RosettaCodeData/Task/Permutations/Haskell/permutations-2.hs

import Data.List (delete)

permutations :: Eq a => [a] -> [[a]]
permutations [] = [[]]
permutations xs = [ x:ys | x <- xs, ys <- permutations (delete x xs)]
tasks a-s 2013-04-10 23:57:08 -07:00			`import Data.List (delete)`

Sync 2013-10-27 22:24:23 +00:00			`permutations :: Eq a => [a] -> [[a]]`
tasks a-s 2013-04-10 23:57:08 -07:00			`permutations [] = [[]]`
			`permutations xs = [ x:ys \| x <- xs, ys <- permutations (delete x xs)]`