Data.NonEmpty

Documentation

data T f a

The type T can be used for many kinds of list-like structures with restrictions on the size.

• T [] a is a lazy list containing at least one element.
• T (T []) a is a lazy list containing at least two elements.
• T Vector a is a vector with at least one element. You may also use unboxed vectors but the first element will be stored in a box and you will not be able to use many functions from this module.
• T Maybe a is a list that contains one or two elements.
• Maybe is isomorphic to Optional Empty.
• T Empty a is a list that contains exactly one element.
• T (T Empty) a is a list that contains exactly two elements.
• Optional (T Empty) a is a list that contains zero or two elements.
• You can create a list type for every finite set of allowed list length by nesting Optional and NonEmpty constructors. If list length n is allowed, then place Optional at depth n, if it is disallowed then place NonEmpty. The maximm length is marked by Empty.

Constructors

Cons

Fields

head :: a

tail :: f a

Instances

(Monad f, Empty f, Cons f, Append f) => Monad (T f)

Functor f => Functor (T f)

(Applicative f, Empty f, Cons f, Append f) => Applicative (T f)

Foldable f => Foldable (T f)

Traversable f => Traversable (T f)

Show f => Show (T f)

(Traversable f, Reverse f) => Reverse (T f)

(Sort f, Insert f) => Sort (T f)

Repeat f => Repeat (T f)

Zip f => Zip (T f)

(Cons f, Append f) => Append (T f)

Empty f => Singleton (T f)

Cons f => Cons (T f)

Tails f => Tails (T f)

RemoveEach f => RemoveEach (T f)

Insert f => Insert (T f)

(Eq a, Eq (f a)) => Eq (T f a)

(Ord a, Ord (f a)) => Ord (T f a)

(Show f, Show a) => Show (T f a)

(Arbitrary a, Arbitrary f) => Arbitrary (T f a)

(!:) :: a -> f a -> T f a

force :: T f a -> T f a

Force immediate generation of Cons.

apply :: (Applicative f, Cons f, Append f) => T f (a -> b) -> T f a -> T f b

Implementation of <*> without the Empty constraint that is needed for pure.

bind :: (Monad f, Cons f, Append f) => T f a -> (a -> T f b) -> T f b

Implementation of >>= without the Empty constraint that is needed for return.

toList :: Foldable f => T f a -> [a]

flatten :: Cons f => T f a -> f a

fetch :: View f => f a -> Maybe (T f a)

cons :: Cons f => a -> T f a -> T f a

singleton :: Empty f => a -> T f a

reverse :: (Traversable f, Reverse f) => T f a -> T f a

mapHead :: (a -> a) -> T f a -> T f a

mapTail :: (f a -> g a) -> T f a -> T g a

init :: (Zip f, Cons f) => T f a -> f a

last :: Foldable f => T f a -> a

foldl1 :: Foldable f => (a -> a -> a) -> T f a -> a

maximum :: (Ord a, Foldable f) => T f a -> a

maximum is a total function

maximumBy :: Foldable f => (a -> a -> Ordering) -> T f a -> a

maximumBy is a total function

maximumKey :: (Ord b, Foldable f) => (a -> b) -> T f a -> a

maximumKey is a total function

minimum :: (Ord a, Foldable f) => T f a -> a

minimum is a total function

minimumBy :: Foldable f => (a -> a -> Ordering) -> T f a -> a

minimumBy is a total function

minimumKey :: (Ord b, Foldable f) => (a -> b) -> T f a -> a

minimumKey is a total function

sum :: (Num a, Foldable f) => T f a -> a

sum does not need a zero for initialization

product :: (Num a, Foldable f) => T f a -> a

product does not need a one for initialization

append :: (Cons f, Append f) => T f a -> T f a -> T f a

appendLeft :: (Append f, View f, Cons f) => f a -> T f a -> T f a

appendRight :: Append f => T f a -> f a -> T f a

cycle :: (Cons f, Append f) => T f a -> T f a

generic variants: cycle or better Semigroup.cycle

zipWith :: Zip f => (a -> b -> c) -> T f a -> T f b -> T f c

mapAdjacent :: Traversable f => (a -> a -> b) -> T f a -> f b

sortBy :: (Sort f, Insert f) => (a -> a -> Ordering) -> T f a -> T f a

If you nest too many non-empty lists then the efficient merge-sort (linear-logarithmic runtime) will degenerate to an inefficient insert-sort (quadratic runtime).

sort :: (Ord a, Sort f, Insert f) => T f a -> T f a

class Insert f where

Methods

insertBy :: (a -> a -> Ordering) -> a -> f a -> T f a

Instances

Insert []

Insert Maybe

Insert Seq

Insert T

Insert f => Insert (T f)

Insert f => Insert (T f)

insert :: (Ord a, Insert f, Sort f) => a -> f a -> T f a

Insert an element into an ordered list while preserving the order. The first element of the resulting list is returned individually. We need this for construction of a non-empty list.

scanl :: Traversable f => (b -> a -> b) -> b -> f a -> T f b

scanr :: Traversable f => (a -> b -> b) -> b -> f a -> T f b

transposeClip :: (Traversable f, Zip g, Repeat g) => f (g a) -> g (f a)

Always returns a rectangular list by clipping all dimensions to the shortest slice. Be aware that transpose [] == repeat [].

class Tails f where

Methods

tails :: (Cons g, Empty g) => f a -> T f (g a)

Instances

Tails []

Tails Maybe

Tails Seq

Tails T

Tails f => Tails (T f)

Tails f => Tails (T f)

class Functor f => RemoveEach f where

Methods

removeEach :: T f a -> T f (a, f a)

Instances

RemoveEach []

RemoveEach Maybe

RemoveEach T

RemoveEach f => RemoveEach (T f)

RemoveEach f => RemoveEach (T f)