ghc-8.8.3: The GHC API
Safe HaskellNone
LanguageHaskell2010

TyCoRep

Synopsis

Documentation

data TyThing Source #

A global typecheckable-thing, essentially anything that has a name. Not to be confused with a TcTyThing, which is also a typecheckable thing but in the *local* context. See TcEnv for how to retrieve a TyThing given a Name.

Instances

Instances details
Outputable TyThing # 
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Defined in TyCoRep

NamedThing TyThing # 
Instance details

Defined in TyCoRep

Types

data Type Source #

Constructors

TyVarTy Var

Vanilla type or kind variable (*never* a coercion variable)

AppTy Type Type

Type application to something other than a TyCon. Parameters:

1) Function: must not be a TyConApp or CastTy, must be another AppTy, or TyVarTy See Note Respecting definitional equality about the no CastTy requirement

2) Argument type

TyConApp TyCon [KindOrType]

Application of a TyCon, including newtypes and synonyms. Invariant: saturated applications of FunTyCon must use FunTy and saturated synonyms must use their own constructors. However, unsaturated FunTyCons do appear as TyConApps. Parameters:

1) Type constructor being applied to.

2) Type arguments. Might not have enough type arguments here to saturate the constructor. Even type synonyms are not necessarily saturated; for example unsaturated type synonyms can appear as the right hand side of a type synonym.

ForAllTy !TyCoVarBinder Type

A Π type.

FunTy Type Type

t1 -> t2 Very common, so an important special case

LitTy TyLit

Type literals are similar to type constructors.

CastTy Type KindCoercion

A kind cast. The coercion is always nominal. INVARIANT: The cast is never refl. INVARIANT: The Type is not a CastTy (use TransCo instead) See Note Respecting definitional equality and (EQ3)

CoercionTy Coercion

Injection of a Coercion into a type This should only ever be used in the RHS of an AppTy, in the list of a TyConApp, when applying a promoted GADT data constructor

Instances

Instances details
Data Type # 
Instance details

Defined in TyCoRep

Methods

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

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

toConstr :: Type -> Constr Source #

dataTypeOf :: Type -> DataType Source #

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

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

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

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

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

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

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

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

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

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

Outputable Type # 
Instance details

Defined in TyCoRep

data TyLit Source #

Instances

Instances details
Eq TyLit # 
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Defined in TyCoRep

Methods

(==) :: TyLit -> TyLit -> Bool #

(/=) :: TyLit -> TyLit -> Bool #

Data TyLit # 
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Defined in TyCoRep

Methods

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

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

toConstr :: TyLit -> Constr Source #

dataTypeOf :: TyLit -> DataType Source #

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

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

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

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

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

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

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

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

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

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

Ord TyLit # 
Instance details

Defined in TyCoRep

Methods

compare :: TyLit -> TyLit -> Ordering #

(<) :: TyLit -> TyLit -> Bool #

(<=) :: TyLit -> TyLit -> Bool #

(>) :: TyLit -> TyLit -> Bool #

(>=) :: TyLit -> TyLit -> Bool #

max :: TyLit -> TyLit -> TyLit #

min :: TyLit -> TyLit -> TyLit #

Outputable TyLit # 
Instance details

Defined in TyCoRep

type KindOrType = Type Source #

The key representation of types within the compiler

type Kind = Type Source #

The key type representing kinds in the compiler.

type KnotTied ty = ty Source #

A type labeled KnotTied might have knot-tied tycons in it. See Note [Type checking recursive type and class declarations] in TcTyClsDecls

type PredType = Type Source #

A type of the form p of kind Constraint represents a value whose type is the Haskell predicate p, where a predicate is what occurs before the => in a Haskell type.

We use PredType as documentation to mark those types that we guarantee to have this kind.

It can be expanded into its representation, but:

  • The type checker must treat it as opaque
  • The rest of the compiler treats it as transparent

Consider these examples:

f :: (Eq a) => a -> Int
g :: (?x :: Int -> Int) => a -> Int
h :: (r\l) => {r} => {l::Int | r}

Here the Eq a and ?x :: Int -> Int and rl are all called "predicates"

type ThetaType = [PredType] Source #

A collection of PredTypes

data ArgFlag Source #

Argument Flag

Is something required to appear in source Haskell (Required), permitted by request (Specified) (visible type application), or prohibited entirely from appearing in source Haskell (Inferred)? See Note [VarBndrs, TyCoVarBinders, TyConBinders, and visibility] in TyCoRep

Constructors

Inferred 
Specified 
Required 

Instances

Instances details
Eq ArgFlag # 
Instance details

Defined in Var

Methods

(==) :: ArgFlag -> ArgFlag -> Bool #

(/=) :: ArgFlag -> ArgFlag -> Bool #

Data ArgFlag # 
Instance details

Defined in Var

Methods

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

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

toConstr :: ArgFlag -> Constr Source #

dataTypeOf :: ArgFlag -> DataType Source #

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

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

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

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

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

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

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

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

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

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

Ord ArgFlag # 
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Defined in Var

Outputable ArgFlag # 
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Defined in Var

Binary ArgFlag # 
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Defined in Var

Outputable tv => Outputable (VarBndr tv ArgFlag) # 
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Defined in Var

Coercions

data Coercion Source #

A Coercion is concrete evidence of the equality/convertibility of two types.

Instances

Instances details
Data Coercion # 
Instance details

Defined in TyCoRep

Methods

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

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

toConstr :: Coercion -> Constr Source #

dataTypeOf :: Coercion -> DataType Source #

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

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

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

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

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

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

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

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

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

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

Outputable Coercion # 
Instance details

Defined in TyCoRep

data UnivCoProvenance Source #

For simplicity, we have just one UnivCo that represents a coercion from some type to some other type, with (in general) no restrictions on the type. The UnivCoProvenance specifies more exactly what the coercion really is and why a program should (or shouldn't!) trust the coercion. It is reasonable to consider each constructor of UnivCoProvenance as a totally independent coercion form; their only commonality is that they don't tell you what types they coercion between. (That info is in the UnivCo constructor of Coercion.

Constructors

UnsafeCoerceProv

From unsafeCoerce#. These are unsound.

PhantomProv KindCoercion

See Note [Phantom coercions]. Only in Phantom roled coercions

ProofIrrelProv KindCoercion

From the fact that any two coercions are considered equivalent. See Note [ProofIrrelProv]. Can be used in Nominal or Representational coercions

PluginProv String

From a plugin, which asserts that this coercion is sound. The string is for the use of the plugin.

Instances

Instances details
Data UnivCoProvenance # 
Instance details

Defined in TyCoRep

Methods

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

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

toConstr :: UnivCoProvenance -> Constr Source #

dataTypeOf :: UnivCoProvenance -> DataType Source #

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

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

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

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

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

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

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

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

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

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

Outputable UnivCoProvenance # 
Instance details

Defined in TyCoRep

data CoercionHole Source #

A coercion to be filled in by the type-checker. See Note [Coercion holes]

Constructors

CoercionHole 

Instances

Instances details
Data CoercionHole # 
Instance details

Defined in TyCoRep

Methods

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

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

toConstr :: CoercionHole -> Constr Source #

dataTypeOf :: CoercionHole -> DataType Source #

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

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

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

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

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

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

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

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

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

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

Outputable CoercionHole # 
Instance details

Defined in TyCoRep

data MCoercion Source #

A semantically more meaningful type to represent what may or may not be a useful Coercion.

Constructors

MRefl 
MCo Coercion 

Instances

Instances details
Data MCoercion # 
Instance details

Defined in TyCoRep

Methods

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

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

toConstr :: MCoercion -> Constr Source #

dataTypeOf :: MCoercion -> DataType Source #

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

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

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

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

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

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

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

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

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

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

Outputable MCoercion # 
Instance details

Defined in TyCoRep

Functions over types

mkTyConTy :: TyCon -> Type Source #

Create the plain type constructor type which has been applied to no type arguments at all.

mkFunTy :: Type -> Type -> Type infixr 3 Source #

Make an arrow type

mkFunTys :: [Type] -> Type -> Type Source #

Make nested arrow types

mkTyCoForAllTy :: TyCoVar -> ArgFlag -> Type -> Type Source #

If tv is a coercion variable and it is not used in the body, returns a FunTy, otherwise makes a forall type. See Note [Unused coercion variable in ForAllTy]

mkForAllTys :: [TyCoVarBinder] -> Type -> Type Source #

Wraps foralls over the type using the provided TyCoVars from left to right

mkForAllTy :: TyCoVar -> ArgFlag -> Type -> Type Source #

Like mkTyCoForAllTy, but does not check the occurrence of the binder See Note [Unused coercion variable in ForAllTy]

mkPiTys :: [TyCoBinder] -> Type -> Type Source #

Like mkTyCoPiTys, but does not check the occurrence of the binder

kindRep_maybe :: HasDebugCallStack => Kind -> Maybe Type Source #

Given a kind (TYPE rr), extract its RuntimeRep classifier rr. For example, kindRep_maybe * = Just LiftedRep Returns Nothing if the kind is not of form (TYPE rr) Treats * and Constraint as the same

kindRep :: HasDebugCallStack => Kind -> Type Source #

Extract the RuntimeRep classifier of a type from its kind. For example, kindRep * = LiftedRep; Panics if this is not possible. Treats * and Constraint as the same

isLiftedTypeKind :: Kind -> Bool Source #

This version considers Constraint to be the same as *. Returns True if the argument is equivalent to Type/Constraint and False otherwise. See Note [Kind Constraint and kind Type]

isUnliftedTypeKind :: Kind -> Bool Source #

Returns True if the kind classifies unlifted types and False otherwise. Note that this returns False for levity-polymorphic kinds, which may be specialized to a kind that classifies unlifted types.

isRuntimeRepTy :: Type -> Bool Source #

Is this the type RuntimeRep?

isRuntimeRepVar :: TyVar -> Bool Source #

Is a tyvar of type RuntimeRep?

sameVis :: ArgFlag -> ArgFlag -> Bool Source #

Do these denote the same level of visibility? Required arguments are visible, others are not. So this function equates Specified and Inferred. Used for printing.

Functions over binders

data TyCoBinder Source #

A TyCoBinder represents an argument to a function. TyCoBinders can be dependent (Named) or nondependent (Anon). They may also be visible or not. See Note [TyCoBinders]

Constructors

Named TyCoVarBinder 
Anon Type 

Instances

Instances details
Data TyCoBinder # 
Instance details

Defined in TyCoRep

Methods

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

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

toConstr :: TyCoBinder -> Constr Source #

dataTypeOf :: TyCoBinder -> DataType Source #

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

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

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

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

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

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

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

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

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

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

Outputable TyCoBinder # 
Instance details

Defined in TyCoRep

type TyCoVarBinder = VarBndr TyCoVar ArgFlag Source #

Variable Binder

A TyCoVarBinder is the binder of a ForAllTy It's convenient to define this synonym here rather its natural home in TyCoRep, because it's used in DataCon.hs-boot

A TyVarBinder is a binder with only TyVar

type TyBinder = TyCoBinder Source #

TyBinder is like TyCoBinder, but there can only be TyVarBinder in the Named field.

binderVar :: VarBndr tv argf -> tv Source #

binderVars :: [VarBndr tv argf] -> [tv] Source #

binderArgFlag :: VarBndr tv argf -> argf Source #

delBinderVar :: VarSet -> TyCoVarBinder -> VarSet Source #

Remove the binder's variable from the set, if the binder has a variable.

isInvisibleArgFlag :: ArgFlag -> Bool Source #

Does this ArgFlag classify an argument that is not written in Haskell?

isVisibleArgFlag :: ArgFlag -> Bool Source #

Does this ArgFlag classify an argument that is written in Haskell?

isInvisibleBinder :: TyCoBinder -> Bool Source #

Does this binder bind an invisible argument?

isVisibleBinder :: TyCoBinder -> Bool Source #

Does this binder bind a visible argument?

isTyBinder :: TyCoBinder -> Bool Source #

If its a named binder, is the binder a tyvar? Returns True for nondependent binder.

Functions over coercions

pickLR :: LeftOrRight -> (a, a) -> a Source #

Pretty-printing

pprUserForAll :: [TyCoVarBinder] -> SDoc Source #

Print a user-level forall; see Note [When to print foralls]

newtype PprPrec Source #

A general-purpose pretty-printing precedence type.

Constructors

PprPrec Int 

Instances

Instances details
Eq PprPrec # 
Instance details

Defined in BasicTypes

Methods

(==) :: PprPrec -> PprPrec -> Bool #

(/=) :: PprPrec -> PprPrec -> Bool #

Ord PprPrec # 
Instance details

Defined in BasicTypes

Show PprPrec # 
Instance details

Defined in BasicTypes

pprWithExplicitKindsWhen :: Bool -> SDoc -> SDoc Source #

Display all kind information (with -fprint-explicit-kinds) when the provided Bool argument is True. See Note [Kind arguments in error messages] in TcErrors.

debugPprType :: Type -> SDoc Source #

debugPprType is a simple pretty printer that prints a type without going through IfaceType. It does not format as prettily as the normal route, but it's much more direct, and that can be useful for debugging. E.g. with -dppr-debug it prints the kind on type-variable occurrences which the normal route fundamentally cannot do.

Free variables

tyCoVarsOfTypeDSet :: Type -> DTyCoVarSet Source #

tyCoFVsOfType that returns free variables of a type in a deterministic set. For explanation of why using VarSet is not deterministic see Note [Deterministic FV] in FV.

tyCoVarsOfTypesDSet :: [Type] -> DTyCoVarSet Source #

Returns free variables of types, including kind variables as a deterministic set. For type synonyms it does not expand the synonym.

tyCoFVsOfType :: Type -> FV Source #

The worker for tyCoFVsOfType and tyCoFVsOfTypeList. The previous implementation used unionVarSet which is O(n+m) and can make the function quadratic. It's exported, so that it can be composed with other functions that compute free variables. See Note [FV naming conventions] in FV.

Eta-expanded because that makes it run faster (apparently) See Note [FV eta expansion] in FV for explanation.

tyCoVarsOfTypeList :: Type -> [TyCoVar] Source #

tyCoFVsOfType that returns free variables of a type in deterministic order. For explanation of why using VarSet is not deterministic see Note [Deterministic FV] in FV.

tyCoVarsOfTypesList :: [Type] -> [TyCoVar] Source #

Returns free variables of types, including kind variables as a deterministically ordered list. For type synonyms it does not expand the synonym.

tyCoVarsOfCoDSet :: Coercion -> DTyCoVarSet Source #

Get a deterministic set of the vars free in a coercion

almostDevoidCoVarOfCo :: CoVar -> Coercion -> Bool Source #

Given a covar and a coercion, returns True if covar is almost devoid in the coercion. That is, covar can only appear in Refl and GRefl. See last wrinkle in Note [Unused coercion variable in ForAllCo] in Coercion

injectiveVarsOfType :: Type -> FV Source #

Returns the free variables of a Type that are in injective positions. For example, if F is a non-injective type family, then:

injectiveTyVarsOf( Either c (Maybe (a, F b c)) ) = {a,c}

If injectiveVarsOfType ty = itvs, then knowing ty fixes itvs. More formally, if a is in injectiveVarsOfType ty and S1(ty) ~ S2(ty), then S1(a) ~ S2(a), where S1 and S2 are arbitrary substitutions.

See Note [When does a tycon application need an explicit kind signature?].

tyConAppNeedsKindSig Source #

Arguments

:: Bool

Should specified binders count towards injective positions in the kind of the TyCon?

-> TyCon 
-> Int

The number of args the TyCon is applied to.

-> Bool

Does T t_1 ... t_n need a kind signature? (Where n is the number of arguments)

Does a TyCon (that is applied to some number of arguments) need to be ascribed with an explicit kind signature to resolve ambiguity if rendered as a source-syntax type? (See Note [When does a tycon application need an explicit kind signature?] for a full explanation of what this function checks for.)

noFreeVarsOfType :: Type -> Bool Source #

Returns True if this type has no free variables. Should be the same as isEmptyVarSet . tyCoVarsOfType, but faster in the non-forall case.

noFreeVarsOfCo :: Coercion -> Bool Source #

Returns True if this coercion has no free variables. Should be the same as isEmptyVarSet . tyCoVarsOfCo, but faster in the non-forall case.

Substitutions

data TCvSubst Source #

Type & coercion substitution

The following invariants must hold of a TCvSubst:

  1. The in-scope set is needed only to guide the generation of fresh uniques
  2. In particular, the kind of the type variables in the in-scope set is not relevant
  3. The substitution is only applied ONCE! This is because in general such application will not reach a fixed point.

Instances

Instances details
Outputable TCvSubst # 
Instance details

Defined in TyCoRep

type TvSubstEnv = TyVarEnv Type Source #

A substitution of Types for TyVars and Kinds for KindVars

type CvSubstEnv = CoVarEnv Coercion Source #

A substitution of Coercions for CoVars

composeTCvSubstEnv :: InScopeSet -> (TvSubstEnv, CvSubstEnv) -> (TvSubstEnv, CvSubstEnv) -> (TvSubstEnv, CvSubstEnv) Source #

(compose env1 env2)(x) is env1(env2(x)); i.e. apply env2 then env1. It assumes that both are idempotent. Typically, env1 is the refinement to a base substitution env2

composeTCvSubst :: TCvSubst -> TCvSubst -> TCvSubst Source #

Composes two substitutions, applying the second one provided first, like in function composition.

mkTvSubst :: InScopeSet -> TvSubstEnv -> TCvSubst Source #

Make a TCvSubst with specified tyvar subst and empty covar subst

mkCvSubst :: InScopeSet -> CvSubstEnv -> TCvSubst Source #

Make a TCvSubst with specified covar subst and empty tyvar subst

getTCvSubstRangeFVs :: TCvSubst -> VarSet Source #

Returns the free variables of the types in the range of a substitution as a non-deterministic set.

mkTyCoInScopeSet :: [Type] -> [Coercion] -> InScopeSet Source #

Generates an in-scope set from the free variables in a list of types and a list of coercions

zipTvSubst :: HasDebugCallStack => [TyVar] -> [Type] -> TCvSubst Source #

Generates the in-scope set for the TCvSubst from the types in the incoming environment. No CoVars, please!

zipCvSubst :: HasDebugCallStack => [CoVar] -> [Coercion] -> TCvSubst Source #

Generates the in-scope set for the TCvSubst from the types in the incoming environment. No TyVars, please!

mkTvSubstPrs :: [(TyVar, Type)] -> TCvSubst Source #

Generates the in-scope set for the TCvSubst from the types in the incoming environment. No CoVars, please!

substTyWith :: HasCallStack => [TyVar] -> [Type] -> Type -> Type Source #

Type substitution, see zipTvSubst

substTyWithCoVars :: [CoVar] -> [Coercion] -> Type -> Type Source #

Substitute covars within a type

substTysWith :: [TyVar] -> [Type] -> [Type] -> [Type] Source #

Type substitution, see zipTvSubst

substTysWithCoVars :: [CoVar] -> [Coercion] -> [Type] -> [Type] Source #

Type substitution, see zipTvSubst

substCoWith :: HasCallStack => [TyVar] -> [Type] -> Coercion -> Coercion Source #

Coercion substitution, see zipTvSubst

substTy :: HasCallStack => TCvSubst -> Type -> Type Source #

Substitute within a Type The substitution has to satisfy the invariants described in Note [The substitution invariant].

substTyAddInScope :: TCvSubst -> Type -> Type Source #

Substitute within a Type after adding the free variables of the type to the in-scope set. This is useful for the case when the free variables aren't already in the in-scope set or easily available. See also Note [The substitution invariant].

substTyUnchecked :: TCvSubst -> Type -> Type Source #

Substitute within a Type disabling the sanity checks. The problems that the sanity checks in substTy catch are described in Note [The substitution invariant]. The goal of #11371 is to migrate all the calls of substTyUnchecked to substTy and remove this function. Please don't use in new code.

substTysUnchecked :: TCvSubst -> [Type] -> [Type] Source #

Substitute within several Types disabling the sanity checks. The problems that the sanity checks in substTys catch are described in Note [The substitution invariant]. The goal of #11371 is to migrate all the calls of substTysUnchecked to substTys and remove this function. Please don't use in new code.

substThetaUnchecked :: TCvSubst -> ThetaType -> ThetaType Source #

Substitute within a ThetaType disabling the sanity checks. The problems that the sanity checks in substTys catch are described in Note [The substitution invariant]. The goal of #11371 is to migrate all the calls of substThetaUnchecked to substTheta and remove this function. Please don't use in new code.

substTyWithUnchecked :: [TyVar] -> [Type] -> Type -> Type Source #

Type substitution, see zipTvSubst. Disables sanity checks. The problems that the sanity checks in substTy catch are described in Note [The substitution invariant]. The goal of #11371 is to migrate all the calls of substTyUnchecked to substTy and remove this function. Please don't use in new code.

substCoUnchecked :: TCvSubst -> Coercion -> Coercion Source #

Substitute within a Coercion disabling sanity checks. The problems that the sanity checks in substCo catch are described in Note [The substitution invariant]. The goal of #11371 is to migrate all the calls of substCoUnchecked to substCo and remove this function. Please don't use in new code.

substCoWithUnchecked :: [TyVar] -> [Type] -> Coercion -> Coercion Source #

Coercion substitution, see zipTvSubst. Disables sanity checks. The problems that the sanity checks in substCo catch are described in Note [The substitution invariant]. The goal of #11371 is to migrate all the calls of substCoUnchecked to substCo and remove this function. Please don't use in new code.

substTyWithInScope :: InScopeSet -> [TyVar] -> [Type] -> Type -> Type Source #

Substitute tyvars within a type using a known InScopeSet. Pre-condition: the in_scope set should satisfy Note [The substitution invariant]; specifically it should include the free vars of tys, and of ty minus the domain of the subst.

substTys :: HasCallStack => TCvSubst -> [Type] -> [Type] Source #

Substitute within several Types The substitution has to satisfy the invariants described in Note [The substitution invariant].

substTheta :: HasCallStack => TCvSubst -> ThetaType -> ThetaType Source #

Substitute within a ThetaType The substitution has to satisfy the invariants described in Note [The substitution invariant].

substCo :: HasCallStack => TCvSubst -> Coercion -> Coercion Source #

Substitute within a Coercion The substitution has to satisfy the invariants described in Note [The substitution invariant].

substCos :: HasCallStack => TCvSubst -> [Coercion] -> [Coercion] Source #

Substitute within several Coercions The substitution has to satisfy the invariants described in Note [The substitution invariant].

checkValidSubst :: HasCallStack => TCvSubst -> [Type] -> [Coercion] -> a -> a Source #

This checks if the substitution satisfies the invariant from Note [The substitution invariant].

isValidTCvSubst :: TCvSubst -> Bool Source #

When calling substTy it should be the case that the in-scope set in the substitution is a superset of the free vars of the range of the substitution. See also Note [The substitution invariant].

Tidying type related things up for printing

tidyOpenTypes :: TidyEnv -> [Type] -> (TidyEnv, [Type]) Source #

Grabs the free type variables, tidies them and then uses tidyType to work over the type itself

tidyVarBndrs :: TidyEnv -> [TyCoVar] -> (TidyEnv, [TyCoVar]) Source #

This tidies up a type for printing in an error message, or in an interface file.

It doesn't change the uniques at all, just the print names.

tidyFreeTyCoVars :: TidyEnv -> [TyCoVar] -> TidyEnv Source #

Add the free TyVars to the env in tidy form, so that we can tidy the type they are free in

tidyOpenTyCoVar :: TidyEnv -> TyCoVar -> (TidyEnv, TyCoVar) Source #

Treat a new TyCoVar as a binder, and give it a fresh tidy name using the environment if one has not already been allocated. See also tidyVarBndr

tidyTopType :: Type -> Type Source #

Calls tidyType on a top-level type (i.e. with an empty tidying environment)

Sizes