Data.HList.HListPrelude

Contents

• Heterogeneous type sequences
• The set of all types of heterogeneous lists
• Public constructors
• Basic list functions
• A class for extension
• Appending HLists
• Reversing HLists
  • Naive HReverse
• A nicer notation for lists
  • Building non-empty lists
• A heterogeneous apply operator
• A heterogeneous fold for all types
• Map
• Map a heterogeneous list to a homogeneous one
• A heterogenous version of mapM.
• A reconstruction of append
• A heterogeneous map for all types
• A function for showing
• Type-level equality for lists
• Staged equality for lists
• Ensure a list to contain HNats only
• Static set property based on HEq
• Find an element in a set based on HEq
• Membership test
  • Another type-level membership test
  • Membership test based on type equality
• Intersection based on HTMember
• Turn a heterogeneous list into a homogeneous one
• With HMaybe
  • Turn list in a list of justs
  • Extract justs from list of maybes
• Annotated lists
• Splitting by HTrue and HFalse

Description

Synopsis

• data HNil = HNil
• data HCons e l = HCons e l
• class HList l
• hNil :: HNil
• hCons :: HList l => e -> l -> HCons e l
• class HHead l h | l -> h where
  • hHead :: l -> h
• class HTail l l' | l -> l' where
  • hTail :: l -> l'
• class HExtend e l l' | e l -> l', l' -> e l where
  • hExtend :: e -> l -> l'
• append :: [a] -> [a] -> [a]
• class HAppend l l' l'' | l l' -> l'' where
  • hAppend :: l -> l' -> l''
• class HReverse l1 l2 | l1 -> l2, l2 -> l1 where
  • hReverse :: l1 -> l2
• class HReverse' l1 l2 l3 | l1 l2 -> l3 where
  • hReverse' :: l1 -> l2 -> l3
• class NaiveHReverse l l' | l -> l' where
  • naiveHReverse :: l -> l'
• hEnd :: HCons t t1 -> HCons t t1
• hBuild :: HBuild' HNil a r => a -> r
• class HBuild' l a r | r -> a l where
  • hBuild' :: l -> a -> r
• class Apply f a r | f a -> r where
  • apply :: f -> a -> r
• data Id = Id
• class HList l => HFoldr f v l r | f v l -> r where
  • hFoldr :: f -> v -> l -> r
• class HMap f l l' | f l -> l' where
  • hMap :: f -> l -> l'
• class HMapOut f r e where
  • hMapOut :: f -> r -> [e]
• hMapM :: (Monad m, HMapOut f l (m e)) => f -> l -> [m e]
• hMapM_ :: (Monad m, HMapOut f l (m ())) => f -> l -> m ()
• append' :: [a] -> [a] -> [a]
• hAppend' :: HFoldr ApplyHCons v l r => l -> v -> r
• data ApplyHCons = ApplyHCons
• data HMap' f = HMap' f
• hMap' :: HFoldr (HMap' f) HNil l r => f -> l -> r
• data HShow = HShow
• data HSeq x = HSeq x
• class HStagedEq' b e e' where
  • hStagedEq' :: b -> e -> e' -> Bool
• class HList l => HNats l
• class HSet l
• class HNat n => HFind e l n | e l -> n where
  • hFind :: e -> l -> n
• class HNat n => HFind' b e l n | b e l -> n where
  • hFind' :: b -> e -> l -> n
• class HBool b => HMember e l b | e l -> b
• hMember :: HMember e l b => e -> l -> b
• class HMemberM e l r | e l -> r
• class HMemberM' b e l r | b e l -> r
• class HBool b => HTMember e l b | e l -> b
• hTMember :: HTMember e l b => e -> l -> b
• class HTIntersect l1 l2 l3 | l1 l2 -> l3 where
  • hTIntersect :: l1 -> l2 -> l3
• class HBool b => HTIntersectBool b h t l1 l2 | b h t l1 -> l2 where
  • hTIntersectBool :: b -> h -> t -> l1 -> l2
• class HList2List l e where
  • hList2List :: l -> [e]
• class ToHJust l l' | l -> l' where
  • toHJust :: l -> l'
• class FromHJust l l' | l -> l' where
  • fromHJust :: l -> l'
• data HAddTag t = HAddTag t
• data HRmTag = HRmTag
• hAddTag :: HMap (HAddTag t) l l' => t -> l -> l'
• hRmTag :: HMap HRmTag l l' => l -> l'
• hFlag :: HMap (HAddTag HTrue) l l' => l -> l'
• class HSplit l l' l'' | l -> l' l'' where
  • hSplit :: l -> (l', l'')

Heterogeneous type sequences

The set of all types of heterogeneous lists

Public constructors

Basic list functions

A class for extension

Appending HLists

Reversing HLists

Naive HReverse

A nicer notation for lists

Building non-empty lists

 HList> let x = hBuild True in hEnd x
 HCons True HNil

 HList> let x = hBuild True 'a' in hEnd x
 HCons True (HCons 'a' HNil)

 HList> let x = hBuild True 'a' "ok" in hEnd x
 HCons True (HCons 'a' (HCons "ok" HNil))

 HList> hEnd (hBuild (Key 42) (Name "Angus") Cow (Price 75.5))
 HCons (Key 42) (HCons (Name "Angus") (HCons Cow (HCons (Price 75.5) HNil)))

 HList> hEnd (hBuild (Key 42) (Name "Angus") Cow (Price 75.5)) == angus
 True

A heterogeneous apply operator

A heterogeneous fold for all types

Map

Map a heterogeneous list to a homogeneous one

A heterogenous version of mapM.

A reconstruction of append

A heterogeneous map for all types

A function for showing

Type-level equality for lists

Staged equality for lists

Ensure a list to contain HNats only

Static set property based on HEq

Find an element in a set based on HEq

Membership test

Another type-level membership test

Membership test based on type equality

Intersection based on HTMember

Turn a heterogeneous list into a homogeneous one

With HMaybe

Turn list in a list of justs

Extract justs from list of maybes

Annotated lists

Splitting by HTrue and HFalse