:: Ord a => [a] -> [a] is:exact -package:imports -package:Cabal -package:errors -package:base -package:extra -package:containers -package:incipit-base -package:integration -package:Cabal-syntax -package:base-prelude

Remove duplicates but keep elements in order. O(n * log n)

cycle ties a finite list into a circular one, or equivalently, the infinite repetition of the original list. It is the identity on infinite lists.

>>> cycle []
*** Exception: Prelude.cycle: empty list

>>> cycle [42]
[42,42,42,42,42,42,42,42,42,42...

>>> cycle [2, 5, 7]
[2,5,7,2,5,7,2,5,7,2,5,7...

Extract the elements after the head of a list, which must be non-empty.

>>> tail [1, 2, 3]
[2,3]

>>> tail [1]
[]

>>> tail []
*** Exception: Prelude.tail: empty list

WARNING: This function is partial. You can use case-matching or uncons instead.

Return all the elements of a list except the last one. The list must be non-empty.

>>> init [1, 2, 3]
[1,2]

>>> init [1]
[]

>>> init []
*** Exception: Prelude.init: empty list

WARNING: This function is partial. You can use reverse with case-matching or uncons instead.

reverse xs returns the elements of xs in reverse order. xs must be finite.

>>> reverse []
[]

>>> reverse [42]
[42]

>>> reverse [2,5,7]
[7,5,2]

>>> reverse [1..]
* Hangs forever *

Identical to tail, namely that fails on an empty list. Useful to avoid the x-partial warning introduced in GHC 9.8.

tailErr [] = error "Prelude.tail: empty list"
tailErr [1,2,3] = [2,3]

tailSafe [] = []
tailSafe [1,3,4] = [3,4]

Sort a vector.

The nub function which removes duplicate elements from a vector.

Sort a vector.

Removes duplicate elements from a list, keeping only the first occurrence. This is asymptotically faster than using nub from Data.List.

>>> ordNub [3,2,1,3,2,1]
[3,2,1]

Generalized version of runInBoundThread.

Generalized version of runInUnboundThread.

Generalized version of mask_.

Generalized version of uninterruptibleMask_.

all nodes of a tree

O(n) Convert a vector to a list.

Temporarily install standard signal handlers for catching ^C, which just throw an exception in the current thread.