Data.Vinyl.ARec

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.

Documentation

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

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

Constructors

ARec (Array Int Any)

Instances

((~) Nat i (RIndex k t ts), NatToInt (RIndex k t ts)) => RecElem k (ARec k) t ts i

Methods

rlens :: Functor g => sing ts -> (f ts -> g (f ts)) -> t f i -> g (t f i)

rget :: sing ts -> t f i -> f ts

rput :: f ts -> t f i -> t f i

((~) [Nat] is (RImage k rs ss), IndexWitnesses is, NatToInt (RLength k rs)) => RecSubset (k -> *) k (ARec k) rs ss is

Methods

rsubset :: Functor g => (ss f is -> g (ss f is)) -> ss f ss -> g (ss f ss)

rcast :: ss f ss -> ss f is

rreplace :: ss f is -> ss f ss -> ss f ss

(AllConstrained k (IndexableField k rs) rs, RecApplicative k rs, Eq (Rec k f rs)) => Eq (ARec k f rs)

Methods

(==) :: ARec k f rs -> ARec k f rs -> Bool

(/=) :: ARec k f rs -> ARec k f rs -> Bool

(AllConstrained k (IndexableField k rs) rs, RecApplicative k rs, Ord (Rec k f rs)) => Ord (ARec k f rs)

Methods

compare :: ARec k f rs -> ARec k f rs -> Ordering

(<) :: ARec k f rs -> ARec k f rs -> Bool

(<=) :: ARec k f rs -> ARec k f rs -> Bool

(>) :: ARec k f rs -> ARec k f rs -> Bool

(>=) :: ARec k f rs -> ARec k f rs -> Bool

max :: ARec k f rs -> ARec k f rs -> ARec k f rs

min :: ARec k f rs -> ARec k f rs -> ARec k f rs

(AllConstrained k (IndexableField k rs) rs, RecApplicative k rs, Show (Rec k f rs)) => Show (ARec k f rs)

Methods

showsPrec :: Int -> ARec k f rs -> ShowS

show :: ARec k f rs -> String

showList :: [ARec k f rs] -> ShowS

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

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

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

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

Instances

NatToInt (RIndex k t ts) => IndexableField k ts t

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

Convert an ARec into a Rec.

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

Get a field from an ARec.

aput :: forall t f ts. NatToInt (RIndex t ts) => f t -> ARec f ts -> ARec f ts

Set a field in an ARec.

alens :: (Functor g, NatToInt (RIndex t ts)) => (f t -> g (f t)) -> ARec f ts -> g (ARec f ts)

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

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

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