Data.HList.HTypeIndexed

The HList library

(C) 2004, Oleg Kiselyov, Ralf Laemmel, Keean Schupke

Type-indexed operations on typeful heterogeneous lists.

Documentation

class HDeleteMany e l l' | e l -> l' where

Methods

hDeleteMany :: Proxy e -> l -> l'

Instances

HDeleteMany e HNil HNil

(HList l, TypeEq e e' b, HDeleteManyCase b e e' l l') => HDeleteMany e (HCons e' l) l'

class HDeleteManyCase b e e' l l' | b e e' l -> l' where

Methods

hDeleteManyCase :: b -> Proxy e -> e' -> l -> l'

Instances

HDeleteMany e l l' => HDeleteManyCase HTrue e e l l'

HDeleteMany e l l' => HDeleteManyCase HFalse e e' l (HCons e' l')

class HNat n => HType2HNat e l n | e l -> n

Map a type to a natural

Instances

(TypeEq e' e b, HType2HNatCase b e l n) => HType2HNat e (HCons e' l) n

class (HBool b, HNat n) => HType2HNatCase b e l n | b e l -> n

Helper class

Instances

HOccursNot e l => HType2HNatCase HTrue e l HZero

HType2HNat e l n => HType2HNatCase HFalse e l (HSucc n)

hType2HNat :: HType2HNat e l n => Proxy e -> l -> n

class HTypes2HNats ps l ns | ps l -> ns where

Map types to naturals

Methods

hTypes2HNats :: ps -> l -> ns

Instances

HTypes2HNats HNil l HNil

(HType2HNat e l n, HTypes2HNats ps l ns) => HTypes2HNats (HCons (Proxy e) ps) l (HCons n ns)

hDeleteAtProxy :: (HDeleteAtHNat n l l', HType2HNat e l n) => Proxy e -> l -> l'

Define type-indexed delete in terms of the natural-based primitive

hUpdateAtType :: (HUpdateAtHNat n e l l', HType2HNat e l n) => e -> l -> l'

Define type-indexed update in terms of the natural-based update

hProjectByProxies :: (HProjectByHNats ns l l', HTypes2HNats ps l ns) => ps -> l -> l'

Projection based on proxies

hSplitByProxies :: (HMap (HAddTag HTrue) l l', HSplitByHNats' ns l' l'1 l'', HTypes2HNats ps l ns) => ps -> l -> (l'1, l'')

Splitting based on proxies