Modulesop-extras-0.4.1.1Haskell2010

Data.SOP.NonEmpty

Type-level non-empty lists

Contents

Proofs
Working with NonEmpty

Synopsis

data NonEmpty
class IsNonEmpty
data ProofNonEmpty
value checkIsNonEmpty
value nonEmptyFromList
value nonEmptyHead
value nonEmptyInit
value nonEmptyLast
value nonEmptyMapOne
value nonEmptyMapTwo
value nonEmptyStrictPrefixes
value nonEmptyToList

Packagesop-extras-0.4.1.1
Exports12
LanguageHaskell2010
LicenceApache-2.0
SourceNonEmpty.hs

datadata NonEmpty (xs :: [Type]) a where

Source#

Non-empty variation on AtMost

Constructors

NonEmptyOne :: !a -> NonEmpty (x ': xs1) a
NonEmptyCons :: !a -> !NonEmpty xs1 a -> NonEmpty (x ': xs1) a

Instances6Functor, Applicative, Foldable, Traversable, Eq, Show

Functor (NonEmpty xs)Defined in sop-extras-0.4.1.1 · Data.SOP.NonEmpty
(IsNonEmpty xs, SListI xs) => Applicative (NonEmpty xs)Defined in sop-extras-0.4.1.1 · Data.SOP.NonEmpty
Foldable (NonEmpty xs)Defined in sop-extras-0.4.1.1 · Data.SOP.NonEmpty
Traversable (NonEmpty xs)Defined in sop-extras-0.4.1.1 · Data.SOP.NonEmpty
Eq a => Eq (NonEmpty xs a)Defined in sop-extras-0.4.1.1 · Data.SOP.NonEmpty
Show a => Show (NonEmpty xs a)Defined in sop-extras-0.4.1.1 · Data.SOP.NonEmpty

Proofs

classclass IsNonEmpty (xs :: [a]) where

Methods

isNonEmpty :: proxy xs -> ProofNonEmpty xs

Instances1IsNonEmpty

IsNonEmpty (x ': xs)Defined in sop-extras-0.4.1.1 · Data.SOP.NonEmpty

datadata ProofNonEmpty (xs :: [a]) where

Constructors

ProofNonEmpty :: Proxy x -> Proxy xs1 -> ProofNonEmpty (x ': xs1)

valuecheckIsNonEmpty :: SListI xs => Proxy xs -> Maybe (ProofNonEmpty xs)

Working with NonEmpty

valuenonEmptyFromList :: SListI xs => [a] -> Maybe (NonEmpty xs a)

Source#

Build a NonEmpty from a list. Returns Nothing when the list is empty or when it's longer than xs.

valuenonEmptyHead :: NonEmpty xs a -> a

Source#

Analogue of head

valuenonEmptyInit :: NonEmpty xs a -> (Maybe (NonEmpty xs a), a)

Source#

Analogue of init

valuenonEmptyLast :: NonEmpty xs a -> a

Source#

Analogue of last

valuenonEmptyMapOne

:: Alternative m
=> a -> m a
-> NonEmpty xs a
-> m (NonEmpty xs a)

Source#

Apply the specified function to exactly one element

valuenonEmptyMapTwo

:: Alternative m
=> a -> m a
-> a -> a -> m (a, a)
-> NonEmpty xs a
-> m (NonEmpty xs a)

Source#

Variation on nonEmptyMapOne where we try to apply the function to pairs of elements

valuenonEmptyStrictPrefixes :: NonEmpty xs a -> [NonEmpty xs a]

Source#

A strict prefixes

   nonEmptyStrictPrefixes (fromJust (nonEmptyFromList [1..4]))
== [ NonEmptyOne  1
   , NonEmptyCons 1 $ NonEmptyOne  2
   , NonEmptyCons 1 $ NonEmptyCons 2 $ NonEmptyOne 3
   ]

valuenonEmptyToList :: NonEmpty xs a -> [a]

Source#

Convert a NonEmpty to a list.