ghc-8.2.2: The GHC API

Safe Haskell | None
Language | Haskell2010

TyCon

Contents

- Main TyCon data types
- TyConBinder
  - Field labels
  - Constructing TyCons
  - Predicates on TyCons
  - Extracting information out of TyCons
  - Manipulating TyCons
- Runtime type representation
- Primitive representations of Types
- Recursion breaking

Synopsis

- data TyCon
- data AlgTyConRhs
  - = AbstractTyCon
  - | DataTyCon {
    - data_cons :: [DataCon]
    - is_enum :: Bool
    }
  - | TupleTyCon {
    - data_con :: DataCon
    - tup_sort :: TupleSort
    }
  - | SumTyCon {
    - data_cons :: [DataCon]
    }
  - | NewTyCon {
    - data_con :: DataCon
    - nt_rhs :: Type
    - nt_etad_rhs :: ([TyVar], Type)
    - nt_co :: CoAxiom Unbranched
    }
- visibleDataCons :: AlgTyConRhs -> [DataCon]
- data AlgTyConFlav
  - = VanillaAlgTyCon TyConRepName
  - | UnboxedAlgTyCon (Maybe TyConRepName)
  - | ClassTyCon Class TyConRepName
  - | DataFamInstTyCon (CoAxiom Unbranched) TyCon [Type]
- isNoParent :: AlgTyConFlav -> Bool
- data FamTyConFlav
  - = DataFamilyTyCon TyConRepName
  - | OpenSynFamilyTyCon
  - | ClosedSynFamilyTyCon (Maybe (CoAxiom Branched))
  - | AbstractClosedSynFamilyTyCon
  - | BuiltInSynFamTyCon BuiltInSynFamily
- data Role
  - = Nominal
  - | Representational
  - | Phantom
- data Injectivity
  - = NotInjective
  - | Injective [Bool]
- data RuntimeRepInfo
  - = NoRRI
  - | RuntimeRep ([Type] -> [PrimRep])
  - | VecCount Int
  - | VecElem PrimElemRep
- type TyConBinder = TyVarBndr TyVar TyConBndrVis
- data TyConBndrVis
  - = NamedTCB ArgFlag
  - | AnonTCB
- mkNamedTyConBinder :: ArgFlag -> TyVar -> TyConBinder
- mkNamedTyConBinders :: ArgFlag -> [TyVar] -> [TyConBinder]
- mkAnonTyConBinder :: TyVar -> TyConBinder
- mkAnonTyConBinders :: [TyVar] -> [TyConBinder]
- tyConBinderArgFlag :: TyConBinder -> ArgFlag
- isNamedTyConBinder :: TyConBinder -> Bool
- isVisibleTyConBinder :: TyVarBndr tv TyConBndrVis -> Bool
- isInvisibleTyConBinder :: TyVarBndr tv TyConBndrVis -> Bool
- tyConFieldLabels :: TyCon -> [FieldLabel]
- lookupTyConFieldLabel :: FieldLabelString -> TyCon -> Maybe FieldLabel
- mkAlgTyCon :: Name -> [TyConBinder] -> Kind -> [Role] -> Maybe CType -> [PredType] -> AlgTyConRhs -> AlgTyConFlav -> Bool -> TyCon
- mkClassTyCon :: Name -> [TyConBinder] -> [Role] -> AlgTyConRhs -> Class -> Name -> TyCon
- mkFunTyCon :: Name -> [TyConBinder] -> Name -> TyCon
- mkPrimTyCon :: Name -> [TyConBinder] -> Kind -> [Role] -> TyCon
- mkKindTyCon :: Name -> [TyConBinder] -> Kind -> [Role] -> Name -> TyCon
- mkLiftedPrimTyCon :: Name -> [TyConBinder] -> Kind -> [Role] -> TyCon
- mkTupleTyCon :: Name -> [TyConBinder] -> Kind -> Arity -> DataCon -> TupleSort -> AlgTyConFlav -> TyCon
- mkSumTyCon :: Name -> [TyConBinder] -> Kind -> Arity -> [TyVar] -> [DataCon] -> AlgTyConFlav -> TyCon
- mkSynonymTyCon :: Name -> [TyConBinder] -> Kind -> [Role] -> Type -> Bool -> Bool -> TyCon
- mkFamilyTyCon :: Name -> [TyConBinder] -> Kind -> Maybe Name -> FamTyConFlav -> Maybe Class -> Injectivity -> TyCon
- mkPromotedDataCon :: DataCon -> Name -> TyConRepName -> [TyConBinder] -> Kind -> [Role] -> RuntimeRepInfo -> TyCon
- mkTcTyCon :: Name -> [TyConBinder] -> Kind -> Bool -> [TyVar] -> TyCon
- isAlgTyCon :: TyCon -> Bool
- isVanillaAlgTyCon :: TyCon -> Bool
- isClassTyCon :: TyCon -> Bool
- isFamInstTyCon :: TyCon -> Bool
- isFunTyCon :: TyCon -> Bool
- isPrimTyCon :: TyCon -> Bool
- isTupleTyCon :: TyCon -> Bool
- isUnboxedTupleTyCon :: TyCon -> Bool
- isBoxedTupleTyCon :: TyCon -> Bool
- isUnboxedSumTyCon :: TyCon -> Bool
- isPromotedTupleTyCon :: TyCon -> Bool
- isTypeSynonymTyCon :: TyCon -> Bool
- mightBeUnsaturatedTyCon :: TyCon -> Bool
- isPromotedDataCon :: TyCon -> Bool
- isPromotedDataCon_maybe :: TyCon -> Maybe DataCon
- isKindTyCon :: TyCon -> Bool
- isLiftedTypeKindTyConName :: Name -> Bool
- isTauTyCon :: TyCon -> Bool
- isFamFreeTyCon :: TyCon -> Bool
- isDataTyCon :: TyCon -> Bool
- isProductTyCon :: TyCon -> Bool
- isDataProductTyCon_maybe :: TyCon -> Maybe DataCon
- isDataSumTyCon_maybe :: TyCon -> Maybe [DataCon]
- isEnumerationTyCon :: TyCon -> Bool
- isNewTyCon :: TyCon -> Bool
- isAbstractTyCon :: TyCon -> Bool
- isFamilyTyCon :: TyCon -> Bool
- isOpenFamilyTyCon :: TyCon -> Bool
- isTypeFamilyTyCon :: TyCon -> Bool
- isDataFamilyTyCon :: TyCon -> Bool
- isOpenTypeFamilyTyCon :: TyCon -> Bool
- isClosedSynFamilyTyConWithAxiom_maybe :: TyCon -> Maybe (CoAxiom Branched)
- familyTyConInjectivityInfo :: TyCon -> Injectivity
- isBuiltInSynFamTyCon_maybe :: TyCon -> Maybe BuiltInSynFamily
- isUnliftedTyCon :: TyCon -> Bool
- isGadtSyntaxTyCon :: TyCon -> Bool
- isInjectiveTyCon :: TyCon -> Role -> Bool
- isGenerativeTyCon :: TyCon -> Role -> Bool
- isGenInjAlgRhs :: AlgTyConRhs -> Bool
- isTyConAssoc :: TyCon -> Bool
- tyConAssoc_maybe :: TyCon -> Maybe Class
- isImplicitTyCon :: TyCon -> Bool
- isTyConWithSrcDataCons :: TyCon -> Bool
- isTcTyCon :: TyCon -> Bool
- isTcLevPoly :: TyCon -> Bool
- tyConName :: TyCon -> Name
- tyConSkolem :: TyCon -> Bool
- 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
- tyConSingleDataCon :: TyCon -> DataCon
- tyConSingleAlgDataCon_maybe :: TyCon -> Maybe DataCon
- tyConFamilySize :: TyCon -> Int
- tyConStupidTheta :: TyCon -> [PredType]
- tyConArity :: TyCon -> Arity
- tyConRoles :: TyCon -> [Role]
- tyConFlavour :: TyCon -> String
- tyConTuple_maybe :: TyCon -> Maybe TupleSort
- tyConClass_maybe :: TyCon -> Maybe Class
- tyConATs :: TyCon -> [TyCon]
- tyConFamInst_maybe :: TyCon -> Maybe (TyCon, [Type])
- tyConFamInstSig_maybe :: TyCon -> Maybe (TyCon, [Type], CoAxiom Unbranched)
- tyConFamilyCoercion_maybe :: TyCon -> Maybe (CoAxiom Unbranched)
- tyConFamilyResVar_maybe :: TyCon -> Maybe Name
- synTyConDefn_maybe :: TyCon -> Maybe ([TyVar], Type)
- synTyConRhs_maybe :: TyCon -> Maybe Type
- famTyConFlav_maybe :: TyCon -> Maybe FamTyConFlav
- famTcResVar :: TyCon -> Maybe Name
- algTyConRhs :: TyCon -> AlgTyConRhs
- newTyConRhs :: TyCon -> ([TyVar], Type)
- newTyConEtadArity :: TyCon -> Int
- newTyConEtadRhs :: TyCon -> ([TyVar], Type)
- unwrapNewTyCon_maybe :: TyCon -> Maybe ([TyVar], Type, CoAxiom Unbranched)
- unwrapNewTyConEtad_maybe :: TyCon -> Maybe ([TyVar], Type, CoAxiom Unbranched)
- newTyConDataCon_maybe :: TyCon -> Maybe DataCon
- algTcFields :: TyCon -> FieldLabelEnv
- tyConRuntimeRepInfo :: TyCon -> RuntimeRepInfo
- tyConBinders :: TyCon -> [TyConBinder]
- tyConResKind :: TyCon -> Kind
- tcTyConScopedTyVars :: TyCon -> [TyVar]
- expandSynTyCon_maybe :: TyCon -> [tyco] -> Maybe ([(TyVar, tyco)], Type, [tyco])
- makeRecoveryTyCon :: TyCon -> TyCon
- newTyConCo :: TyCon -> CoAxiom Unbranched
- newTyConCo_maybe :: TyCon -> Maybe (CoAxiom Unbranched)
- pprPromotionQuote :: TyCon -> SDoc
- mkTyConKind :: [TyConBinder] -> Kind -> Kind
- type TyConRepName = Name
- tyConRepName_maybe :: TyCon -> Maybe TyConRepName
- mkPrelTyConRepName :: Name -> TyConRepName
- tyConRepModOcc :: Module -> OccName -> (Module, OccName)
- data PrimRep
  - = VoidRep
  - | LiftedRep
  - | UnliftedRep
  - | IntRep
  - | WordRep
  - | Int64Rep
  - | Word64Rep
  - | AddrRep
  - | FloatRep
  - | DoubleRep
  - | VecRep Int PrimElemRep
- data PrimElemRep
  - = Int8ElemRep
  - | Int16ElemRep
  - | Int32ElemRep
  - | Int64ElemRep
  - | Word8ElemRep
  - | Word16ElemRep
  - | Word32ElemRep
  - | Word64ElemRep
  - | FloatElemRep
  - | DoubleElemRep
- isVoidRep :: PrimRep -> Bool
- isGcPtrRep :: PrimRep -> Bool
- primRepSizeW :: DynFlags -> PrimRep -> Int
- primElemRepSizeB :: PrimElemRep -> Int
- primRepIsFloat :: PrimRep -> Maybe Bool
- data RecTcChecker
- initRecTc :: RecTcChecker
- checkRecTc :: RecTcChecker -> TyCon -> Maybe RecTcChecker

# Main TyCon data types

data TyCon #

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.

Instances

Eq TyCon # |
Methods (==) :: TyCon -> TyCon -> Bool # (/=) :: TyCon -> TyCon -> Bool #
Data TyCon # |

Methods

gfoldl :: (forall d b. Data d => c (d -> b) -> d -> c b) -> (forall g. g -> c g) -> TyCon -> c TyCon Source #

gunfold :: (forall b r. Data b => c (b -> r) -> c r) -> (forall r. r -> c r) -> Constr -> c TyCon Source #

toConstr :: TyCon -> Constr Source #

dataTypeOf :: TyCon -> DataType Source #

dataCast1 :: Typeable (* -> *) t => (forall d. Data d => c (t d)) -> Maybe (c TyCon) Source #

dataCast2 :: Typeable (* -> * -> *) t => (forall d e. (Data d, Data e) => c (t d e)) -> Maybe (c TyCon) Source #

gmapT :: (forall b. Data b => b -> b) -> TyCon -> TyCon Source #

gmapQl :: (r -> r' -> r) -> r -> (forall d. Data d => d -> r') -> TyCon -> r Source #

gmapQr :: (r' -> r -> r) -> r -> (forall d. Data d => d -> r') -> TyCon -> r Source #

gmapQ :: (forall d. Data d => d -> u) -> TyCon -> [u] Source #

gmapQi :: Int -> (forall d. Data d => d -> u) -> TyCon -> u Source #

gmapM :: Monad m => (forall d. Data d => d -> m d) -> TyCon -> m TyCon Source #

gmapMp :: MonadPlus m => (forall d. Data d => d -> m d) -> TyCon -> m TyCon Source #

gmapMo :: MonadPlus m => (forall d. Data d => d -> m d) -> TyCon -> m TyCon Source #

Outputable TyCon # |
Methods ppr :: TyCon -> SDoc # pprPrec :: Rational -> TyCon -> SDoc #
Uniquable TyCon # |
Methods getUnique :: TyCon -> Unique #
NamedThing TyCon # |
Methods getOccName :: TyCon -> OccName # getName :: TyCon -> Name #

data AlgTyConRhs #

Represents right-hand-sides of `TyCon`s for algebraic types

Constructors

AbstractTyCon | 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.
DataTyCon | Information about those `TyCon`s derived from a `data` declaration. This includes data types with no constructors at all.

Fields

- data_cons :: [DataCon]

  The data type constructors; can be empty if the user declares the type to have no constructors

  INVARIANT: Kept in order of increasing `DataCon` tag (see the tag assignment in DataCon.mkDataCon)

- is_enum :: Bool

  Cached value: is this an enumeration type? See Note [Enumeration types]

TupleTyCon |

Fields

- data_con :: DataCon

  The unique constructor for the `newtype`. It has no existentials

- tup_sort :: TupleSort

  Is this a boxed, unboxed or constraint tuple?

SumTyCon |

Fields

- data_cons :: [DataCon]

  The data type constructors; can be empty if the user declares the type to have no constructors

  INVARIANT: Kept in order of increasing `DataCon` tag (see the tag assignment in DataCon.mkDataCon)

NewTyCon | Information about those `TyCon`s derived from a `newtype` declaration

Fields

- data_con :: DataCon

  The unique constructor for the `newtype`. It has no existentials

- nt_rhs :: Type

  Cached value: the argument type of the constructor, which is just the representation type of the `TyCon` (remember that `newtype`s do not exist at runtime so need a different representation type).

  The free `TyVar`s of this type are the `tyConTyVars` from the corresponding `TyCon`

- nt_etad_rhs :: ([TyVar], Type)

  Same as the `nt_rhs`, but this time eta-reduced. Hence the list of `TyVar`s in this field may be shorter than the declared arity of the `TyCon`.

- nt_co :: CoAxiom Unbranched

visibleDataCons :: AlgTyConRhs -> [DataCon] #

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.

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 AlgTyConFlav #

Constructors

VanillaAlgTyCon TyConRepName | An ordinary type constructor has no parent.
UnboxedAlgTyCon (Maybe TyConRepName) | An unboxed type constructor. The TyConRepName is a Maybe since we currently don't allow unboxed sums to be Typeable since there are too many of them. See #13276.
ClassTyCon Class TyConRepName | Type constructors representing a class dictionary. See Note [ATyCon for classes] in TyCoRep

DataFamInstTyCon (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 `tyConTyVars` of the current `TyCon` (not the family one). INVARIANT: the number of types matches the arity of the family `TyCon`

3) A `CoTyCon` identifying the representation type with the type instance family

Instances

Outputable AlgTyConFlav # |
Methods ppr :: AlgTyConFlav -> SDoc # pprPrec :: Rational -> AlgTyConFlav -> SDoc #

isNoParent :: AlgTyConFlav -> Bool #

data FamTyConFlav #

Information pertaining to the expansion of a type synonym (`type`)

Constructors

DataFamilyTyCon TyConRepName

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 family T a :: *

Or an associated data type declaration, within a class declaration:

    class C a b where
      data T b :: *

OpenSynFamilyTyCon | An open type synonym family e.g. `type family F x y :: * -> *`
ClosedSynFamilyTyCon (Maybe (CoAxiom Branched)) | A closed type synonym family e.g. `type family F x where { F Int = Bool }`
AbstractClosedSynFamilyTyCon | A closed type synonym family declared in an hs-boot file with type family F a where ..
BuiltInSynFamTyCon BuiltInSynFamily | Built-in type family used by the TypeNats solver

Instances

Outputable FamTyConFlav # |
Methods ppr :: FamTyConFlav -> SDoc # pprPrec :: Rational -> FamTyConFlav -> SDoc #

data Role #

Constructors

Nominal |
Representational |
Phantom |

Instances

Eq Role # |
Methods (==) :: Role -> Role -> Bool # (/=) :: Role -> Role -> Bool #
Data Role # |

Methods

gfoldl :: (forall d b. Data d => c (d -> b) -> d -> c b) -> (forall g. g -> c g) -> Role -> c Role Source #

gunfold :: (forall b r. Data b => c (b -> r) -> c r) -> (forall r. r -> c r) -> Constr -> c Role Source #

toConstr :: Role -> Constr Source #

dataTypeOf :: Role -> DataType Source #

dataCast1 :: Typeable (* -> *) t => (forall d. Data d => c (t d)) -> Maybe (c Role) Source #

dataCast2 :: Typeable (* -> * -> *) t => (forall d e. (Data d, Data e) => c (t d e)) -> Maybe (c Role) Source #

gmapT :: (forall b. Data b => b -> b) -> Role -> Role Source #

gmapQl :: (r -> r' -> r) -> r -> (forall d. Data d => d -> r') -> Role -> r Source #

gmapQr :: (r' -> r -> r) -> r -> (forall d. Data d => d -> r') -> Role -> r Source #

gmapQ :: (forall d. Data d => d -> u) -> Role -> [u] Source #

gmapQi :: Int -> (forall d. Data d => d -> u) -> Role -> u Source #

gmapM :: Monad m => (forall d. Data d => d -> m d) -> Role -> m Role Source #

gmapMp :: MonadPlus m => (forall d. Data d => d -> m d) -> Role -> m Role Source #

gmapMo :: MonadPlus m => (forall d. Data d => d -> m d) -> Role -> m Role Source #

Ord Role # |
Methods compare :: Role -> Role -> Ordering # (<) :: Role -> Role -> Bool # (<=) :: Role -> Role -> Bool # (>) :: Role -> Role -> Bool # (>=) :: Role -> Role -> Bool # max :: Role -> Role -> Role # min :: Role -> Role -> Role #
Outputable Role # |
Methods ppr :: Role -> SDoc # pprPrec :: Rational -> Role -> SDoc #
Binary Role # |
Methods put_ :: BinHandle -> Role -> IO () # put :: BinHandle -> Role -> IO (Bin * Role) # get :: BinHandle -> IO Role #

data Injectivity #

Constructors

NotInjective |
Injective [Bool] |

Instances

Eq Injectivity # |
Methods (==) :: Injectivity -> Injectivity -> Bool # (/=) :: Injectivity -> Injectivity -> Bool #
Binary Injectivity # |
Methods put_ :: BinHandle -> Injectivity -> IO () # put :: BinHandle -> Injectivity -> IO (Bin * Injectivity) # get :: BinHandle -> IO Injectivity #

data RuntimeRepInfo #

Some promoted datacons signify extra info relevant to GHC. For example, the `IntRep` constructor of `RuntimeRep` corresponds to the `IntRep` constructor of `PrimRep`. This data structure allows us to store this information right in the `TyCon`. The other approach would be to look up things like `RuntimeRep`'s `PrimRep` by known-key every time.

Constructors

NoRRI | an ordinary promoted data con
RuntimeRep ([Type] -> [PrimRep]) | A constructor of `RuntimeRep`. The argument to the function should be the list of arguments to the promoted datacon.
VecCount Int | A constructor of `VecCount`
VecElem PrimElemRep | A constructor of `VecElem`

# TyConBinder

type TyConBinder = TyVarBndr TyVar TyConBndrVis #

data TyConBndrVis #

Constructors

NamedTCB ArgFlag |
AnonTCB |

Instances

Binary TyConBndrVis # |
Methods put_ :: BinHandle -> TyConBndrVis -> IO () # put :: BinHandle -> TyConBndrVis -> IO (Bin * TyConBndrVis) # get :: BinHandle -> IO TyConBndrVis #
Outputable tv => Outputable (TyVarBndr tv TyConBndrVis) # |
Methods ppr :: TyVarBndr tv TyConBndrVis -> SDoc # pprPrec :: Rational -> TyVarBndr tv TyConBndrVis -> SDoc #

mkNamedTyConBinder :: ArgFlag -> TyVar -> TyConBinder #

mkNamedTyConBinders :: ArgFlag -> [TyVar] -> [TyConBinder] #

mkAnonTyConBinder :: TyVar -> TyConBinder #

mkAnonTyConBinders :: [TyVar] -> [TyConBinder] #

tyConBinderArgFlag :: TyConBinder -> ArgFlag #

isNamedTyConBinder :: TyConBinder -> Bool #

isVisibleTyConBinder :: TyVarBndr tv TyConBndrVis -> Bool #

isInvisibleTyConBinder :: TyVarBndr tv TyConBndrVis -> Bool #

## Field labels

tyConFieldLabels :: TyCon -> [FieldLabel] #

The labels for the fields of this particular `TyCon`

lookupTyConFieldLabel :: FieldLabelString -> TyCon -> Maybe FieldLabel #

Look up a field label belonging to this `TyCon`

## Constructing TyCons

mkAlgTyCon #

Arguments

:: Name |
-> [TyConBinder] | Binders of the `TyCon`
-> Kind | Result kind
-> [Role] | The roles for each TyVar
-> Maybe CType | The C type this type corresponds to when using the CAPI FFI
-> [PredType] | Stupid theta: see `algTcStupidTheta`
-> AlgTyConRhs | Information about data constructors
-> AlgTyConFlav | What flavour is it? (e.g. vanilla, type family)
-> Bool | Was the `TyCon` declared with GADT syntax?
-> 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 -> [TyConBinder] -> [Role] -> AlgTyConRhs -> Class -> Name -> TyCon #

Simpler specialization of `mkAlgTyCon` for classes

mkFunTyCon :: Name -> [TyConBinder] -> Name -> TyCon #

Given the name of the function type constructor and it's kind, create the corresponding `TyCon`. It is recomended to use `funTyCon` if you want this functionality

mkPrimTyCon #

Arguments

:: Name |
-> [TyConBinder] |
-> Kind | result kind, never levity-polymorphic
-> [Role] |
-> TyCon |

Create an unlifted primitive `TyCon`, such as `Int#`.

mkKindTyCon #

Arguments

:: Name |
-> [TyConBinder] |
-> Kind | result kind
-> [Role] |
-> Name |
-> TyCon |

Kind constructors

mkLiftedPrimTyCon #

Arguments

:: Name |
-> [TyConBinder] |
-> Kind | result kind
-> [Role] |
-> TyCon |

Create a lifted primitive `TyCon` such as `RealWorld`

mkTupleTyCon #

Arguments

:: Name |
-> [TyConBinder] |
-> Kind | Result kind of the `TyCon`
-> Arity | Arity of the tuple `TyCon`
-> DataCon |
-> TupleSort | Whether the tuple is boxed or unboxed
-> AlgTyConFlav |
-> TyCon |

mkSumTyCon #

Arguments

:: Name |
-> [TyConBinder] |
-> Kind | Kind of the resulting `TyCon`
-> Arity | Arity of the sum
-> [TyVar] | `TyVar`s scoped over: see `tyConTyVars`
-> [DataCon] |
-> AlgTyConFlav |
-> TyCon |

mkSynonymTyCon #

Arguments

:: Name |
-> [TyConBinder] |
-> Kind | result kind
-> [Role] |
-> Type |
-> Bool |
-> Bool |
-> TyCon |

Create a type synonym `TyCon`

mkFamilyTyCon #

Arguments

:: Name |
-> [TyConBinder] |
-> Kind | result kind
-> Maybe Name |
-> FamTyConFlav |
-> Maybe Class |
-> Injectivity |
-> TyCon |

Create a type family `TyCon`

mkPromotedDataCon :: DataCon -> Name -> TyConRepName -> [TyConBinder] -> Kind -> [Role] -> RuntimeRepInfo -> TyCon #

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

mkTcTyCon #

Arguments

:: Name |
-> [TyConBinder] |
-> Kind | result kind only
-> Bool | Can this be unsaturated?
-> [TyVar] | Scoped type variables, see Note [TcTyCon]
-> TyCon |

Makes a tycon suitable for use during type-checking. The only real need for this is for printing error messages during a recursive type/class type-checking knot. It has a kind because TcErrors sometimes calls typeKind. See also Note [Kind checking recursive type and class declarations] in TcTyClsDecls.

## Predicates on TyCons

isAlgTyCon :: TyCon -> Bool #

Returns `True` if the supplied `TyCon` resulted from either a `data` or `newtype` declaration

isVanillaAlgTyCon :: TyCon -> Bool #

Returns `True` for vanilla AlgTyCons -- that is, those created with a `data` or `newtype` declaration.

isClassTyCon :: TyCon -> Bool #

Is this `TyCon` that for a class instance?

isFamInstTyCon :: TyCon -> Bool #

Is this `TyCon` that for a data family instance?

isFunTyCon :: TyCon -> Bool #

isPrimTyCon :: TyCon -> Bool #

Does this `TyCon` represent something that cannot be defined in Haskell?

isTupleTyCon :: TyCon -> Bool #

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 #

Is this the `TyCon` for an unboxed tuple?

isBoxedTupleTyCon :: TyCon -> Bool #

Is this the `TyCon` for a boxed tuple?

isUnboxedSumTyCon :: TyCon -> Bool #

Is this the `TyCon` for an unboxed sum?

isPromotedTupleTyCon :: TyCon -> Bool #

Is this the `TyCon` for a promoted tuple?

isTypeSynonymTyCon :: TyCon -> Bool #

Is this a `TyCon` representing a regular H98 type synonym (`type`)?

mightBeUnsaturatedTyCon :: TyCon -> Bool #

True iff we can decompose (T a b c) into ((T a b) c) I.e. is it injective and generative w.r.t nominal equality? That is, if (T a b) ~N d e f, is it always the case that (T ~N d), (a ~N e) and (b ~N f)? Specifically NOT true of synonyms (open and otherwise)

It'd be unusual to call mightBeUnsaturatedTyCon on a regular H98 type synonym, because you should probably have expanded it first But regardless, it's not decomposable

isPromotedDataCon :: TyCon -> Bool #

Is this a PromotedDataCon?

isPromotedDataCon_maybe :: TyCon -> Maybe DataCon #

Retrieves the promoted DataCon if this is a PromotedDataCon;

isKindTyCon :: TyCon -> Bool #

Is this tycon really meant for use at the kind level? That is, should it be permitted without -XDataKinds?

isLiftedTypeKindTyConName :: Name -> Bool #

isTauTyCon :: TyCon -> Bool #

isFamFreeTyCon :: TyCon -> Bool #

isDataTyCon :: TyCon -> Bool #

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, unboxed sums 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 #

isDataProductTyCon_maybe :: TyCon -> Maybe DataCon #

isDataSumTyCon_maybe :: TyCon -> Maybe [DataCon] #

isEnumerationTyCon :: TyCon -> Bool #

Is this an algebraic `TyCon` which is just an enumeration of values?

isNewTyCon :: TyCon -> Bool #

Is this `TyCon` that for a `newtype`

isAbstractTyCon :: TyCon -> Bool #

Test if the `TyCon` is algebraic but abstract (invisible data constructors)

isFamilyTyCon :: TyCon -> Bool #

Is this a `TyCon`, synonym or otherwise, that defines a family?

isOpenFamilyTyCon :: TyCon -> Bool #

Is this a `TyCon`, synonym or otherwise, that defines a family with instances?

isTypeFamilyTyCon :: TyCon -> Bool #

Is this a synonym `TyCon` that can have may have further instances appear?

isDataFamilyTyCon :: TyCon -> Bool #

Is this a synonym `TyCon` that can have may have further instances appear?

isOpenTypeFamilyTyCon :: TyCon -> Bool #

Is this an open type family TyCon?

isClosedSynFamilyTyConWithAxiom_maybe :: TyCon -> Maybe (CoAxiom Branched) #

Is this a non-empty closed type family? Returns `Nothing` for abstract or empty closed families.

familyTyConInjectivityInfo :: TyCon -> Injectivity #

Try to read the injectivity information from a FamilyTyCon. For every other TyCon this function panics.

isBuiltInSynFamTyCon_maybe :: TyCon -> Maybe BuiltInSynFamily #

isUnliftedTyCon :: TyCon -> Bool #

Is this `TyCon` unlifted (i.e. cannot contain bottom)? Note that this can only be true for primitive and unboxed-tuple `TyCon`s

isGadtSyntaxTyCon :: TyCon -> Bool #

Is this an algebraic `TyCon` declared with the GADT syntax?

isInjectiveTyCon :: TyCon -> Role -> Bool #

`isInjectiveTyCon` is true of `TyCon`s for which this property holds (where X is the role passed in): If (T a1 b1 c1) ~X (T a2 b2 c2), then (a1 ~X1 a2), (b1 ~X2 b2), and (c1 ~X3 c2) (where X1, X2, and X3, are the roles given by tyConRolesX tc X) See also Note [Decomposing equality] in TcCanonical

isGenerativeTyCon :: TyCon -> Role -> Bool #

`isGenerativeTyCon` is true of `TyCon`s for which this property holds (where X is the role passed in): If (T tys ~X t), then (t's head ~X T). See also Note [Decomposing equality] in TcCanonical

isGenInjAlgRhs :: AlgTyConRhs -> Bool #

Is this an `AlgTyConRhs` of a `TyCon` that is generative and injective with respect to representational equality?

isTyConAssoc :: TyCon -> Bool #

Are we able to extract information `TyVar` to class argument list mapping from a given `TyCon`?

tyConAssoc_maybe :: TyCon -> Maybe Class #

isImplicitTyCon :: TyCon -> Bool #

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).
- Tuples are implicit iff they have a wired-in name (namely: boxed and unboxed tupeles are wired-in and implicit, but constraint tuples are not)

isTyConWithSrcDataCons :: TyCon -> Bool #

Check if the tycon actually refers to a proper `data` or `newtype` with user defined constructors rather than one from a class or other construction.

isTcTyCon :: TyCon -> Bool #

Is this a TcTyCon? (That is, one only used during type-checking?)

isTcLevPoly :: TyCon -> Bool #

Could this TyCon ever be levity-polymorphic when fully applied? True is safe. False means we're sure. Does only a quick check based on the TyCon's category. Precondition: The fully-applied TyCon has kind (TYPE blah)

## Extracting information out of TyCons

tyConName :: TyCon -> Name #

Name of the constructor

tyConSkolem :: TyCon -> Bool #

Returns whether or not this `TyCon` is definite, or a hole that may be filled in at some later point. See Note [Skolem abstract data]

tyConKind :: TyCon -> Kind #

Kind of this TyCon

tyConUnique :: TyCon -> Unique #

A Unique of this TyCon. Invariant: identical to Unique of Name stored in tyConName field.

tyConTyVars :: TyCon -> [TyVar] #

TyVar binders

tyConCType :: TyCon -> Maybe CType #

The C type that should be used for this type when using the FFI and CAPI

tyConCType_maybe :: TyCon -> Maybe CType #

tyConDataCons :: TyCon -> [DataCon] #

As `tyConDataCons_maybe`, but returns the empty list of constructors if no constructors could be found

tyConDataCons_maybe :: TyCon -> Maybe [DataCon] #

Determine the `DataCon`s originating from the given `TyCon`, if the `TyCon` is the sort that can have any constructors (note: this does not include abstract algebraic types)

tyConSingleDataCon_maybe :: TyCon -> Maybe DataCon #

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

tyConSingleDataCon :: TyCon -> DataCon #

tyConSingleAlgDataCon_maybe :: TyCon -> Maybe DataCon #

tyConFamilySize :: TyCon -> Int #

Determine the number of value constructors a `TyCon` has. Panics if the `TyCon` is not algebraic or a tuple

tyConStupidTheta :: TyCon -> [PredType] #

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 #

Arity

tyConRoles :: TyCon -> [Role] #

Get the list of roles for the type parameters of a TyCon

tyConFlavour :: TyCon -> String #

tyConTuple_maybe :: TyCon -> Maybe TupleSort #

tyConClass_maybe :: TyCon -> Maybe Class #

If this `TyCon` is that for a class instance, return the class it is for. Otherwise returns `Nothing`

tyConATs :: TyCon -> [TyCon] #

Return the associated types of the `TyCon`, if any

tyConFamInst_maybe :: TyCon -> Maybe (TyCon, [Type]) #

If this `TyCon` is that of a data family instance, return the family in question and the instance types. Otherwise, return `Nothing`

tyConFamInstSig_maybe :: TyCon -> Maybe (TyCon, [Type], CoAxiom Unbranched) #

tyConFamilyCoercion_maybe :: TyCon -> Maybe (CoAxiom Unbranched) #

If this `TyCon` is that of a data family instance, return a `TyCon` which represents a coercion identifying the representation type with the type instance family. Otherwise, return `Nothing`

tyConFamilyResVar_maybe :: TyCon -> Maybe Name #

Extract type variable naming the result of injective type family

synTyConDefn_maybe :: TyCon -> Maybe ([TyVar], Type) #

Extract the `TyVar`s bound by a vanilla type synonym and the corresponding (unsubstituted) right hand side.

synTyConRhs_maybe :: TyCon -> Maybe Type #

Extract the information pertaining to the right hand side of a type synonym (`type`) declaration.

famTyConFlav_maybe :: TyCon -> Maybe FamTyConFlav #

Extract the flavour of a type family (with all the extra information that it carries)

famTcResVar :: TyCon -> Maybe Name #

Name of result type variable, used for pretty-printing with --show-iface and for reifying TyCon in Template Haskell

algTyConRhs :: TyCon -> AlgTyConRhs #

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) #

Extract the bound type variables and type expansion of a type synonym `TyCon`. Panics if the `TyCon` is not a synonym

newTyConEtadArity :: TyCon -> Int #

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) #

Extract the bound type variables and type expansion of an eta-contracted type synonym `TyCon`. Panics if the `TyCon` is not a synonym

unwrapNewTyCon_maybe :: TyCon -> Maybe ([TyVar], Type, CoAxiom Unbranched) #

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.

unwrapNewTyConEtad_maybe :: TyCon -> Maybe ([TyVar], Type, CoAxiom Unbranched) #

newTyConDataCon_maybe :: TyCon -> Maybe DataCon #

algTcFields :: TyCon -> FieldLabelEnv #

Maps a label to information about the field

tyConRuntimeRepInfo :: TyCon -> RuntimeRepInfo #

Extract any `RuntimeRepInfo` from this TyCon

tyConBinders :: TyCon -> [TyConBinder] #

Full binders

tyConResKind :: TyCon -> Kind #

Result kind

tcTyConScopedTyVars :: TyCon -> [TyVar] #

Scoped tyvars over the tycon's body. See Note [TcTyCon]

## Manipulating TyCons

expandSynTyCon_maybe #

Arguments

:: TyCon |
-> [tyco] | Arguments to `TyCon`
-> Maybe ([(TyVar, tyco)], Type, [tyco]) | Returns a `TyVar` substitution, the body type of the synonym (not yet substituted) and any arguments remaining from the application

Expand a type synonym application, if any

makeRecoveryTyCon :: TyCon -> TyCon #

Make an fake, recovery `TyCon` from an existing one. Used when recovering from errors

newTyConCo :: TyCon -> CoAxiom Unbranched #

newTyConCo_maybe :: TyCon -> Maybe (CoAxiom Unbranched) #

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`

pprPromotionQuote :: TyCon -> SDoc #

mkTyConKind :: [TyConBinder] -> Kind -> Kind #

# Runtime type representation

type TyConRepName = Name #

tyConRepName_maybe :: TyCon -> Maybe TyConRepName #

mkPrelTyConRepName :: Name -> TyConRepName #

Make a `Name` for the `Typeable` representation of the given wired-in type

tyConRepModOcc :: Module -> OccName -> (Module, OccName) #

The name (and defining module) for the Typeable representation (TyCon) of a type constructor.

See Note [Grand plan for Typeable] in `TcTypeable` in TcTypeable.

# Primitive representations of Types

data PrimRep #

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 |
LiftedRep |
UnliftedRep | Unlifted pointer
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 '(Un)liftedRep')
FloatRep |
DoubleRep |
VecRep Int PrimElemRep | A vector

Instances

Eq PrimRep # |
Methods (==) :: PrimRep -> PrimRep -> Bool # (/=) :: PrimRep -> PrimRep -> Bool #
Show PrimRep # |
Methods showsPrec :: Int -> PrimRep -> ShowS Source # show :: PrimRep -> String Source # showList :: [PrimRep] -> ShowS Source #
Outputable PrimRep # |
Methods ppr :: PrimRep -> SDoc # pprPrec :: Rational -> PrimRep -> SDoc #

data PrimElemRep #

Constructors

Int8ElemRep |
Int16ElemRep |
Int32ElemRep |
Int64ElemRep |
Word8ElemRep |
Word16ElemRep |
Word32ElemRep |
Word64ElemRep |
FloatElemRep |
DoubleElemRep |

Instances

Eq PrimElemRep # |
Methods (==) :: PrimElemRep -> PrimElemRep -> Bool # (/=) :: PrimElemRep -> PrimElemRep -> Bool #
Show PrimElemRep # |
Methods showsPrec :: Int -> PrimElemRep -> ShowS Source # show :: PrimElemRep -> String Source # showList :: [PrimElemRep] -> ShowS Source #
Outputable PrimElemRep # |
Methods ppr :: PrimElemRep -> SDoc # pprPrec :: Rational -> PrimElemRep -> SDoc #

isVoidRep :: PrimRep -> Bool #

isGcPtrRep :: PrimRep -> Bool #

primRepSizeW :: DynFlags -> PrimRep -> Int #

Find the size of a `PrimRep`, in words

primElemRepSizeB :: PrimElemRep -> Int #

primRepIsFloat :: PrimRep -> Maybe Bool #

Return if Rep stands for floating type, returns Nothing for vector types.

# Recursion breaking

data RecTcChecker #

initRecTc :: RecTcChecker #

checkRecTc :: RecTcChecker -> TyCon -> Maybe RecTcChecker #