Safe Haskell | None |
---|---|
Language | Haskell2010 |
Generics.SOP.Type.Metadata
Contents
Description
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
Synopsis
- class DemoteAssociativity (a :: Associativity) where
- class DemoteFieldInfo (x :: FieldInfo) (a :: *) where
- class SListI xs => DemoteFieldInfos (fs :: [FieldInfo]) (xs :: [*]) where
- class DemoteConstructorInfo (x :: ConstructorInfo) (xs :: [*]) where
- class DemoteConstructorInfos (cs :: [ConstructorInfo]) (xss :: [[*]]) where
- class DemoteDatatypeInfo (x :: DatatypeInfo) (xss :: [[*]]) where
- type Fixity = Nat
- type FieldName = Symbol
- type ConstructorName = Symbol
- type ModuleName = Symbol
- type DatatypeName = Symbol
- data FieldInfo = FieldInfo FieldName
- data ConstructorInfo
- data DatatypeInfo
- data Associativity
Documentation
class DemoteAssociativity (a :: Associativity) where Source #
Class for computing term-level associativity information from type-level associativity information.
Since: 0.3.0.0
Minimal complete definition
Methods
demoteAssociativity :: proxy a -> Associativity Source #
Given a proxy of some type-level associativity information, return the corresponding term-level information.
Since: 0.3.0.0
Instances
DemoteAssociativity LeftAssociative Source # | |
Defined in Generics.SOP.Type.Metadata Methods demoteAssociativity :: proxy LeftAssociative -> Associativity Source # | |
DemoteAssociativity RightAssociative Source # | |
Defined in Generics.SOP.Type.Metadata Methods demoteAssociativity :: proxy RightAssociative -> Associativity Source # | |
DemoteAssociativity NotAssociative Source # | |
Defined in Generics.SOP.Type.Metadata Methods demoteAssociativity :: proxy NotAssociative -> Associativity Source # |
class DemoteFieldInfo (x :: FieldInfo) (a :: *) where Source #
Class for computing term-level field information from type-level field information.
Since: 0.3.0.0
Minimal complete definition
Methods
demoteFieldInfo :: proxy x -> FieldInfo a Source #
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 Source # | |
Defined in Generics.SOP.Type.Metadata Methods demoteFieldInfo :: proxy (FieldInfo s) -> FieldInfo0 a Source # |
class SListI xs => DemoteFieldInfos (fs :: [FieldInfo]) (xs :: [*]) where Source #
Class for computing term-level field information from type-level field information.
Since: 0.3.0.0
Minimal complete definition
Methods
demoteFieldInfos :: proxy fs -> NP FieldInfo xs Source #
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]) ([] :: [*]) Source # | |
Defined in Generics.SOP.Type.Metadata Methods demoteFieldInfos :: proxy [] -> NP FieldInfo0 [] Source # | |
(DemoteFieldInfo f x, DemoteFieldInfos fs xs) => DemoteFieldInfos (f ': fs) (x ': xs) Source # | |
Defined in Generics.SOP.Type.Metadata Methods demoteFieldInfos :: proxy (f ': fs) -> NP FieldInfo (x ': xs) Source # |
class DemoteConstructorInfo (x :: ConstructorInfo) (xs :: [*]) where Source #
Class for computing term-level constructor information from type-level constructor information.
Since: 0.3.0.0
Minimal complete definition
Methods
demoteConstructorInfo :: proxy x -> ConstructorInfo xs Source #
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 Source # | |
Defined in Generics.SOP.Type.Metadata Methods demoteConstructorInfo :: proxy (Constructor s) -> ConstructorInfo xs Source # | |
(KnownSymbol s, DemoteFieldInfos fs xs) => DemoteConstructorInfo (Record s fs) xs Source # | |
Defined in Generics.SOP.Type.Metadata Methods demoteConstructorInfo :: proxy (Record s fs) -> ConstructorInfo xs Source # | |
(KnownSymbol s, DemoteAssociativity a, KnownNat f) => DemoteConstructorInfo (Infix s a f) (y ': (z ': ([] :: [*]))) Source # | |
Defined in Generics.SOP.Type.Metadata Methods demoteConstructorInfo :: proxy (Infix s a f) -> ConstructorInfo (y ': (z ': [])) Source # |
class DemoteConstructorInfos (cs :: [ConstructorInfo]) (xss :: [[*]]) where Source #
Class for computing term-level constructor information from type-level constructor information.
Since: 0.3.0.0
Minimal complete definition
Methods
demoteConstructorInfos :: proxy cs -> NP ConstructorInfo xss Source #
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]) ([] :: [[*]]) Source # | |
Defined in Generics.SOP.Type.Metadata Methods demoteConstructorInfos :: proxy [] -> NP ConstructorInfo0 [] Source # | |
(DemoteConstructorInfo c xs, DemoteConstructorInfos cs xss) => DemoteConstructorInfos (c ': cs) (xs ': xss) Source # | |
Defined in Generics.SOP.Type.Metadata Methods demoteConstructorInfos :: proxy (c ': cs) -> NP ConstructorInfo (xs ': xss) Source # |
class DemoteDatatypeInfo (x :: DatatypeInfo) (xss :: [[*]]) where Source #
Class for computing term-level datatype information from type-level datatype information.
Since: 0.3.0.0
Minimal complete definition
Methods
demoteDatatypeInfo :: proxy x -> DatatypeInfo xss Source #
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 Source # | |
Defined in Generics.SOP.Type.Metadata Methods demoteDatatypeInfo :: proxy (ADT m d cs) -> DatatypeInfo xss Source # | |
(KnownSymbol m, KnownSymbol d, DemoteConstructorInfo c (x ': ([] :: [*]))) => DemoteDatatypeInfo (Newtype m d c) ((x ': ([] :: [*])) ': ([] :: [[*]])) Source # | |
Defined in Generics.SOP.Type.Metadata Methods demoteDatatypeInfo :: proxy (Newtype m d c) -> DatatypeInfo ((x ': []) ': []) Source # |
type ConstructorName = Symbol Source #
The name of a data constructor.
type ModuleName = Symbol Source #
The name of a module.
type DatatypeName = Symbol Source #
The name of a datatype.
Metadata for a single record field (to be used promoted).
Since: 0.3.0.0
Instances
DemoteFieldInfos ([] :: [FieldInfo]) ([] :: [*]) Source # | |
Defined in Generics.SOP.Type.Metadata Methods demoteFieldInfos :: proxy [] -> NP FieldInfo0 [] Source # | |
(DemoteFieldInfo f x, DemoteFieldInfos fs xs) => DemoteFieldInfos (f ': fs) (x ': xs) Source # | |
Defined in Generics.SOP.Type.Metadata Methods demoteFieldInfos :: proxy (f ': fs) -> NP FieldInfo (x ': xs) Source # |
data ConstructorInfo Source #
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]) ([] :: [[*]]) Source # | |
Defined in Generics.SOP.Type.Metadata Methods demoteConstructorInfos :: proxy [] -> NP ConstructorInfo0 [] Source # | |
(DemoteConstructorInfo c xs, DemoteConstructorInfos cs xss) => DemoteConstructorInfos (c ': cs) (xs ': xss) Source # | |
Defined in Generics.SOP.Type.Metadata Methods demoteConstructorInfos :: proxy (c ': cs) -> NP ConstructorInfo (xs ': xss) Source # |
data DatatypeInfo Source #
Metadata for a datatype (to be used promoted).
A type of kind
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.DatatypeInfo
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 |