Data.HList

Documentation

data HList as where

Constructors

HNil :: HList []

HCons :: a -> HList as -> HList (a : as) infixr 6

class HNth as n where

Methods

hnth :: HList as -> Proxy n -> as :!: n

Instances

HNth ((:) * a as) NZ

HNth as n => HNth ((:) * b as) (NS n)

type family Map f as

Equations

Map f [] = []

Map f (a : as) = f a : Map f as

class HMap as f g where

Methods

hmap :: Proxy as -> (forall i. f i -> g i) -> HList (Map f as) -> HList (Map g as)

Instances

HMap k ([] k) f g

HMap k as f g => HMap k ((:) k a as) f g

class HLookup n as where

Methods

hlookup :: Proxy n -> Proxy as -> HList as -> as :!: n

Instances

HLookup NZ ((:) * a as)

HLookup n as => HLookup (NS n) ((:) * a as)