Safe Haskell | None |
---|---|
Language | Haskell98 |
TyCon
Contents
- data TyCon
- type FieldLabel = Name
- data AlgTyConRhs
- = AbstractTyCon Bool
- | DataFamilyTyCon
- | DataTyCon { }
- | NewTyCon {
- data_con :: DataCon
- nt_rhs :: Type
- nt_etad_rhs :: ([TyVar], Type)
- nt_co :: CoAxiom Unbranched
- visibleDataCons :: AlgTyConRhs -> [DataCon]
- data TyConParent
- isNoParent :: TyConParent -> Bool
- data SynTyConRhs
- data Role
- mkAlgTyCon :: Name -> Kind -> [TyVar] -> [Role] -> Maybe CType -> [PredType] -> AlgTyConRhs -> TyConParent -> RecFlag -> Bool -> Maybe TyCon -> TyCon
- mkClassTyCon :: Name -> Kind -> [TyVar] -> [Role] -> AlgTyConRhs -> Class -> RecFlag -> TyCon
- mkFunTyCon :: Name -> Kind -> TyCon
- mkPrimTyCon :: Name -> Kind -> [Role] -> PrimRep -> TyCon
- mkKindTyCon :: Name -> Kind -> TyCon
- mkLiftedPrimTyCon :: Name -> Kind -> [Role] -> PrimRep -> TyCon
- mkTupleTyCon :: Name -> Kind -> Arity -> [TyVar] -> DataCon -> TupleSort -> Maybe TyCon -> TyCon
- mkSynTyCon :: Name -> Kind -> [TyVar] -> [Role] -> SynTyConRhs -> TyConParent -> TyCon
- mkForeignTyCon :: Name -> Maybe FastString -> Kind -> TyCon
- mkPromotedDataCon :: DataCon -> Name -> Unique -> Kind -> [Role] -> TyCon
- mkPromotedTyCon :: TyCon -> Kind -> TyCon
- isAlgTyCon :: TyCon -> Bool
- isClassTyCon :: TyCon -> Bool
- isFamInstTyCon :: TyCon -> Bool
- isFunTyCon :: TyCon -> Bool
- isPrimTyCon :: TyCon -> Bool
- isTupleTyCon :: TyCon -> Bool
- isUnboxedTupleTyCon :: TyCon -> Bool
- isBoxedTupleTyCon :: TyCon -> Bool
- isSynTyCon :: TyCon -> Bool
- isDecomposableTyCon :: TyCon -> Bool
- isForeignTyCon :: TyCon -> Bool
- isPromotedDataCon :: TyCon -> Bool
- isPromotedTyCon :: TyCon -> Bool
- isPromotedDataCon_maybe :: TyCon -> Maybe DataCon
- isPromotedTyCon_maybe :: TyCon -> Maybe TyCon
- promotableTyCon_maybe :: TyCon -> Maybe TyCon
- promoteTyCon :: TyCon -> TyCon
- isInjectiveTyCon :: TyCon -> Bool
- isDataTyCon :: TyCon -> Bool
- isProductTyCon :: TyCon -> Bool
- isDataProductTyCon_maybe :: TyCon -> Maybe DataCon
- isEnumerationTyCon :: TyCon -> Bool
- isNewTyCon :: TyCon -> Bool
- isAbstractTyCon :: TyCon -> Bool
- isFamilyTyCon :: TyCon -> Bool
- isOpenFamilyTyCon :: TyCon -> Bool
- isSynFamilyTyCon :: TyCon -> Bool
- isDataFamilyTyCon :: TyCon -> Bool
- isOpenSynFamilyTyCon :: TyCon -> Bool
- isClosedSynFamilyTyCon_maybe :: TyCon -> Maybe (CoAxiom Branched)
- isBuiltInSynFamTyCon_maybe :: TyCon -> Maybe BuiltInSynFamily
- isUnLiftedTyCon :: TyCon -> Bool
- isGadtSyntaxTyCon :: TyCon -> Bool
- isDistinctTyCon :: TyCon -> Bool
- isDistinctAlgRhs :: AlgTyConRhs -> Bool
- isTyConAssoc :: TyCon -> Bool
- tyConAssoc_maybe :: TyCon -> Maybe Class
- isRecursiveTyCon :: TyCon -> Bool
- isImplicitTyCon :: TyCon -> Bool
- tyConName :: TyCon -> Name
- tyConKind :: TyCon -> Kind
- tyConUnique :: TyCon -> Unique
- tyConTyVars :: TyCon -> [TyVar]
- tyConCType :: TyCon -> Maybe CType
- tyConCType_maybe :: TyCon -> Maybe CType
- tyConDataCons :: TyCon -> [DataCon]
- tyConDataCons_maybe :: TyCon -> Maybe [DataCon]
- tyConSingleDataCon_maybe :: TyCon -> Maybe DataCon
- tyConSingleAlgDataCon_maybe :: TyCon -> Maybe DataCon
- tyConFamilySize :: TyCon -> Int
- tyConStupidTheta :: TyCon -> [PredType]
- tyConArity :: TyCon -> Arity
- tyConRoles :: TyCon -> [Role]
- tyConParent :: TyCon -> TyConParent
- tyConTuple_maybe :: TyCon -> Maybe TupleSort
- tyConClass_maybe :: TyCon -> Maybe Class
- tyConFamInst_maybe :: TyCon -> Maybe (TyCon, [Type])
- tyConFamInstSig_maybe :: TyCon -> Maybe (TyCon, [Type], CoAxiom Unbranched)
- tyConFamilyCoercion_maybe :: TyCon -> Maybe (CoAxiom Unbranched)
- synTyConDefn_maybe :: TyCon -> Maybe ([TyVar], Type)
- synTyConRhs_maybe :: TyCon -> Maybe SynTyConRhs
- tyConExtName :: TyCon -> Maybe FastString
- algTyConRhs :: TyCon -> AlgTyConRhs
- newTyConRhs :: TyCon -> ([TyVar], Type)
- newTyConEtadArity :: TyCon -> Int
- newTyConEtadRhs :: TyCon -> ([TyVar], Type)
- unwrapNewTyCon_maybe :: TyCon -> Maybe ([TyVar], Type, CoAxiom Unbranched)
- tupleTyConBoxity :: TyCon -> Boxity
- tupleTyConSort :: TyCon -> TupleSort
- tupleTyConArity :: TyCon -> Arity
- tcExpandTyCon_maybe :: TyCon -> [tyco] -> Maybe ([(TyVar, tyco)], Type, [tyco])
- coreExpandTyCon_maybe :: TyCon -> [tyco] -> Maybe ([(TyVar, tyco)], Type, [tyco])
- makeTyConAbstract :: TyCon -> TyCon
- newTyConCo :: TyCon -> CoAxiom Unbranched
- newTyConCo_maybe :: TyCon -> Maybe (CoAxiom Unbranched)
- pprPromotionQuote :: TyCon -> SDoc
- data PrimRep
- data PrimElemRep
- tyConPrimRep :: TyCon -> PrimRep
- isVoidRep :: PrimRep -> Bool
- isGcPtrRep :: PrimRep -> Bool
- primRepSizeW :: DynFlags -> PrimRep -> Int
- primElemRepSizeB :: PrimElemRep -> Int
- data RecTcChecker
- initRecTc :: RecTcChecker
- checkRecTc :: RecTcChecker -> TyCon -> Maybe RecTcChecker
Main TyCon data types
TyCons represent type constructors. Type constructors are introduced by things such as:
1) Data declarations: data Foo = ...
creates the Foo
type constructor of kind *
2) Type synonyms: type Foo = ...
creates the Foo
type constructor
3) Newtypes: newtype Foo a = MkFoo ...
creates the Foo
type constructor of kind * -> *
4) Class declarations: class Foo where
creates the Foo
type constructor of kind *
This data type also encodes a number of primitive, built in type constructors such as those for function and tuple types.
type FieldLabel = Name Source
Names of the fields in an algebraic record type
data AlgTyConRhs Source
Represents right-hand-sides of TyCon
s for algebraic types
Constructors
AbstractTyCon Bool | Says that 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. |
DataFamilyTyCon | Represents an open type family without a fixed right hand side. Additional instances can appear at any time. These are introduced by either a top level declaration: data T a :: * Or an associated data type declaration, within a class declaration: class C a b where data T b :: * |
DataTyCon | Information about those |
Fields | |
NewTyCon | Information about those |
Fields
|
visibleDataCons :: AlgTyConRhs -> [DataCon] Source
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 TyCon
s.
Extract those DataCon
s that we are able to learn about. Note
that visibility in this sense does not correspond to visibility in
the context of any particular user program!
data TyConParent Source
Constructors
NoParentTyCon | An ordinary type constructor has no parent. |
ClassTyCon Class | Type constructors representing a class dictionary. See Note [ATyCon for classes] in TypeRep |
AssocFamilyTyCon Class | An *associated* type of a class. |
FamInstTyCon (CoAxiom Unbranched) TyCon [Type] | Type constructors representing an instance of a *data* family. Parameters: 1) The type family in question 2) Instance types; free variables are the 3) A |
Instances
isNoParent :: TyConParent -> Bool Source
data SynTyConRhs Source
Information pertaining to the expansion of a type synonym (type
)
Constructors
SynonymTyCon Type | An ordinary type synonyn. |
OpenSynFamilyTyCon | An open type synonym family e.g. |
ClosedSynFamilyTyCon (CoAxiom Branched) | A closed type synonym family e.g. |
AbstractClosedSynFamilyTyCon | A closed type synonym family declared in an hs-boot file with type family F a where .. |
BuiltInSynFamTyCon BuiltInSynFamily |
Constructors
Nominal | |
Representational | |
Phantom |
Constructing TyCons
Arguments
:: Name | |
-> Kind | Kind of the resulting |
-> [TyVar] |
|
-> [Role] | The roles for each TyVar |
-> Maybe CType | The C type this type corresponds to when using the CAPI FFI |
-> [PredType] | Stupid theta: see |
-> AlgTyConRhs | Information about dat aconstructors |
-> TyConParent | |
-> RecFlag | Is the |
-> Bool | Was the |
-> Maybe TyCon | Promoted version |
-> TyCon |
This is the making of an algebraic TyCon
. Notably, you have to
pass in the generic (in the -XGenerics sense) information about the
type constructor - you can get hold of it easily (see Generics
module)
mkClassTyCon :: Name -> Kind -> [TyVar] -> [Role] -> AlgTyConRhs -> Class -> RecFlag -> TyCon Source
Simpler specialization of mkAlgTyCon
for classes
mkFunTyCon :: Name -> Kind -> TyCon Source
mkPrimTyCon :: Name -> Kind -> [Role] -> PrimRep -> TyCon Source
Create an unlifted primitive TyCon
, such as Int#
mkKindTyCon :: Name -> Kind -> TyCon Source
Kind constructors
mkLiftedPrimTyCon :: Name -> Kind -> [Role] -> PrimRep -> TyCon Source
Create a lifted primitive TyCon
such as RealWorld
Arguments
:: Name | |
-> Kind | Kind of the resulting |
-> Arity | Arity of the tuple |
-> [TyVar] |
|
-> DataCon | |
-> TupleSort | Whether the tuple is boxed or unboxed |
-> Maybe TyCon | Promoted version |
-> TyCon |
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 thunkT
mkSynTyCon :: Name -> Kind -> [TyVar] -> [Role] -> SynTyConRhs -> TyConParent -> TyCon Source
Create a type synonym TyCon
Arguments
:: Name | |
-> Maybe FastString | Name of the foreign imported thing, maybe |
-> Kind | |
-> TyCon |
mkPromotedDataCon :: DataCon -> Name -> Unique -> Kind -> [Role] -> TyCon Source
Create a promoted data constructor TyCon
Somewhat dodgily, we give it the same Name
as the data constructor itself; when we pretty-print
the TyCon we add a quote; see the Outputable TyCon instance
mkPromotedTyCon :: TyCon -> Kind -> TyCon Source
Create a promoted type constructor TyCon
Somewhat dodgily, we give it the same Name
as the type constructor itself
Predicates on TyCons
isAlgTyCon :: TyCon -> Bool Source
Returns True
if the supplied TyCon
resulted from either a
data
or newtype
declaration
isClassTyCon :: TyCon -> Bool Source
Is this TyCon
that for a class instance?
isFamInstTyCon :: TyCon -> Bool Source
Is this TyCon
that for a data family instance?
isFunTyCon :: TyCon -> Bool Source
isPrimTyCon :: TyCon -> Bool Source
Does this TyCon
represent something that cannot be defined in Haskell?
isTupleTyCon :: TyCon -> Bool Source
Does this TyCon
represent a tuple?
NB: when compiling Data.Tuple
, the tycons won't reply True
to
isTupleTyCon
, because they are built as AlgTyCons
. However they
get spat into the interface file as tuple tycons, so I don't think
it matters.
isUnboxedTupleTyCon :: TyCon -> Bool Source
Is this the TyCon
for an unboxed tuple?
isBoxedTupleTyCon :: TyCon -> Bool Source
Is this the TyCon
for a boxed tuple?
isSynTyCon :: TyCon -> Bool Source
Is this a TyCon
representing a type synonym (type
)?
isDecomposableTyCon :: TyCon -> Bool Source
isForeignTyCon :: TyCon -> Bool Source
Is this the TyCon
of a foreign-imported type constructor?
isPromotedDataCon :: TyCon -> Bool Source
Is this a PromotedDataCon?
isPromotedTyCon :: TyCon -> Bool Source
Is this a PromotedTyCon?
isPromotedDataCon_maybe :: TyCon -> Maybe DataCon Source
Retrieves the promoted DataCon if this is a PromotedDataCon;
isPromotedTyCon_maybe :: TyCon -> Maybe TyCon Source
Retrieves the promoted TyCon if this is a PromotedTyCon;
promoteTyCon :: TyCon -> TyCon Source
isInjectiveTyCon :: TyCon -> Bool Source
Injective TyCon
s can be decomposed, so that
T ty1 ~ T ty2 => ty1 ~ ty2
isDataTyCon :: TyCon -> Bool Source
Returns True
for data types that are definitely represented by
heap-allocated constructors. These are scrutinised by Core-level
case
expressions, and they get info tables allocated for them.
Generally, the function will be true for all data
types and false
for newtype
s, unboxed tuples and type family TyCon
s. But it is
not guaranteed to return True
in all cases that it could.
NB: for a data type family, only the instance TyCon
s
get an info table. The family declaration TyCon
does not
isProductTyCon :: TyCon -> Bool Source
isEnumerationTyCon :: TyCon -> Bool Source
Is this an algebraic TyCon
which is just an enumeration of values?
isNewTyCon :: TyCon -> Bool Source
Is this TyCon
that for a newtype
isAbstractTyCon :: TyCon -> Bool Source
Test if the TyCon
is algebraic but abstract (invisible data constructors)
isFamilyTyCon :: TyCon -> Bool Source
Is this a TyCon
, synonym or otherwise, that defines a family?
isOpenFamilyTyCon :: TyCon -> Bool Source
Is this a TyCon
, synonym or otherwise, that defines an family with
instances?
isSynFamilyTyCon :: TyCon -> Bool Source
Is this a synonym TyCon
that can have may have further instances appear?
isDataFamilyTyCon :: TyCon -> Bool Source
Is this a synonym TyCon
that can have may have further instances appear?
isOpenSynFamilyTyCon :: TyCon -> Bool Source
isUnLiftedTyCon :: TyCon -> Bool Source
isGadtSyntaxTyCon :: TyCon -> Bool Source
Is this an algebraic TyCon
declared with the GADT syntax?
isDistinctTyCon :: TyCon -> Bool Source
isDistinctTyCon
is true of TyCon
s that are equal only to
themselves, even via coercions (except for unsafeCoerce).
This excludes newtypes, type functions, type synonyms.
It relates directly to the FC consistency story:
If the axioms are consistent,
and co : S tys ~ T tys, and S,T are "distinct" TyCons,
then S=T.
Cf Note [Pruning dead case alternatives] in Unify
isTyConAssoc :: TyCon -> Bool Source
tyConAssoc_maybe :: TyCon -> Maybe Class Source
isRecursiveTyCon :: TyCon -> Bool Source
Is this a recursive TyCon
?
isImplicitTyCon :: TyCon -> Bool Source
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).
Extracting information out of TyCons
tyConUnique :: TyCon -> Unique Source
Same Unique as the type constructor
Same Unique as the data constructor
tyConTyVars :: TyCon -> [TyVar] Source
The kind and type variables used in the type constructor. Invariant: length tyvars = arity Precisely, this list scopes over:
- The
algTcStupidTheta
- The cached types in 'algTyConRhs.NewTyCon'
- The family instance types if present
Note that it does not scope over the data constructors.
tyConCType :: TyCon -> Maybe CType Source
tyConCType_maybe :: TyCon -> Maybe CType Source
tyConDataCons :: TyCon -> [DataCon] Source
As tyConDataCons_maybe
, but returns the empty list of constructors if no constructors
could be found
tyConDataCons_maybe :: TyCon -> Maybe [DataCon] Source
tyConSingleDataCon_maybe :: TyCon -> Maybe DataCon Source
If the given TyCon
has a single data constructor, i.e. it is a data
type with one
alternative, a tuple type or a newtype
then that constructor is returned. If the TyCon
has more than one constructor, or represents a primitive or function type constructor then
Nothing
is returned. In any other case, the function panics
tyConFamilySize :: TyCon -> Int Source
tyConStupidTheta :: TyCon -> [PredType] Source
Find the "stupid theta" of the TyCon
. A "stupid theta" is the context to the left of
an algebraic type declaration, e.g. Eq a
in the declaration data Eq a => T a ...
tyConArity :: TyCon -> Arity Source
n if ty_con :: * -> ... -> * n times
tyConRoles :: TyCon -> [Role] Source
Get the list of roles for the type parameters of a TyCon
tyConParent :: TyCon -> TyConParent Source
tyConClass_maybe :: TyCon -> Maybe Class Source
If this TyCon
is that for a class instance, return the class it is for.
Otherwise returns Nothing
tyConFamInst_maybe :: TyCon -> Maybe (TyCon, [Type]) Source
If this TyCon
is that of a family instance, return the family in question
and the instance types. Otherwise, return Nothing
tyConFamInstSig_maybe :: TyCon -> Maybe (TyCon, [Type], CoAxiom Unbranched) Source
synTyConDefn_maybe :: TyCon -> Maybe ([TyVar], Type) Source
Extract the TyVar
s bound by a vanilla type synonym (not familiy)
and the corresponding (unsubstituted) right hand side.
synTyConRhs_maybe :: TyCon -> Maybe SynTyConRhs Source
Extract the information pertaining to the right hand side of a type synonym (type
) declaration.
tyConExtName :: TyCon -> Maybe FastString Source
Just e
for foreign-imported types,
holds the name of the imported thing
algTyConRhs :: TyCon -> AlgTyConRhs Source
Extract an AlgTyConRhs
with information about data constructors from an algebraic or tuple
TyCon
. Panics for any other sort of TyCon
newTyConRhs :: TyCon -> ([TyVar], Type) Source
newTyConEtadArity :: TyCon -> Int Source
The number of type parameters that need to be passed to a newtype to resolve it. May be less than in the definition if it can be eta-contracted.
newTyConEtadRhs :: TyCon -> ([TyVar], Type) Source
unwrapNewTyCon_maybe :: TyCon -> Maybe ([TyVar], Type, CoAxiom Unbranched) Source
tupleTyConBoxity :: TyCon -> Boxity Source
Extract the boxity of the given TyCon
, if it is a TupleTyCon
.
Panics otherwise
tupleTyConSort :: TyCon -> TupleSort Source
tupleTyConArity :: TyCon -> Arity Source
Extract the arity of the given TyCon
, if it is a TupleTyCon
.
Panics otherwise
Manipulating TyCons
Arguments
:: TyCon | |
-> [tyco] | Arguments to |
-> Maybe ([(TyVar, tyco)], Type, [tyco]) | Returns a |
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
Used to create the view the typechecker has on TyCon
s.
We expand (closed) synonyms only, cf. coreExpandTyCon_maybe
Arguments
:: TyCon | |
-> [tyco] | Arguments to |
-> Maybe ([(TyVar, tyco)], Type, [tyco]) | Returns a |
Used to create the view the typechecker has on TyCon
s.
We expand (closed) synonyms only, cf. coreExpandTyCon_maybe
makeTyConAbstract :: TyCon -> TyCon Source
newTyConCo :: TyCon -> CoAxiom Unbranched Source
newTyConCo_maybe :: TyCon -> Maybe (CoAxiom Unbranched) Source
pprPromotionQuote :: TyCon -> SDoc Source
Primitive representations of Types
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.
Constructors
VoidRep | |
PtrRep | |
IntRep | Signed, word-sized value |
WordRep | Unsigned, word-sized value |
Int64Rep | Signed, 64 bit value (with 32-bit words only) |
Word64Rep | Unsigned, 64 bit value (with 32-bit words only) |
AddrRep | A pointer, but not to a Haskell value (use |
FloatRep | |
DoubleRep | |
VecRep Int PrimElemRep | A vector |
data PrimElemRep Source
Constructors
Int8ElemRep | |
Int16ElemRep | |
Int32ElemRep | |
Int64ElemRep | |
Word8ElemRep | |
Word16ElemRep | |
Word32ElemRep | |
Word64ElemRep | |
FloatElemRep | |
DoubleElemRep |
Instances
tyConPrimRep :: TyCon -> PrimRep Source
Find the primitive representation of a TyCon
isGcPtrRep :: PrimRep -> Bool Source
primElemRepSizeB :: PrimElemRep -> Int Source
Recursion breaking
data RecTcChecker Source
checkRecTc :: RecTcChecker -> TyCon -> Maybe RecTcChecker Source