X-Git-Url: http://git.megacz.com/?p=ghc-hetmet.git;a=blobdiff_plain;f=compiler%2Ftypes%2FTyCon.lhs;h=915207621ff2a6652a9110156efff7d1930f5d48;hp=b552c24b63f1649a3f7b080eed57b011c33ad3d1;hb=927df6486bc0dcb598b82702ca40c8fad0d9b25f;hpb=d2ce0f52d42edf32bb9f13796e6ba6edba8bd516 diff --git a/compiler/types/TyCon.lhs b/compiler/types/TyCon.lhs index b552c24..9152076 100644 --- a/compiler/types/TyCon.lhs +++ b/compiler/types/TyCon.lhs @@ -13,7 +13,9 @@ module TyCon( AlgTyConRhs(..), visibleDataCons, TyConParent(..), isNoParent, SynTyConRhs(..), - CoTyConDesc(..), + + -- ** Coercion axiom constructors + CoAxiom(..), coAxiomName, coAxiomArity, -- ** Constructing TyCons mkAlgTyCon, @@ -25,7 +27,6 @@ module TyCon( mkTupleTyCon, mkSynTyCon, mkSuperKindTyCon, - mkCoercionTyCon, mkForeignTyCon, mkAnyTyCon, @@ -35,21 +36,20 @@ module TyCon( isFunTyCon, isPrimTyCon, isTupleTyCon, isUnboxedTupleTyCon, isBoxedTupleTyCon, - isSynTyCon, isClosedSynTyCon, + isSynTyCon, isClosedSynTyCon, isSuperKindTyCon, isDecomposableTyCon, - isCoercionTyCon, isCoercionTyCon_maybe, isForeignTyCon, isAnyTyCon, tyConHasKind, isInjectiveTyCon, isDataTyCon, isProductTyCon, isEnumerationTyCon, - isNewTyCon, isAbstractTyCon, + isNewTyCon, isAbstractTyCon, isFamilyTyCon, isSynFamilyTyCon, isDataFamilyTyCon, isUnLiftedTyCon, isGadtSyntaxTyCon, isTyConAssoc, isRecursiveTyCon, isHiBootTyCon, - isImplicitTyCon, tyConHasGenerics, + isImplicitTyCon, -- ** Extracting information out of TyCons tyConName, @@ -63,16 +63,16 @@ module TyCon( tyConParent, tyConClass_maybe, tyConFamInst_maybe, tyConFamilyCoercion_maybe,tyConFamInstSig_maybe, - synTyConDefn, synTyConRhs, synTyConType, - tyConExtName, -- External name for foreign types + synTyConDefn, synTyConRhs, synTyConType, + tyConExtName, -- External name for foreign types algTyConRhs, newTyConRhs, newTyConEtadRhs, unwrapNewTyCon_maybe, - tupleTyConBoxity, + tupleTyConBoxity, tupleTyConArity, -- ** Manipulating TyCons tcExpandTyCon_maybe, coreExpandTyCon_maybe, makeTyConAbstract, - newTyConCo_maybe, + newTyConCo, newTyConCo_maybe, -- * Primitive representations of Types PrimRep(..), @@ -113,7 +113,7 @@ Note [Type synonym families] * Reply "yes" to isSynFamilyTyCon, and isFamilyTyCon -* From the user's point of view (F Int) and Bool are simply +* From the user's point of view (F Int) and Bool are simply equivalent types. * A Haskell 98 type synonym is a degenerate form of a type synonym @@ -129,6 +129,36 @@ Note [Type synonym families] * Translation of type instance decl: type instance F [a] = Maybe a + translates to a "representation TyCon", 'R:FList', where + R:FList is a SynTyCon, whose + SynTyConRhs is (SynonymTyCon (Maybe a)) + TyConParent is (FamInstTyCon F [a] co) + where co :: F [a] ~ R:FList a + + It's very much as if the user had written + type instance F [a] = R:FList a + type R:FList a = Maybe a + Indeed, in GHC's internal representation, the RHS of every + 'type instance' is simply an application of the representation + TyCon to the quantified varaibles. + + The intermediate representation TyCon is a bit gratuitous, but + it means that: + + each 'type instance' decls is in 1-1 correspondance + with its representation TyCon + + So the result of typechecking a 'type instance' decl is just a + TyCon. In turn this means that type and data families can be + treated uniformly. + +* Translation of type family decl: + type family F a :: * + translates to + a SynTyCon 'F', whose SynTyConRhs is SynFamilyTyCon + +* Translation of type instance decl: + type instance F [a] = Maybe a translates to A SynTyCon 'R:FList a', whose SynTyConRhs is (SynonymTyCon (Maybe a)) @@ -156,6 +186,8 @@ See also Note [Wrappers for data instance tycons] in MkId.lhs * Reply "yes" to isDataFamilyTyCon, and isFamilyTyCon +* Reply "yes" to isDataFamilyTyCon, and isFamilyTyCon + * The user does not see any "equivalent types" as he did with type synonym families. He just sees constructors with types T1 :: T Int @@ -253,9 +285,6 @@ See also Note [Wrappers for data instance tycons] in MkId.lhs -- -- 4) Class declarations: @class Foo where@ creates the @Foo@ type constructor of kind @*@ -- --- 5) Type coercions! This is because we represent a coercion from @t1@ to @t2@ --- as a 'Type', where that type has kind @t1 ~ t2@. See "Coercion" for more on this --- -- This data type also encodes a number of primitive, built in type constructors such as those -- for function and tuple types. data TyCon @@ -304,11 +333,7 @@ data TyCon algTcRec :: RecFlag, -- ^ Tells us whether the data type is part -- of a mutually-recursive group or not - - hasGenerics :: Bool, -- ^ Whether generic (in the -XGenerics sense) - -- to\/from functions are available in the exports - -- of the data type's source module. - + algTcParent :: TyConParent -- ^ Gives the class or family declaration 'TyCon' -- for derived 'TyCon's representing class -- or family instances, respectively. @@ -324,8 +349,7 @@ data TyCon tyConArity :: Arity, tyConBoxed :: Boxity, tyConTyVars :: [TyVar], - dataCon :: DataCon, -- ^ Corresponding tuple data constructor - hasGenerics :: Bool + dataCon :: DataCon -- ^ Corresponding tuple data constructor } -- | Represents type synonyms @@ -368,17 +392,6 @@ data TyCon -- holds the name of the imported thing } - -- | Type coercions, such as @(~)@, @sym@, @trans@, @left@ and @right@. - -- INVARIANT: Coercion TyCons are always fully applied - -- But note that a CoTyCon can be *over*-saturated in a type. - -- E.g. (sym g1) Int will be represented as (TyConApp sym [g1,Int]) - | CoTyCon { - tyConUnique :: Unique, - tyConName :: Name, - tyConArity :: Arity, - coTcDesc :: CoTyConDesc - } - -- | Any types. Like tuples, this is a potentially-infinite family of TyCons -- one for each distinct Kind. They have no values at all. -- Because there are infinitely many of them (like tuples) they are @@ -388,7 +401,7 @@ data TyCon | AnyTyCon { tyConUnique :: Unique, tyConName :: Name, - tc_kind :: Kind -- Never = *; that is done via PrimTyCon + tc_kind :: Kind -- Never = *; that is done via PrimTyCon -- See Note [Any types] in TysPrim } @@ -440,7 +453,7 @@ data AlgTyConRhs -- (see the tag assignment in DataCon.mkDataCon) is_enum :: Bool -- ^ Cached value: is this an enumeration type? - -- (See 'isEnumerationTyCon') + -- See Note [Enumeration types] } -- | Information about those 'TyCon's derived from a @newtype@ declaration @@ -462,18 +475,14 @@ data AlgTyConRhs -- shorter than the declared arity of the 'TyCon'. -- See Note [Newtype eta] - - nt_co :: Maybe TyCon -- ^ A 'TyCon' (which is always a 'CoTyCon') that can - -- have a 'Coercion' extracted from it to create - -- the @newtype@ from the representation 'Type'. - -- - -- This field is optional for non-recursive @newtype@s only. - - -- 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_co :: CoAxiom -- The axiom coercion that creates the @newtype@ from + -- the representation 'Type'. + + -- 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. } -- | Extract those 'DataCon's that we are able to learn about. Note @@ -500,7 +509,24 @@ data TyConParent -- | An *associated* type of a class. | AssocFamilyTyCon - Class -- The class in whose declaration the family is declared + Class -- The class in whose declaration the family is declared + -- The 'tyConTyVars' of this 'TyCon' may mention some + -- of the same type variables as the classTyVars of the + -- parent 'Class'. E.g. + -- + -- @ + -- class C a b where + -- data T c a + -- @ + -- + -- Here the 'a' is shared with the 'Class', and that is + -- important. In an instance declaration we expect the + -- two to be instantiated the same way. Eg. + -- + -- @ + -- instanc C [x] (Tree y) where + -- data T c [x] = T1 x | T2 c + -- @ -- | Type constructors representing an instance of a type family. Parameters: -- @@ -516,7 +542,7 @@ data TyConParent -- and Note [Type synonym families] TyCon -- The family TyCon [Type] -- Argument types (mentions the tyConTyVars of this TyCon) - TyCon -- The coercion constructor + CoAxiom -- The coercion constructor -- E.g. data intance T [a] = ... -- gives a representation tycon: @@ -539,28 +565,36 @@ isNoParent _ = False -- | Information pertaining to the expansion of a type synonym (@type@) data SynTyConRhs - = SynonymTyCon -- ^ An ordinary type synony - Type -- ^ The rhs, which mentions head type variables. It acts as a - -- template for the expansion when the 'TyCon' is applied to some - -- types. - - | SynFamilyTyCon -- A type synonym family e.g. type family F x y :: * -> * - --------------------- -data CoTyConDesc - = CoSym | CoTrans - | CoLeft | CoRight - | CoCsel1 | CoCsel2 | CoCselR - | CoInst - - | CoAxiom -- C tvs : F lhs-tys ~ rhs-ty - { co_ax_tvs :: [TyVar] - , co_ax_lhs :: Type - , co_ax_rhs :: Type } - - | CoUnsafe + = -- | An ordinary type synonyn. + SynonymTyCon + Type -- This 'Type' is the rhs, and may mention from 'tyConTyVars'. + -- It acts as a template for the expansion when the 'TyCon' + -- is applied to some types. + + -- | A type synonym family e.g. @type family F x y :: * -> *@ + | SynFamilyTyCon \end{code} +Note [Enumeration types] +~~~~~~~~~~~~~~~~~~~~~~~~ +We define datatypes with no constructors to *not* be +enumerations; this fixes trac #2578, Otherwise we +end up generating an empty table for + __closure_tbl +which is used by tagToEnum# to map Int# to constructors +in an enumeration. The empty table apparently upset +the linker. + +Moreover, all the data constructor must be enumerations, meaning +they have type (forall abc. T a b c). GADTs are not enumerations. +For example consider + data T a where + T1 :: T Int + T2 :: T Bool + T3 :: T a +What would [T1 ..] be? [T1,T3] :: T Int? Easiest thing is to exclude them. +See Trac #4528. + Note [Newtype coercions] ~~~~~~~~~~~~~~~~~~~~~~~~ The NewTyCon field nt_co is a a TyCon (a coercion constructor in fact) @@ -637,6 +671,31 @@ so the coercion tycon CoT must have %************************************************************************ %* * + Coercion axioms +%* * +%************************************************************************ + +\begin{code} +-- | A 'CoAxiom' is a \"coercion constructor\", i.e. a named equality axiom. +data CoAxiom + = CoAxiom -- type equality axiom. + { co_ax_unique :: Unique -- unique identifier + , co_ax_name :: Name -- name for pretty-printing + , co_ax_tvs :: [TyVar] -- bound type variables + , co_ax_lhs :: Type -- left-hand side of the equality + , co_ax_rhs :: Type -- right-hand side of the equality + } + +coAxiomArity :: CoAxiom -> Arity +coAxiomArity ax = length (co_ax_tvs ax) + +coAxiomName :: CoAxiom -> Name +coAxiomName = co_ax_name +\end{code} + + +%************************************************************************ +%* * \subsection{PrimRep} %* * %************************************************************************ @@ -724,10 +783,9 @@ mkAlgTyCon :: Name -> AlgTyConRhs -- ^ Information about dat aconstructors -> TyConParent -> RecFlag -- ^ Is the 'TyCon' recursive? - -> Bool -- ^ Does it have generic functions? See 'hasGenerics' -> Bool -- ^ Was the 'TyCon' declared with GADT syntax? -> TyCon -mkAlgTyCon name kind tyvars stupid rhs parent is_rec gen_info gadt_syn +mkAlgTyCon name kind tyvars stupid rhs parent is_rec gadt_syn = AlgTyCon { tyConName = name, tyConUnique = nameUnique name, @@ -738,14 +796,13 @@ mkAlgTyCon name kind tyvars stupid rhs parent is_rec gen_info gadt_syn algTcRhs = rhs, algTcParent = ASSERT( okParent name parent ) parent, algTcRec = is_rec, - algTcGadtSyntax = gadt_syn, - hasGenerics = gen_info + algTcGadtSyntax = gadt_syn } -- | Simpler specialization of 'mkAlgTyCon' for classes 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 + mkAlgTyCon name kind tyvars [] rhs (ClassTyCon clas) is_rec False mkTupleTyCon :: Name -> Kind -- ^ Kind of the resulting 'TyCon' @@ -753,9 +810,8 @@ mkTupleTyCon :: Name -> [TyVar] -- ^ 'TyVar's scoped over: see 'tyConTyVars' -> DataCon -> Boxity -- ^ Whether the tuple is boxed or unboxed - -> Bool -- ^ Does it have generic functions? See 'hasGenerics' -> TyCon -mkTupleTyCon name kind arity tyvars con boxed gen_info +mkTupleTyCon name kind arity tyvars con boxed = TupleTyCon { tyConUnique = nameUnique name, tyConName = name, @@ -763,8 +819,7 @@ mkTupleTyCon name kind arity tyvars con boxed gen_info tyConArity = arity, tyConBoxed = boxed, tyConTyVars = tyvars, - dataCon = con, - hasGenerics = gen_info + dataCon = con } -- ^ Foreign-imported (.NET) type constructors are represented @@ -828,17 +883,6 @@ mkSynTyCon name kind tyvars rhs parent synTcParent = parent } --- | Create a coercion 'TyCon' -mkCoercionTyCon :: Name -> Arity - -> CoTyConDesc - -> TyCon -mkCoercionTyCon name arity desc - = CoTyCon { - tyConName = name, - tyConUnique = nameUnique name, - tyConArity = arity, - coTcDesc = desc } - mkAnyTyCon :: Name -> Kind -> TyCon mkAnyTyCon name kind = AnyTyCon { tyConName = name, @@ -916,11 +960,11 @@ isNewTyCon _ = False -- | Take a 'TyCon' apart into the 'TyVar's it scopes over, the 'Type' it expands -- into, and (possibly) a coercion from the representation type to the @newtype@. -- Returns @Nothing@ if this is not possible. -unwrapNewTyCon_maybe :: TyCon -> Maybe ([TyVar], Type, Maybe TyCon) +unwrapNewTyCon_maybe :: TyCon -> Maybe ([TyVar], Type, CoAxiom) unwrapNewTyCon_maybe (AlgTyCon { tyConTyVars = tvs, - algTcRhs = NewTyCon { nt_co = mb_co, + algTcRhs = NewTyCon { nt_co = co, nt_rhs = rhs }}) - = Just (tvs, rhs, mb_co) + = Just (tvs, rhs, co) unwrapNewTyCon_maybe _ = Nothing isProductTyCon :: TyCon -> Bool @@ -952,9 +996,8 @@ isSynTyCon _ = False isDecomposableTyCon :: TyCon -> Bool -- True iff we can decompose (T a b c) into ((T a b) c) --- Specifically NOT true of synonyms (open and otherwise) and coercions +-- Specifically NOT true of synonyms (open and otherwise) isDecomposableTyCon (SynTyCon {}) = False -isDecomposableTyCon (CoTyCon {}) = False isDecomposableTyCon _other = True -- | Is this an algebraic 'TyCon' declared with the GADT syntax? @@ -964,6 +1007,7 @@ isGadtSyntaxTyCon _ = False -- | Is this an algebraic 'TyCon' which is just an enumeration of values? isEnumerationTyCon :: TyCon -> Bool +-- See Note [Enumeration types] in TyCon isEnumerationTyCon (AlgTyCon {algTcRhs = DataTyCon { is_enum = res }}) = res isEnumerationTyCon (TupleTyCon {tyConArity = arity}) = arity == 0 isEnumerationTyCon _ = False @@ -995,7 +1039,7 @@ isInjectiveTyCon tc = not (isSynTyCon tc) -- Ultimately we may have injective associated types -- in which case this test will become more interesting -- - -- It'd be unusual to call isInjectiveTyCon on a regular H98 + -- It'd be unusual to call isInjectiveTyCon on a regular H98 -- type synonym, because you should probably have expanded it first -- But regardless, it's not injective! @@ -1034,6 +1078,11 @@ isBoxedTupleTyCon _ = False tupleTyConBoxity :: TyCon -> Boxity tupleTyConBoxity tc = tyConBoxed tc +-- | Extract the arity of the given 'TyCon', if it is a 'TupleTyCon'. +-- Panics otherwise +tupleTyConArity :: TyCon -> Arity +tupleTyConArity tc = tyConArity tc + -- | Is this a recursive 'TyCon'? isRecursiveTyCon :: TyCon -> Bool isRecursiveTyCon (AlgTyCon {algTcRec = Recursive}) = True @@ -1060,19 +1109,6 @@ isAnyTyCon :: TyCon -> Bool isAnyTyCon (AnyTyCon {}) = True isAnyTyCon _ = False --- | Attempt to pull a 'TyCon' apart into the arity and 'coKindFun' of --- a coercion 'TyCon'. Returns @Nothing@ if the 'TyCon' is not of the --- appropriate kind -isCoercionTyCon_maybe :: TyCon -> Maybe (Arity, CoTyConDesc) -isCoercionTyCon_maybe (CoTyCon {tyConArity = ar, coTcDesc = desc}) - = Just (ar, desc) -isCoercionTyCon_maybe _ = Nothing - --- | Is this a 'TyCon' that represents a coercion? -isCoercionTyCon :: TyCon -> Bool -isCoercionTyCon (CoTyCon {}) = True -isCoercionTyCon _ = False - -- | Identifies implicit tycons that, in particular, do not go into interface -- files (because they are implicitly reconstructed when the interface is -- read). @@ -1102,14 +1138,15 @@ isImplicitTyCon _other = True \begin{code} tcExpandTyCon_maybe, coreExpandTyCon_maybe :: TyCon - -> [Type] -- ^ Arguments to 'TyCon' - -> Maybe ([(TyVar,Type)], + -> [tyco] -- ^ Arguments to 'TyCon' + -> Maybe ([(TyVar,tyco)], Type, - [Type]) -- ^ Returns a 'TyVar' substitution, the body type - -- of the synonym (not yet substituted) and any arguments - -- remaining from the application + [tyco]) -- ^ Returns a 'TyVar' substitution, the body type + -- of the synonym (not yet substituted) and any arguments + -- remaining from the application --- ^ Used to create the view the /typechecker/ has on 'TyCon's. We expand (closed) synonyms only, cf. 'coreExpandTyCon_maybe' +-- ^ Used to create the view the /typechecker/ has on 'TyCon's. +-- We expand (closed) synonyms only, cf. 'coreExpandTyCon_maybe' tcExpandTyCon_maybe (SynTyCon {tyConTyVars = tvs, synTcRhs = SynonymTyCon rhs }) tys = expand tvs rhs tys @@ -1117,36 +1154,26 @@ tcExpandTyCon_maybe _ _ = Nothing --------------- --- ^ Used to create the view /Core/ has on 'TyCon's. We expand not only closed synonyms like 'tcExpandTyCon_maybe', +-- ^ Used to create the view /Core/ has on 'TyCon's. We expand +-- not only closed synonyms like 'tcExpandTyCon_maybe', -- but also non-recursive @newtype@s -coreExpandTyCon_maybe (AlgTyCon { - algTcRhs = NewTyCon { nt_etad_rhs = etad_rhs, nt_co = Nothing }}) 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 :: [TyVar] -> Type -- Template + -> [a] -- Args + -> Maybe ([(TyVar,a)], Type, [a]) -- 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 + GT -> Nothing where n_tvs = length tvs \end{code} \begin{code} --- | Does this 'TyCon' have any generic to\/from functions available? See also 'hasGenerics' -tyConHasGenerics :: TyCon -> Bool -tyConHasGenerics (AlgTyCon {hasGenerics = hg}) = hg -tyConHasGenerics (TupleTyCon {hasGenerics = hg}) = hg -tyConHasGenerics _ = False -- Synonyms tyConKind :: TyCon -> Kind tyConKind (FunTyCon { tc_kind = k }) = k @@ -1159,7 +1186,6 @@ tyConKind tc = pprPanic "tyConKind" (ppr tc) -- SuperKindTyCon and CoTyCon tyConHasKind :: TyCon -> Bool tyConHasKind (SuperKindTyCon {}) = False -tyConHasKind (CoTyCon {}) = False tyConHasKind _ = True -- | As 'tyConDataCons_maybe', but returns the empty list of constructors if no constructors @@ -1212,9 +1238,14 @@ newTyConEtadRhs tycon = pprPanic "newTyConEtadRhs" (ppr tycon) -- | Extracts the @newtype@ coercion from such a 'TyCon', which can be used to construct something -- with the @newtype@s type from its representation type (right hand side). If the supplied 'TyCon' -- is not a @newtype@, returns @Nothing@ -newTyConCo_maybe :: TyCon -> Maybe TyCon -newTyConCo_maybe (AlgTyCon {algTcRhs = NewTyCon { nt_co = co }}) = co -newTyConCo_maybe _ = Nothing +newTyConCo_maybe :: TyCon -> Maybe CoAxiom +newTyConCo_maybe (AlgTyCon {algTcRhs = NewTyCon { nt_co = co }}) = Just co +newTyConCo_maybe _ = Nothing + +newTyConCo :: TyCon -> CoAxiom +newTyConCo tc = case newTyConCo_maybe tc of + Just co -> co + Nothing -> pprPanic "newTyConCo" (ppr tc) -- | Find the primitive representation of a 'TyCon' tyConPrimRep :: TyCon -> PrimRep @@ -1284,6 +1315,7 @@ tyConParent (AlgTyCon {algTcParent = parent}) = parent tyConParent (SynTyCon {synTcParent = parent}) = parent tyConParent _ = NoParentTyCon +---------------------------------------------------------------------------- -- | Is this 'TyCon' that for a family instance, be that for a synonym or an -- algebraic family instance? isFamInstTyCon :: TyCon -> Bool @@ -1291,7 +1323,7 @@ isFamInstTyCon tc = case tyConParent tc of FamInstTyCon {} -> True _ -> False -tyConFamInstSig_maybe :: TyCon -> Maybe (TyCon, [Type], TyCon) +tyConFamInstSig_maybe :: TyCon -> Maybe (TyCon, [Type], CoAxiom) tyConFamInstSig_maybe tc = case tyConParent tc of FamInstTyCon f ts co_tc -> Just (f, ts, co_tc) @@ -1308,7 +1340,7 @@ tyConFamInst_maybe tc -- | If this 'TyCon' is that of a family instance, return a 'TyCon' which represents -- a coercion identifying the representation type with the type instance family. -- Otherwise, return @Nothing@ -tyConFamilyCoercion_maybe :: TyCon -> Maybe TyCon +tyConFamilyCoercion_maybe :: TyCon -> Maybe CoAxiom tyConFamilyCoercion_maybe tc = case tyConParent tc of FamInstTyCon _ _ co -> Just co @@ -1342,18 +1374,6 @@ instance Ord TyCon where instance Uniquable TyCon where getUnique tc = tyConUnique tc -instance Outputable CoTyConDesc where - ppr CoSym = ptext (sLit "SYM") - ppr CoTrans = ptext (sLit "TRANS") - ppr CoLeft = ptext (sLit "LEFT") - ppr CoRight = ptext (sLit "RIGHT") - ppr CoCsel1 = ptext (sLit "CSEL1") - ppr CoCsel2 = ptext (sLit "CSEL2") - ppr CoCselR = ptext (sLit "CSELR") - ppr CoInst = ptext (sLit "INST") - ppr CoUnsafe = ptext (sLit "UNSAFE") - ppr (CoAxiom {}) = ptext (sLit "AXIOM") - instance Outputable TyCon where ppr tc = ppr (getName tc) @@ -1368,4 +1388,34 @@ instance Data.Data TyCon where toConstr _ = abstractConstr "TyCon" gunfold _ _ = error "gunfold" dataTypeOf _ = mkNoRepType "TyCon" + +------------------- +instance Eq CoAxiom where + a == b = case (a `compare` b) of { EQ -> True; _ -> False } + a /= b = case (a `compare` b) of { EQ -> False; _ -> True } + +instance Ord CoAxiom where + 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 CoAxiom where + getUnique = co_ax_unique + +instance Outputable CoAxiom where + ppr = ppr . getName + +instance NamedThing CoAxiom where + getName = co_ax_name + +instance Data.Typeable CoAxiom where + typeOf _ = Data.mkTyConApp (Data.mkTyCon "CoAxiom") [] + +instance Data.Data CoAxiom where + -- don't traverse? + toConstr _ = abstractConstr "CoAxiom" + gunfold _ _ = error "gunfold" + dataTypeOf _ = mkNoRepType "CoAxiom" \end{code}