- to get (say) C a -> (a -> a)
-In general, a field is naughty if its type mentions a type variable that
-isn't in the result type of the constructor.
+ info = noCafIdInfo
+ `setArityInfo` 1
+ `setAllStrictnessInfo` Just strict_sig
+ `setUnfoldingInfo` (if no_unf then noUnfolding
+ else mkImplicitUnfolding rhs)
-Note [GADT record selectors]
-~~~~~~~~~~~~~~~~~~~~~~~~~~~~
-For GADTs, we require that all constructors with a common field 'f' have the same
-result type (modulo alpha conversion). [Checked in TcTyClsDecls.checkValidTyCon]
-E.g.
- data T where
- T1 { f :: a } :: T [a]
- T2 { f :: a, y :: b } :: T [a]
-and now the selector takes that type as its argument:
- f :: forall a. T [a] -> a
- f t = case t of
- T1 { f = v } -> v
- T2 { f = v } -> v
-Note the forall'd tyvars of the selector are just the free tyvars
-of the result type; there may be other tyvars in the constructor's
-type (e.g. 'b' in T2).
+ -- We no longer use 'must-inline' on record selectors. They'll
+ -- inline like crazy if they scrutinise a constructor
-Note [Selector running example]
-~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
-It's OK to combine GADTs and type families. Here's a running example:
+ -- The strictness signature is of the form U(AAAVAAAA) -> T
+ -- where the V depends on which item we are selecting
+ -- It's worth giving one, so that absence info etc is generated
+ -- even if the selector isn't inlined
+ strict_sig = mkStrictSig (mkTopDmdType [arg_dmd] TopRes)
+ arg_dmd | isNewTyCon tycon = evalDmd
+ | otherwise = Eval (Prod [ if the_arg_id == id then evalDmd else Abs
+ | id <- arg_ids ])
- data instance T [a] where
- T1 { fld :: b } :: T [Maybe b]
+ tycon = classTyCon clas
+ [data_con] = tyConDataCons tycon
+ tyvars = dataConUnivTyVars data_con
+ arg_tys = {- ASSERT( isVanillaDataCon data_con ) -} dataConRepArgTys data_con
+ eq_theta = dataConEqTheta data_con
+ the_arg_id = assoc "MkId.mkDictSelId" (map idName (classSelIds clas) `zip` arg_ids) name
-The representation type looks like this
- data :R7T a where
- T1 { fld :: b } :: :R7T (Maybe b)
+ pred = mkClassPred clas (mkTyVarTys tyvars)
+ dict_id = mkTemplateLocal 1 $ mkPredTy pred
+ (eq_ids,n) = mkCoVarLocals 2 $ mkPredTys eq_theta
+ arg_ids = mkTemplateLocalsNum n arg_tys
-and there's coercion from the family type to the representation type
- :CoR7T a :: T [a] ~ :R7T a
+ mkCoVarLocals i [] = ([],i)
+ mkCoVarLocals i (x:xs) = let (ys,j) = mkCoVarLocals (i+1) xs
+ y = mkCoVar (mkSysTvName (mkBuiltinUnique i) (fsLit "dc_co")) x
+ in (y:ys,j)
-The selector we want for fld looks like this:
+ rhs = mkLams tyvars (Lam dict_id rhs_body)
+ rhs_body | isNewTyCon tycon = unwrapNewTypeBody tycon (map mkTyVarTy tyvars) (Var dict_id)
+ | otherwise = Case (Var dict_id) dict_id (idType the_arg_id)
+ [(DataAlt data_con, eq_ids ++ arg_ids, Var the_arg_id)]
+\end{code}
- fld :: forall b. T [Maybe b] -> b
- fld = /\b. \(d::T [Maybe b]).
- case d `cast` :CoR7T (Maybe b) of
- T1 (x::b) -> x
-The scrutinee of the case has type :R7T (Maybe b), which can be
-gotten by appying the eq_spec to the univ_tvs of the data con.
+%************************************************************************
+%* *
+ Boxing and unboxing
+%* *
+%************************************************************************
\begin{code}
-mkRecordSelId :: TyCon -> FieldLabel -> Id
-mkRecordSelId tycon field_label
- -- Assumes that all fields with the same field label have the same type
- = sel_id
- where
- -- Because this function gets called by implicitTyThings, we need to
- -- produce the OccName of the Id without doing any suspend type checks.
- -- (see the note [Tricky iface loop]).
- -- A suspended type-check is sometimes necessary to compute field_ty,
- -- so we need to make sure that we suspend anything that depends on field_ty.
-
- -- the overall result
- sel_id = mkGlobalId sel_id_details field_label theType theInfo
-
- -- check whether the type is naughty: this thunk does not get forced
- -- until the type is actually needed
- field_ty = dataConFieldType con1 field_label
- is_naughty = not (tyVarsOfType field_ty `subVarSet` data_tv_set)
-
- -- it's important that this doesn't force the if
- (theType, theInfo) = if is_naughty
- -- Escapist case here for naughty constructors
- -- We give it no IdInfo, and a type of
- -- forall a.a (never looked at)
- then (forall_a_a, noCafIdInfo)
- -- otherwise do the real case
- else (selector_ty, info)
-
- sel_id_details = RecordSelId { sel_tycon = tycon,
- sel_label = field_label,
- sel_naughty = is_naughty }
- -- For a data type family, the tycon is the *instance* TyCon
-
- -- for naughty case
- forall_a_a = mkForAllTy alphaTyVar (mkTyVarTy alphaTyVar)
-
- -- real case starts here:
- data_cons = tyConDataCons tycon
- data_cons_w_field = filter has_field data_cons -- Can't be empty!
- has_field con = field_label `elem` dataConFieldLabels con
-
- con1 = ASSERT( not (null data_cons_w_field) ) head data_cons_w_field
- (univ_tvs, _, eq_spec, _, _, _, data_ty) = dataConFullSig con1
- -- For a data type family, the data_ty (and hence selector_ty) mentions
- -- only the family TyCon, not the instance TyCon
- data_tv_set = tyVarsOfType data_ty
- data_tvs = varSetElems data_tv_set
-
- -- _Very_ tiresomely, the selectors are (unnecessarily!) overloaded over
- -- just the dictionaries in the types of the constructors that contain
- -- the relevant field. [The Report says that pattern matching on a
- -- constructor gives the same constraints as applying it.] Urgh.
- --
- -- However, not all data cons have all constraints (because of
- -- BuildTyCl.mkDataConStupidTheta). So we need to find all the data cons
- -- involved in the pattern match and take the union of their constraints.
- stupid_dict_tys = mkPredTys (dataConsStupidTheta data_cons_w_field)
- n_stupid_dicts = length stupid_dict_tys
-
- (field_tyvars,pre_field_theta,field_tau) = tcSplitSigmaTy field_ty
- field_theta = filter (not . isEqPred) pre_field_theta
- field_dict_tys = mkPredTys field_theta
- n_field_dict_tys = length field_dict_tys
- -- If the field has a universally quantified type we have to
- -- be a bit careful. Suppose we have
- -- data R = R { op :: forall a. Foo a => a -> a }
- -- Then we can't give op the type
- -- op :: R -> forall a. Foo a => a -> a
- -- because the typechecker doesn't understand foralls to the
- -- right of an arrow. The "right" type to give it is
- -- op :: forall a. Foo a => R -> a -> a
- -- But then we must generate the right unfolding too:
- -- op = /\a -> \dfoo -> \ r ->
- -- case r of
- -- R op -> op a dfoo
- -- Note that this is exactly the type we'd infer from a user defn
- -- op (R op) = op
-
- selector_ty :: Type
- selector_ty = mkForAllTys data_tvs $ mkForAllTys field_tyvars $
- mkFunTys stupid_dict_tys $ mkFunTys field_dict_tys $
- mkFunTy data_ty field_tau
-
- arity = 1 + n_stupid_dicts + n_field_dict_tys
-
- (strict_sig, rhs_w_str) = dmdAnalTopRhs sel_rhs
- -- Use the demand analyser to work out strictness.
- -- With all this unpackery it's not easy!
-
- info = noCafIdInfo
- `setCafInfo` caf_info
- `setArityInfo` arity
- `setUnfoldingInfo` mkTopUnfolding rhs_w_str
- `setAllStrictnessInfo` Just strict_sig
-
- -- Allocate Ids. We do it a funny way round because field_dict_tys is
- -- almost always empty. Also note that we use max_dict_tys
- -- rather than n_dict_tys, because the latter gives an infinite loop:
- -- n_dict tys depends on the_alts, which depens on arg_ids, which
- -- depends on arity, which depends on n_dict tys. Sigh! Mega sigh!
- stupid_dict_ids = mkTemplateLocalsNum 1 stupid_dict_tys
- max_stupid_dicts = length (tyConStupidTheta tycon)
- field_dict_base = max_stupid_dicts + 1
- field_dict_ids = mkTemplateLocalsNum field_dict_base field_dict_tys
- dict_id_base = field_dict_base + n_field_dict_tys
- data_id = mkTemplateLocal dict_id_base data_ty
- scrut_id = mkTemplateLocal (dict_id_base+1) scrut_ty
- arg_base = dict_id_base + 2
-
- the_alts :: [CoreAlt]
- the_alts = map mk_alt data_cons_w_field -- Already sorted by data-con
- no_default = length data_cons == length data_cons_w_field -- No default needed
-
- default_alt | no_default = []
- | otherwise = [(DEFAULT, [], error_expr)]
-
- -- The default branch may have CAF refs, because it calls recSelError etc.
- caf_info | no_default = NoCafRefs
- | otherwise = MayHaveCafRefs
-
- sel_rhs = mkLams data_tvs $ mkLams field_tyvars $
- mkLams stupid_dict_ids $ mkLams field_dict_ids $
- Lam data_id $ mk_result sel_body
-
- scrut_ty_args = substTyVars (mkTopTvSubst eq_spec) univ_tvs
- scrut_ty = mkTyConApp tycon scrut_ty_args
- scrut = unwrapFamInstScrut tycon scrut_ty_args (Var data_id)
- -- First coerce from the type family to the representation type
-
- -- NB: A newtype always has a vanilla DataCon; no existentials etc
- -- data_tys will simply be the dataConUnivTyVars
- sel_body | isNewTyCon tycon = unwrapNewTypeBody tycon scrut_ty_args scrut
- | otherwise = Case scrut scrut_id field_ty (default_alt ++ the_alts)
-
- mk_result poly_result = mkVarApps (mkVarApps poly_result field_tyvars) field_dict_ids
- -- We pull the field lambdas to the top, so we need to
- -- apply them in the body. For example:
- -- data T = MkT { foo :: forall a. a->a }
- --
- -- foo :: forall a. T -> a -> a
- -- foo = /\a. \t:T. case t of { MkT f -> f a }
-
- mk_alt data_con
- = ASSERT2( data_ty `tcEqType` field_ty,
- ppr data_con $$ ppr data_ty $$ ppr field_ty )
- mkReboxingAlt rebox_uniqs data_con (ex_tvs ++ co_tvs ++ arg_vs) rhs
- where
- -- get pattern binders with types appropriately instantiated
- arg_uniqs = map mkBuiltinUnique [arg_base..]
- (ex_tvs, co_tvs, arg_vs) = dataConOrigInstPat arg_uniqs data_con
- scrut_ty_args
-
- rebox_base = arg_base + length ex_tvs + length co_tvs + length arg_vs
- rebox_uniqs = map mkBuiltinUnique [rebox_base..]
-
- -- data T :: *->* where T1 { fld :: Maybe b } -> T [b]
- -- Hence T1 :: forall a b. (a=[b]) => b -> T a
- -- fld :: forall b. T [b] -> Maybe b
- -- fld = /\b.\(t:T[b]). case t of
- -- T1 b' (c : [b]=[b']) (x:Maybe b')
- -- -> x `cast` Maybe (sym (right c))
-
- -- Generate the refinement for b'=b,
- -- and apply to (Maybe b'), to get (Maybe b)
- reft = matchRefine co_tvs
- the_arg_id_ty = idType the_arg_id
- (rhs, data_ty) =
- case refineType reft the_arg_id_ty of
- Just (co, data_ty) -> (Cast (Var the_arg_id) co, data_ty)
- Nothing -> (Var the_arg_id, the_arg_id_ty)
-
- field_vs = filter (not . isPredTy . idType) arg_vs
- the_arg_id = assoc "mkRecordSelId:mk_alt"
- (field_lbls `zip` field_vs) field_label
- field_lbls = dataConFieldLabels data_con
-
- error_expr = mkRuntimeErrorApp rEC_SEL_ERROR_ID field_ty full_msg
- full_msg = showSDoc (sep [text "No match in record selector", ppr sel_id])
-
-- unbox a product type...
-- we will recurse into newtypes, casting along the way, and unbox at the
-- first product data constructor we find. e.g.
%************************************************************************
%* *
-\subsection{Dictionary selectors}
-%* *
-%************************************************************************
-
-Selecting a field for a dictionary. If there is just one field, then
-there's nothing to do.
-
-Dictionary selectors may get nested forall-types. Thus:
-
- class Foo a where
- op :: forall b. Ord b => a -> b -> b
-
-Then the top-level type for op is
-
- op :: forall a. Foo a =>
- forall b. Ord b =>
- a -> b -> b
-
-This is unlike ordinary record selectors, which have all the for-alls
-at the outside. When dealing with classes it's very convenient to
-recover the original type signature from the class op selector.
-
-\begin{code}
-mkDictSelId :: Bool -- True <=> don't include the unfolding
- -- Little point on imports without -O, because the
- -- dictionary itself won't be visible
- -> Name -> Class -> Id
-mkDictSelId no_unf name clas
- = mkGlobalId (ClassOpId clas) name sel_ty info
- where
- sel_ty = mkForAllTys tyvars (mkFunTy (idType dict_id) (idType the_arg_id))
- -- We can't just say (exprType rhs), because that would give a type
- -- C a -> C a
- -- for a single-op class (after all, the selector is the identity)
- -- But it's type must expose the representation of the dictionary
- -- to get (say) C a -> (a -> a)
-
- info = noCafIdInfo
- `setArityInfo` 1
- `setAllStrictnessInfo` Just strict_sig
- `setUnfoldingInfo` (if no_unf then noUnfolding
- else mkTopUnfolding rhs)
-
- -- We no longer use 'must-inline' on record selectors. They'll
- -- inline like crazy if they scrutinise a constructor
-
- -- The strictness signature is of the form U(AAAVAAAA) -> T
- -- where the V depends on which item we are selecting
- -- It's worth giving one, so that absence info etc is generated
- -- even if the selector isn't inlined
- strict_sig = mkStrictSig (mkTopDmdType [arg_dmd] TopRes)
- arg_dmd | isNewTyCon tycon = evalDmd
- | otherwise = Eval (Prod [ if the_arg_id == id then evalDmd else Abs
- | id <- arg_ids ])
-
- tycon = classTyCon clas
- [data_con] = tyConDataCons tycon
- tyvars = dataConUnivTyVars data_con
- arg_tys = {- ASSERT( isVanillaDataCon data_con ) -} dataConRepArgTys data_con
- eq_theta = dataConEqTheta data_con
- the_arg_id = assoc "MkId.mkDictSelId" (map idName (classSelIds clas) `zip` arg_ids) name
-
- pred = mkClassPred clas (mkTyVarTys tyvars)
- dict_id = mkTemplateLocal 1 $ mkPredTy pred
- (eq_ids,n) = mkCoVarLocals 2 $ mkPredTys eq_theta
- arg_ids = mkTemplateLocalsNum n arg_tys
-
- mkCoVarLocals i [] = ([],i)
- mkCoVarLocals i (x:xs) = let (ys,j) = mkCoVarLocals (i+1) xs
- y = mkCoVar (mkSysTvName (mkBuiltinUnique i) (fsLit "dc_co")) x
- in (y:ys,j)
-
- rhs = mkLams tyvars (Lam dict_id rhs_body)
- rhs_body | isNewTyCon tycon = unwrapNewTypeBody tycon (map mkTyVarTy tyvars) (Var dict_id)
- | otherwise = Case (Var dict_id) dict_id (idType the_arg_id)
- [(DataAlt data_con, eq_ids ++ arg_ids, Var the_arg_id)]
-\end{code}
-
-
-%************************************************************************
-%* *
Wrapping and unwrapping newtypes and type families
%* *
%************************************************************************
-> Id
mkDictFunId dfun_name inst_tyvars dfun_theta clas inst_tys
- = mkExportedLocalId dfun_name dfun_ty
+ = mkExportedLocalVar DFunId dfun_name dfun_ty vanillaIdInfo
where
dfun_ty = mkSigmaTy inst_tyvars dfun_theta (mkDictTy clas inst_tys)
-
-{- 1 dec 99: disable the Mark Jones optimisation for the sake
- of compatibility with Hugs.
- See `types/InstEnv' for a discussion related to this.
-
- (class_tyvars, sc_theta, _, _) = classBigSig clas
- not_const (clas, tys) = not (isEmptyVarSet (tyVarsOfTypes tys))
- sc_theta' = substClasses (zipTopTvSubst class_tyvars inst_tys) sc_theta
- dfun_theta = case inst_decl_theta of
- [] -> [] -- If inst_decl_theta is empty, then we don't
- -- want to have any dict arguments, so that we can
- -- expose the constant methods.
-
- other -> nub (inst_decl_theta ++ filter not_const sc_theta')
- -- Otherwise we pass the superclass dictionaries to
- -- the dictionary function; the Mark Jones optimisation.
- --
- -- NOTE the "nub". I got caught by this one:
- -- class Monad m => MonadT t m where ...
- -- instance Monad m => MonadT (EnvT env) m where ...
- -- Here, the inst_decl_theta has (Monad m); but so
- -- does the sc_theta'!
- --
- -- NOTE the "not_const". I got caught by this one too:
- -- class Foo a => Baz a b where ...
- -- instance Wob b => Baz T b where..
- -- Now sc_theta' has Foo T
--}
\end{code}
lazyIdName = mkWiredInIdName gHC_BASE (fsLit "lazy") lazyIdKey lazyId
errorName = mkWiredInIdName gHC_ERR (fsLit "error") errorIdKey eRROR_ID
-recSelErrorName = mkWiredInIdName cONTROL_EXCEPTION (fsLit "recSelError") recSelErrorIdKey rEC_SEL_ERROR_ID
-runtimeErrorName = mkWiredInIdName cONTROL_EXCEPTION (fsLit "runtimeError") runtimeErrorIdKey rUNTIME_ERROR_ID
-irrefutPatErrorName = mkWiredInIdName cONTROL_EXCEPTION (fsLit "irrefutPatError") irrefutPatErrorIdKey iRREFUT_PAT_ERROR_ID
-recConErrorName = mkWiredInIdName cONTROL_EXCEPTION (fsLit "recConError") recConErrorIdKey rEC_CON_ERROR_ID
-patErrorName = mkWiredInIdName cONTROL_EXCEPTION (fsLit "patError") patErrorIdKey pAT_ERROR_ID
-noMethodBindingErrorName = mkWiredInIdName cONTROL_EXCEPTION (fsLit "noMethodBindingError")
+recSelErrorName = mkWiredInIdName cONTROL_EXCEPTION_BASE (fsLit "recSelError") recSelErrorIdKey rEC_SEL_ERROR_ID
+runtimeErrorName = mkWiredInIdName cONTROL_EXCEPTION_BASE (fsLit "runtimeError") runtimeErrorIdKey rUNTIME_ERROR_ID
+irrefutPatErrorName = mkWiredInIdName cONTROL_EXCEPTION_BASE (fsLit "irrefutPatError") irrefutPatErrorIdKey iRREFUT_PAT_ERROR_ID
+recConErrorName = mkWiredInIdName cONTROL_EXCEPTION_BASE (fsLit "recConError") recConErrorIdKey rEC_CON_ERROR_ID
+patErrorName = mkWiredInIdName cONTROL_EXCEPTION_BASE (fsLit "patError") patErrorIdKey pAT_ERROR_ID
+noMethodBindingErrorName = mkWiredInIdName cONTROL_EXCEPTION_BASE (fsLit "noMethodBindingError")
noMethodBindingErrorIdKey nO_METHOD_BINDING_ERROR_ID
nonExhaustiveGuardsErrorName
- = mkWiredInIdName gHC_ERR (fsLit "nonExhaustiveGuardsError")
+ = mkWiredInIdName cONTROL_EXCEPTION_BASE (fsLit "nonExhaustiveGuardsError")
nonExhaustiveGuardsErrorIdKey nON_EXHAUSTIVE_GUARDS_ERROR_ID
\end{code}
where
err_string = Lit (mkMachString err_msg)
+mkImpossibleExpr :: Type -> CoreExpr
+mkImpossibleExpr res_ty
+ = mkRuntimeErrorApp rUNTIME_ERROR_ID res_ty "Impossible case alternative"
+
rEC_SEL_ERROR_ID = mkRuntimeErrorId recSelErrorName
rUNTIME_ERROR_ID = mkRuntimeErrorId runtimeErrorName
iRREFUT_PAT_ERROR_ID = mkRuntimeErrorId irrefutPatErrorName
mkRuntimeErrorId name = pc_bottoming_Id name runtimeErrorTy
runtimeErrorTy :: Type
-runtimeErrorTy = mkSigmaTy [openAlphaTyVar] [] (mkFunTy addrPrimTy openAlphaTy)
+runtimeErrorTy = mkSigmaTy [openAlphaTyVar] [] (mkFunTy addrPrimTy openAlphaTy)
\end{code}
\begin{code}
projects / ghc-hetmet.git / blobdiff