\begin{code}
module TyCon(
- TyCon, KindCon, SuperKindCon, ArgVrcs,
+ TyCon, KindCon, SuperKindCon, ArgVrcs, AlgTyConFlavour(..),
isFunTyCon, isUnLiftedTyCon, isBoxedTyCon, isProductTyCon,
isAlgTyCon, isDataTyCon, isSynTyCon, isNewTyCon, isPrimTyCon,
- isEnumerationTyCon, isTupleTyCon, isUnboxedTupleTyCon,
+ isEnumerationTyCon,
+ isTupleTyCon, isUnboxedTupleTyCon, isBoxedTupleTyCon, tupleTyConBoxity,
+ isRecursiveTyCon, newTyConRep,
mkAlgTyCon,
+ mkClassTyCon,
mkFunTyCon,
mkPrimTyCon,
mkTupleTyCon,
tyConUnique,
tyConTyVars,
tyConArgVrcs_maybe,
- tyConDataCons,
+ tyConDataCons, tyConDataConsIfAvailable,
tyConFamilySize,
tyConDerivings,
tyConTheta,
#include "HsVersions.h"
-import {-# SOURCE #-} Type ( Type, Kind, SuperKind )
-import {-# SOURCE #-} DataCon ( DataCon )
+import {-# SOURCE #-} TypeRep ( Type, Kind, SuperKind )
+ -- 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 Class ( Class )
+import {-# SOURCE #-} DataCon ( DataCon, isExistentialDataCon )
+
+import Class ( Class, ClassContext )
import Var ( TyVar )
-import BasicTypes ( Arity, NewOrData(..), RecFlag(..) )
+import BasicTypes ( Arity, NewOrData(..), RecFlag(..), Boxity(..), isBoxed )
import Maybes
import Name ( Name, nameUnique, NamedThing(getName) )
import Unique ( Unique, Uniquable(..), anyBoxConKey )
tyConKind :: Kind,
tyConArity :: Arity,
- tyConTyVars :: [TyVar],
- dataTyConTheta :: [(Class,[Type])],
- dataTyConArgVrcs :: ArgVrcs,
+ tyConTyVars :: [TyVar],
+ tyConArgVrcs :: ArgVrcs,
+ algTyConTheta :: ClassContext,
dataCons :: [DataCon],
-- Its data constructors, with fully polymorphic types
-- (b) in a quest for fast compilation we don't import
-- the constructors
- dataTyConDerivings :: [Class], -- Classes which have derived instances
+ noOfDataCons :: Int, -- Number of data constructors
+ -- Usually this is the same as the length of the
+ -- dataCons field, but the latter may be empty if
+ -- we imported the type abstractly. But even if we import
+ -- abstractly we still need to know the number of constructors
+ -- so we can get the return convention right. Tiresome!
+
+ algTyConDerivings :: [Class], -- Classes which have derived instances
+
+ algTyConFlavour :: AlgTyConFlavour,
+ algTyConRec :: RecFlag, -- Tells whether the data type is part of
+ -- a mutually-recursive group or not
- dataTyConClass_maybe :: (Maybe Class), -- Nothing for ordinary types;
+ algTyConClass_maybe :: Maybe Class -- Nothing for ordinary types;
-- Just c for the type constructor
-- for dictionaries of class c.
- algTyConFlavour :: NewOrData,
- algTyConRec :: RecFlag -- Tells whether the data type is part of
- -- a mutually-recursive group or not
+
}
| PrimTyCon { -- Primitive types; cannot be defined in Haskell
tyConName :: Name,
tyConKind :: Kind,
tyConArity :: Arity,
- primTyConArgVrcs :: ArgVrcs,
+ tyConArgVrcs :: ArgVrcs,
primTyConRep :: PrimRep
}
tyConName :: Name,
tyConKind :: Kind,
tyConArity :: Arity,
- tyConBoxed :: Bool, -- True for boxed; False for unboxed
+ tyConBoxed :: Boxity,
tyConTyVars :: [TyVar],
dataCon :: DataCon
}
synTyConDefn :: Type, -- Right-hand side, mentioning these type vars.
-- Acts as a template for the expansion when
-- the tycon is applied to some types.
- synTyConArgVrcs :: ArgVrcs
+ tyConArgVrcs :: ArgVrcs
}
| KindCon { -- Type constructor at the kind level
type ArgVrcs = [(Bool,Bool)] -- Tyvar variance info: [(occPos,occNeg)]
-- *NB*: this is tyvar variance info, *not*
-- termvar usage info.
+
+data AlgTyConFlavour
+ = DataTyCon -- Data type
+ | EnumTyCon -- Special sort of enumeration type
+ | NewTyCon Type -- Newtype, with its *ultimate* representation type
+ -- By 'ultimate' I mean that the rep type is not itself
+ -- a newtype or type synonym.
+
+ -- The rep type has explicit for-alls for the tyvars of
+ -- the TyCon. Thus:
+ -- newtype T a = MkT [(a,Int)]
+ -- The rep type is forall a. [(a,Int)]
+ --
+ -- The rep type isn't entirely simple:
+ -- for a recursive newtype we pick () as the rep type
+ -- newtype T = MkT T
\end{code}
%************************************************************************
tyConArity = 2
}
-mkAlgTyCon name kind tyvars theta argvrcs cons derivs maybe_clas flavour rec
+mkAlgTyCon name kind tyvars theta argvrcs cons ncons derivs flavour rec
= AlgTyCon {
- tyConName = name,
- tyConUnique = nameUnique name,
- tyConKind = kind,
- tyConArity = length tyvars,
- tyConTyVars = tyvars,
- dataTyConTheta = theta,
- dataTyConArgVrcs = argvrcs,
- dataCons = cons,
- dataTyConDerivings = derivs,
- dataTyConClass_maybe = maybe_clas,
- algTyConFlavour = flavour,
- algTyConRec = rec
+ tyConName = name,
+ tyConUnique = nameUnique name,
+ tyConKind = kind,
+ tyConArity = length tyvars,
+ tyConTyVars = tyvars,
+ tyConArgVrcs = argvrcs,
+ algTyConTheta = theta,
+ dataCons = cons,
+ noOfDataCons = ncons,
+ algTyConDerivings = derivs,
+ algTyConClass_maybe = Nothing,
+ algTyConFlavour = flavour,
+ algTyConRec = rec
}
+mkClassTyCon name kind tyvars argvrcs con clas flavour
+ = AlgTyCon {
+ tyConName = name,
+ tyConUnique = nameUnique name,
+ tyConKind = kind,
+ tyConArity = length tyvars,
+ tyConTyVars = tyvars,
+ tyConArgVrcs = argvrcs,
+ algTyConTheta = [],
+ dataCons = [con],
+ noOfDataCons = 1,
+ algTyConDerivings = [],
+ algTyConClass_maybe = Just clas,
+ algTyConFlavour = flavour,
+ algTyConRec = NonRecursive
+ }
+
+
mkTupleTyCon name kind arity tyvars con boxed
= TupleTyCon {
tyConUnique = nameUnique name,
tyConUnique = nameUnique name,
tyConKind = kind,
tyConArity = arity,
- primTyConArgVrcs = arg_vrcs,
+ tyConArgVrcs = arg_vrcs,
primTyConRep = rep
}
tyConArity = arity,
tyConTyVars = tyvars,
synTyConDefn = rhs,
- synTyConArgVrcs = argvrcs
+ tyConArgVrcs = argvrcs
}
setTyConName tc name = tc {tyConName = name, tyConUnique = nameUnique name}
isPrimTyCon _ = False
isUnLiftedTyCon (PrimTyCon {}) = True
-isUnLiftedTyCon (TupleTyCon { tyConBoxed = False }) = True
+isUnLiftedTyCon (TupleTyCon { tyConBoxed = boxity}) = not (isBoxed boxity)
isUnLiftedTyCon _ = False
-- isBoxedTyCon should not be applied to SynTyCon, nor KindCon
isBoxedTyCon (AlgTyCon {}) = True
isBoxedTyCon (FunTyCon {}) = True
-isBoxedTyCon (TupleTyCon {tyConBoxed = boxed}) = boxed
+isBoxedTyCon (TupleTyCon {tyConBoxed = boxity}) = isBoxed boxity
isBoxedTyCon (PrimTyCon {primTyConRep = rep}) = isFollowableRep rep
-- isAlgTyCon returns True for both @data@ and @newtype@
-- isDataTyCon returns False for @newtype@ and for unboxed tuples
isDataTyCon (AlgTyCon {algTyConFlavour = new_or_data}) = case new_or_data of
- NewType -> False
+ NewTyCon _ -> False
other -> True
-isDataTyCon (TupleTyCon {tyConBoxed = True}) = True
+isDataTyCon (TupleTyCon {tyConBoxed = boxity}) = isBoxed boxity
isDataTyCon other = False
-isNewTyCon (AlgTyCon {algTyConFlavour = NewType}) = True
-isNewTyCon other = False
+isNewTyCon (AlgTyCon {algTyConFlavour = NewTyCon _}) = True
+isNewTyCon other = False
+
+newTyConRep (AlgTyCon {algTyConFlavour = NewTyCon rep}) = Just rep
+newTyConRep other = Nothing
--- A "product" tycon is non-recursive and has one constructor, and is *not* an unboxed tuple
--- whether DataType or NewType
-isProductTyCon (AlgTyCon {dataCons = [c], algTyConRec = NonRecursive}) = True
-isProductTyCon (TupleTyCon { tyConBoxed = boxed }) = boxed
-isProductTyCon other = False
+-- 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 (AlgTyCon {dataCons = [data_con]}) = not (isExistentialDataCon data_con)
+isProductTyCon (TupleTyCon {}) = True
+isProductTyCon other = False
isSynTyCon (SynTyCon {}) = True
isSynTyCon _ = False
-isEnumerationTyCon (AlgTyCon {algTyConFlavour = EnumType}) = True
-isEnumerationTyCon other = False
+isEnumerationTyCon (AlgTyCon {algTyConFlavour = EnumTyCon}) = True
+isEnumerationTyCon other = False
--- The unit tycon isn't classed as a tuple tycon
-isTupleTyCon (TupleTyCon {tyConArity = arity, tyConBoxed = True}) = arity >= 2
-isTupleTyCon other = False
+-- 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
+isTupleTyCon (TupleTyCon {}) = True
+isTupleTyCon other = False
-isUnboxedTupleTyCon (TupleTyCon {tyConBoxed = False}) = True
+isUnboxedTupleTyCon (TupleTyCon {tyConBoxed = boxity}) = not (isBoxed boxity)
isUnboxedTupleTyCon other = False
+
+isBoxedTupleTyCon (TupleTyCon {tyConBoxed = boxity}) = isBoxed boxity
+isBoxedTupleTyCon other = False
+
+tupleTyConBoxity tc = tyConBoxed tc
+
+isRecursiveTyCon (AlgTyCon {algTyConRec = Recursive}) = True
+isRecursiveTyCon other = False
\end{code}
\begin{code}
tyConDataCons :: TyCon -> [DataCon]
-tyConDataCons (AlgTyCon {dataCons = cons}) = cons
-tyConDataCons (TupleTyCon {dataCon = con}) = [con]
-tyConDataCons other = []
+tyConDataCons tycon = ASSERT2( not (null cons), ppr tycon ) cons
+ where
+ cons = tyConDataConsIfAvailable tycon
+
+tyConDataConsIfAvailable (AlgTyCon {dataCons = cons}) = cons -- Empty for abstract types
+tyConDataConsIfAvailable (TupleTyCon {dataCon = con}) = [con]
+tyConDataConsIfAvailable 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.
tyConFamilySize :: TyCon -> Int
-tyConFamilySize (AlgTyCon {dataCons = cons}) = length cons
-tyConFamilySize (TupleTyCon {}) = 1
+tyConFamilySize (AlgTyCon {noOfDataCons = n}) = n
+tyConFamilySize (TupleTyCon {}) = 1
#ifdef DEBUG
tyConFamilySize other = pprPanic "tyConFamilySize:" (ppr other)
#endif
\begin{code}
tyConDerivings :: TyCon -> [Class]
-tyConDerivings (AlgTyCon {dataTyConDerivings = derivs}) = derivs
-tyConDerivings other = []
+tyConDerivings (AlgTyCon {algTyConDerivings = derivs}) = derivs
+tyConDerivings other = []
\end{code}
\begin{code}
-tyConTheta :: TyCon -> [(Class, [Type])]
-tyConTheta (AlgTyCon {dataTyConTheta = theta}) = theta
+tyConTheta :: TyCon -> ClassContext
+tyConTheta (AlgTyCon {algTyConTheta = theta}) = theta
-- should ask about anything else
\end{code}
tyConArgVrcs_maybe :: TyCon -> Maybe ArgVrcs
tyConArgVrcs_maybe (FunTyCon {} ) = Just [(False,True),(True,False)]
-tyConArgVrcs_maybe (AlgTyCon {dataTyConArgVrcs = oi}) = Just oi
-tyConArgVrcs_maybe (PrimTyCon {primTyConArgVrcs = oi}) = Just oi
+tyConArgVrcs_maybe (AlgTyCon {tyConArgVrcs = oi}) = Just oi
+tyConArgVrcs_maybe (PrimTyCon {tyConArgVrcs = oi}) = Just oi
tyConArgVrcs_maybe (TupleTyCon {tyConArity = arity }) = Just (replicate arity (True,False))
-tyConArgVrcs_maybe (SynTyCon {synTyConArgVrcs = oi }) = Just oi
+tyConArgVrcs_maybe (SynTyCon {tyConArgVrcs = oi }) = Just oi
tyConArgVrcs_maybe _ = Nothing
\end{code}
\begin{code}
tyConClass_maybe :: TyCon -> Maybe Class
-tyConClass_maybe (AlgTyCon {dataTyConClass_maybe = maybe_cls}) = maybe_cls
-tyConClass_maybe other_tycon = Nothing
+tyConClass_maybe (AlgTyCon {algTyConClass_maybe = maybe_cls}) = maybe_cls
+tyConClass_maybe other_tycon = Nothing
\end{code}