Data.List.NonEmpty

A type-safe list that has at least one element.

Documentation

data NonEmpty a

An list with at least one element.

Instances

Monad NonEmpty

Functor NonEmpty

Applicative NonEmpty

Foldable NonEmpty

Traversable NonEmpty

Eq a => Eq (NonEmpty a)

Ord a => Ord (NonEmpty a)

Show a => Show (NonEmpty a)

Arbitrary a => Arbitrary (NonEmpty a)

Accessors

neHead :: NonEmpty a -> a

The head of the non-empty list.

neTail :: NonEmpty a -> [a]

The tail of the non-empty list.

Constructors

nonEmpty

Arguments

:: a

The head.

-> [a]

The tail.

-> NonEmpty a

Constructs a non-empty list with the given head and tail.

(|:)

Arguments

:: a

The head.

-> [a]

The tail.

-> NonEmpty a

Constructs a non-empty list with the given head and tail (an alias for nonEmpty).

toNonEmpty

Arguments

:: [a]

The list to convert.

-> Maybe (NonEmpty a)

Tries to convert a list to a NonEmpty returning Nothing if the given list is empty.

unsafeToNonEmpty

Arguments

:: [a]

The list to convert (must not be empty).

-> NonEmpty a

WARNING: Fails if given the empty list. Tries to convert a list to a NonEmpty.

(.:)

Arguments

:: a

The value to prepend.

-> NonEmpty a

The non-empty list to prepend to.

-> NonEmpty a

Prepends a value to a non-empty list.

(.++)

Arguments

:: NonEmpty a

The non-empty list to prepend.

-> NonEmpty a

The non-empty list to prepend to.

-> NonEmpty a

Prepends a non-empty list to another non-empty list.

List functions

reverse :: NonEmpty a -> NonEmpty a

Reverses the elements of the (finite) non-empty list.

scanl :: (b -> a -> b) -> b -> NonEmpty a -> NonEmpty b

scanl1 :: (a -> a -> a) -> NonEmpty a -> NonEmpty a

scanr :: (a -> b -> b) -> b -> NonEmpty a -> NonEmpty b

scanr1 :: (a -> a -> a) -> NonEmpty a -> NonEmpty a

iterate :: (a -> a) -> a -> NonEmpty a

repeat :: a -> NonEmpty a

cycle :: Foldable f => f a -> NonEmpty a

inits :: [a] -> NonEmpty [a]

tails :: [a] -> NonEmpty [a]

sort :: Ord a => NonEmpty a -> NonEmpty a

insert :: Ord a => a -> NonEmpty a -> NonEmpty a

zip :: NonEmpty a -> NonEmpty b -> NonEmpty (a, b)

unzip :: NonEmpty (a, b) -> (NonEmpty a, NonEmpty b)

Tests

prop_neHead :: String -> [String] -> Bool

prop_neTail :: String -> [String] -> Bool

prop_nonEmpty :: String -> [String] -> Bool

prop_nonEmptyAlias :: String -> [String] -> Bool

prop_toNonEmpty :: [String] -> Bool

prop_unsafeNonEmpty :: [String] -> Property

prop_cons :: String -> NonEmpty String -> Bool

prop_append :: NonEmpty String -> NonEmpty String -> Bool

prop_reverse :: NonEmpty String -> Bool