Safe Haskell	None
Language	Haskell2010

Data.Vinyl.ARec

Description

Constant-time field accessors for extensible records. The trade-off is the usual lists vs arrays one: it is fast to add an element to the head of a list, but element access is linear time; array access time is uniform, but extending the array is more slower.

Synopsis

newtype ARec (f :: k -> *) (ts :: [k]) = ARec (Array Int Any)
toARec :: forall f ts. NatToInt (RLength ts) => Rec f ts -> ARec f ts
class NatToInt (RIndex t ts) => IndexableField ts t
fromARec :: forall f ts. (RecApplicative ts, RPureConstrained (IndexableField ts) ts) => ARec f ts -> Rec f ts
aget :: forall t f ts. NatToInt (RIndex t ts) => ARec f ts -> f t
aput :: forall t t' f ts ts'. NatToInt (RIndex t ts) => f t' -> ARec f ts -> ARec f ts'
alens :: forall f g t t' ts ts'. (Functor g, NatToInt (RIndex t ts)) => (f t -> g (f t')) -> ARec f ts -> g (ARec f ts')
arecGetSubset :: forall rs ss f. (IndexWitnesses (RImage rs ss), NatToInt (RLength rs)) => ARec f ss -> ARec f rs
arecSetSubset :: forall rs ss f. IndexWitnesses (RImage rs ss) => ARec f ss -> ARec f rs -> ARec f ss

Documentation

newtype ARec (f :: k -> *) (ts :: [k]) Source #

An array-backed extensible record with constant-time field access.

Constructors

ARec (Array Int Any)

Instances

(is ~ RImage rs ss, IndexWitnesses is, NatToInt (RLength rs)) => RecSubset (ARec :: (k -> Type) -> [k] -> Type) (rs :: [k]) (ss :: [k]) is Source #
Instance details Defined in Data.Vinyl.ARec Associated Types type RecSubsetFCtx ARec f :: Constraint Source # Methods rsubsetC :: (Functor g, RecSubsetFCtx ARec f) => (ARec f rs -> g (ARec f rs)) -> ARec f ss -> g (ARec f ss) Source # rcastC :: RecSubsetFCtx ARec f => ARec f ss -> ARec f rs Source # rreplaceC :: RecSubsetFCtx ARec f => ARec f rs -> ARec f ss -> ARec f ss Source #
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 Associated Types type RecElemFCtx ARec f :: Constraint Source # Methods rlensC :: (Functor g, RecElemFCtx ARec f) => (f t -> g (f t')) -> ARec f (t ': ts) -> g (ARec f (t' ': ts)) Source # rgetC :: (RecElemFCtx ARec f, t ~ t') => ARec f (t ': ts) -> f t Source # rputC :: RecElemFCtx ARec f => f t' -> ARec f (t ': ts) -> ARec f (t' ': ts) 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 Associated Types type RecElemFCtx ARec f :: Constraint Source # Methods rlensC :: (Functor g, RecElemFCtx ARec f) => (f t -> g (f t')) -> ARec f (s ': ts) -> g (ARec f (s ': ts')) Source # rgetC :: (RecElemFCtx ARec f, t ~ t') => ARec f (s ': ts) -> f t Source # rputC :: RecElemFCtx ARec f => f t' -> ARec f (s ': ts) -> ARec f (s ': ts') Source #
(RPureConstrained (IndexableField rs) rs, RecApplicative rs, Eq (Rec f rs)) => Eq (ARec f rs) Source #
Instance details Defined in Data.Vinyl.ARec Methods (==) :: ARec f rs -> ARec f rs -> Bool # (/=) :: ARec f rs -> ARec f rs -> Bool #
(RPureConstrained (IndexableField rs) rs, RecApplicative rs, Ord (Rec f rs)) => Ord (ARec f rs) Source #
Instance details Defined in Data.Vinyl.ARec Methods compare :: ARec f rs -> ARec f rs -> Ordering # (<) :: ARec f rs -> ARec f rs -> Bool # (<=) :: ARec f rs -> ARec f rs -> Bool # (>) :: ARec f rs -> ARec f rs -> Bool # (>=) :: ARec f rs -> ARec f rs -> Bool # max :: ARec f rs -> ARec f rs -> ARec f rs # min :: ARec f rs -> ARec f rs -> ARec f rs #
(RPureConstrained (IndexableField rs) rs, RecApplicative rs, Show (Rec f rs)) => Show (ARec f rs) Source #
Instance details Defined in Data.Vinyl.ARec Methods showsPrec :: Int -> ARec f rs -> ShowS # show :: ARec f rs -> String # showList :: [ARec f rs] -> ShowS #
type RecSubsetFCtx (ARec :: (k -> Type) -> [k] -> Type) (f :: k -> Type) Source #
Instance details Defined in Data.Vinyl.ARec type RecSubsetFCtx (ARec :: (k -> Type) -> [k] -> Type) (f :: k -> Type) = ()
type RecElemFCtx (ARec :: (a -> Type) -> [a] -> Type) (f :: a -> Type) Source #
Instance details Defined in Data.Vinyl.ARec type RecElemFCtx (ARec :: (a -> Type) -> [a] -> Type) (f :: a -> Type) = ()
type RecElemFCtx (ARec :: (a -> Type) -> [a] -> Type) (f :: a -> Type) Source #
Instance details Defined in Data.Vinyl.ARec type RecElemFCtx (ARec :: (a -> Type) -> [a] -> Type) (f :: a -> Type) = ()

toARec :: forall f ts. NatToInt (RLength ts) => Rec f ts -> ARec f ts Source #

Convert a Rec into an ARec for constant-time field access.

class NatToInt (RIndex t ts) => IndexableField ts t Source #

Defines a constraint that lets us index into an ARec in order to produce a Rec using fromARec.

Instances

NatToInt (RIndex t ts) => IndexableField (ts :: [k]) (t :: k) Source #
Instance details Defined in Data.Vinyl.ARec

fromARec :: forall f ts. (RecApplicative ts, RPureConstrained (IndexableField ts) ts) => ARec f ts -> Rec f ts Source #

Convert an ARec into a Rec.

aget :: forall t f ts. NatToInt (RIndex t ts) => ARec f ts -> f t Source #

Get a field from an ARec.

aput :: forall t t' f ts ts'. NatToInt (RIndex t ts) => f t' -> ARec f ts -> ARec f ts' Source #

Set a field in an ARec.

alens :: forall f g t t' ts ts'. (Functor g, NatToInt (RIndex t ts)) => (f t -> g (f t')) -> ARec f ts -> g (ARec f ts') Source #

Define a lens for a field of an ARec.

arecGetSubset :: forall rs ss f. (IndexWitnesses (RImage rs ss), NatToInt (RLength rs)) => ARec f ss -> ARec f rs Source #

Get a subset of a record's fields.

arecSetSubset :: forall rs ss f. IndexWitnesses (RImage rs ss) => ARec f ss -> ARec f rs -> ARec f ss Source #

Set a subset of a larger record's fields to all of the fields of a smaller record.