\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,
+ isRecursiveTyCon, newTyConRep,
mkAlgTyCon,
+ mkClassTyCon,
mkFunTyCon,
mkPrimTyCon,
mkTupleTyCon,
#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 {-# SOURCE #-} DataCon ( DataCon, isExistentialDataCon )
import Class ( Class )
import Var ( TyVar )
tyConKind :: Kind,
tyConArity :: Arity,
- tyConTyVars :: [TyVar],
- dataTyConTheta :: [(Class,[Type])],
- dataTyConArgVrcs :: ArgVrcs,
+ tyConTyVars :: [TyVar],
+ tyConArgVrcs :: ArgVrcs,
+ algTyConTheta :: [(Class,[Type])],
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
+ 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
}
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 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,
+ 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],
+ 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}
-- 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 other = False
-isNewTyCon (AlgTyCon {algTyConFlavour = NewType}) = True
-isNewTyCon other = False
+isNewTyCon (AlgTyCon {algTyConFlavour = NewTyCon _}) = True
+isNewTyCon other = False
--- A "product" tycon is non-recursive and has one constructor,
--- whether DataType or NewType
-isProductTyCon (AlgTyCon {dataCons = [c], algTyConRec = NonRecursive}) = True
-isProductTyCon (TupleTyCon {}) = True
-isProductTyCon other = False
+newTyConRep (AlgTyCon {algTyConFlavour = NewTyCon rep}) = Just rep
+newTyConRep other = Nothing
+
+-- 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
isUnboxedTupleTyCon (TupleTyCon {tyConBoxed = False}) = True
isUnboxedTupleTyCon other = False
+
+isRecursiveTyCon (AlgTyCon {algTyConRec = Recursive}) = True
+isRecursiveTyCon other = False
\end{code}
\begin{code}
\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 (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}