Safe Haskell	None
Language	Haskell2010

Data.Vinyl.Lens

Description

Lenses into record fields.

Synopsis

class (i ~ RIndex r rs, NatToInt i) => RecElem (record :: (k -> Type) -> [k] -> Type) (r :: k) (r' :: k) (rs :: [k]) (rs' :: [k]) (i :: Nat) | r r' rs i -> rs' where
- type RecElemFCtx (record :: (k -> Type) -> [k] -> Type) (f :: k -> Type)
- rlensC :: (Functor g, RecElemFCtx record f) => (f r -> g (f r')) -> record f rs -> g (record f rs')
- rgetC :: (RecElemFCtx record f, r ~ r') => record f rs -> f r
- rputC :: RecElemFCtx record f => f r' -> record f rs -> record f rs'
rget :: forall {k} (r :: k) (rs :: [k]) f record. (RecElem record r r rs rs (RIndex r rs), RecElemFCtx record f) => record f rs -> f r
rput :: forall k (r :: k) (rs :: [k]) record f. (RecElem record r r rs rs (RIndex r rs), RecElemFCtx record f) => f r -> record f rs -> record f rs
rput' :: forall k (r :: k) (r' :: k) (rs :: [k]) (rs' :: [k]) record f. (RecElem record r r' rs rs' (RIndex r rs), RecElemFCtx record f) => f r' -> record f rs -> record f rs'
rlens :: forall {k} (r :: k) record (rs :: [k]) f g. (RecElem record r r rs rs (RIndex r rs), RecElemFCtx record f, Functor g) => (f r -> g (f r)) -> record f rs -> g (record f rs)
rlens' :: forall {k} (r :: k) (r' :: k) record (rs :: [k]) (rs' :: [k]) f g. (RecElem record r r' rs rs' (RIndex r rs), RecElemFCtx record f, Functor g) => (f r -> g (f r')) -> record f rs -> g (record f rs')
type RElem (x :: k) (rs :: [k]) = RecElem (Rec :: (k -> Type) -> [k] -> Type) x x rs rs
class is ~ RImage rs ss => RecSubset (record :: (k -> Type) -> [k1] -> Type) (rs :: [k1]) (ss :: [k1]) (is :: [Nat]) where
- type RecSubsetFCtx (record :: (k -> Type) -> [k1] -> Type) (f :: k -> Type)
- rsubsetC :: forall g (f :: k -> Type). (Functor g, RecSubsetFCtx record f) => (record f rs -> g (record f rs)) -> record f ss -> g (record f ss)
- rcastC :: forall (f :: k -> Type). RecSubsetFCtx record f => record f ss -> record f rs
- rreplaceC :: forall (f :: k -> Type). RecSubsetFCtx record f => record f rs -> record f ss -> record f ss
rsubset :: forall {k1} k2 (rs :: [k2]) (ss :: [k2]) (f :: k1 -> Type) g record (is :: [Nat]). (RecSubset record rs ss is, Functor g, RecSubsetFCtx record f) => (record f rs -> g (record f rs)) -> record f ss -> g (record f ss)
rcast :: forall {k1} {k2} (rs :: [k1]) (ss :: [k1]) (f :: k2 -> Type) record (is :: [Nat]). (RecSubset record rs ss is, RecSubsetFCtx record f) => record f ss -> record f rs
rreplace :: forall {k1} {k2} (rs :: [k1]) (ss :: [k1]) (f :: k2 -> Type) record (is :: [Nat]). (RecSubset record rs ss is, RecSubsetFCtx record f) => record f rs -> record f ss -> record f ss
rdowncast :: forall {u} (ss :: [u]) (rs :: [u]) (f :: u -> Type). (RecApplicative ss, RMap rs, rs ⊆ ss) => Rec f rs -> Rec (Maybe :. f) ss
type RSubset = RecSubset (Rec :: (k -> Type) -> [k] -> Type)
type REquivalent (rs :: [k]) (ss :: [k]) (is :: [Nat]) (js :: [Nat]) = (RSubset rs ss is, RSubset ss rs js)
type (∈) (r :: k) (rs :: [k]) = RElem r rs (RIndex r rs)
type (⊆) (rs :: [k]) (ss :: [k]) = RSubset rs ss (RImage rs ss)
type (≅) (rs :: [k]) (ss :: [k]) = REquivalent rs ss (RImage rs ss) (RImage ss rs)
type (<:) (rs :: [k]) (ss :: [k]) = rs ⊆ ss
type (:~:) (rs :: [k]) (ss :: [k]) = rs ≅ ss

Documentation

class (i ~ RIndex r rs, NatToInt i) => RecElem (record :: (k -> Type) -> [k] -> Type) (r :: k) (r' :: k) (rs :: [k]) (rs' :: [k]) (i :: Nat) | r r' rs i -> rs' where Source #

The presence of a field in a record is witnessed by a lens into its value. The fifth parameter to RecElem, i, is there to help the constraint solver realize that this is a decidable predicate with respect to the judgemental equality in k.

Associated Types

type RecElemFCtx (record :: (k -> Type) -> [k] -> Type) (f :: k -> Type) Source #

An opportunity for instances to generate constraints based on the functor parameter of records passed to class methods.

type RecElemFCtx (record :: (k -> Type) -> [k] -> Type) (f :: k -> Type) = ()

Methods

rlensC :: (Functor g, RecElemFCtx record f) => (f r -> g (f r')) -> record f rs -> g (record f rs') Source #

We can get a lens for getting and setting the value of a field which is in a record. As a convenience, we take a proxy argument to fix the particular field being viewed. These lenses are compatible with the lens library. Morally:

rlensC :: Lens' (Rec f rs) (Rec f rs') (f r) (f r')

rgetC :: (RecElemFCtx record f, r ~ r') => record f rs -> f r Source #

For Vinyl users who are not using the lens package, we provide a getter.

rputC :: RecElemFCtx record f => f r' -> record f rs -> record f rs' Source #

For Vinyl users who are not using the lens package, we also provide a setter. In general, it will be unambiguous what field is being written to, and so we do not take a proxy argument here.

Instances

Instances details

RecElem (ARec :: (a -> Type) -> [a] -> Type) (t :: a) (t' :: a) (t ': ts :: [a]) (t' ': ts :: [a]) 'Z Source #

Instance details

Defined in Data.Vinyl.ARec.Internal

Methods

rlensC :: (Functor g, RecElemFCtx (ARec :: (a -> Type) -> [a] -> Type) f) => (f t -> g (f t')) -> ARec f (t ': ts) -> g (ARec f (t' ': ts)) Source #

rgetC :: (RecElemFCtx (ARec :: (a -> Type) -> [a] -> Type) f, t ~ t') => ARec f (t ': ts) -> f t Source #

rputC :: RecElemFCtx (ARec :: (a -> Type) -> [a] -> Type) f => f t' -> ARec f (t ': ts) -> ARec f (t' ': ts) Source #

RecElem (Rec :: (a -> Type) -> [a] -> Type) (r :: a) (r' :: a) (r ': rs :: [a]) (r' ': rs :: [a]) 'Z Source #

Instance details

Defined in Data.Vinyl.Lens

Methods

rlensC :: (Functor g, RecElemFCtx (Rec :: (a -> Type) -> [a] -> Type) f) => (f r -> g (f r')) -> Rec f (r ': rs) -> g (Rec f (r' ': rs)) Source #

rgetC :: (RecElemFCtx (Rec :: (a -> Type) -> [a] -> Type) f, r ~ r') => Rec f (r ': rs) -> f r Source #

rputC :: RecElemFCtx (Rec :: (a -> Type) -> [a] -> Type) f => f r' -> Rec f (r ': rs) -> Rec f (r' ': rs) Source #

(RIndex t (s ': ts) ~ 'S i, NatToInt i, RecElem (ARec :: (a -> Type) -> [a] -> Type) t t' ts ts' i) => RecElem (ARec :: (a -> Type) -> [a] -> Type) (t :: a) (t' :: a) (s ': ts :: [a]) (s ': ts' :: [a]) ('S i) Source #

Instance details

Defined in Data.Vinyl.ARec.Internal

Methods

rlensC :: (Functor g, RecElemFCtx (ARec :: (a -> Type) -> [a] -> Type) f) => (f t -> g (f t')) -> ARec f (s ': ts) -> g (ARec f (s ': ts')) Source #

rgetC :: (RecElemFCtx (ARec :: (a -> Type) -> [a] -> Type) f, t ~ t') => ARec f (s ': ts) -> f t Source #

rputC :: RecElemFCtx (ARec :: (a -> Type) -> [a] -> Type) f => f t' -> ARec f (s ': ts) -> ARec f (s ': ts') Source #

(RIndex r (s ': rs) ~ 'S i, RecElem (Rec :: (a -> Type) -> [a] -> Type) r r' rs rs' i) => RecElem (Rec :: (a -> Type) -> [a] -> Type) (r :: a) (r' :: a) (s ': rs :: [a]) (s ': rs' :: [a]) ('S i) Source #

Instance details

Defined in Data.Vinyl.Lens

Methods

rlensC :: (Functor g, RecElemFCtx (Rec :: (a -> Type) -> [a] -> Type) f) => (f r -> g (f r')) -> Rec f (s ': rs) -> g (Rec f (s ': rs')) Source #

rgetC :: (RecElemFCtx (Rec :: (a -> Type) -> [a] -> Type) f, r ~ r') => Rec f (s ': rs) -> f r Source #

rputC :: RecElemFCtx (Rec :: (a -> Type) -> [a] -> Type) f => f r' -> Rec f (s ': rs) -> Rec f (s ': rs') Source #

(i ~ RIndex t ts, NatToInt i, FieldOffset ElField ts t, Storable (Rec ElField ts), AllConstrained (FieldOffset ElField ts) ts) => RecElem (SRec :: ((Symbol, Type) -> Type) -> [(Symbol, Type)] -> Type) (t :: (Symbol, Type)) (t :: (Symbol, Type)) (ts :: [(Symbol, Type)]) (ts :: [(Symbol, Type)]) i Source #

Instance details

Defined in Data.Vinyl.SRec

Associated Types

type RecElemFCtx (SRec :: ((Symbol, Type) -> Type) -> [(Symbol, Type)] -> Type) (f :: (Symbol, Type) -> Type)
Instance details Defined in Data.Vinyl.SRec type RecElemFCtx (SRec :: ((Symbol, Type) -> Type) -> [(Symbol, Type)] -> Type) (f :: (Symbol, Type) -> Type) = f ~ ElField

Methods

rlensC :: (Functor g, RecElemFCtx (SRec :: ((Symbol, Type) -> Type) -> [(Symbol, Type)] -> Type) f) => (f t -> g (f t)) -> SRec f ts -> g (SRec f ts) Source #

rgetC :: (RecElemFCtx (SRec :: ((Symbol, Type) -> Type) -> [(Symbol, Type)] -> Type) f, t ~ t) => SRec f ts -> f t Source #

rputC :: RecElemFCtx (SRec :: ((Symbol, Type) -> Type) -> [(Symbol, Type)] -> Type) f => f t -> SRec f ts -> SRec f ts Source #

(i ~ RIndex t ts, NatToInt i, FieldOffset ElField ts t, Storable (Rec ElField ts), AllConstrained (FieldOffset ElField ts) ts) => RecElem (SRec2 ElField) (t :: (Symbol, Type)) (t :: (Symbol, Type)) (ts :: [(Symbol, Type)]) (ts :: [(Symbol, Type)]) i Source #

Field accessors for SRec2 specialized to ElField as the functor.

Instance details

Defined in Data.Vinyl.SRec

Associated Types

type RecElemFCtx (SRec2 ElField) (f :: (Symbol, Type) -> Type)
Instance details Defined in Data.Vinyl.SRec type RecElemFCtx (SRec2 ElField) (f :: (Symbol, Type) -> Type) = f ~ ElField

Methods

rlensC :: (Functor g, RecElemFCtx (SRec2 ElField) f) => (f t -> g (f t)) -> SRec2 ElField f ts -> g (SRec2 ElField f ts) Source #

rgetC :: (RecElemFCtx (SRec2 ElField) f, t ~ t) => SRec2 ElField f ts -> f t Source #

rputC :: RecElemFCtx (SRec2 ElField) f => f t -> SRec2 ElField f ts -> SRec2 ElField f ts Source #

rget :: forall {k} (r :: k) (rs :: [k]) f record. (RecElem record r r rs rs (RIndex r rs), RecElemFCtx record f) => record f rs -> f r Source #

rput :: forall k (r :: k) (rs :: [k]) record f. (RecElem record r r rs rs (RIndex r rs), RecElemFCtx record f) => f r -> record f rs -> record f rs Source #

Type-preserving field setter. This type is simpler to work with than that of rput'.

rput' :: forall k (r :: k) (r' :: k) (rs :: [k]) (rs' :: [k]) record f. (RecElem record r r' rs rs' (RIndex r rs), RecElemFCtx record f) => f r' -> record f rs -> record f rs' Source #

The type-changing field setter rputC with the type arguments re-ordered for more convenient usage with TypeApplications.

rlens :: forall {k} (r :: k) record (rs :: [k]) f g. (RecElem record r r rs rs (RIndex r rs), RecElemFCtx record f, Functor g) => (f r -> g (f r)) -> record f rs -> g (record f rs) Source #

Type-preserving field lens. This type is simpler to work with than that of rlens'.

rlens' :: forall {k} (r :: k) (r' :: k) record (rs :: [k]) (rs' :: [k]) f g. (RecElem record r r' rs rs' (RIndex r rs), RecElemFCtx record f, Functor g) => (f r -> g (f r')) -> record f rs -> g (record f rs') Source #

Type-changing field lens rlensC with the type arguments re-ordered for more convenient usage with TypeApplications.

type RElem (x :: k) (rs :: [k]) = RecElem (Rec :: (k -> Type) -> [k] -> Type) x x rs rs Source #

RecElem for classic vinyl Rec types.

class is ~ RImage rs ss => RecSubset (record :: (k -> Type) -> [k1] -> Type) (rs :: [k1]) (ss :: [k1]) (is :: [Nat]) where Source #

If one field set is a subset another, then a lens of from the latter's record to the former's is evident. That is, we can either cast a larger record to a smaller one, or we may replace the values in a slice of a record.

Minimal complete definition

rsubsetC

Associated Types

type RecSubsetFCtx (record :: (k -> Type) -> [k1] -> Type) (f :: k -> Type) Source #

An opportunity for instances to generate constraints based on the functor parameter of records passed to class methods.

type RecSubsetFCtx (record :: (k -> Type) -> [k1] -> Type) (f :: k -> Type) = ()

Methods

rsubsetC :: forall g (f :: k -> Type). (Functor g, RecSubsetFCtx record f) => (record f rs -> g (record f rs)) -> record f ss -> g (record f ss) Source #

This is a lens into a slice of the larger record. Morally, we have:

rsubset :: Lens' (Rec f ss) (Rec f rs)

rcastC :: forall (f :: k -> Type). RecSubsetFCtx record f => record f ss -> record f rs Source #

The getter of the rsubset lens is rcast, which takes a larger record to a smaller one by forgetting fields.

rreplaceC :: forall (f :: k -> Type). RecSubsetFCtx record f => record f rs -> record f ss -> record f ss Source #

The setter of the rsubset lens is rreplace, which allows a slice of a record to be replaced with different values.

Instances

Instances details

(is ~ RImage rs ss, IndexWitnesses is, NatToInt (RLength rs)) => RecSubset (ARec :: (k1 -> Type) -> [k1] -> Type) (rs :: [k1]) (ss :: [k1]) is Source #

Instance details

Defined in Data.Vinyl.ARec.Internal

Methods

rsubsetC :: forall g (f :: k1 -> Type). (Functor g, RecSubsetFCtx (ARec :: (k1 -> Type) -> [k1] -> Type) f) => (ARec f rs -> g (ARec f rs)) -> ARec f ss -> g (ARec f ss) Source #

rcastC :: forall (f :: k1 -> Type). RecSubsetFCtx (ARec :: (k1 -> Type) -> [k1] -> Type) f => ARec f ss -> ARec f rs Source #

rreplaceC :: forall (f :: k1 -> Type). RecSubsetFCtx (ARec :: (k1 -> Type) -> [k1] -> Type) f => ARec f rs -> ARec f ss -> ARec f ss Source #

RecSubset (Rec :: (k -> Type) -> [k] -> Type) ('[] :: [k]) (ss :: [k]) ('[] :: [Nat]) Source #

Instance details

Defined in Data.Vinyl.Lens

Methods

rsubsetC :: forall g (f :: k -> Type). (Functor g, RecSubsetFCtx (Rec :: (k -> Type) -> [k] -> Type) f) => (Rec f ('[] :: [k]) -> g (Rec f ('[] :: [k]))) -> Rec f ss -> g (Rec f ss) Source #

rcastC :: forall (f :: k -> Type). RecSubsetFCtx (Rec :: (k -> Type) -> [k] -> Type) f => Rec f ss -> Rec f ('[] :: [k]) Source #

rreplaceC :: forall (f :: k -> Type). RecSubsetFCtx (Rec :: (k -> Type) -> [k] -> Type) f => Rec f ('[] :: [k]) -> Rec f ss -> Rec f ss Source #

(RElem r ss i, RSubset rs ss is) => RecSubset (Rec :: (k -> Type) -> [k] -> Type) (r ': rs :: [k]) (ss :: [k]) (i ': is) Source #

Instance details

Defined in Data.Vinyl.Lens

Methods

rsubsetC :: forall g (f :: k -> Type). (Functor g, RecSubsetFCtx (Rec :: (k -> Type) -> [k] -> Type) f) => (Rec f (r ': rs) -> g (Rec f (r ': rs))) -> Rec f ss -> g (Rec f ss) Source #

rcastC :: forall (f :: k -> Type). RecSubsetFCtx (Rec :: (k -> Type) -> [k] -> Type) f => Rec f ss -> Rec f (r ': rs) Source #

rreplaceC :: forall (f :: k -> Type). RecSubsetFCtx (Rec :: (k -> Type) -> [k] -> Type) f => Rec f (r ': rs) -> Rec f ss -> Rec f ss Source #

(is ~ RImage rs ss, RecSubset (Rec :: ((Symbol, Type) -> Type) -> [(Symbol, Type)] -> Type) rs ss is, Storable (Rec ElField rs), Storable (Rec ElField ss), RPureConstrained (FieldOffset ElField ss) rs, RPureConstrained (FieldOffset ElField rs) rs, RFoldMap rs, RMap rs, RApply rs) => RecSubset (SRec :: ((Symbol, Type) -> Type) -> [(Symbol, Type)] -> Type) (rs :: [(Symbol, Type)]) (ss :: [(Symbol, Type)]) is Source #

Instance details

Defined in Data.Vinyl.SRec

Associated Types

type RecSubsetFCtx (SRec :: ((Symbol, Type) -> Type) -> [(Symbol, Type)] -> Type) (f :: (Symbol, Type) -> Type)
Instance details Defined in Data.Vinyl.SRec type RecSubsetFCtx (SRec :: ((Symbol, Type) -> Type) -> [(Symbol, Type)] -> Type) (f :: (Symbol, Type) -> Type) = f ~ ElField

Methods

rsubsetC :: forall g (f :: (Symbol, Type) -> Type). (Functor g, RecSubsetFCtx (SRec :: ((Symbol, Type) -> Type) -> [(Symbol, Type)] -> Type) f) => (SRec f rs -> g (SRec f rs)) -> SRec f ss -> g (SRec f ss) Source #

rcastC :: forall (f :: (Symbol, Type) -> Type). RecSubsetFCtx (SRec :: ((Symbol, Type) -> Type) -> [(Symbol, Type)] -> Type) f => SRec f ss -> SRec f rs Source #

rreplaceC :: forall (f :: (Symbol, Type) -> Type). RecSubsetFCtx (SRec :: ((Symbol, Type) -> Type) -> [(Symbol, Type)] -> Type) f => SRec f rs -> SRec f ss -> SRec f ss Source #

(is ~ RImage rs ss, RecSubset (Rec :: ((Symbol, Type) -> Type) -> [(Symbol, Type)] -> Type) rs ss is, Storable (Rec ElField rs), Storable (Rec ElField ss), RPureConstrained (FieldOffset ElField ss) rs, RPureConstrained (FieldOffset ElField rs) rs, RFoldMap rs, RMap rs, RApply rs) => RecSubset (SRec2 ElField) (rs :: [(Symbol, Type)]) (ss :: [(Symbol, Type)]) is Source #

Instance details

Defined in Data.Vinyl.SRec

Associated Types

type RecSubsetFCtx (SRec2 ElField) (f :: (Symbol, Type) -> Type)
Instance details Defined in Data.Vinyl.SRec type RecSubsetFCtx (SRec2 ElField) (f :: (Symbol, Type) -> Type) = f ~ ElField

Methods

rsubsetC :: forall g (f :: (Symbol, Type) -> Type). (Functor g, RecSubsetFCtx (SRec2 ElField) f) => (SRec2 ElField f rs -> g (SRec2 ElField f rs)) -> SRec2 ElField f ss -> g (SRec2 ElField f ss) Source #

rcastC :: forall (f :: (Symbol, Type) -> Type). RecSubsetFCtx (SRec2 ElField) f => SRec2 ElField f ss -> SRec2 ElField f rs Source #

rreplaceC :: forall (f :: (Symbol, Type) -> Type). RecSubsetFCtx (SRec2 ElField) f => SRec2 ElField f rs -> SRec2 ElField f ss -> SRec2 ElField f ss Source #

rsubset :: forall {k1} k2 (rs :: [k2]) (ss :: [k2]) (f :: k1 -> Type) g record (is :: [Nat]). (RecSubset record rs ss is, Functor g, RecSubsetFCtx record f) => (record f rs -> g (record f rs)) -> record f ss -> g (record f ss) Source #

A lens into a slice of the larger record. This is rsubsetC with the type arguments reordered for more convenient usage with TypeApplications.

rcast :: forall {k1} {k2} (rs :: [k1]) (ss :: [k1]) (f :: k2 -> Type) record (is :: [Nat]). (RecSubset record rs ss is, RecSubsetFCtx record f) => record f ss -> record f rs Source #

Takes a larger record to a smaller one by forgetting fields. This is rcastC with the type arguments reordered for more convenient usage with TypeApplications.

rreplace :: forall {k1} {k2} (rs :: [k1]) (ss :: [k1]) (f :: k2 -> Type) record (is :: [Nat]). (RecSubset record rs ss is, RecSubsetFCtx record f) => record f rs -> record f ss -> record f ss Source #

Allows a slice of a record to be replaced with different values. This is rreplaceC with the type arguments reordered for more convenient usage with TypeApplications.

rdowncast :: forall {u} (ss :: [u]) (rs :: [u]) (f :: u -> Type). (RecApplicative ss, RMap rs, rs ⊆ ss) => Rec f rs -> Rec (Maybe :. f) ss Source #

Takes a smaller record to a larger one, a downcast, by layering a Maybe interpretation that lets us use Nothing for the fields not present in the smaller record.

type RSubset = RecSubset (Rec :: (k -> Type) -> [k] -> Type) Source #

type REquivalent (rs :: [k]) (ss :: [k]) (is :: [Nat]) (js :: [Nat]) = (RSubset rs ss is, RSubset ss rs js) Source #

Two record types are equivalent when they are subtypes of each other.

type (∈) (r :: k) (rs :: [k]) = RElem r rs (RIndex r rs) Source #

A shorthand for RElem which supplies its index.

type (⊆) (rs :: [k]) (ss :: [k]) = RSubset rs ss (RImage rs ss) Source #

A shorthand for RSubset which supplies its image.

type (≅) (rs :: [k]) (ss :: [k]) = REquivalent rs ss (RImage rs ss) (RImage ss rs) Source #

A shorthand for REquivalent which supplies its images.

type (<:) (rs :: [k]) (ss :: [k]) = rs ⊆ ss Source #

A non-unicode equivalent of (⊆).

type (:~:) (rs :: [k]) (ss :: [k]) = rs ≅ ss Source #

A non-unicode equivalent of (≅).