Generics.SOP.Type.Metadata

Type-level metadata

This module provides datatypes (to be used promoted) that can represent the metadata of Haskell datatypes on the type level.

We do not reuse the term-level metadata types, because these are GADTs that incorporate additional invariants. We could (at least in GHC 8) impose the same invariants on the type level as well, but some tests have revealed that the resulting type are rather inconvenient to work with.

So we use simple datatypes to represent the type-level metadata, even if this means that some invariants are not explicitly captured.

We establish a relation between the term- and type-level versions of the metadata by automatically computing the term-level version from the type-level version.

As we now have two versions of metadata (term-level and type-level) with very similar, yet slightly different datatype definitions, the names between the modules clash, and this module is recommended to be imported qualified when needed.

The interface exported by this module is still somewhat experimental.

Since: 0.3.0.0

Documentation

class DemoteAssociativity (a :: Associativity) where

Class for computing term-level associativity information from type-level associativity information.

Since: 0.3.0.0

Methods

demoteAssociativity :: proxy a -> Associativity

Given a proxy of some type-level associativity information, return the corresponding term-level information.

Since: 0.3.0.0

Instances

DemoteAssociativity LeftAssociative

Defined in Generics.SOP.Type.Metadata

Methods

demoteAssociativity :: proxy LeftAssociative -> Associativity

DemoteAssociativity RightAssociative

Defined in Generics.SOP.Type.Metadata

Methods

demoteAssociativity :: proxy RightAssociative -> Associativity

DemoteAssociativity NotAssociative

Defined in Generics.SOP.Type.Metadata

Methods

demoteAssociativity :: proxy NotAssociative -> Associativity

class DemoteFieldInfo (x :: FieldInfo) (a :: Type) where

Class for computing term-level field information from type-level field information.

Since: 0.3.0.0

Methods

demoteFieldInfo :: proxy x -> FieldInfo a

Given a proxy of some type-level field information, return the corresponding term-level information.

Since: 0.3.0.0

Instances

KnownSymbol s => DemoteFieldInfo (FieldInfo s) a

Defined in Generics.SOP.Type.Metadata

Methods

demoteFieldInfo :: proxy (FieldInfo s) -> FieldInfo0 a

class SListI xs => DemoteFieldInfos (fs :: [FieldInfo]) (xs :: [Type]) where

Class for computing term-level field information from type-level field information.

Since: 0.3.0.0

Methods

demoteFieldInfos :: proxy fs -> NP FieldInfo xs

Given a proxy of some type-level field information, return the corresponding term-level information as a product.

Since: 0.3.0.0

Instances

DemoteFieldInfos ([] :: [FieldInfo]) ([] :: [Type])

Defined in Generics.SOP.Type.Metadata

Methods

demoteFieldInfos :: proxy [] -> NP FieldInfo0 []

(DemoteFieldInfo f x, DemoteFieldInfos fs xs) => DemoteFieldInfos (f ': fs) (x ': xs)

Defined in Generics.SOP.Type.Metadata

Methods

demoteFieldInfos :: proxy (f ': fs) -> NP FieldInfo (x ': xs)

class DemoteConstructorInfo (x :: ConstructorInfo) (xs :: [Type]) where

Class for computing term-level constructor information from type-level constructor information.

Since: 0.3.0.0

Methods

demoteConstructorInfo :: proxy x -> ConstructorInfo xs

Given a proxy of some type-level constructor information, return the corresponding term-level information.

Since: 0.3.0.0

Instances

(KnownSymbol s, SListI xs) => DemoteConstructorInfo (Constructor s) xs

Defined in Generics.SOP.Type.Metadata

Methods

demoteConstructorInfo :: proxy (Constructor s) -> ConstructorInfo xs

(KnownSymbol s, DemoteFieldInfos fs xs) => DemoteConstructorInfo (Record s fs) xs

Defined in Generics.SOP.Type.Metadata

Methods

demoteConstructorInfo :: proxy (Record s fs) -> ConstructorInfo xs

(KnownSymbol s, DemoteAssociativity a, KnownNat f) => DemoteConstructorInfo (Infix s a f) (y ': (z ': ([] :: [Type])))

Defined in Generics.SOP.Type.Metadata

Methods

demoteConstructorInfo :: proxy (Infix s a f) -> ConstructorInfo (y ': (z ': []))

class DemoteConstructorInfos (cs :: [ConstructorInfo]) (xss :: [[Type]]) where

Class for computing term-level constructor information from type-level constructor information.

Since: 0.3.0.0

Methods

demoteConstructorInfos :: proxy cs -> NP ConstructorInfo xss

Given a proxy of some type-level constructor information, return the corresponding term-level information as a product.

Since: 0.3.0.0

Instances

DemoteConstructorInfos ([] :: [ConstructorInfo]) ([] :: [[Type]])

Defined in Generics.SOP.Type.Metadata

Methods

demoteConstructorInfos :: proxy [] -> NP ConstructorInfo0 []

(DemoteConstructorInfo c xs, DemoteConstructorInfos cs xss) => DemoteConstructorInfos (c ': cs) (xs ': xss)

Defined in Generics.SOP.Type.Metadata

Methods

demoteConstructorInfos :: proxy (c ': cs) -> NP ConstructorInfo (xs ': xss)

class DemoteDatatypeInfo (x :: DatatypeInfo) (xss :: [[Type]]) where

Class for computing term-level datatype information from type-level datatype information.

Since: 0.3.0.0

Methods

demoteDatatypeInfo :: proxy x -> DatatypeInfo xss

Given a proxy of some type-level datatype information, return the corresponding term-level information.

Since: 0.3.0.0

Instances

(KnownSymbol m, KnownSymbol d, DemoteConstructorInfos cs xss) => DemoteDatatypeInfo (ADT m d cs) xss

Defined in Generics.SOP.Type.Metadata

Methods

demoteDatatypeInfo :: proxy (ADT m d cs) -> DatatypeInfo xss

(KnownSymbol m, KnownSymbol d, DemoteConstructorInfo c (x ': ([] :: [Type]))) => DemoteDatatypeInfo (Newtype m d c) ((x ': ([] :: [Type])) ': ([] :: [[Type]]))

Defined in Generics.SOP.Type.Metadata

Methods

demoteDatatypeInfo :: proxy (Newtype m d c) -> DatatypeInfo ((x ': []) ': [])

type Fixity = Nat

The fixity of an infix constructor.

type FieldName = Symbol

The name of a field / record selector.

type ConstructorName = Symbol

The name of a data constructor.

type ModuleName = Symbol

The name of a module.

type DatatypeName = Symbol

The name of a datatype.

data FieldInfo

Metadata for a single record field (to be used promoted).

Since: 0.3.0.0

Constructors

FieldInfo FieldName

Instances

DemoteFieldInfos ([] :: [FieldInfo]) ([] :: [Type])

Defined in Generics.SOP.Type.Metadata

Methods

demoteFieldInfos :: proxy [] -> NP FieldInfo0 []

(DemoteFieldInfo f x, DemoteFieldInfos fs xs) => DemoteFieldInfos (f ': fs) (x ': xs)

Defined in Generics.SOP.Type.Metadata

Methods

demoteFieldInfos :: proxy (f ': fs) -> NP FieldInfo (x ': xs)

data ConstructorInfo

Metadata for a single constructors (to be used promoted).

Since: 0.3.0.0

Constructors

Constructor ConstructorName

Normal constructor

Infix ConstructorName Associativity Fixity

Infix constructor

Record ConstructorName [FieldInfo]

Record constructor

Instances

DemoteConstructorInfos ([] :: [ConstructorInfo]) ([] :: [[Type]])

Defined in Generics.SOP.Type.Metadata

Methods

demoteConstructorInfos :: proxy [] -> NP ConstructorInfo0 []

(DemoteConstructorInfo c xs, DemoteConstructorInfos cs xss) => DemoteConstructorInfos (c ': cs) (xs ': xss)

Defined in Generics.SOP.Type.Metadata

Methods

demoteConstructorInfos :: proxy (c ': cs) -> NP ConstructorInfo (xs ': xss)

data DatatypeInfo

Metadata for a datatype (to be used promoted).

A type of kind DatatypeInfo contains meta-information about a datatype that is not contained in its code. This information consists primarily of the names of the datatype, its constructors, and possibly its record selectors.

The constructor indicates whether the datatype has been declared using newtype or not.

Since: 0.3.0.0

Constructors

ADT ModuleName DatatypeName [ConstructorInfo]

Standard algebraic datatype

Newtype ModuleName DatatypeName ConstructorInfo

Newtype

re-exports

data Associativity

Datatype to represent the associativity of a constructor

Constructors

LeftAssociative

RightAssociative

NotAssociative

Instances

Bounded Associativity

Since: base-4.9.0.0

Defined in GHC.Generics

Methods

minBound :: Associativity

maxBound :: Associativity

Enum Associativity

Since: base-4.9.0.0

Defined in GHC.Generics

Methods

succ :: Associativity -> Associativity

pred :: Associativity -> Associativity

toEnum :: Int -> Associativity

fromEnum :: Associativity -> Int

enumFrom :: Associativity -> [Associativity]

enumFromThen :: Associativity -> Associativity -> [Associativity]

enumFromTo :: Associativity -> Associativity -> [Associativity]

enumFromThenTo :: Associativity -> Associativity -> Associativity -> [Associativity]

Eq Associativity

Since: base-4.6.0.0

Defined in GHC.Generics

Methods

(==) :: Associativity -> Associativity -> Bool

(/=) :: Associativity -> Associativity -> Bool

Data Associativity

Since: base-4.9.0.0

Defined in Data.Data

Methods

gfoldl :: (forall d b. Data d => c (d -> b) -> d -> c b) -> (forall g. g -> c g) -> Associativity -> c Associativity

gunfold :: (forall b r. Data b => c (b -> r) -> c r) -> (forall r. r -> c r) -> Constr -> c Associativity

toConstr :: Associativity -> Constr

dataTypeOf :: Associativity -> DataType

dataCast1 :: Typeable t => (forall d. Data d => c (t d)) -> Maybe (c Associativity)

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

gmapT :: (forall b. Data b => b -> b) -> Associativity -> Associativity

gmapQl :: (r -> r' -> r) -> r -> (forall d. Data d => d -> r') -> Associativity -> r

gmapQr :: (r' -> r -> r) -> r -> (forall d. Data d => d -> r') -> Associativity -> r

gmapQ :: (forall d. Data d => d -> u) -> Associativity -> [u]

gmapQi :: Int -> (forall d. Data d => d -> u) -> Associativity -> u

gmapM :: Monad m => (forall d. Data d => d -> m d) -> Associativity -> m Associativity

gmapMp :: MonadPlus m => (forall d. Data d => d -> m d) -> Associativity -> m Associativity

gmapMo :: MonadPlus m => (forall d. Data d => d -> m d) -> Associativity -> m Associativity

Ord Associativity

Since: base-4.6.0.0

Defined in GHC.Generics

Methods

compare :: Associativity -> Associativity -> Ordering

(<) :: Associativity -> Associativity -> Bool

(<=) :: Associativity -> Associativity -> Bool

(>) :: Associativity -> Associativity -> Bool

(>=) :: Associativity -> Associativity -> Bool

max :: Associativity -> Associativity -> Associativity

min :: Associativity -> Associativity -> Associativity

Read Associativity

Since: base-4.6.0.0

Defined in GHC.Generics

Methods

readsPrec :: Int -> ReadS Associativity

readList :: ReadS [Associativity]

readPrec :: ReadPrec Associativity

readListPrec :: ReadPrec [Associativity]

Show Associativity

Since: base-4.6.0.0

Defined in GHC.Generics

Methods

showsPrec :: Int -> Associativity -> ShowS

show :: Associativity -> String

showList :: [Associativity] -> ShowS

Ix Associativity

Since: base-4.9.0.0

Defined in GHC.Generics

Methods

range :: (Associativity, Associativity) -> [Associativity]

index :: (Associativity, Associativity) -> Associativity -> Int

unsafeIndex :: (Associativity, Associativity) -> Associativity -> Int

inRange :: (Associativity, Associativity) -> Associativity -> Bool

rangeSize :: (Associativity, Associativity) -> Int

unsafeRangeSize :: (Associativity, Associativity) -> Int

Generic Associativity

Defined in GHC.Generics

Associated Types

type Rep Associativity :: Type -> Type

Methods

from :: Associativity -> Rep Associativity x

to :: Rep Associativity x -> Associativity

SingKind Associativity

Since: base-4.0.0.0

Defined in GHC.Generics

Associated Types

type DemoteRep Associativity :: Type

Methods

fromSing :: Sing a -> DemoteRep Associativity

HasDatatypeInfo Associativity

Defined in Generics.SOP.Instances

Associated Types

type DatatypeInfoOf Associativity :: DatatypeInfo

Methods

datatypeInfo :: proxy Associativity -> DatatypeInfo (Code Associativity)

Generic Associativity

Defined in Generics.SOP.Instances

Associated Types

type Code Associativity :: [[Type]]

Methods

from :: Associativity -> Rep Associativity

to :: Rep Associativity -> Associativity

SingI LeftAssociative

Since: base-4.9.0.0

Defined in GHC.Generics

Methods

sing :: Sing LeftAssociative

SingI RightAssociative

Since: base-4.9.0.0

Defined in GHC.Generics

Methods

sing :: Sing RightAssociative

SingI NotAssociative

Since: base-4.9.0.0

Defined in GHC.Generics

Methods

sing :: Sing NotAssociative

type Rep Associativity

Since: base-4.7.0.0

Defined in GHC.Generics

type Rep Associativity = D1 (MetaData "Associativity" "GHC.Generics" "base" False) (C1 (MetaCons "LeftAssociative" PrefixI False) (U1 :: Type -> Type) :+: (C1 (MetaCons "RightAssociative" PrefixI False) (U1 :: Type -> Type) :+: C1 (MetaCons "NotAssociative" PrefixI False) (U1 :: Type -> Type)))

data Sing (a :: Associativity)

Defined in GHC.Generics

data Sing (a :: Associativity) where

• SLeftAssociative :: forall (a :: Associativity). Sing LeftAssociative
• SRightAssociative :: forall (a :: Associativity). Sing RightAssociative
• SNotAssociative :: forall (a :: Associativity). Sing NotAssociative

type DemoteRep Associativity

Defined in GHC.Generics

type DemoteRep Associativity = Associativity

type DatatypeInfoOf Associativity

Defined in Generics.SOP.Instances

type DatatypeInfoOf Associativity = ADT "GHC.Generics" "Associativity" (Constructor "LeftAssociative" ': (Constructor "RightAssociative" ': (Constructor "NotAssociative" ': ([] :: [ConstructorInfo]))))

type Code Associativity

Defined in Generics.SOP.Instances

type Code Associativity = ([] :: [Type]) ': (([] :: [Type]) ': (([] :: [Type]) ': ([] :: [[Type]])))