%
-% (c) The GRASP/AQUA Project, Glasgow University, 1992-1996
+% (c) The GRASP/AQUA Project, Glasgow University, 1992-1998
%
\section[TyCon]{The @TyCon@ datatype}
\begin{code}
-#include "HsVersions.h"
-
module TyCon(
- TyCon(..), -- NB: some pals need to see representation
+ TyCon, ArgVrcs, FieldLabel,
+
+ PrimRep(..),
+ tyConPrimRep,
+
+ AlgTyConRhs(..), visibleDataCons,
- SYN_IE(Arity), NewOrData(..),
+ isFunTyCon, isUnLiftedTyCon, isProductTyCon,
+ isAlgTyCon, isDataTyCon, isSynTyCon, isNewTyCon, isPrimTyCon,
+ isEnumerationTyCon,
+ isTupleTyCon, isUnboxedTupleTyCon, isBoxedTupleTyCon, tupleTyConBoxity,
+ isRecursiveTyCon, newTyConRep, newTyConRhs,
+ isHiBootTyCon,
- isFunTyCon, isPrimTyCon, isBoxedTyCon,
- isAlgTyCon, isDataTyCon, isSynTyCon, isNewTyCon, maybeNewTyCon,
+ tcExpandTyCon_maybe, coreExpandTyCon_maybe,
- mkDataTyCon,
+ makeTyConAbstract, isAbstractTyCon,
+
+ mkForeignTyCon, isForeignTyCon,
+
+ mkAlgTyCon,
+ mkClassTyCon,
mkFunTyCon,
mkPrimTyCon,
- mkSpecTyCon,
+ mkLiftedPrimTyCon,
mkTupleTyCon,
-
mkSynTyCon,
+ tyConName,
tyConKind,
tyConUnique,
tyConTyVars,
- tyConDataCons,
- tyConFamilySize,
- tyConDerivings,
- tyConTheta,
- tyConPrimRep,
- synTyConArity,
- getSynTyConDefn,
+ tyConArgVrcs,
+ algTyConRhs, tyConDataCons, tyConDataCons_maybe, tyConFamilySize,
+ tyConSelIds,
+ tyConStupidTheta,
+ tyConArity,
+ isClassTyCon, tyConClass_maybe,
+ synTyConDefn, synTyConRhs,
+ tyConExtName, -- External name for foreign types
maybeTyConSingleCon,
- isEnumerationTyCon, isTupleTyCon,
- derivedClasses
+
+ -- Generics
+ tyConHasGenerics
) where
-CHK_Ubiq() -- debugging consistency check
-
-#if defined(__GLASGOW_HASKELL__) && __GLASGOW_HASKELL__ <= 201
-IMPORT_DELOOPER(TyLoop) ( SYN_IE(Type), GenType,
- SYN_IE(Class), GenClass,
- SYN_IE(Id), GenId,
- splitSigmaTy, splitFunTy,
- tupleCon, isNullaryDataCon, idType
- --LATER: specMaybeTysSuffix
- )
-#else
-import {-# SOURCE #-} Type ( Type, splitSigmaTy, splitFunTy )
-import {-# SOURCE #-} Class ( Class )
-import {-# SOURCE #-} Id ( Id, isNullaryDataCon, idType )
-import {-# SOURCE #-} TysWiredIn ( tupleCon )
-#endif
+#include "HsVersions.h"
+
+import {-# SOURCE #-} TypeRep ( Type, PredType )
+ -- Should just be Type(Type), but this fails due to bug present up to
+ -- and including 4.02 involving slurping of hi-boot files. Bug is now fixed.
+
+import {-# SOURCE #-} DataCon ( DataCon, isVanillaDataCon )
-import BasicTypes ( SYN_IE(Arity), NewOrData(..) )
-import TyVar ( GenTyVar, alphaTyVars, alphaTyVar, betaTyVar, SYN_IE(TyVar) )
-import Usage ( GenUsage, SYN_IE(Usage) )
-import Kind ( Kind, mkBoxedTypeKind, mkArrowKind, resultKind, argKind )
-
-import Maybes
-import Name ( Name, nameUnique, mkWiredInTyConName, NamedThing(getName) )
-import Unique ( Unique, funTyConKey, Uniquable(..) )
-import Pretty ( Doc )
-import PrimRep ( PrimRep(..) )
-import PrelMods ( gHC__, pREL_TUP, pREL_BASE )
-import Lex ( mkTupNameStr )
-import SrcLoc ( SrcLoc, mkBuiltinSrcLoc )
-import Util ( nOfThem, isIn, Ord3(..), panic, panic#, assertPanic )
+
+import Var ( TyVar, Id )
+import Class ( Class )
+import Kind ( Kind )
+import BasicTypes ( Arity, RecFlag(..), Boxity(..), isBoxed )
+import Name ( Name, nameUnique, NamedThing(getName) )
+import PrelNames ( Unique, Uniquable(..) )
+import Maybes ( orElse )
+import Outputable
+import FastString
\end{code}
+%************************************************************************
+%* *
+\subsection{The data type}
+%* *
+%************************************************************************
+
\begin{code}
data TyCon
- = FunTyCon -- Kind = Type -> Type -> Type
-
- | DataTyCon Unique{-TyConKey-}
- Name
- Kind
- [TyVar]
- [(Class,Type)] -- Its context
- [Id{-DataCon-}] -- Its data constructors, with fully polymorphic types
- -- This list can be empty, when we import a data type abstractly,
- -- either (a) the interface is hand-written and doesn't give
- -- the constructors, or
- -- (b) in a quest for fast compilation we don't import
- -- the constructors
- [Class] -- Classes which have derived instances
- NewOrData
-
- | TupleTyCon Unique -- cached
- Name -- again, we could do without this, but
- -- it makes life somewhat easier
- Arity -- just a special case of DataTyCon
- -- Kind = BoxedTypeKind
- -- -> ... (n times) ...
- -- -> BoxedTypeKind
- -- -> BoxedTypeKind
-
- | PrimTyCon -- Primitive types; cannot be defined in Haskell
- Unique -- Always unboxed; hence never represented by a closure
- Name -- Often represented by a bit-pattern for the thing
- Kind -- itself (eg Int#), but sometimes by a pointer to
- PrimRep
-
- | SpecTyCon -- A specialised TyCon; eg (Arr# Int#), or (List Int#)
- TyCon
- [Maybe Type] -- Specialising types
-
- -- OLD STUFF ABOUT Array types. Use SpecTyCon instead
- -- ([PrimRep] -> PrimRep) -- a heap-allocated object (eg ArrInt#).
- -- The primitive types Arr# and StablePtr# have
- -- parameters (hence arity /= 0); but the rest don't.
- -- Only arrays use the list in a non-trivial way.
- -- Length of that list must == arity.
-
- | SynTyCon
- Unique
- Name
- Kind
- Arity
- [TyVar] -- Argument type variables
- Type -- Right-hand side, mentioning these type vars.
- -- Acts as a template for the expansion when
- -- the tycon is applied to some types.
+ = FunTyCon {
+ tyConUnique :: Unique,
+ tyConName :: Name,
+ tyConKind :: Kind,
+ tyConArity :: Arity
+ }
+
+
+ | AlgTyCon { -- Data type, and newtype decls.
+ -- All lifted, all boxed
+ tyConUnique :: Unique,
+ tyConName :: Name,
+ tyConKind :: Kind,
+ tyConArity :: Arity,
+
+ tyConTyVars :: [TyVar], -- Scopes over (a) the [PredType] in AlgTyConRhs.DataTyCon
+ -- (b) the cached types in AlgTyConRhs.NewTyCon
+ -- But not over the data constructors
+ argVrcs :: ArgVrcs,
+
+ algTcSelIds :: [Id], -- Its record selectors (empty if none):
+
+ algTcStupidTheta :: [PredType], -- The "stupid theta" for the data type
+ -- (always empty for GADTs)
+
+ algTcRhs :: AlgTyConRhs, -- Data constructors in here
+
+ algTcRec :: RecFlag, -- Tells whether the data type is part of
+ -- a mutually-recursive group or not
+
+ hasGenerics :: Bool, -- True <=> generic to/from functions are available
+ -- (in the exports of the data type's source module)
+
+ algTcClass :: Maybe Class
+ -- Just cl if this tycon came from a class declaration
+ }
+
+ | PrimTyCon { -- Primitive types; cannot be defined in Haskell
+ -- Now includes foreign-imported types
+ tyConUnique :: Unique,
+ tyConName :: Name,
+ tyConKind :: Kind,
+ tyConArity :: Arity,
+ argVrcs :: ArgVrcs,
+
+ primTyConRep :: PrimRep,
+ -- Many primitive tycons are unboxed, but some are
+ -- boxed (represented by pointers). The CgRep tells.
+
+ isUnLifted :: Bool, -- Most primitive tycons are unlifted,
+ -- but foreign-imported ones may not be
+ tyConExtName :: Maybe FastString -- Just xx for foreign-imported types
+ }
+
+ | TupleTyCon {
+ tyConUnique :: Unique,
+ tyConName :: Name,
+ tyConKind :: Kind,
+ tyConArity :: Arity,
+ tyConBoxed :: Boxity,
+ tyConTyVars :: [TyVar],
+ dataCon :: DataCon,
+ hasGenerics :: Bool
+ }
+
+ | SynTyCon {
+ tyConUnique :: Unique,
+ tyConName :: Name,
+ tyConKind :: Kind,
+ tyConArity :: Arity,
+
+ tyConTyVars :: [TyVar], -- Bound tyvars
+ synTcRhs :: Type, -- Right-hand side, mentioning these type vars.
+ -- Acts as a template for the expansion when
+ -- the tycon is applied to some types.
+ argVrcs :: ArgVrcs
+ }
+
+type FieldLabel = Name
+
+type ArgVrcs = [(Bool,Bool)] -- Tyvar variance info: [(occPos,occNeg)]
+ -- [] means "no information, assume the worst"
+
+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
+
+ | 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)
+ is_enum :: Bool -- Cached: True <=> an enumeration type
+ } -- Includes data types with no constructors.
+
+ | NewTyCon {
+ data_con :: DataCon, -- The unique constructor; it has no existentials
+
+ nt_rhs :: Type, -- Cached: the argument type of the constructor
+ -- = the representation type of the tycon
+
+ 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 (DataTyCon{ data_cons = cs }) = cs
+visibleDataCons (NewTyCon{ data_con = c }) = [c]
\end{code}
-\begin{code}
-mkFunTyCon = FunTyCon
-mkFunTyConName = mkWiredInTyConName funTyConKey gHC__ SLIT("->") FunTyCon
+Note [Newtype eta]
+~~~~~~~~~~~~~~~~~~
+Consider
+ newtype Parser m a = MkParser (Foogle m a)
+Are these two types equal (to Core)?
+ Monad (Parser m)
+ Monad (Foogle m)
+Well, yes. But to see that easily we eta-reduce the RHS type of
+Parser, in this case to ([], Froogle), so that even unsaturated applications
+of Parser will work right. This eta reduction is done when the type
+constructor is built, and cached in NewTyCon. The cached field is
+only used in coreExpandTyCon_maybe.
+
+Here's an example that I think showed up in practice
+Source code:
+ newtype T a = MkT [a]
+ newtype Foo m = MkFoo (forall a. m a -> Int)
+
+ w1 :: Foo []
+ w1 = ...
+
+ w2 :: Foo T
+ w2 = MkFoo (\(MkT x) -> case w1 of MkFoo f -> f x)
+
+After desugaring, and discading 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==[]
-mkSpecTyCon = SpecTyCon
-mkTupleTyCon = TupleTyCon
-mkDataTyCon name = DataTyCon (nameUnique name) name
-mkPrimTyCon name = PrimTyCon (nameUnique name) name
-mkSynTyCon name = SynTyCon (nameUnique name) name
+%************************************************************************
+%* *
+\subsection{PrimRep}
+%* *
+%************************************************************************
-isFunTyCon FunTyCon = True
-isFunTyCon _ = False
+A PrimRep is an abstraction of a type. It contains information that
+the code generator needs in order to pass arguments, return results,
+and store values of this type.
-isPrimTyCon (PrimTyCon _ _ _ _) = True
-isPrimTyCon _ = False
+A PrimRep is somewhat similar to a CgRep (see codeGen/SMRep) and a
+MachRep (see cmm/MachOp), although each of these types has a distinct
+and clearly defined purpose:
--- At present there are no unboxed non-primitive types, so
--- isBoxedTyCon is just the negation of isPrimTyCon.
-isBoxedTyCon = not . isPrimTyCon
+ - A PrimRep is a CgRep + information about signedness + information
+ about primitive pointers (AddrRep). Signedness and primitive
+ pointers are required when passing a primitive type to a foreign
+ function, but aren't needed for call/return conventions of Haskell
+ functions.
--- isAlgTyCon returns True for both @data@ and @newtype@
-isAlgTyCon (DataTyCon _ _ _ _ _ _ _ _) = True
-isAlgTyCon (TupleTyCon _ _ _) = True
-isAlgTyCon other = False
-
--- isDataTyCon returns False for @newtype@.
-isDataTyCon (DataTyCon _ _ _ _ _ _ _ DataType) = True
-isDataTyCon (TupleTyCon _ _ _) = True
-isDataTyCon other = False
-
-maybeNewTyCon :: TyCon -> Maybe ([TyVar], Type) -- Returns representation type info
-maybeNewTyCon (DataTyCon _ _ _ _ _ (con:null_cons) _ NewType)
- = ASSERT( null null_cons && null null_tys)
- Just (tyvars, rep_ty)
- where
- (tyvars, theta, tau) = splitSigmaTy (idType con)
- (rep_ty:null_tys, res_ty) = splitFunTy tau
-
-maybeNewTyCon other = Nothing
-
-isNewTyCon (DataTyCon _ _ _ _ _ _ _ NewType) = True
-isNewTyCon other = False
-
-isSynTyCon (SynTyCon _ _ _ _ _ _) = True
-isSynTyCon _ = False
-\end{code}
+ - A MachRep is a basic machine type (non-void, doesn't contain
+ information on pointerhood or signedness, but contains some
+ reps that don't have corresponding Haskell types).
\begin{code}
--- Special cases to avoid reconstructing lots of kinds
-kind1 = mkBoxedTypeKind `mkArrowKind` mkBoxedTypeKind
-kind2 = mkBoxedTypeKind `mkArrowKind` kind1
-
-tyConKind :: TyCon -> Kind
-tyConKind FunTyCon = kind2
-tyConKind (DataTyCon _ _ kind _ _ _ _ _) = kind
-tyConKind (PrimTyCon _ _ kind _) = kind
-tyConKind (SynTyCon _ _ k _ _ _) = k
-
-tyConKind (TupleTyCon _ _ n)
- = mkArrow n
- where
- mkArrow 0 = mkBoxedTypeKind
- mkArrow 1 = kind1
- mkArrow 2 = kind2
- mkArrow n = mkBoxedTypeKind `mkArrowKind` mkArrow (n-1)
-
-tyConKind (SpecTyCon tc tys)
- = spec (tyConKind tc) tys
- where
- spec kind [] = kind
- spec kind (Just _ : tys) = spec (resultKind kind) tys
- spec kind (Nothing : tys) =
- argKind kind `mkArrowKind` spec (resultKind kind) tys
+data PrimRep
+ = VoidRep
+ | PtrRep
+ | IntRep -- signed, word-sized
+ | WordRep -- unsinged, word-sized
+ | Int64Rep -- signed, 64 bit (32-bit words only)
+ | Word64Rep -- unsigned, 64 bit (32-bit words only)
+ | AddrRep -- a pointer, but not to a Haskell value
+ | FloatRep
+ | DoubleRep
\end{code}
+%************************************************************************
+%* *
+\subsection{TyCon Construction}
+%* *
+%************************************************************************
+
+Note: the TyCon constructors all take a Kind as one argument, even though
+they could, in principle, work out their Kind from their other arguments.
+But to do so they need functions from Types, and that makes a nasty
+module mutual-recursion. And they aren't called from many places.
+So we compromise, and move their Kind calculation to the call site.
+
\begin{code}
-tyConUnique :: TyCon -> Unique
-tyConUnique FunTyCon = funTyConKey
-tyConUnique (DataTyCon uniq _ _ _ _ _ _ _) = uniq
-tyConUnique (TupleTyCon uniq _ _) = uniq
-tyConUnique (PrimTyCon uniq _ _ _) = uniq
-tyConUnique (SynTyCon uniq _ _ _ _ _) = uniq
-tyConUnique (SpecTyCon _ _ ) = panic "tyConUnique:SpecTyCon"
-
-synTyConArity :: TyCon -> Maybe Arity -- Nothing <=> not a syn tycon
-synTyConArity (SynTyCon _ _ _ arity _ _) = Just arity
-synTyConArity _ = Nothing
+mkFunTyCon :: Name -> Kind -> TyCon
+mkFunTyCon name kind
+ = FunTyCon {
+ tyConUnique = nameUnique name,
+ tyConName = name,
+ tyConKind = kind,
+ tyConArity = 2
+ }
+
+-- 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 tyvars argvrcs stupid rhs sel_ids is_rec gen_info
+ = AlgTyCon {
+ tyConName = name,
+ tyConUnique = nameUnique name,
+ tyConKind = kind,
+ tyConArity = length tyvars,
+ tyConTyVars = tyvars,
+ argVrcs = argvrcs,
+ algTcStupidTheta = stupid,
+ algTcRhs = rhs,
+ algTcSelIds = sel_ids,
+ algTcClass = Nothing,
+ algTcRec = is_rec,
+ hasGenerics = gen_info
+ }
+
+mkClassTyCon name kind tyvars argvrcs rhs clas is_rec
+ = AlgTyCon {
+ tyConName = name,
+ tyConUnique = nameUnique name,
+ tyConKind = kind,
+ tyConArity = length tyvars,
+ tyConTyVars = tyvars,
+ argVrcs = argvrcs,
+ algTcStupidTheta = [],
+ algTcRhs = rhs,
+ algTcSelIds = [],
+ algTcClass = Just clas,
+ algTcRec = is_rec,
+ hasGenerics = False
+ }
+
+
+mkTupleTyCon name kind arity tyvars con boxed gen_info
+ = TupleTyCon {
+ tyConUnique = nameUnique name,
+ tyConName = name,
+ tyConKind = kind,
+ tyConArity = arity,
+ tyConBoxed = boxed,
+ tyConTyVars = tyvars,
+ dataCon = con,
+ hasGenerics = gen_info
+ }
+
+-- Foreign-imported (.NET) type constructors are represented
+-- 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 ext_name kind arity arg_vrcs
+ = PrimTyCon {
+ tyConName = name,
+ tyConUnique = nameUnique name,
+ tyConKind = kind,
+ tyConArity = arity,
+ argVrcs = arg_vrcs,
+ primTyConRep = PtrRep, -- they all do
+ isUnLifted = False,
+ tyConExtName = ext_name
+ }
+
+
+-- most Prim tycons are lifted
+mkPrimTyCon name kind arity arg_vrcs rep
+ = mkPrimTyCon' name kind arity arg_vrcs rep True
+
+-- but RealWorld is lifted
+mkLiftedPrimTyCon name kind arity arg_vrcs rep
+ = mkPrimTyCon' name kind arity arg_vrcs rep False
+
+mkPrimTyCon' name kind arity arg_vrcs rep is_unlifted
+ = PrimTyCon {
+ tyConName = name,
+ tyConUnique = nameUnique name,
+ tyConKind = kind,
+ tyConArity = arity,
+ argVrcs = arg_vrcs,
+ primTyConRep = rep,
+ isUnLifted = is_unlifted,
+ tyConExtName = Nothing
+ }
+
+mkSynTyCon name kind tyvars rhs argvrcs
+ = SynTyCon {
+ tyConName = name,
+ tyConUnique = nameUnique name,
+ tyConKind = kind,
+ tyConArity = length tyvars,
+ tyConTyVars = tyvars,
+ synTcRhs = rhs,
+ argVrcs = argvrcs
+ }
\end{code}
\begin{code}
-tyConTyVars :: TyCon -> [TyVar]
-tyConTyVars FunTyCon = [alphaTyVar,betaTyVar]
-tyConTyVars (DataTyCon _ _ _ tvs _ _ _ _) = tvs
-tyConTyVars (TupleTyCon _ _ arity) = take arity alphaTyVars
-tyConTyVars (SynTyCon _ _ _ _ tvs _) = tvs
-#ifdef DEBUG
-tyConTyVars (PrimTyCon _ _ _ _) = panic "tyConTyVars:PrimTyCon"
-tyConTyVars (SpecTyCon _ _ ) = panic "tyConTyVars:SpecTyCon"
-#endif
+isFunTyCon :: TyCon -> Bool
+isFunTyCon (FunTyCon {}) = True
+isFunTyCon _ = False
+
+isAbstractTyCon :: TyCon -> Bool
+isAbstractTyCon (AlgTyCon { algTcRhs = AbstractTyCon }) = True
+isAbstractTyCon _ = False
+
+makeTyConAbstract :: TyCon -> TyCon
+makeTyConAbstract tc@(AlgTyCon {}) = tc { algTcRhs = AbstractTyCon }
+makeTyConAbstract tc = pprPanic "makeTyConAbstract" (ppr tc)
+
+isPrimTyCon :: TyCon -> Bool
+isPrimTyCon (PrimTyCon {}) = True
+isPrimTyCon _ = False
+
+isUnLiftedTyCon :: TyCon -> Bool
+isUnLiftedTyCon (PrimTyCon {isUnLifted = is_unlifted}) = is_unlifted
+isUnLiftedTyCon (TupleTyCon {tyConBoxed = boxity}) = not (isBoxed boxity)
+isUnLiftedTyCon _ = False
+
+-- isAlgTyCon returns True for both @data@ and @newtype@
+isAlgTyCon :: TyCon -> Bool
+isAlgTyCon (AlgTyCon {}) = True
+isAlgTyCon (TupleTyCon {}) = True
+isAlgTyCon other = False
+
+isDataTyCon :: TyCon -> Bool
+-- isDataTyCon returns True for data types that are 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})
+ = case rhs of
+ DataTyCon {} -> True
+ NewTyCon {} -> False
+ AbstractTyCon -> pprPanic "isDataTyCon" (ppr tc)
+
+isDataTyCon (TupleTyCon {tyConBoxed = boxity}) = isBoxed boxity
+isDataTyCon other = False
+
+isNewTyCon :: TyCon -> Bool
+isNewTyCon (AlgTyCon {algTcRhs = NewTyCon {}}) = True
+isNewTyCon other = False
+
+isProductTyCon :: TyCon -> Bool
+-- A "product" tycon
+-- has *one* constructor,
+-- is *not* existential
+-- but
+-- may be DataType or NewType,
+-- may be unboxed or not,
+-- may be recursive or not
+isProductTyCon tc@(AlgTyCon {}) = case algTcRhs tc of
+ DataTyCon{ data_cons = [data_con] }
+ -> isVanillaDataCon data_con
+ NewTyCon {} -> True
+ other -> False
+isProductTyCon (TupleTyCon {}) = True
+isProductTyCon other = False
+
+isSynTyCon :: TyCon -> Bool
+isSynTyCon (SynTyCon {}) = True
+isSynTyCon _ = False
+
+isEnumerationTyCon :: TyCon -> Bool
+isEnumerationTyCon (AlgTyCon {algTcRhs = DataTyCon { is_enum = res }}) = res
+isEnumerationTyCon other = False
+
+isTupleTyCon :: TyCon -> Bool
+-- The unit tycon didn't used to be classed as a tuple tycon
+-- but I thought that was silly so I've undone it
+-- If it can't be for some reason, it should be a AlgTyCon
+--
+-- NB: when compiling Data.Tuple, the tycons won't reply True to
+-- isTupleTyCon, becuase they are built as AlgTyCons. However they
+-- get spat into the interface file as tuple tycons, so I don't think
+-- it matters.
+isTupleTyCon (TupleTyCon {}) = True
+isTupleTyCon other = False
+
+isUnboxedTupleTyCon :: TyCon -> Bool
+isUnboxedTupleTyCon (TupleTyCon {tyConBoxed = boxity}) = not (isBoxed boxity)
+isUnboxedTupleTyCon other = False
+
+isBoxedTupleTyCon :: TyCon -> Bool
+isBoxedTupleTyCon (TupleTyCon {tyConBoxed = boxity}) = isBoxed boxity
+isBoxedTupleTyCon other = False
+
+tupleTyConBoxity tc = tyConBoxed tc
+
+isRecursiveTyCon :: TyCon -> Bool
+isRecursiveTyCon (AlgTyCon {algTcRec = Recursive}) = True
+isRecursiveTyCon other = False
+
+isHiBootTyCon :: TyCon -> Bool
+-- Used for knot-tying in hi-boot files
+isHiBootTyCon (AlgTyCon {algTcRhs = AbstractTyCon}) = True
+isHiBootTyCon other = False
+
+isForeignTyCon :: TyCon -> Bool
+-- isForeignTyCon identifies foreign-imported type constructors
+isForeignTyCon (PrimTyCon {tyConExtName = Just _}) = True
+isForeignTyCon other = False
\end{code}
+
+-----------------------------------------------
+-- Expand type-constructor applications
+-----------------------------------------------
+
\begin{code}
-tyConDataCons :: TyCon -> [Id]
-tyConFamilySize :: TyCon -> Int
+tcExpandTyCon_maybe, coreExpandTyCon_maybe
+ :: TyCon
+ -> [Type] -- Args to tycon
+ -> Maybe ([(TyVar,Type)], -- Substitution
+ Type, -- Body type (not yet substituted)
+ [Type]) -- Leftover args
+
+-- For the *typechecker* view, we expand synonyms only
+tcExpandTyCon_maybe (SynTyCon {tyConTyVars = tvs, synTcRhs = rhs }) tys
+ = expand tvs rhs tys
+tcExpandTyCon_maybe other_tycon tys = Nothing
+
+---------------
+-- For the *Core* view, we expand synonyms *and* non-recursive newtypes
+coreExpandTyCon_maybe (AlgTyCon {algTcRec = NonRecursive, -- Not recursive
+ algTcRhs = NewTyCon { nt_etad_rhs = etad_rhs }}) tys
+ = case etad_rhs of -- Don't do this in the pattern match, lest we accidentally
+ -- match the etad_rhs of a *recursive* newtype
+ (tvs,rhs) -> expand tvs rhs tys
+
+coreExpandTyCon_maybe tycon tys = tcExpandTyCon_maybe tycon tys
+
+----------------
+expand :: [TyVar] -> Type -- Template
+ -> [Type] -- Args
+ -> Maybe ([(TyVar,Type)], Type, [Type]) -- Expansion
+expand tvs rhs tys
+ = case n_tvs `compare` length tys of
+ LT -> Just (tvs `zip` tys, rhs, drop n_tvs tys)
+ EQ -> Just (tvs `zip` tys, rhs, [])
+ GT -> Nothing
+ where
+ n_tvs = length tvs
+\end{code}
-tyConDataCons (DataTyCon _ _ _ _ _ data_cons _ _) = data_cons
-tyConDataCons (TupleTyCon _ _ a) = [tupleCon a]
-tyConDataCons other = []
- -- You may think this last equation should fail,
- -- but it's quite convenient to return no constructors for
- -- a synonym; see for example the call in TcTyClsDecls.
+\begin{code}
+tyConHasGenerics :: TyCon -> Bool
+tyConHasGenerics (AlgTyCon {hasGenerics = hg}) = hg
+tyConHasGenerics (TupleTyCon {hasGenerics = hg}) = hg
+tyConHasGenerics other = False -- Synonyms
+
+tyConDataCons :: TyCon -> [DataCon]
+-- It's convenient for tyConDataCons to return the
+-- empty list for type synonyms etc
+tyConDataCons tycon = tyConDataCons_maybe tycon `orElse` []
+
+tyConDataCons_maybe :: TyCon -> Maybe [DataCon]
+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
-tyConFamilySize (DataTyCon _ _ _ _ _ data_cons _ _) = length data_cons
-tyConFamilySize (TupleTyCon _ _ _) = 1
+tyConFamilySize :: TyCon -> Int
+tyConFamilySize (AlgTyCon {algTcRhs = DataTyCon { data_cons = cons }}) = length cons
+tyConFamilySize (AlgTyCon {algTcRhs = NewTyCon {}}) = 1
+tyConFamilySize (TupleTyCon {}) = 1
#ifdef DEBUG
---tyConFamilySize other = pprPanic "tyConFamilySize:" (pprTyCon PprDebug other)
+tyConFamilySize other = pprPanic "tyConFamilySize:" (ppr other)
#endif
-tyConPrimRep :: TyCon -> PrimRep
-tyConPrimRep (PrimTyCon _ _ _ rep) = rep
-tyConPrimRep _ = PtrRep
+tyConSelIds :: TyCon -> [Id]
+tyConSelIds (AlgTyCon {algTcSelIds = fs}) = fs
+tyConSelIds other_tycon = []
+
+algTyConRhs :: TyCon -> AlgTyConRhs
+algTyConRhs (AlgTyCon {algTcRhs = rhs}) = rhs
+algTyConRhs (TupleTyCon {dataCon = con}) = DataTyCon { data_cons = [con], is_enum = False }
+algTyConRhs other = pprPanic "algTyConRhs" (ppr other)
\end{code}
\begin{code}
-tyConDerivings :: TyCon -> [Class]
-tyConDerivings (DataTyCon _ _ _ _ _ _ derivs _) = derivs
-tyConDerivings other = []
+newTyConRhs :: TyCon -> ([TyVar], Type)
+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)
+
+tyConPrimRep :: TyCon -> PrimRep
+tyConPrimRep (PrimTyCon {primTyConRep = rep}) = rep
+tyConPrimRep tc = ASSERT(not (isUnboxedTupleTyCon tc)) PtrRep
\end{code}
\begin{code}
-tyConTheta :: TyCon -> [(Class,Type)]
-tyConTheta (DataTyCon _ _ _ _ theta _ _ _) = theta
-tyConTheta (TupleTyCon _ _ _) = []
--- should ask about anything else
+tyConStupidTheta :: TyCon -> [PredType]
+tyConStupidTheta (AlgTyCon {algTcStupidTheta = stupid}) = stupid
+tyConStupidTheta (TupleTyCon {}) = []
+tyConStupidTheta tycon = pprPanic "tyConStupidTheta" (ppr tycon)
\end{code}
+@tyConArgVrcs_maybe@ gives a list of (occPos,occNeg) flags, one for
+each tyvar, if available. See @calcAlgTyConArgVrcs@ for how this is
+actually computed (in another file).
+
\begin{code}
-getSynTyConDefn :: TyCon -> ([TyVar], Type)
-getSynTyConDefn (SynTyCon _ _ _ _ tyvars ty) = (tyvars,ty)
+tyConArgVrcs :: TyCon -> ArgVrcs
+tyConArgVrcs (FunTyCon {}) = [(False,True),(True,False)]
+tyConArgVrcs (AlgTyCon {argVrcs = oi}) = oi
+tyConArgVrcs (PrimTyCon {argVrcs = oi}) = oi
+tyConArgVrcs (TupleTyCon {tyConArity = arity}) = (replicate arity (True,False))
+tyConArgVrcs (SynTyCon {argVrcs = oi}) = oi
\end{code}
\begin{code}
-maybeTyConSingleCon :: TyCon -> Maybe Id
-
-maybeTyConSingleCon (TupleTyCon _ _ arity) = Just (tupleCon arity)
-maybeTyConSingleCon (DataTyCon _ _ _ _ _ [c] _ _) = Just c
-maybeTyConSingleCon (DataTyCon _ _ _ _ _ _ _ _) = Nothing
-maybeTyConSingleCon (PrimTyCon _ _ _ _) = Nothing
-maybeTyConSingleCon (SpecTyCon tc tys) = panic "maybeTyConSingleCon:SpecTyCon"
- -- requires DataCons of TyCon
-
-isEnumerationTyCon (TupleTyCon _ _ arity)
- = arity == 0
-isEnumerationTyCon (DataTyCon _ _ _ _ _ data_cons _ _)
- = not (null data_cons) && all isNullaryDataCon data_cons
-
-
-isTupleTyCon (TupleTyCon _ _ arity) = arity >= 2 -- treat "0-tuple" specially
-isTupleTyCon (SpecTyCon tc tys) = isTupleTyCon tc
-isTupleTyCon other = False
-
+synTyConDefn :: TyCon -> ([TyVar], Type)
+synTyConDefn (SynTyCon {tyConTyVars = tyvars, synTcRhs = ty}) = (tyvars,ty)
+synTyConDefn tycon = pprPanic "getSynTyConDefn" (ppr tycon)
+synTyConRhs :: TyCon -> Type
+synTyConRhs tc = synTcRhs tc
\end{code}
-@derivedFor@ reports if we have an {\em obviously}-derived instance
-for the given class/tycon. Of course, you might be deriving something
-because it a superclass of some other obviously-derived class --- this
-function doesn't deal with that.
-
-ToDo: what about derivings for specialised tycons !!!
+\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
+\end{code}
\begin{code}
-derivedClasses :: TyCon -> [Class]
-derivedClasses (DataTyCon _ _ _ _ _ _ derivs _) = derivs
-derivedClasses something_weird = []
+isClassTyCon :: TyCon -> Bool
+isClassTyCon (AlgTyCon {algTcClass = Just _}) = True
+isClassTyCon other_tycon = False
+
+tyConClass_maybe :: TyCon -> Maybe Class
+tyConClass_maybe (AlgTyCon {algTcClass = maybe_clas}) = maybe_clas
+tyConClass_maybe ther_tycon = Nothing
\end{code}
+
%************************************************************************
%* *
\subsection[TyCon-instances]{Instance declarations for @TyCon@}
the property @(a<=b) || (b<=a)@.
\begin{code}
-instance Ord3 TyCon where
- cmp tc1 tc2 = uniqueOf tc1 `cmp` uniqueOf tc2
-
instance Eq TyCon where
- a == b = case (a `cmp` b) of { EQ_ -> True; _ -> False }
- a /= b = case (a `cmp` b) of { EQ_ -> False; _ -> True }
+ a == b = case (a `compare` b) of { EQ -> True; _ -> False }
+ a /= b = case (a `compare` b) of { EQ -> False; _ -> True }
instance Ord TyCon where
- a <= b = case (a `cmp` b) of { LT_ -> True; EQ_ -> True; GT__ -> False }
- a < b = case (a `cmp` b) of { LT_ -> True; EQ_ -> False; GT__ -> False }
- a >= b = case (a `cmp` b) of { LT_ -> False; EQ_ -> True; GT__ -> True }
- a > b = case (a `cmp` b) of { LT_ -> False; EQ_ -> False; GT__ -> True }
- _tagCmp a b = case (a `cmp` b) of { LT_ -> _LT; EQ_ -> _EQ; GT__ -> _GT }
+ a <= b = case (a `compare` b) of { LT -> True; EQ -> True; GT -> False }
+ a < b = case (a `compare` b) of { LT -> True; EQ -> False; GT -> False }
+ a >= b = case (a `compare` b) of { LT -> False; EQ -> True; GT -> True }
+ a > b = case (a `compare` b) of { LT -> False; EQ -> False; GT -> True }
+ compare a b = getUnique a `compare` getUnique b
instance Uniquable TyCon where
- uniqueOf (DataTyCon u _ _ _ _ _ _ _) = u
- uniqueOf (TupleTyCon u _ _) = u
- uniqueOf (PrimTyCon u _ _ _) = u
- uniqueOf (SynTyCon u _ _ _ _ _) = u
- uniqueOf tc@(SpecTyCon _ _) = panic "uniqueOf:SpecTyCon"
- uniqueOf tc = uniqueOf (getName tc)
-\end{code}
+ getUnique tc = tyConUnique tc
-\begin{code}
-instance NamedThing TyCon where
- getName (DataTyCon _ n _ _ _ _ _ _) = n
- getName (PrimTyCon _ n _ _) = n
- getName (SpecTyCon tc _) = getName tc
- getName (SynTyCon _ n _ _ _ _) = n
- getName FunTyCon = mkFunTyConName
- getName (TupleTyCon _ n _) = n
- getName tc = panic "TyCon.getName"
-
-{- LATER:
- getName (SpecTyCon tc tys) = let (OrigName m n) = origName "????" tc in
- (m, n _APPEND_ specMaybeTysSuffix tys)
- getName other_tc = moduleNamePair (expectJust "tycon1" (getName other_tc))
- getName other = Nothing
--}
+instance Outputable TyCon where
+ ppr tc = ppr (getName tc)
+instance NamedThing TyCon where
+ getName = tyConName
\end{code}
projects / ghc-hetmet.git / blobdiff