%
+% (c) The University of Glasgow 2006
% (c) The GRASP/AQUA Project, Glasgow University, 1992-1998
%
-\section[TyCon]{The @TyCon@ datatype}
+
+The @TyCon@ datatype
\begin{code}
module TyCon(
PrimRep(..),
tyConPrimRep,
+ primRepSizeW,
- AlgTyConRhs(..), visibleDataCons, AlgTyConParent(..),
+ AlgTyConRhs(..), visibleDataCons,
+ TyConParent(..),
SynTyConRhs(..),
isFunTyCon, isUnLiftedTyCon, isProductTyCon,
- isAlgTyCon, isDataTyCon, isSynTyCon, isNewTyCon, isPrimTyCon,
+ isAlgTyCon, isDataTyCon,
+ isNewTyCon, unwrapNewTyCon_maybe,
+ isSynTyCon, isClosedSynTyCon, isOpenSynTyCon,
+ isPrimTyCon,
+
isEnumerationTyCon, isGadtSyntaxTyCon, isOpenTyCon,
+ assocTyConArgPoss_maybe, isTyConAssoc, setTyConArgPoss,
isTupleTyCon, isUnboxedTupleTyCon, isBoxedTupleTyCon, tupleTyConBoxity,
- isRecursiveTyCon, newTyConRep, newTyConRhs, newTyConCo,
+ isRecursiveTyCon, newTyConRhs, newTyConEtadRhs, newTyConCo_maybe,
isHiBootTyCon, isSuperKindTyCon,
isCoercionTyCon_maybe, isCoercionTyCon,
+ isImplicitTyCon,
tcExpandTyCon_maybe, coreExpandTyCon_maybe,
tyConStupidTheta,
tyConArity,
isClassTyCon, tyConClass_maybe,
- isFamInstTyCon, tyConFamily_maybe,
+ isFamInstTyCon, tyConFamInst_maybe, tyConFamilyCoercion_maybe,
synTyConDefn, synTyConRhs, synTyConType, synTyConResKind,
tyConExtName, -- External name for foreign types
- maybeTyConSingleCon,
+ tyConSingleDataCon_maybe,
-- Generics
tyConHasGenerics
#include "HsVersions.h"
-import {-# SOURCE #-} TypeRep ( Kind, Type, Coercion, PredType )
+import {-# SOURCE #-} TypeRep ( Kind, Type, PredType )
import {-# SOURCE #-} DataCon ( DataCon, isVanillaDataCon )
-import Var ( TyVar, Id )
-import Class ( Class )
-import BasicTypes ( Arity, RecFlag(..), Boxity(..), isBoxed )
-import Name ( Name, nameUnique, NamedThing(getName) )
-import PrelNames ( Unique, Uniquable(..) )
-import Maybes ( orElse )
+import Var
+import Class
+import BasicTypes
+import Name
+import PrelNames
+import Maybes
import Outputable
import FastString
+import Constants
\end{code}
%************************************************************************
tyConName :: Name,
tyConKind :: Kind,
tyConArity :: Arity,
-
+
tyConTyVars :: [TyVar], -- Scopes over (a) the algTcStupidTheta
-- (b) the cached types in
-- algTyConRhs.NewTyCon
+ -- (c) the family instance
+ -- types if present
-- But not over the data constructors
+
algTcSelIds :: [Id], -- Its record selectors (empty if none)
algTcGadtSyntax :: Bool, -- True <=> the data type was declared using GADT syntax
hasGenerics :: Bool, -- True <=> generic to/from functions are available
-- (in the exports of the data type's source module)
- algTcParent :: AlgTyConParent -- Gives the class or family tycon for
+ algTcParent :: TyConParent -- Gives the class or family tycon for
-- derived tycons representing classes
-- or family instances, respectively.
}
}
| SynTyCon {
- tyConUnique :: Unique,
- tyConName :: Name,
- tyConKind :: Kind,
- tyConArity :: Arity,
+ tyConUnique :: Unique,
+ tyConName :: Name,
+ tyConKind :: Kind,
+ tyConArity :: Arity,
+
+ tyConTyVars :: [TyVar], -- Bound tyvars
+
+ synTcRhs :: SynTyConRhs, -- Expanded type in here
+
+ synTcParent :: TyConParent -- Gives the family tycon of
+ -- representation tycons of family
+ -- instances
- tyConTyVars :: [TyVar], -- Bound tyvars
- synTcRhs :: SynTyConRhs -- Expanded type in here
}
| PrimTyCon { -- Primitive types; cannot be defined in Haskell
tyConUnique :: Unique,
tyConName :: Name,
tyConKind :: Kind,
- tyConArity :: Arity,
+ tyConArity :: Arity, -- SLPJ Oct06: I'm not sure what the significance
+ -- of the arity of a primtycon is!
primTyConRep :: PrimRep,
-- Many primitive tycons are unboxed, but some are
tyConUnique :: Unique,
tyConName :: Name,
tyConArity :: Arity,
- coKindFun :: [Type] -> Kind
- }
+ coKindFun :: [Type] -> (Type,Type)
+ } -- INVARIANT: coKindFun is always applied to exactly 'arity' args
+ -- E.g. for trans (c1 :: ta=tb) (c2 :: tb=tc), the coKindFun returns
+ -- the kind as a pair of types: (ta,tc)
| SuperKindTyCon { -- Super Kinds, TY (box) and CO (diamond).
-- They have no kind; and arity zero
tyConName :: Name
}
-type KindCon = TyCon
-
-type SuperKindCon = TyCon
-
type FieldLabel = Name
+-- Right hand sides of type constructors for algebraic types
+--
data AlgTyConRhs
- = AbstractTyCon -- We know nothing about this data type, except
- -- that it's represented by a pointer
- -- Used when we export a data type abstractly into
- -- an hi file
- | OpenDataTyCon -- data family (further instances can appear
- | OpenNewTyCon -- newtype family at any time)
+ -- We know nothing about this data type, except that it's represented by a
+ -- pointer. Used when we export a data type abstractly into an hi file.
+ --
+ = AbstractTyCon
+
+ -- The constructor represents an open family without a fixed right hand
+ -- side. Additional instances can appear at any time.
+ --
+ -- These are introduced by either a top level decl:
+ -- data T a :: *
+ -- or an assoicated data type decl, in a class decl:
+ -- class C a b where
+ -- data T b :: *
+
+ | OpenTyCon {
+
+ otArgPoss :: Maybe [Int]
+ -- Nothing <=> top-level indexed type family
+ -- Just ns <=> associated (not toplevel) family
+ -- In the latter case, for each tyvar in the AT decl, 'ns' gives the
+ -- position of that tyvar in the class argument list (starting from 0).
+ -- NB: Length is less than tyConArity iff higher kind signature.
+
+ }
| DataTyCon {
data_cons :: [DataCon],
-- The constructors; can be empty if the user declares
-- the type to have no constructors
-- INVARIANT: Kept in order of increasing tag
- -- (see the tag assignment in DataCon.mkDataCon)
+ -- (see the tag assignment in DataCon.mkDataCon)
is_enum :: Bool -- Cached: True <=> an enumeration type
} -- Includes data types with no constructors.
-- = the representation type of the tycon
-- The free tyvars of this type are the tyConTyVars
- nt_co :: Maybe TyCon, -- The coercion used to create the newtype
+ nt_co :: Maybe TyCon, -- A CoercionTyCon used to create the newtype
-- from the representation
- -- optional for non-recursive newtypes
+ -- Optional for non-recursive newtypes
-- See Note [Newtype coercions]
+ -- Invariant: arity = #tvs in nt_etad_rhs;
+ -- See Note [Newtype eta]
+ -- Watch out! If any newtypes become transparent
+ -- again check Trac #1072.
- nt_etad_rhs :: ([TyVar], Type) ,
+ nt_etad_rhs :: ([TyVar], Type)
-- The same again, but this time eta-reduced
-- hence the [TyVar] which may be shorter than the declared
-- arity of the TyCon. See Note [Newtype eta]
-
- nt_rep :: Type -- Cached: the *ultimate* representation type
- -- By 'ultimate' I mean that the top-level constructor
- -- of the rep type is not itself a newtype or type synonym.
- -- The rep type isn't entirely simple:
- -- for a recursive newtype we pick () as the rep type
- -- newtype T = MkT T
- --
- -- This one does not need to be eta reduced; hence its
- -- free type variables are conveniently tyConTyVars
- -- Thus:
- -- newtype T a = MkT [(a,Int)]
- -- The rep type is [(a,Int)]
- -- NB: the rep type isn't necessarily the original RHS of the
- -- newtype decl, because the rep type looks through other
- } -- newtypes.
+ }
visibleDataCons :: AlgTyConRhs -> [DataCon]
visibleDataCons AbstractTyCon = []
-visibleDataCons OpenDataTyCon = []
-visibleDataCons OpenNewTyCon = []
+visibleDataCons OpenTyCon {} = []
visibleDataCons (DataTyCon{ data_cons = cs }) = cs
visibleDataCons (NewTyCon{ data_con = c }) = [c]
-data AlgTyConParent = NoParentTyCon -- ordinary data type
- | ClassTyCon Class -- class dictionary
- | FamilyTyCon TyCon -- instance of type family
-
+-- Both type classes as well as family instances imply implicit
+-- type constructors. These implicit type constructors refer to their parent
+-- structure (ie, the class or family from which they derive) using a type of
+-- the following form. We use `TyConParent' for both algebraic and synonym
+-- types, but the variant `ClassTyCon' will only be used by algebraic tycons.
+
+data TyConParent
+ = NoParentTyCon -- An ordinary type constructor has no parent.
+
+ | ClassTyCon -- Type constructors representing a class dictionary.
+ Class -- INVARIANT: the classTyCon of this Class is the current tycon
+
+ | FamilyTyCon -- Type constructors representing an instance of a type
+ TyCon -- The type family
+ [Type] -- Instance types; free variables are the tyConTyVars
+ -- of the current TyCon (not the family one)
+ -- INVARIANT: the number of types matches the arity
+ -- of the family tycon
+ TyCon -- A CoercionTyCon identifying the representation
+ -- type with the type instance family.
+ -- c.f. Note [Newtype coercions]
+
+ --
+ -- E.g. data intance T [a] = ...
+ -- gives a representation tycon:
+ -- data :R7T a = ...
+ -- axiom co a :: T [a] ~ :R7T a
+ -- with :R7T's algTcParent = FamilyTyCon T [a] co
+
+okParent :: Name -> TyConParent -> Bool -- Checks invariants
+okParent _ NoParentTyCon = True
+okParent tc_name (ClassTyCon cls) = tyConName (classTyCon cls) == tc_name
+okParent _ (FamilyTyCon fam_tc tys _co_tc) = tyConArity fam_tc == length tys
+
+--------------------
data SynTyConRhs
- = OpenSynTyCon Kind -- Type family: *result* kind given
+ = OpenSynTyCon Kind -- Type family: *result* kind given
+ (Maybe [Int]) -- for associated families: for each tyvars in
+ -- the AT decl, gives the position of that
+ -- tyvar in the class argument list (starting
+ -- from 0).
+ -- NB: Length is less than tyConArity
+ -- if higher kind signature.
+
| SynonymTyCon Type -- Mentioning head type vars. Acts as a template for
-- the expansion when the tycon is applied to some
- -- types.
+ -- types.
\end{code}
Note [Newtype coercions]
~~~~~~~~~~~~~~~~~~~~~~~~
-
The NewTyCon field nt_co is a a TyCon (a coercion constructor in fact)
which is used for coercing from the representation type of the
newtype, to the newtype itself. For example,
CoT @ s
which encodes as (TyConApp instCoercionTyCon [TyConApp CoT [], s])
-But in GHC we instead make CoT into a new piece of type syntax
+But in GHC we instead make CoT into a new piece of type syntax, CoercionTyCon,
(like instCoercionTyCon, symCoercionTyCon etc), which must always
be saturated, but which encodes as
TyConApp CoT [s]
w2 :: Foo T
w2 = MkFoo (\(MkT x) -> case w1 of MkFoo f -> f x)
-After desugaring, and discading the data constructors for the newtypes,
+After desugaring, and discarding the data constructors for the newtypes,
we get:
w2 :: Foo T
w2 = w1
And now Lint complains unless Foo T == Foo [], and that requires T==[]
+This point carries over to the newtype coercion, because we need to
+say
+ w2 = w1 `cast` Foo CoT
+
+so the coercion tycon CoT must have
+ kind: T ~ []
+ and arity: 0
+
+
+Note [Indexed data types] (aka data type families)
+~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+ See also Note [Wrappers for data instance tycons] in MkId.lhs
+
+Consider
+ data family T a
+
+ data instance T (b,c) where
+ T1 :: b -> c -> T (b,c)
+
+Then
+ * T is the "family TyCon"
+
+ * We make "representation TyCon" :R1T, thus:
+ data :R1T b c where
+ T1 :: forall b c. b -> c -> :R1T b c
+
+ * It has a top-level coercion connecting it to the family TyCon
+
+ axiom :Co:R1T b c : T (b,c) ~ :R1T b c
+
+ * The data contructor T1 has a wrapper (which is what the source-level
+ "T1" invokes):
+
+ $WT1 :: forall b c. b -> c -> T (b,c)
+ $WT1 b c (x::b) (y::c) = T1 b c x y `cast` sym (:Co:R1T b c)
+
+ * The representation TyCon :R1T has an AlgTyConParent of
+
+ FamilyTyCon T [(b,c)] :Co:R1T
+
+
%************************************************************************
%* *
| AddrRep -- a pointer, but not to a Haskell value
| FloatRep
| DoubleRep
+ deriving( Eq, Show )
+
+instance Outputable PrimRep where
+ ppr r = text (show r)
+
+-- Size of a PrimRep, in words
+primRepSizeW :: PrimRep -> Int
+primRepSizeW IntRep = 1
+primRepSizeW WordRep = 1
+primRepSizeW Int64Rep = wORD64_SIZE `quot` wORD_SIZE
+primRepSizeW Word64Rep= wORD64_SIZE `quot` wORD_SIZE
+primRepSizeW FloatRep = 1 -- NB. might not take a full word
+primRepSizeW DoubleRep= dOUBLE_SIZE `quot` wORD_SIZE
+primRepSizeW AddrRep = 1
+primRepSizeW PtrRep = 1
+primRepSizeW VoidRep = 0
\end{code}
%************************************************************************
-- This is the making of a TyCon. Just the same as the old mkAlgTyCon,
-- but now you also have to pass in the generic information about the type
-- constructor - you can get hold of it easily (see Generics module)
+mkAlgTyCon :: Name
+ -> Kind
+ -> [TyVar]
+ -> [PredType]
+ -> AlgTyConRhs
+ -> [Id]
+ -> TyConParent
+ -> RecFlag
+ -> Bool
+ -> Bool
+ -> TyCon
mkAlgTyCon name kind tyvars stupid rhs sel_ids parent is_rec gen_info gadt_syn
= AlgTyCon {
tyConName = name,
algTcStupidTheta = stupid,
algTcRhs = rhs,
algTcSelIds = sel_ids,
- algTcParent = parent,
+ algTcParent = ASSERT( okParent name parent ) parent,
algTcRec = is_rec,
algTcGadtSyntax = gadt_syn,
hasGenerics = gen_info
}
+mkClassTyCon :: Name -> Kind -> [TyVar] -> AlgTyConRhs -> Class -> RecFlag -> TyCon
mkClassTyCon name kind tyvars rhs clas is_rec =
mkAlgTyCon name kind tyvars [] rhs [] (ClassTyCon clas) is_rec False False
+mkTupleTyCon :: Name -> Kind -> Arity -> [TyVar] -> DataCon -> Boxity -> Bool -> TyCon
mkTupleTyCon name kind arity tyvars con boxed gen_info
= TupleTyCon {
tyConUnique = nameUnique name,
-- as primitive, but *lifted*, TyCons for now. They are lifted
-- because the Haskell type T representing the (foreign) .NET
-- type T is actually implemented (in ILX) as a thunk<T>
+mkForeignTyCon :: Name -> Maybe FastString -> Kind -> Arity -> TyCon
mkForeignTyCon name ext_name kind arity
= PrimTyCon {
tyConName = name,
-- most Prim tycons are lifted
+mkPrimTyCon :: Name -> Kind -> Arity -> PrimRep -> TyCon
mkPrimTyCon name kind arity rep
= mkPrimTyCon' name kind arity rep True
+mkVoidPrimTyCon :: Name -> Kind -> Arity -> TyCon
mkVoidPrimTyCon name kind arity
= mkPrimTyCon' name kind arity VoidRep True
-- but RealWorld is lifted
+mkLiftedPrimTyCon :: Name -> Kind -> Arity -> PrimRep -> TyCon
mkLiftedPrimTyCon name kind arity rep
= mkPrimTyCon' name kind arity rep False
+mkPrimTyCon' :: Name -> Kind -> Arity -> PrimRep -> Bool -> TyCon
mkPrimTyCon' name kind arity rep is_unlifted
= PrimTyCon {
tyConName = name,
tyConExtName = Nothing
}
-mkSynTyCon name kind tyvars rhs
+mkSynTyCon :: Name -> Kind -> [TyVar] -> SynTyConRhs -> TyConParent -> TyCon
+mkSynTyCon name kind tyvars rhs parent
= SynTyCon {
tyConName = name,
tyConUnique = nameUnique name,
tyConKind = kind,
tyConArity = length tyvars,
tyConTyVars = tyvars,
- synTcRhs = rhs
+ synTcRhs = rhs,
+ synTcParent = parent
}
+mkCoercionTyCon :: Name -> Arity -> ([Type] -> (Type,Type)) -> TyCon
mkCoercionTyCon name arity kindRule
= CoercionTyCon {
tyConName = name,
}
-- Super kinds always have arity zero
+mkSuperKindTyCon :: Name -> TyCon
mkSuperKindTyCon name
= SuperKindTyCon {
tyConName = name,
isAlgTyCon :: TyCon -> Bool
isAlgTyCon (AlgTyCon {}) = True
isAlgTyCon (TupleTyCon {}) = True
-isAlgTyCon other = False
+isAlgTyCon _ = False
isDataTyCon :: TyCon -> Bool
--- isDataTyCon returns True for data types that are represented by
--- heap-allocated constructors.
+-- isDataTyCon returns True for data types that are definitely
+-- represented by heap-allocated constructors.
-- These are srcutinised by Core-level @case@ expressions, and they
-- get info tables allocated for them.
-- True for all @data@ types
-- False for newtypes
-- unboxed tuples
-isDataTyCon tc@(AlgTyCon {algTcRhs = rhs})
+-- type families
+--
+-- NB: for a data type family, T, only the *instance* tycons are
+-- get an info table etc. The family tycon does not.
+-- Hence False for OpenTyCon
+isDataTyCon (AlgTyCon {algTcRhs = rhs})
= case rhs of
- OpenDataTyCon -> True
+ OpenTyCon {} -> False
DataTyCon {} -> True
- OpenNewTyCon -> False
NewTyCon {} -> False
- AbstractTyCon -> pprPanic "isDataTyCon" (ppr tc)
-
+ AbstractTyCon -> False -- We don't know, so return False
isDataTyCon (TupleTyCon {tyConBoxed = boxity}) = isBoxed boxity
-isDataTyCon other = False
+isDataTyCon _ = False
isNewTyCon :: TyCon -> Bool
-isNewTyCon (AlgTyCon {algTcRhs = NewTyCon {}}) = True
-isNewTyCon other = False
+isNewTyCon (AlgTyCon {algTcRhs = NewTyCon {}}) = True
+isNewTyCon _ = False
+
+unwrapNewTyCon_maybe :: TyCon -> Maybe ([TyVar], Type, Maybe TyCon)
+unwrapNewTyCon_maybe (AlgTyCon { tyConTyVars = tvs,
+ algTcRhs = NewTyCon { nt_co = mb_co,
+ nt_rhs = rhs }})
+ = Just (tvs, rhs, mb_co)
+unwrapNewTyCon_maybe _ = Nothing
isProductTyCon :: TyCon -> Bool
-- A "product" tycon
DataTyCon{ data_cons = [data_con] }
-> isVanillaDataCon data_con
NewTyCon {} -> True
- other -> False
+ _ -> False
isProductTyCon (TupleTyCon {}) = True
-isProductTyCon other = False
+isProductTyCon _ = False
isSynTyCon :: TyCon -> Bool
isSynTyCon (SynTyCon {}) = True
isSynTyCon _ = False
+-- As for newtypes, it is in some contexts important to distinguish between
+-- closed synonyms and synonym families, as synonym families have no unique
+-- right hand side to which a synonym family application can expand.
+--
+isClosedSynTyCon :: TyCon -> Bool
+isClosedSynTyCon tycon = isSynTyCon tycon && not (isOpenTyCon tycon)
+
+isOpenSynTyCon :: TyCon -> Bool
+isOpenSynTyCon tycon = isSynTyCon tycon && isOpenTyCon tycon
+
isGadtSyntaxTyCon :: TyCon -> Bool
isGadtSyntaxTyCon (AlgTyCon { algTcGadtSyntax = res }) = res
-isGadtSyntaxTyCon other = False
+isGadtSyntaxTyCon _ = False
isEnumerationTyCon :: TyCon -> Bool
isEnumerationTyCon (AlgTyCon {algTcRhs = DataTyCon { is_enum = res }}) = res
-isEnumerationTyCon other = False
+isEnumerationTyCon _ = False
isOpenTyCon :: TyCon -> Bool
-isOpenTyCon (SynTyCon {synTcRhs = OpenSynTyCon _}) = True
-isOpenTyCon (AlgTyCon {algTcRhs = OpenDataTyCon }) = True
-isOpenTyCon (AlgTyCon {algTcRhs = OpenNewTyCon }) = True
-isOpenTyCon _ = False
+isOpenTyCon (SynTyCon {synTcRhs = OpenSynTyCon _ _}) = True
+isOpenTyCon (AlgTyCon {algTcRhs = OpenTyCon {} }) = True
+isOpenTyCon _ = False
+
+assocTyConArgPoss_maybe :: TyCon -> Maybe [Int]
+assocTyConArgPoss_maybe (AlgTyCon {
+ algTcRhs = OpenTyCon {otArgPoss = poss}}) = poss
+assocTyConArgPoss_maybe (SynTyCon { synTcRhs = OpenSynTyCon _ poss }) = poss
+assocTyConArgPoss_maybe _ = Nothing
+
+isTyConAssoc :: TyCon -> Bool
+isTyConAssoc = isJust . assocTyConArgPoss_maybe
+
+setTyConArgPoss :: TyCon -> [Int] -> TyCon
+setTyConArgPoss tc@(AlgTyCon { algTcRhs = rhs }) poss =
+ tc { algTcRhs = rhs {otArgPoss = Just poss} }
+setTyConArgPoss tc@(SynTyCon { synTcRhs = OpenSynTyCon ki _ }) poss =
+ tc { synTcRhs = OpenSynTyCon ki (Just poss) }
+setTyConArgPoss tc _ = pprPanic "setTyConArgPoss" (ppr tc)
isTupleTyCon :: TyCon -> Bool
-- The unit tycon didn't used to be classed as a tuple tycon
-- get spat into the interface file as tuple tycons, so I don't think
-- it matters.
isTupleTyCon (TupleTyCon {}) = True
-isTupleTyCon other = False
+isTupleTyCon _ = False
isUnboxedTupleTyCon :: TyCon -> Bool
isUnboxedTupleTyCon (TupleTyCon {tyConBoxed = boxity}) = not (isBoxed boxity)
-isUnboxedTupleTyCon other = False
+isUnboxedTupleTyCon _ = False
isBoxedTupleTyCon :: TyCon -> Bool
isBoxedTupleTyCon (TupleTyCon {tyConBoxed = boxity}) = isBoxed boxity
-isBoxedTupleTyCon other = False
+isBoxedTupleTyCon _ = False
+tupleTyConBoxity :: TyCon -> Boxity
tupleTyConBoxity tc = tyConBoxed tc
isRecursiveTyCon :: TyCon -> Bool
isRecursiveTyCon (AlgTyCon {algTcRec = Recursive}) = True
-isRecursiveTyCon other = False
+isRecursiveTyCon _ = False
isHiBootTyCon :: TyCon -> Bool
-- Used for knot-tying in hi-boot files
isHiBootTyCon (AlgTyCon {algTcRhs = AbstractTyCon}) = True
-isHiBootTyCon other = False
+isHiBootTyCon _ = False
isForeignTyCon :: TyCon -> Bool
-- isForeignTyCon identifies foreign-imported type constructors
isForeignTyCon (PrimTyCon {tyConExtName = Just _}) = True
-isForeignTyCon other = False
+isForeignTyCon _ = False
isSuperKindTyCon :: TyCon -> Bool
isSuperKindTyCon (SuperKindTyCon {}) = True
-isSuperKindTyCon other = False
+isSuperKindTyCon _ = False
-isCoercionTyCon_maybe :: TyCon -> Maybe (Arity, [Type] -> Kind)
+isCoercionTyCon_maybe :: TyCon -> Maybe (Arity, [Type] -> (Type,Type))
isCoercionTyCon_maybe (CoercionTyCon {tyConArity = ar, coKindFun = rule})
= Just (ar, rule)
-isCoercionTyCon_maybe other = Nothing
+isCoercionTyCon_maybe _ = Nothing
+isCoercionTyCon :: TyCon -> Bool
isCoercionTyCon (CoercionTyCon {}) = True
-isCoercionTyCon other = False
+isCoercionTyCon _ = False
+
+-- Identifies implicit tycons that, in particular, do not go into interface
+-- files (because they are implicitly reconstructed when the interface is
+-- read).
+--
+-- Note that
+--
+-- * associated families are implicit, as they are re-constructed from
+-- the class declaration in which they reside, and
+-- * family instances are *not* implicit as they represent the instance body
+-- (similar to a dfun does that for a class instance).
+--
+isImplicitTyCon :: TyCon -> Bool
+isImplicitTyCon tycon | isTyConAssoc tycon = True
+ | isSynTyCon tycon = False
+ | isAlgTyCon tycon = isClassTyCon tycon ||
+ isTupleTyCon tycon
+isImplicitTyCon _other = True
+ -- catches: FunTyCon, PrimTyCon,
+ -- CoercionTyCon, SuperKindTyCon
\end{code}
Type, -- Body type (not yet substituted)
[Type]) -- Leftover args
--- For the *typechecker* view, we expand synonyms only
+-- For the *typechecker* view, we expand (closed) synonyms only
tcExpandTyCon_maybe (SynTyCon {tyConTyVars = tvs,
synTcRhs = SynonymTyCon rhs }) tys
= expand tvs rhs tys
-tcExpandTyCon_maybe other_tycon tys = Nothing
+tcExpandTyCon_maybe _ _ = Nothing
---------------
-- For the *Core* view, we expand synonyms only as well
tyConHasGenerics :: TyCon -> Bool
tyConHasGenerics (AlgTyCon {hasGenerics = hg}) = hg
tyConHasGenerics (TupleTyCon {hasGenerics = hg}) = hg
-tyConHasGenerics other = False -- Synonyms
+tyConHasGenerics _ = False -- Synonyms
tyConDataCons :: TyCon -> [DataCon]
-- It's convenient for tyConDataCons to return the
tyConDataCons_maybe (AlgTyCon {algTcRhs = DataTyCon { data_cons = cons }}) = Just cons
tyConDataCons_maybe (AlgTyCon {algTcRhs = NewTyCon { data_con = con }}) = Just [con]
tyConDataCons_maybe (TupleTyCon {dataCon = con}) = Just [con]
-tyConDataCons_maybe other = Nothing
+tyConDataCons_maybe _ = Nothing
tyConFamilySize :: TyCon -> Int
tyConFamilySize (AlgTyCon {algTcRhs = DataTyCon {data_cons = cons}}) =
length cons
tyConFamilySize (AlgTyCon {algTcRhs = NewTyCon {}}) = 1
-tyConFamilySize (AlgTyCon {algTcRhs = OpenDataTyCon}) = 0
+tyConFamilySize (AlgTyCon {algTcRhs = OpenTyCon {}}) = 0
tyConFamilySize (TupleTyCon {}) = 1
-#ifdef DEBUG
tyConFamilySize other = pprPanic "tyConFamilySize:" (ppr other)
-#endif
tyConSelIds :: TyCon -> [Id]
tyConSelIds (AlgTyCon {algTcSelIds = fs}) = fs
-tyConSelIds other_tycon = []
+tyConSelIds _ = []
algTyConRhs :: TyCon -> AlgTyConRhs
algTyConRhs (AlgTyCon {algTcRhs = rhs}) = rhs
newTyConRhs (AlgTyCon {tyConTyVars = tvs, algTcRhs = NewTyCon { nt_rhs = rhs }}) = (tvs, rhs)
newTyConRhs tycon = pprPanic "newTyConRhs" (ppr tycon)
-newTyConRep :: TyCon -> ([TyVar], Type)
-newTyConRep (AlgTyCon {tyConTyVars = tvs, algTcRhs = NewTyCon { nt_rep = rep }}) = (tvs, rep)
-newTyConRep tycon = pprPanic "newTyConRep" (ppr tycon)
+newTyConEtadRhs :: TyCon -> ([TyVar], Type)
+newTyConEtadRhs (AlgTyCon {algTcRhs = NewTyCon { nt_etad_rhs = tvs_rhs }}) = tvs_rhs
+newTyConEtadRhs tycon = pprPanic "newTyConEtadRhs" (ppr tycon)
-newTyConCo :: TyCon -> Maybe TyCon
-newTyConCo (AlgTyCon {tyConTyVars = tvs, algTcRhs = NewTyCon { nt_co = co }}) = co
-newTyConCo tycon = pprPanic "newTyConCo" (ppr tycon)
+newTyConCo_maybe :: TyCon -> Maybe TyCon
+newTyConCo_maybe (AlgTyCon {algTcRhs = NewTyCon { nt_co = co }}) = co
+newTyConCo_maybe _ = Nothing
tyConPrimRep :: TyCon -> PrimRep
tyConPrimRep (PrimTyCon {primTyConRep = rep}) = rep
_ -> pprPanic "synTyConType" (ppr tc)
synTyConResKind :: TyCon -> Kind
-synTyConResKind (SynTyCon {synTcRhs = OpenSynTyCon kind}) = kind
+synTyConResKind (SynTyCon {synTcRhs = OpenSynTyCon kind _}) = kind
synTyConResKind tycon = pprPanic "synTyConResKind" (ppr tycon)
\end{code}
\begin{code}
-maybeTyConSingleCon :: TyCon -> Maybe DataCon
-maybeTyConSingleCon (AlgTyCon {algTcRhs = DataTyCon {data_cons = [c] }}) = Just c
-maybeTyConSingleCon (AlgTyCon {algTcRhs = NewTyCon { data_con = c }}) = Just c
-maybeTyConSingleCon (AlgTyCon {}) = Nothing
-maybeTyConSingleCon (TupleTyCon {dataCon = con}) = Just con
-maybeTyConSingleCon (PrimTyCon {}) = Nothing
-maybeTyConSingleCon (FunTyCon {}) = Nothing -- case at funty
-maybeTyConSingleCon tc = pprPanic "maybeTyConSingleCon: unexpected tycon " $ ppr tc
+tyConSingleDataCon_maybe :: TyCon -> Maybe DataCon
+tyConSingleDataCon_maybe (AlgTyCon {algTcRhs = DataTyCon {data_cons = [c] }}) = Just c
+tyConSingleDataCon_maybe (AlgTyCon {algTcRhs = NewTyCon { data_con = c }}) = Just c
+tyConSingleDataCon_maybe (AlgTyCon {}) = Nothing
+tyConSingleDataCon_maybe (TupleTyCon {dataCon = con}) = Just con
+tyConSingleDataCon_maybe (PrimTyCon {}) = Nothing
+tyConSingleDataCon_maybe (FunTyCon {}) = Nothing -- case at funty
+tyConSingleDataCon_maybe tc = pprPanic "tyConSingleDataCon_maybe: unexpected tycon " $ ppr tc
\end{code}
\begin{code}
isClassTyCon :: TyCon -> Bool
isClassTyCon (AlgTyCon {algTcParent = ClassTyCon _}) = True
-isClassTyCon other_tycon = False
+isClassTyCon _ = False
tyConClass_maybe :: TyCon -> Maybe Class
tyConClass_maybe (AlgTyCon {algTcParent = ClassTyCon clas}) = Just clas
-tyConClass_maybe ther_tycon = Nothing
+tyConClass_maybe _ = Nothing
isFamInstTyCon :: TyCon -> Bool
-isFamInstTyCon (AlgTyCon {algTcParent = FamilyTyCon _}) = True
-isFamInstTyCon other_tycon = False
-
-tyConFamily_maybe :: TyCon -> Maybe TyCon
-tyConFamily_maybe (AlgTyCon {algTcParent = FamilyTyCon fam}) = Just fam
-tyConFamily_maybe ther_tycon = Nothing
+isFamInstTyCon (AlgTyCon {algTcParent = FamilyTyCon _ _ _ }) = True
+isFamInstTyCon (SynTyCon {synTcParent = FamilyTyCon _ _ _ }) = True
+isFamInstTyCon _ = False
+
+tyConFamInst_maybe :: TyCon -> Maybe (TyCon, [Type])
+tyConFamInst_maybe (AlgTyCon {algTcParent = FamilyTyCon fam instTys _}) =
+ Just (fam, instTys)
+tyConFamInst_maybe (SynTyCon {synTcParent = FamilyTyCon fam instTys _}) =
+ Just (fam, instTys)
+tyConFamInst_maybe _ =
+ Nothing
+
+tyConFamilyCoercion_maybe :: TyCon -> Maybe TyCon
+tyConFamilyCoercion_maybe (AlgTyCon {algTcParent = FamilyTyCon _ _ coe}) =
+ Just coe
+tyConFamilyCoercion_maybe (SynTyCon {synTcParent = FamilyTyCon _ _ coe}) =
+ Just coe
+tyConFamilyCoercion_maybe _ =
+ Nothing
\end{code}
projects / ghc-hetmet.git / blobdiff