Sorting algorithms/Bogosort: Difference between revisions

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@@ Line 864: / Line 864: @@
 import Data.Array.IO
 import Control.Monad
+isSortedBy :: (a -> a -> Bool) -> [a] -> Bool
+isSortedBy _ [] = True
+isSortedBy f xs = all (uncurry f) . (zip <*> tail) $ xs
-isSorted :: (Ord a) => [a] -> Bool
-isSorted (e1:e2:r) = e1 <= e2 && isSorted (e2:r)
-isSorted _         = True
 -- from http://www.haskell.org/haskellwiki/Random_shuffle
 shuffle :: [a] -> IO [a]
@@ Line 883: / Line 884: @@
     newArray :: Int -> [a] -> IO (IOArray Int a)
     newArray n xs =  newListArray (1,n) xs
+bogosortBy :: (a -> a -> Bool) -> [a] -> IO [a]
+bogosortBy _ [] = return []
+bogosortBy f xs | isSortedBy f xs = return xs
+                | otherwise       = shuffle xs >>= bogosortBy f
-bogosort :: (Ord a) => [a] -> IO [a]
+bogosort :: Ord a => [a] -> IO [a]
-bogosort li | isSorted li = return li
+bogosort = bogosortBy (<)</lang>
-            | otherwise   = shuffle li >>= bogosort</lang>
 Example:
 <pre>