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<pre><a name="line-1"></a><span class='hs-comment'>{-# OPTIONS_GHC -XNoImplicitPrelude #-}</span>
<a name="line-2"></a><span class='hs-comment'>-----------------------------------------------------------------------------</span>
<a name="line-3"></a><span class='hs-comment'>-- |</span>
<a name="line-4"></a><span class='hs-comment'>-- Module : Data.List</span>
<a name="line-5"></a><span class='hs-comment'>-- Copyright : (c) The University of Glasgow 2001</span>
<a name="line-6"></a><span class='hs-comment'>-- License : BSD-style (see the file libraries/base/LICENSE)</span>
<a name="line-7"></a><span class='hs-comment'>-- </span>
<a name="line-8"></a><span class='hs-comment'>-- Maintainer : libraries@haskell.org</span>
<a name="line-9"></a><span class='hs-comment'>-- Stability : stable</span>
<a name="line-10"></a><span class='hs-comment'>-- Portability : portable</span>
<a name="line-11"></a><span class='hs-comment'>--</span>
<a name="line-12"></a><span class='hs-comment'>-- Operations on lists.</span>
<a name="line-13"></a><span class='hs-comment'>--</span>
<a name="line-14"></a><span class='hs-comment'>-----------------------------------------------------------------------------</span>
<a name="line-15"></a>
<a name="line-16"></a><span class='hs-keyword'>module</span> <span class='hs-conid'>Data</span><span class='hs-varop'>.</span><span class='hs-conid'>List</span>
<a name="line-17"></a> <span class='hs-layout'>(</span>
<a name="line-18"></a><span class='hs-cpp'>#ifdef __NHC__</span>
<a name="line-19"></a> <span class='hs-conid'>[]</span> <span class='hs-layout'>(</span><span class='hs-keyglyph'>..</span><span class='hs-layout'>)</span>
<a name="line-20"></a> <span class='hs-layout'>,</span>
<a name="line-21"></a><span class='hs-cpp'>#endif</span>
<a name="line-22"></a>
<a name="line-23"></a> <span class='hs-comment'>-- * Basic functions</span>
<a name="line-24"></a>
<a name="line-25"></a> <span class='hs-layout'>(</span><span class='hs-varop'>++</span><span class='hs-layout'>)</span> <span class='hs-comment'>-- :: [a] -> [a] -> [a]</span>
<a name="line-26"></a> <span class='hs-layout'>,</span> <span class='hs-varid'>head</span> <span class='hs-comment'>-- :: [a] -> a</span>
<a name="line-27"></a> <span class='hs-layout'>,</span> <span class='hs-varid'>last</span> <span class='hs-comment'>-- :: [a] -> a</span>
<a name="line-28"></a> <span class='hs-layout'>,</span> <span class='hs-varid'>tail</span> <span class='hs-comment'>-- :: [a] -> [a]</span>
<a name="line-29"></a> <span class='hs-layout'>,</span> <span class='hs-varid'>init</span> <span class='hs-comment'>-- :: [a] -> [a]</span>
<a name="line-30"></a> <span class='hs-layout'>,</span> <span class='hs-varid'>null</span> <span class='hs-comment'>-- :: [a] -> Bool</span>
<a name="line-31"></a> <span class='hs-layout'>,</span> <span class='hs-varid'>length</span> <span class='hs-comment'>-- :: [a] -> Int</span>
<a name="line-32"></a>
<a name="line-33"></a> <span class='hs-comment'>-- * List transformations</span>
<a name="line-34"></a> <span class='hs-layout'>,</span> <span class='hs-varid'>map</span> <span class='hs-comment'>-- :: (a -> b) -> [a] -> [b]</span>
<a name="line-35"></a> <span class='hs-layout'>,</span> <span class='hs-varid'>reverse</span> <span class='hs-comment'>-- :: [a] -> [a]</span>
<a name="line-36"></a>
<a name="line-37"></a> <span class='hs-layout'>,</span> <span class='hs-varid'>intersperse</span> <span class='hs-comment'>-- :: a -> [a] -> [a]</span>
<a name="line-38"></a> <span class='hs-layout'>,</span> <span class='hs-varid'>intercalate</span> <span class='hs-comment'>-- :: [a] -> [[a]] -> [a]</span>
<a name="line-39"></a> <span class='hs-layout'>,</span> <span class='hs-varid'>transpose</span> <span class='hs-comment'>-- :: [[a]] -> [[a]]</span>
<a name="line-40"></a>
<a name="line-41"></a> <span class='hs-layout'>,</span> <span class='hs-varid'>subsequences</span> <span class='hs-comment'>-- :: [a] -> [[a]]</span>
<a name="line-42"></a> <span class='hs-layout'>,</span> <span class='hs-varid'>permutations</span> <span class='hs-comment'>-- :: [a] -> [[a]]</span>
<a name="line-43"></a>
<a name="line-44"></a> <span class='hs-comment'>-- * Reducing lists (folds)</span>
<a name="line-45"></a>
<a name="line-46"></a> <span class='hs-layout'>,</span> <span class='hs-varid'>foldl</span> <span class='hs-comment'>-- :: (a -> b -> a) -> a -> [b] -> a</span>
<a name="line-47"></a> <span class='hs-layout'>,</span> <span class='hs-varid'>foldl'</span> <span class='hs-comment'>-- :: (a -> b -> a) -> a -> [b] -> a</span>
<a name="line-48"></a> <span class='hs-layout'>,</span> <span class='hs-varid'>foldl1</span> <span class='hs-comment'>-- :: (a -> a -> a) -> [a] -> a</span>
<a name="line-49"></a> <span class='hs-layout'>,</span> <span class='hs-varid'>foldl1'</span> <span class='hs-comment'>-- :: (a -> a -> a) -> [a] -> a</span>
<a name="line-50"></a> <span class='hs-layout'>,</span> <span class='hs-varid'>foldr</span> <span class='hs-comment'>-- :: (a -> b -> b) -> b -> [a] -> b</span>
<a name="line-51"></a> <span class='hs-layout'>,</span> <span class='hs-varid'>foldr1</span> <span class='hs-comment'>-- :: (a -> a -> a) -> [a] -> a</span>
<a name="line-52"></a>
<a name="line-53"></a> <span class='hs-comment'>-- ** Special folds</span>
<a name="line-54"></a>
<a name="line-55"></a> <span class='hs-layout'>,</span> <span class='hs-varid'>concat</span> <span class='hs-comment'>-- :: [[a]] -> [a]</span>
<a name="line-56"></a> <span class='hs-layout'>,</span> <span class='hs-varid'>concatMap</span> <span class='hs-comment'>-- :: (a -> [b]) -> [a] -> [b]</span>
<a name="line-57"></a> <span class='hs-layout'>,</span> <span class='hs-varid'>and</span> <span class='hs-comment'>-- :: [Bool] -> Bool</span>
<a name="line-58"></a> <span class='hs-layout'>,</span> <span class='hs-varid'>or</span> <span class='hs-comment'>-- :: [Bool] -> Bool</span>
<a name="line-59"></a> <span class='hs-layout'>,</span> <span class='hs-varid'>any</span> <span class='hs-comment'>-- :: (a -> Bool) -> [a] -> Bool</span>
<a name="line-60"></a> <span class='hs-layout'>,</span> <span class='hs-varid'>all</span> <span class='hs-comment'>-- :: (a -> Bool) -> [a] -> Bool</span>
<a name="line-61"></a> <span class='hs-layout'>,</span> <span class='hs-varid'>sum</span> <span class='hs-comment'>-- :: (Num a) => [a] -> a</span>
<a name="line-62"></a> <span class='hs-layout'>,</span> <span class='hs-varid'>product</span> <span class='hs-comment'>-- :: (Num a) => [a] -> a</span>
<a name="line-63"></a> <span class='hs-layout'>,</span> <span class='hs-varid'>maximum</span> <span class='hs-comment'>-- :: (Ord a) => [a] -> a</span>
<a name="line-64"></a> <span class='hs-layout'>,</span> <span class='hs-varid'>minimum</span> <span class='hs-comment'>-- :: (Ord a) => [a] -> a</span>
<a name="line-65"></a>
<a name="line-66"></a> <span class='hs-comment'>-- * Building lists</span>
<a name="line-67"></a>
<a name="line-68"></a> <span class='hs-comment'>-- ** Scans</span>
<a name="line-69"></a> <span class='hs-layout'>,</span> <span class='hs-varid'>scanl</span> <span class='hs-comment'>-- :: (a -> b -> a) -> a -> [b] -> [a]</span>
<a name="line-70"></a> <span class='hs-layout'>,</span> <span class='hs-varid'>scanl1</span> <span class='hs-comment'>-- :: (a -> a -> a) -> [a] -> [a]</span>
<a name="line-71"></a> <span class='hs-layout'>,</span> <span class='hs-varid'>scanr</span> <span class='hs-comment'>-- :: (a -> b -> b) -> b -> [a] -> [b]</span>
<a name="line-72"></a> <span class='hs-layout'>,</span> <span class='hs-varid'>scanr1</span> <span class='hs-comment'>-- :: (a -> a -> a) -> [a] -> [a]</span>
<a name="line-73"></a>
<a name="line-74"></a> <span class='hs-comment'>-- ** Accumulating maps</span>
<a name="line-75"></a> <span class='hs-layout'>,</span> <span class='hs-varid'>mapAccumL</span> <span class='hs-comment'>-- :: (a -> b -> (a,c)) -> a -> [b] -> (a,[c])</span>
<a name="line-76"></a> <span class='hs-layout'>,</span> <span class='hs-varid'>mapAccumR</span> <span class='hs-comment'>-- :: (a -> b -> (a,c)) -> a -> [b] -> (a,[c])</span>
<a name="line-77"></a>
<a name="line-78"></a> <span class='hs-comment'>-- ** Infinite lists</span>
<a name="line-79"></a> <span class='hs-layout'>,</span> <span class='hs-varid'>iterate</span> <span class='hs-comment'>-- :: (a -> a) -> a -> [a]</span>
<a name="line-80"></a> <span class='hs-layout'>,</span> <span class='hs-varid'>repeat</span> <span class='hs-comment'>-- :: a -> [a]</span>
<a name="line-81"></a> <span class='hs-layout'>,</span> <span class='hs-varid'>replicate</span> <span class='hs-comment'>-- :: Int -> a -> [a]</span>
<a name="line-82"></a> <span class='hs-layout'>,</span> <span class='hs-varid'>cycle</span> <span class='hs-comment'>-- :: [a] -> [a]</span>
<a name="line-83"></a>
<a name="line-84"></a> <span class='hs-comment'>-- ** Unfolding</span>
<a name="line-85"></a> <span class='hs-layout'>,</span> <span class='hs-varid'>unfoldr</span> <span class='hs-comment'>-- :: (b -> Maybe (a, b)) -> b -> [a]</span>
<a name="line-86"></a>
<a name="line-87"></a> <span class='hs-comment'>-- * Sublists</span>
<a name="line-88"></a>
<a name="line-89"></a> <span class='hs-comment'>-- ** Extracting sublists</span>
<a name="line-90"></a> <span class='hs-layout'>,</span> <span class='hs-varid'>take</span> <span class='hs-comment'>-- :: Int -> [a] -> [a]</span>
<a name="line-91"></a> <span class='hs-layout'>,</span> <span class='hs-varid'>drop</span> <span class='hs-comment'>-- :: Int -> [a] -> [a]</span>
<a name="line-92"></a> <span class='hs-layout'>,</span> <span class='hs-varid'>splitAt</span> <span class='hs-comment'>-- :: Int -> [a] -> ([a], [a])</span>
<a name="line-93"></a>
<a name="line-94"></a> <span class='hs-layout'>,</span> <span class='hs-varid'>takeWhile</span> <span class='hs-comment'>-- :: (a -> Bool) -> [a] -> [a]</span>
<a name="line-95"></a> <span class='hs-layout'>,</span> <span class='hs-varid'>dropWhile</span> <span class='hs-comment'>-- :: (a -> Bool) -> [a] -> [a]</span>
<a name="line-96"></a> <span class='hs-layout'>,</span> <span class='hs-varid'>span</span> <span class='hs-comment'>-- :: (a -> Bool) -> [a] -> ([a], [a])</span>
<a name="line-97"></a> <span class='hs-layout'>,</span> <span class='hs-varid'>break</span> <span class='hs-comment'>-- :: (a -> Bool) -> [a] -> ([a], [a])</span>
<a name="line-98"></a>
<a name="line-99"></a> <span class='hs-layout'>,</span> <span class='hs-varid'>stripPrefix</span> <span class='hs-comment'>-- :: Eq a => [a] -> [a] -> Maybe [a]</span>
<a name="line-100"></a>
<a name="line-101"></a> <span class='hs-layout'>,</span> <span class='hs-varid'>group</span> <span class='hs-comment'>-- :: Eq a => [a] -> [[a]]</span>
<a name="line-102"></a>
<a name="line-103"></a> <span class='hs-layout'>,</span> <span class='hs-varid'>inits</span> <span class='hs-comment'>-- :: [a] -> [[a]]</span>
<a name="line-104"></a> <span class='hs-layout'>,</span> <span class='hs-varid'>tails</span> <span class='hs-comment'>-- :: [a] -> [[a]]</span>
<a name="line-105"></a>
<a name="line-106"></a> <span class='hs-comment'>-- ** Predicates</span>
<a name="line-107"></a> <span class='hs-layout'>,</span> <span class='hs-varid'>isPrefixOf</span> <span class='hs-comment'>-- :: (Eq a) => [a] -> [a] -> Bool</span>
<a name="line-108"></a> <span class='hs-layout'>,</span> <span class='hs-varid'>isSuffixOf</span> <span class='hs-comment'>-- :: (Eq a) => [a] -> [a] -> Bool</span>
<a name="line-109"></a> <span class='hs-layout'>,</span> <span class='hs-varid'>isInfixOf</span> <span class='hs-comment'>-- :: (Eq a) => [a] -> [a] -> Bool</span>
<a name="line-110"></a>
<a name="line-111"></a> <span class='hs-comment'>-- * Searching lists</span>
<a name="line-112"></a>
<a name="line-113"></a> <span class='hs-comment'>-- ** Searching by equality</span>
<a name="line-114"></a> <span class='hs-layout'>,</span> <span class='hs-varid'>elem</span> <span class='hs-comment'>-- :: a -> [a] -> Bool</span>
<a name="line-115"></a> <span class='hs-layout'>,</span> <span class='hs-varid'>notElem</span> <span class='hs-comment'>-- :: a -> [a] -> Bool</span>
<a name="line-116"></a> <span class='hs-layout'>,</span> <span class='hs-varid'>lookup</span> <span class='hs-comment'>-- :: (Eq a) => a -> [(a,b)] -> Maybe b</span>
<a name="line-117"></a>
<a name="line-118"></a> <span class='hs-comment'>-- ** Searching with a predicate</span>
<a name="line-119"></a> <span class='hs-layout'>,</span> <span class='hs-varid'>find</span> <span class='hs-comment'>-- :: (a -> Bool) -> [a] -> Maybe a</span>
<a name="line-120"></a> <span class='hs-layout'>,</span> <span class='hs-varid'>filter</span> <span class='hs-comment'>-- :: (a -> Bool) -> [a] -> [a]</span>
<a name="line-121"></a> <span class='hs-layout'>,</span> <span class='hs-varid'>partition</span> <span class='hs-comment'>-- :: (a -> Bool) -> [a] -> ([a], [a])</span>
<a name="line-122"></a>
<a name="line-123"></a> <span class='hs-comment'>-- * Indexing lists</span>
<a name="line-124"></a> <span class='hs-comment'>-- | These functions treat a list @xs@ as a indexed collection,</span>
<a name="line-125"></a> <span class='hs-comment'>-- with indices ranging from 0 to @'length' xs - 1@.</span>
<a name="line-126"></a>
<a name="line-127"></a> <span class='hs-layout'>,</span> <span class='hs-layout'>(</span><span class='hs-varop'>!!</span><span class='hs-layout'>)</span> <span class='hs-comment'>-- :: [a] -> Int -> a</span>
<a name="line-128"></a>
<a name="line-129"></a> <span class='hs-layout'>,</span> <span class='hs-varid'>elemIndex</span> <span class='hs-comment'>-- :: (Eq a) => a -> [a] -> Maybe Int</span>
<a name="line-130"></a> <span class='hs-layout'>,</span> <span class='hs-varid'>elemIndices</span> <span class='hs-comment'>-- :: (Eq a) => a -> [a] -> [Int]</span>
<a name="line-131"></a>
<a name="line-132"></a> <span class='hs-layout'>,</span> <span class='hs-varid'>findIndex</span> <span class='hs-comment'>-- :: (a -> Bool) -> [a] -> Maybe Int</span>
<a name="line-133"></a> <span class='hs-layout'>,</span> <span class='hs-varid'>findIndices</span> <span class='hs-comment'>-- :: (a -> Bool) -> [a] -> [Int]</span>
<a name="line-134"></a>
<a name="line-135"></a> <span class='hs-comment'>-- * Zipping and unzipping lists</span>
<a name="line-136"></a>
<a name="line-137"></a> <span class='hs-layout'>,</span> <span class='hs-varid'>zip</span> <span class='hs-comment'>-- :: [a] -> [b] -> [(a,b)]</span>
<a name="line-138"></a> <span class='hs-layout'>,</span> <span class='hs-varid'>zip3</span>
<a name="line-139"></a> <span class='hs-layout'>,</span> <span class='hs-varid'>zip4</span><span class='hs-layout'>,</span> <span class='hs-varid'>zip5</span><span class='hs-layout'>,</span> <span class='hs-varid'>zip6</span><span class='hs-layout'>,</span> <span class='hs-varid'>zip7</span>
<a name="line-140"></a>
<a name="line-141"></a> <span class='hs-layout'>,</span> <span class='hs-varid'>zipWith</span> <span class='hs-comment'>-- :: (a -> b -> c) -> [a] -> [b] -> [c]</span>
<a name="line-142"></a> <span class='hs-layout'>,</span> <span class='hs-varid'>zipWith3</span>
<a name="line-143"></a> <span class='hs-layout'>,</span> <span class='hs-varid'>zipWith4</span><span class='hs-layout'>,</span> <span class='hs-varid'>zipWith5</span><span class='hs-layout'>,</span> <span class='hs-varid'>zipWith6</span><span class='hs-layout'>,</span> <span class='hs-varid'>zipWith7</span>
<a name="line-144"></a>
<a name="line-145"></a> <span class='hs-layout'>,</span> <span class='hs-varid'>unzip</span> <span class='hs-comment'>-- :: [(a,b)] -> ([a],[b])</span>
<a name="line-146"></a> <span class='hs-layout'>,</span> <span class='hs-varid'>unzip3</span>
<a name="line-147"></a> <span class='hs-layout'>,</span> <span class='hs-varid'>unzip4</span><span class='hs-layout'>,</span> <span class='hs-varid'>unzip5</span><span class='hs-layout'>,</span> <span class='hs-varid'>unzip6</span><span class='hs-layout'>,</span> <span class='hs-varid'>unzip7</span>
<a name="line-148"></a>
<a name="line-149"></a> <span class='hs-comment'>-- * Special lists</span>
<a name="line-150"></a>
<a name="line-151"></a> <span class='hs-comment'>-- ** Functions on strings</span>
<a name="line-152"></a> <span class='hs-layout'>,</span> <span class='hs-varid'>lines</span> <span class='hs-comment'>-- :: String -> [String]</span>
<a name="line-153"></a> <span class='hs-layout'>,</span> <span class='hs-varid'>words</span> <span class='hs-comment'>-- :: String -> [String]</span>
<a name="line-154"></a> <span class='hs-layout'>,</span> <span class='hs-varid'>unlines</span> <span class='hs-comment'>-- :: [String] -> String</span>
<a name="line-155"></a> <span class='hs-layout'>,</span> <span class='hs-varid'>unwords</span> <span class='hs-comment'>-- :: [String] -> String</span>
<a name="line-156"></a>
<a name="line-157"></a> <span class='hs-comment'>-- ** \"Set\" operations</span>
<a name="line-158"></a>
<a name="line-159"></a> <span class='hs-layout'>,</span> <span class='hs-varid'>nub</span> <span class='hs-comment'>-- :: (Eq a) => [a] -> [a]</span>
<a name="line-160"></a>
<a name="line-161"></a> <span class='hs-layout'>,</span> <span class='hs-varid'>delete</span> <span class='hs-comment'>-- :: (Eq a) => a -> [a] -> [a]</span>
<a name="line-162"></a> <span class='hs-layout'>,</span> <span class='hs-layout'>(</span><span class='hs-varop'>\\</span><span class='hs-layout'>)</span> <span class='hs-comment'>-- :: (Eq a) => [a] -> [a] -> [a]</span>
<a name="line-163"></a>
<a name="line-164"></a> <span class='hs-layout'>,</span> <span class='hs-varid'>union</span> <span class='hs-comment'>-- :: (Eq a) => [a] -> [a] -> [a]</span>
<a name="line-165"></a> <span class='hs-layout'>,</span> <span class='hs-varid'>intersect</span> <span class='hs-comment'>-- :: (Eq a) => [a] -> [a] -> [a]</span>
<a name="line-166"></a>
<a name="line-167"></a> <span class='hs-comment'>-- ** Ordered lists</span>
<a name="line-168"></a> <span class='hs-layout'>,</span> <span class='hs-varid'>sort</span> <span class='hs-comment'>-- :: (Ord a) => [a] -> [a]</span>
<a name="line-169"></a> <span class='hs-layout'>,</span> <span class='hs-varid'>insert</span> <span class='hs-comment'>-- :: (Ord a) => a -> [a] -> [a]</span>
<a name="line-170"></a>
<a name="line-171"></a> <span class='hs-comment'>-- * Generalized functions</span>
<a name="line-172"></a>
<a name="line-173"></a> <span class='hs-comment'>-- ** The \"@By@\" operations</span>
<a name="line-174"></a> <span class='hs-comment'>-- | By convention, overloaded functions have a non-overloaded</span>
<a name="line-175"></a> <span class='hs-comment'>-- counterpart whose name is suffixed with \`@By@\'.</span>
<a name="line-176"></a> <span class='hs-comment'>--</span>
<a name="line-177"></a> <span class='hs-comment'>-- It is often convenient to use these functions together with</span>
<a name="line-178"></a> <span class='hs-comment'>-- 'Data.Function.on', for instance @'sortBy' ('compare'</span>
<a name="line-179"></a> <span class='hs-comment'>-- \`on\` 'fst')@.</span>
<a name="line-180"></a>
<a name="line-181"></a> <span class='hs-comment'>-- *** User-supplied equality (replacing an @Eq@ context)</span>
<a name="line-182"></a> <span class='hs-comment'>-- | The predicate is assumed to define an equivalence.</span>
<a name="line-183"></a> <span class='hs-layout'>,</span> <span class='hs-varid'>nubBy</span> <span class='hs-comment'>-- :: (a -> a -> Bool) -> [a] -> [a]</span>
<a name="line-184"></a> <span class='hs-layout'>,</span> <span class='hs-varid'>deleteBy</span> <span class='hs-comment'>-- :: (a -> a -> Bool) -> a -> [a] -> [a]</span>
<a name="line-185"></a> <span class='hs-layout'>,</span> <span class='hs-varid'>deleteFirstsBy</span> <span class='hs-comment'>-- :: (a -> a -> Bool) -> [a] -> [a] -> [a]</span>
<a name="line-186"></a> <span class='hs-layout'>,</span> <span class='hs-varid'>unionBy</span> <span class='hs-comment'>-- :: (a -> a -> Bool) -> [a] -> [a] -> [a]</span>
<a name="line-187"></a> <span class='hs-layout'>,</span> <span class='hs-varid'>intersectBy</span> <span class='hs-comment'>-- :: (a -> a -> Bool) -> [a] -> [a] -> [a]</span>
<a name="line-188"></a> <span class='hs-layout'>,</span> <span class='hs-varid'>groupBy</span> <span class='hs-comment'>-- :: (a -> a -> Bool) -> [a] -> [[a]]</span>
<a name="line-189"></a>
<a name="line-190"></a> <span class='hs-comment'>-- *** User-supplied comparison (replacing an @Ord@ context)</span>
<a name="line-191"></a> <span class='hs-comment'>-- | The function is assumed to define a total ordering.</span>
<a name="line-192"></a> <span class='hs-layout'>,</span> <span class='hs-varid'>sortBy</span> <span class='hs-comment'>-- :: (a -> a -> Ordering) -> [a] -> [a]</span>
<a name="line-193"></a> <span class='hs-layout'>,</span> <span class='hs-varid'>insertBy</span> <span class='hs-comment'>-- :: (a -> a -> Ordering) -> a -> [a] -> [a]</span>
<a name="line-194"></a> <span class='hs-layout'>,</span> <span class='hs-varid'>maximumBy</span> <span class='hs-comment'>-- :: (a -> a -> Ordering) -> [a] -> a</span>
<a name="line-195"></a> <span class='hs-layout'>,</span> <span class='hs-varid'>minimumBy</span> <span class='hs-comment'>-- :: (a -> a -> Ordering) -> [a] -> a</span>
<a name="line-196"></a>
<a name="line-197"></a> <span class='hs-comment'>-- ** The \"@generic@\" operations</span>
<a name="line-198"></a> <span class='hs-comment'>-- | The prefix \`@generic@\' indicates an overloaded function that</span>
<a name="line-199"></a> <span class='hs-comment'>-- is a generalized version of a "Prelude" function.</span>
<a name="line-200"></a>
<a name="line-201"></a> <span class='hs-layout'>,</span> <span class='hs-varid'>genericLength</span> <span class='hs-comment'>-- :: (Integral a) => [b] -> a</span>
<a name="line-202"></a> <span class='hs-layout'>,</span> <span class='hs-varid'>genericTake</span> <span class='hs-comment'>-- :: (Integral a) => a -> [b] -> [b]</span>
<a name="line-203"></a> <span class='hs-layout'>,</span> <span class='hs-varid'>genericDrop</span> <span class='hs-comment'>-- :: (Integral a) => a -> [b] -> [b]</span>
<a name="line-204"></a> <span class='hs-layout'>,</span> <span class='hs-varid'>genericSplitAt</span> <span class='hs-comment'>-- :: (Integral a) => a -> [b] -> ([b], [b])</span>
<a name="line-205"></a> <span class='hs-layout'>,</span> <span class='hs-varid'>genericIndex</span> <span class='hs-comment'>-- :: (Integral a) => [b] -> a -> b</span>
<a name="line-206"></a> <span class='hs-layout'>,</span> <span class='hs-varid'>genericReplicate</span> <span class='hs-comment'>-- :: (Integral a) => a -> b -> [b]</span>
<a name="line-207"></a>
<a name="line-208"></a> <span class='hs-layout'>)</span> <span class='hs-keyword'>where</span>
<a name="line-209"></a>
<a name="line-210"></a><span class='hs-cpp'>#ifdef __NHC__</span>
<a name="line-211"></a><span class='hs-keyword'>import</span> <span class='hs-conid'>Prelude</span>
<a name="line-212"></a><span class='hs-cpp'>#endif</span>
<a name="line-213"></a>
<a name="line-214"></a><span class='hs-keyword'>import</span> <span class='hs-conid'>Data</span><span class='hs-varop'>.</span><span class='hs-conid'>Maybe</span>
<a name="line-215"></a><span class='hs-keyword'>import</span> <span class='hs-conid'>Data</span><span class='hs-varop'>.</span><span class='hs-conid'>Char</span> <span class='hs-layout'>(</span> <span class='hs-varid'>isSpace</span> <span class='hs-layout'>)</span>
<a name="line-216"></a>
<a name="line-217"></a><span class='hs-cpp'>#ifdef __GLASGOW_HASKELL__</span>
<a name="line-218"></a><span class='hs-keyword'>import</span> <span class='hs-conid'>GHC</span><span class='hs-varop'>.</span><span class='hs-conid'>Num</span>
<a name="line-219"></a><span class='hs-keyword'>import</span> <span class='hs-conid'>GHC</span><span class='hs-varop'>.</span><span class='hs-conid'>Real</span>
<a name="line-220"></a><span class='hs-keyword'>import</span> <span class='hs-conid'>GHC</span><span class='hs-varop'>.</span><span class='hs-conid'>List</span>
<a name="line-221"></a><span class='hs-keyword'>import</span> <span class='hs-conid'>GHC</span><span class='hs-varop'>.</span><span class='hs-conid'>Base</span>
<a name="line-222"></a><span class='hs-cpp'>#endif</span>
<a name="line-223"></a>
<a name="line-224"></a><span class='hs-keyword'>infix</span> <span class='hs-num'>5</span> <span class='hs-varop'>\\</span> <span class='hs-comment'>-- comment to fool cpp</span>
<a name="line-225"></a>
<a name="line-226"></a><span class='hs-comment'>-- -----------------------------------------------------------------------------</span>
<a name="line-227"></a><span class='hs-comment'>-- List functions</span>
<a name="line-228"></a>
<a name="line-229"></a><a name="stripPrefix"></a><span class='hs-comment'>-- | The 'stripPrefix' function drops the given prefix from a list.</span>
<a name="line-230"></a><span class='hs-comment'>-- It returns 'Nothing' if the list did not start with the prefix</span>
<a name="line-231"></a><span class='hs-comment'>-- given, or 'Just' the list after the prefix, if it does.</span>
<a name="line-232"></a><span class='hs-comment'>--</span>
<a name="line-233"></a><span class='hs-comment'>-- > stripPrefix "foo" "foobar" == Just "bar"</span>
<a name="line-234"></a><span class='hs-comment'>-- > stripPrefix "foo" "foo" == Just ""</span>
<a name="line-235"></a><span class='hs-comment'>-- > stripPrefix "foo" "barfoo" == Nothing</span>
<a name="line-236"></a><span class='hs-comment'>-- > stripPrefix "foo" "barfoobaz" == Nothing</span>
<a name="line-237"></a><span class='hs-definition'>stripPrefix</span> <span class='hs-keyglyph'>::</span> <span class='hs-conid'>Eq</span> <span class='hs-varid'>a</span> <span class='hs-keyglyph'>=></span> <span class='hs-keyglyph'>[</span><span class='hs-varid'>a</span><span class='hs-keyglyph'>]</span> <span class='hs-keyglyph'>-></span> <span class='hs-keyglyph'>[</span><span class='hs-varid'>a</span><span class='hs-keyglyph'>]</span> <span class='hs-keyglyph'>-></span> <span class='hs-conid'>Maybe</span> <span class='hs-keyglyph'>[</span><span class='hs-varid'>a</span><span class='hs-keyglyph'>]</span>
<a name="line-238"></a><span class='hs-definition'>stripPrefix</span> <span class='hs-conid'>[]</span> <span class='hs-varid'>ys</span> <span class='hs-keyglyph'>=</span> <span class='hs-conid'>Just</span> <span class='hs-varid'>ys</span>
<a name="line-239"></a><span class='hs-definition'>stripPrefix</span> <span class='hs-layout'>(</span><span class='hs-varid'>x</span><span class='hs-conop'>:</span><span class='hs-varid'>xs</span><span class='hs-layout'>)</span> <span class='hs-layout'>(</span><span class='hs-varid'>y</span><span class='hs-conop'>:</span><span class='hs-varid'>ys</span><span class='hs-layout'>)</span>
<a name="line-240"></a> <span class='hs-keyglyph'>|</span> <span class='hs-varid'>x</span> <span class='hs-varop'>==</span> <span class='hs-varid'>y</span> <span class='hs-keyglyph'>=</span> <span class='hs-varid'>stripPrefix</span> <span class='hs-varid'>xs</span> <span class='hs-varid'>ys</span>
<a name="line-241"></a><span class='hs-definition'>stripPrefix</span> <span class='hs-keyword'>_</span> <span class='hs-keyword'>_</span> <span class='hs-keyglyph'>=</span> <span class='hs-conid'>Nothing</span>
<a name="line-242"></a>
<a name="line-243"></a><a name="elemIndex"></a><span class='hs-comment'>-- | The 'elemIndex' function returns the index of the first element</span>
<a name="line-244"></a><span class='hs-comment'>-- in the given list which is equal (by '==') to the query element,</span>
<a name="line-245"></a><span class='hs-comment'>-- or 'Nothing' if there is no such element.</span>
<a name="line-246"></a><span class='hs-definition'>elemIndex</span> <span class='hs-keyglyph'>::</span> <span class='hs-conid'>Eq</span> <span class='hs-varid'>a</span> <span class='hs-keyglyph'>=></span> <span class='hs-varid'>a</span> <span class='hs-keyglyph'>-></span> <span class='hs-keyglyph'>[</span><span class='hs-varid'>a</span><span class='hs-keyglyph'>]</span> <span class='hs-keyglyph'>-></span> <span class='hs-conid'>Maybe</span> <span class='hs-conid'>Int</span>
<a name="line-247"></a><span class='hs-definition'>elemIndex</span> <span class='hs-varid'>x</span> <span class='hs-keyglyph'>=</span> <span class='hs-varid'>findIndex</span> <span class='hs-layout'>(</span><span class='hs-varid'>x</span><span class='hs-varop'>==</span><span class='hs-layout'>)</span>
<a name="line-248"></a>
<a name="line-249"></a><a name="elemIndices"></a><span class='hs-comment'>-- | The 'elemIndices' function extends 'elemIndex', by returning the</span>
<a name="line-250"></a><span class='hs-comment'>-- indices of all elements equal to the query element, in ascending order.</span>
<a name="line-251"></a><span class='hs-definition'>elemIndices</span> <span class='hs-keyglyph'>::</span> <span class='hs-conid'>Eq</span> <span class='hs-varid'>a</span> <span class='hs-keyglyph'>=></span> <span class='hs-varid'>a</span> <span class='hs-keyglyph'>-></span> <span class='hs-keyglyph'>[</span><span class='hs-varid'>a</span><span class='hs-keyglyph'>]</span> <span class='hs-keyglyph'>-></span> <span class='hs-keyglyph'>[</span><span class='hs-conid'>Int</span><span class='hs-keyglyph'>]</span>
<a name="line-252"></a><span class='hs-definition'>elemIndices</span> <span class='hs-varid'>x</span> <span class='hs-keyglyph'>=</span> <span class='hs-varid'>findIndices</span> <span class='hs-layout'>(</span><span class='hs-varid'>x</span><span class='hs-varop'>==</span><span class='hs-layout'>)</span>
<a name="line-253"></a>
<a name="line-254"></a><a name="find"></a><span class='hs-comment'>-- | The 'find' function takes a predicate and a list and returns the</span>
<a name="line-255"></a><span class='hs-comment'>-- first element in the list matching the predicate, or 'Nothing' if</span>
<a name="line-256"></a><span class='hs-comment'>-- there is no such element.</span>
<a name="line-257"></a><span class='hs-definition'>find</span> <span class='hs-keyglyph'>::</span> <span class='hs-layout'>(</span><span class='hs-varid'>a</span> <span class='hs-keyglyph'>-></span> <span class='hs-conid'>Bool</span><span class='hs-layout'>)</span> <span class='hs-keyglyph'>-></span> <span class='hs-keyglyph'>[</span><span class='hs-varid'>a</span><span class='hs-keyglyph'>]</span> <span class='hs-keyglyph'>-></span> <span class='hs-conid'>Maybe</span> <span class='hs-varid'>a</span>
<a name="line-258"></a><span class='hs-definition'>find</span> <span class='hs-varid'>p</span> <span class='hs-keyglyph'>=</span> <span class='hs-varid'>listToMaybe</span> <span class='hs-varop'>.</span> <span class='hs-varid'>filter</span> <span class='hs-varid'>p</span>
<a name="line-259"></a>
<a name="line-260"></a><a name="findIndex"></a><span class='hs-comment'>-- | The 'findIndex' function takes a predicate and a list and returns</span>
<a name="line-261"></a><span class='hs-comment'>-- the index of the first element in the list satisfying the predicate,</span>
<a name="line-262"></a><span class='hs-comment'>-- or 'Nothing' if there is no such element.</span>
<a name="line-263"></a><span class='hs-definition'>findIndex</span> <span class='hs-keyglyph'>::</span> <span class='hs-layout'>(</span><span class='hs-varid'>a</span> <span class='hs-keyglyph'>-></span> <span class='hs-conid'>Bool</span><span class='hs-layout'>)</span> <span class='hs-keyglyph'>-></span> <span class='hs-keyglyph'>[</span><span class='hs-varid'>a</span><span class='hs-keyglyph'>]</span> <span class='hs-keyglyph'>-></span> <span class='hs-conid'>Maybe</span> <span class='hs-conid'>Int</span>
<a name="line-264"></a><span class='hs-definition'>findIndex</span> <span class='hs-varid'>p</span> <span class='hs-keyglyph'>=</span> <span class='hs-varid'>listToMaybe</span> <span class='hs-varop'>.</span> <span class='hs-varid'>findIndices</span> <span class='hs-varid'>p</span>
<a name="line-265"></a>
<a name="line-266"></a><a name="findIndices"></a><span class='hs-comment'>-- | The 'findIndices' function extends 'findIndex', by returning the</span>
<a name="line-267"></a><span class='hs-comment'>-- indices of all elements satisfying the predicate, in ascending order.</span>
<a name="line-268"></a><span class='hs-definition'>findIndices</span> <span class='hs-keyglyph'>::</span> <span class='hs-layout'>(</span><span class='hs-varid'>a</span> <span class='hs-keyglyph'>-></span> <span class='hs-conid'>Bool</span><span class='hs-layout'>)</span> <span class='hs-keyglyph'>-></span> <span class='hs-keyglyph'>[</span><span class='hs-varid'>a</span><span class='hs-keyglyph'>]</span> <span class='hs-keyglyph'>-></span> <span class='hs-keyglyph'>[</span><span class='hs-conid'>Int</span><span class='hs-keyglyph'>]</span>
<a name="line-269"></a>
<a name="line-270"></a><span class='hs-cpp'>#if defined(USE_REPORT_PRELUDE) || !defined(__GLASGOW_HASKELL__)</span>
<a name="line-271"></a><span class='hs-definition'>findIndices</span> <span class='hs-varid'>p</span> <span class='hs-varid'>xs</span> <span class='hs-keyglyph'>=</span> <span class='hs-keyglyph'>[</span> <span class='hs-varid'>i</span> <span class='hs-keyglyph'>|</span> <span class='hs-layout'>(</span><span class='hs-varid'>x</span><span class='hs-layout'>,</span><span class='hs-varid'>i</span><span class='hs-layout'>)</span> <span class='hs-keyglyph'><-</span> <span class='hs-varid'>zip</span> <span class='hs-varid'>xs</span> <span class='hs-keyglyph'>[</span><span class='hs-num'>0</span><span class='hs-keyglyph'>..</span><span class='hs-keyglyph'>]</span><span class='hs-layout'>,</span> <span class='hs-varid'>p</span> <span class='hs-varid'>x</span><span class='hs-keyglyph'>]</span>
<a name="line-272"></a><span class='hs-cpp'>#else</span>
<a name="line-273"></a><span class='hs-comment'>-- Efficient definition</span>
<a name="line-274"></a><span class='hs-definition'>findIndices</span> <span class='hs-varid'>p</span> <span class='hs-varid'>ls</span> <span class='hs-keyglyph'>=</span> <span class='hs-varid'>loop</span> <span class='hs-num'>0</span><span class='hs-cpp'>#</span> <span class='hs-varid'>ls</span>
<a name="line-275"></a> <span class='hs-keyword'>where</span>
<a name="line-276"></a> <span class='hs-varid'>loop</span> <span class='hs-keyword'>_</span> <span class='hs-conid'>[]</span> <span class='hs-keyglyph'>=</span> <span class='hs-conid'>[]</span>
<a name="line-277"></a> <span class='hs-varid'>loop</span> <span class='hs-varid'>n</span> <span class='hs-layout'>(</span><span class='hs-varid'>x</span><span class='hs-conop'>:</span><span class='hs-varid'>xs</span><span class='hs-layout'>)</span> <span class='hs-keyglyph'>|</span> <span class='hs-varid'>p</span> <span class='hs-varid'>x</span> <span class='hs-keyglyph'>=</span> <span class='hs-conid'>I</span><span class='hs-cpp'>#</span> <span class='hs-varid'>n</span> <span class='hs-conop'>:</span> <span class='hs-varid'>loop</span> <span class='hs-layout'>(</span><span class='hs-varid'>n</span> <span class='hs-varop'>+#</span> <span class='hs-num'>1</span><span class='hs-cpp'>#</span><span class='hs-layout'>)</span> <span class='hs-varid'>xs</span>
<a name="line-278"></a> <span class='hs-keyglyph'>|</span> <span class='hs-varid'>otherwise</span> <span class='hs-keyglyph'>=</span> <span class='hs-varid'>loop</span> <span class='hs-layout'>(</span><span class='hs-varid'>n</span> <span class='hs-varop'>+#</span> <span class='hs-num'>1</span><span class='hs-cpp'>#</span><span class='hs-layout'>)</span> <span class='hs-varid'>xs</span>
<a name="line-279"></a><span class='hs-cpp'>#endif /* USE_REPORT_PRELUDE */</span>
<a name="line-280"></a>
<a name="line-281"></a><a name="isPrefixOf"></a><span class='hs-comment'>-- | The 'isPrefixOf' function takes two lists and returns 'True'</span>
<a name="line-282"></a><span class='hs-comment'>-- iff the first list is a prefix of the second.</span>
<a name="line-283"></a><span class='hs-definition'>isPrefixOf</span> <span class='hs-keyglyph'>::</span> <span class='hs-layout'>(</span><span class='hs-conid'>Eq</span> <span class='hs-varid'>a</span><span class='hs-layout'>)</span> <span class='hs-keyglyph'>=></span> <span class='hs-keyglyph'>[</span><span class='hs-varid'>a</span><span class='hs-keyglyph'>]</span> <span class='hs-keyglyph'>-></span> <span class='hs-keyglyph'>[</span><span class='hs-varid'>a</span><span class='hs-keyglyph'>]</span> <span class='hs-keyglyph'>-></span> <span class='hs-conid'>Bool</span>
<a name="line-284"></a><span class='hs-definition'>isPrefixOf</span> <span class='hs-conid'>[]</span> <span class='hs-keyword'>_</span> <span class='hs-keyglyph'>=</span> <span class='hs-conid'>True</span>
<a name="line-285"></a><span class='hs-definition'>isPrefixOf</span> <span class='hs-keyword'>_</span> <span class='hs-conid'>[]</span> <span class='hs-keyglyph'>=</span> <span class='hs-conid'>False</span>
<a name="line-286"></a><span class='hs-definition'>isPrefixOf</span> <span class='hs-layout'>(</span><span class='hs-varid'>x</span><span class='hs-conop'>:</span><span class='hs-varid'>xs</span><span class='hs-layout'>)</span> <span class='hs-layout'>(</span><span class='hs-varid'>y</span><span class='hs-conop'>:</span><span class='hs-varid'>ys</span><span class='hs-layout'>)</span><span class='hs-keyglyph'>=</span> <span class='hs-varid'>x</span> <span class='hs-varop'>==</span> <span class='hs-varid'>y</span> <span class='hs-varop'>&&</span> <span class='hs-varid'>isPrefixOf</span> <span class='hs-varid'>xs</span> <span class='hs-varid'>ys</span>
<a name="line-287"></a>
<a name="line-288"></a><a name="isSuffixOf"></a><span class='hs-comment'>-- | The 'isSuffixOf' function takes two lists and returns 'True'</span>
<a name="line-289"></a><span class='hs-comment'>-- iff the first list is a suffix of the second.</span>
<a name="line-290"></a><span class='hs-comment'>-- Both lists must be finite.</span>
<a name="line-291"></a><span class='hs-definition'>isSuffixOf</span> <span class='hs-keyglyph'>::</span> <span class='hs-layout'>(</span><span class='hs-conid'>Eq</span> <span class='hs-varid'>a</span><span class='hs-layout'>)</span> <span class='hs-keyglyph'>=></span> <span class='hs-keyglyph'>[</span><span class='hs-varid'>a</span><span class='hs-keyglyph'>]</span> <span class='hs-keyglyph'>-></span> <span class='hs-keyglyph'>[</span><span class='hs-varid'>a</span><span class='hs-keyglyph'>]</span> <span class='hs-keyglyph'>-></span> <span class='hs-conid'>Bool</span>
<a name="line-292"></a><span class='hs-definition'>isSuffixOf</span> <span class='hs-varid'>x</span> <span class='hs-varid'>y</span> <span class='hs-keyglyph'>=</span> <span class='hs-varid'>reverse</span> <span class='hs-varid'>x</span> <span class='hs-varop'>`isPrefixOf`</span> <span class='hs-varid'>reverse</span> <span class='hs-varid'>y</span>
<a name="line-293"></a>
<a name="line-294"></a><a name="isInfixOf"></a><span class='hs-comment'>-- | The 'isInfixOf' function takes two lists and returns 'True'</span>
<a name="line-295"></a><span class='hs-comment'>-- iff the first list is contained, wholly and intact,</span>
<a name="line-296"></a><span class='hs-comment'>-- anywhere within the second.</span>
<a name="line-297"></a><span class='hs-comment'>--</span>
<a name="line-298"></a><span class='hs-comment'>-- Example:</span>
<a name="line-299"></a><span class='hs-comment'>--</span>
<a name="line-300"></a><span class='hs-comment'>-- >isInfixOf "Haskell" "I really like Haskell." == True</span>
<a name="line-301"></a><span class='hs-comment'>-- >isInfixOf "Ial" "I really like Haskell." == False</span>
<a name="line-302"></a><span class='hs-definition'>isInfixOf</span> <span class='hs-keyglyph'>::</span> <span class='hs-layout'>(</span><span class='hs-conid'>Eq</span> <span class='hs-varid'>a</span><span class='hs-layout'>)</span> <span class='hs-keyglyph'>=></span> <span class='hs-keyglyph'>[</span><span class='hs-varid'>a</span><span class='hs-keyglyph'>]</span> <span class='hs-keyglyph'>-></span> <span class='hs-keyglyph'>[</span><span class='hs-varid'>a</span><span class='hs-keyglyph'>]</span> <span class='hs-keyglyph'>-></span> <span class='hs-conid'>Bool</span>
<a name="line-303"></a><span class='hs-definition'>isInfixOf</span> <span class='hs-varid'>needle</span> <span class='hs-varid'>haystack</span> <span class='hs-keyglyph'>=</span> <span class='hs-varid'>any</span> <span class='hs-layout'>(</span><span class='hs-varid'>isPrefixOf</span> <span class='hs-varid'>needle</span><span class='hs-layout'>)</span> <span class='hs-layout'>(</span><span class='hs-varid'>tails</span> <span class='hs-varid'>haystack</span><span class='hs-layout'>)</span>
<a name="line-304"></a>
<a name="line-305"></a><a name="nub"></a><span class='hs-comment'>-- | /O(n^2)/. The 'nub' function removes duplicate elements from a list.</span>
<a name="line-306"></a><span class='hs-comment'>-- In particular, it keeps only the first occurrence of each element.</span>
<a name="line-307"></a><span class='hs-comment'>-- (The name 'nub' means \`essence\'.)</span>
<a name="line-308"></a><span class='hs-comment'>-- It is a special case of 'nubBy', which allows the programmer to supply</span>
<a name="line-309"></a><span class='hs-comment'>-- their own equality test.</span>
<a name="line-310"></a><span class='hs-definition'>nub</span> <span class='hs-keyglyph'>::</span> <span class='hs-layout'>(</span><span class='hs-conid'>Eq</span> <span class='hs-varid'>a</span><span class='hs-layout'>)</span> <span class='hs-keyglyph'>=></span> <span class='hs-keyglyph'>[</span><span class='hs-varid'>a</span><span class='hs-keyglyph'>]</span> <span class='hs-keyglyph'>-></span> <span class='hs-keyglyph'>[</span><span class='hs-varid'>a</span><span class='hs-keyglyph'>]</span>
<a name="line-311"></a><span class='hs-cpp'>#ifdef USE_REPORT_PRELUDE</span>
<a name="line-312"></a><span class='hs-definition'>nub</span> <span class='hs-keyglyph'>=</span> <span class='hs-varid'>nubBy</span> <span class='hs-layout'>(</span><span class='hs-varop'>==</span><span class='hs-layout'>)</span>
<a name="line-313"></a><span class='hs-cpp'>#else</span>
<a name="line-314"></a><span class='hs-comment'>-- stolen from HBC</span>
<a name="line-315"></a><span class='hs-definition'>nub</span> <span class='hs-varid'>l</span> <span class='hs-keyglyph'>=</span> <span class='hs-varid'>nub'</span> <span class='hs-varid'>l</span> <span class='hs-conid'>[]</span> <span class='hs-comment'>-- '</span>
<a name="line-316"></a> <span class='hs-keyword'>where</span>
<a name="line-317"></a> <span class='hs-varid'>nub'</span> <span class='hs-conid'>[]</span> <span class='hs-keyword'>_</span> <span class='hs-keyglyph'>=</span> <span class='hs-conid'>[]</span> <span class='hs-comment'>-- '</span>
<a name="line-318"></a> <span class='hs-varid'>nub'</span> <span class='hs-layout'>(</span><span class='hs-varid'>x</span><span class='hs-conop'>:</span><span class='hs-varid'>xs</span><span class='hs-layout'>)</span> <span class='hs-varid'>ls</span> <span class='hs-comment'>-- '</span>
<a name="line-319"></a> <span class='hs-keyglyph'>|</span> <span class='hs-varid'>x</span> <span class='hs-varop'>`elem`</span> <span class='hs-varid'>ls</span> <span class='hs-keyglyph'>=</span> <span class='hs-varid'>nub'</span> <span class='hs-varid'>xs</span> <span class='hs-varid'>ls</span> <span class='hs-comment'>-- '</span>
<a name="line-320"></a> <span class='hs-keyglyph'>|</span> <span class='hs-varid'>otherwise</span> <span class='hs-keyglyph'>=</span> <span class='hs-varid'>x</span> <span class='hs-conop'>:</span> <span class='hs-varid'>nub'</span> <span class='hs-varid'>xs</span> <span class='hs-layout'>(</span><span class='hs-varid'>x</span><span class='hs-conop'>:</span><span class='hs-varid'>ls</span><span class='hs-layout'>)</span> <span class='hs-comment'>-- '</span>
<a name="line-321"></a><span class='hs-cpp'>#endif</span>
<a name="line-322"></a>
<a name="line-323"></a><a name="nubBy"></a><span class='hs-comment'>-- | The 'nubBy' function behaves just like 'nub', except it uses a</span>
<a name="line-324"></a><span class='hs-comment'>-- user-supplied equality predicate instead of the overloaded '=='</span>
<a name="line-325"></a><span class='hs-comment'>-- function.</span>
<a name="line-326"></a><span class='hs-definition'>nubBy</span> <span class='hs-keyglyph'>::</span> <span class='hs-layout'>(</span><span class='hs-varid'>a</span> <span class='hs-keyglyph'>-></span> <span class='hs-varid'>a</span> <span class='hs-keyglyph'>-></span> <span class='hs-conid'>Bool</span><span class='hs-layout'>)</span> <span class='hs-keyglyph'>-></span> <span class='hs-keyglyph'>[</span><span class='hs-varid'>a</span><span class='hs-keyglyph'>]</span> <span class='hs-keyglyph'>-></span> <span class='hs-keyglyph'>[</span><span class='hs-varid'>a</span><span class='hs-keyglyph'>]</span>
<a name="line-327"></a><span class='hs-cpp'>#ifdef USE_REPORT_PRELUDE</span>
<a name="line-328"></a><span class='hs-definition'>nubBy</span> <span class='hs-varid'>eq</span> <span class='hs-conid'>[]</span> <span class='hs-keyglyph'>=</span> <span class='hs-conid'>[]</span>
<a name="line-329"></a><span class='hs-definition'>nubBy</span> <span class='hs-varid'>eq</span> <span class='hs-layout'>(</span><span class='hs-varid'>x</span><span class='hs-conop'>:</span><span class='hs-varid'>xs</span><span class='hs-layout'>)</span> <span class='hs-keyglyph'>=</span> <span class='hs-varid'>x</span> <span class='hs-conop'>:</span> <span class='hs-varid'>nubBy</span> <span class='hs-varid'>eq</span> <span class='hs-layout'>(</span><span class='hs-varid'>filter</span> <span class='hs-layout'>(</span><span class='hs-keyglyph'>\</span> <span class='hs-varid'>y</span> <span class='hs-keyglyph'>-></span> <span class='hs-varid'>not</span> <span class='hs-layout'>(</span><span class='hs-varid'>eq</span> <span class='hs-varid'>x</span> <span class='hs-varid'>y</span><span class='hs-layout'>)</span><span class='hs-layout'>)</span> <span class='hs-varid'>xs</span><span class='hs-layout'>)</span>
<a name="line-330"></a><span class='hs-cpp'>#else</span>
<a name="line-331"></a><span class='hs-definition'>nubBy</span> <span class='hs-varid'>eq</span> <span class='hs-varid'>l</span> <span class='hs-keyglyph'>=</span> <span class='hs-varid'>nubBy'</span> <span class='hs-varid'>l</span> <span class='hs-conid'>[]</span>
<a name="line-332"></a> <span class='hs-keyword'>where</span>
<a name="line-333"></a> <span class='hs-varid'>nubBy'</span> <span class='hs-conid'>[]</span> <span class='hs-keyword'>_</span> <span class='hs-keyglyph'>=</span> <span class='hs-conid'>[]</span>
<a name="line-334"></a> <span class='hs-varid'>nubBy'</span> <span class='hs-layout'>(</span><span class='hs-varid'>y</span><span class='hs-conop'>:</span><span class='hs-varid'>ys</span><span class='hs-layout'>)</span> <span class='hs-varid'>xs</span>
<a name="line-335"></a> <span class='hs-keyglyph'>|</span> <span class='hs-varid'>elem_by</span> <span class='hs-varid'>eq</span> <span class='hs-varid'>y</span> <span class='hs-varid'>xs</span> <span class='hs-keyglyph'>=</span> <span class='hs-varid'>nubBy'</span> <span class='hs-varid'>ys</span> <span class='hs-varid'>xs</span>
<a name="line-336"></a> <span class='hs-keyglyph'>|</span> <span class='hs-varid'>otherwise</span> <span class='hs-keyglyph'>=</span> <span class='hs-varid'>y</span> <span class='hs-conop'>:</span> <span class='hs-varid'>nubBy'</span> <span class='hs-varid'>ys</span> <span class='hs-layout'>(</span><span class='hs-varid'>y</span><span class='hs-conop'>:</span><span class='hs-varid'>xs</span><span class='hs-layout'>)</span>
<a name="line-337"></a>
<a name="line-338"></a><a name="elem_by"></a><span class='hs-comment'>-- Not exported:</span>
<a name="line-339"></a><span class='hs-comment'>-- Note that we keep the call to `eq` with arguments in the</span>
<a name="line-340"></a><span class='hs-comment'>-- same order as in the reference implementation</span>
<a name="line-341"></a><span class='hs-comment'>-- 'xs' is the list of things we've seen so far, </span>
<a name="line-342"></a><span class='hs-comment'>-- 'y' is the potential new element</span>
<a name="line-343"></a><span class='hs-definition'>elem_by</span> <span class='hs-keyglyph'>::</span> <span class='hs-layout'>(</span><span class='hs-varid'>a</span> <span class='hs-keyglyph'>-></span> <span class='hs-varid'>a</span> <span class='hs-keyglyph'>-></span> <span class='hs-conid'>Bool</span><span class='hs-layout'>)</span> <span class='hs-keyglyph'>-></span> <span class='hs-varid'>a</span> <span class='hs-keyglyph'>-></span> <span class='hs-keyglyph'>[</span><span class='hs-varid'>a</span><span class='hs-keyglyph'>]</span> <span class='hs-keyglyph'>-></span> <span class='hs-conid'>Bool</span>
<a name="line-344"></a><span class='hs-definition'>elem_by</span> <span class='hs-keyword'>_</span> <span class='hs-keyword'>_</span> <span class='hs-conid'>[]</span> <span class='hs-keyglyph'>=</span> <span class='hs-conid'>False</span>
<a name="line-345"></a><span class='hs-definition'>elem_by</span> <span class='hs-varid'>eq</span> <span class='hs-varid'>y</span> <span class='hs-layout'>(</span><span class='hs-varid'>x</span><span class='hs-conop'>:</span><span class='hs-varid'>xs</span><span class='hs-layout'>)</span> <span class='hs-keyglyph'>=</span> <span class='hs-varid'>y</span> <span class='hs-varop'>`eq`</span> <span class='hs-varid'>x</span> <span class='hs-varop'>||</span> <span class='hs-varid'>elem_by</span> <span class='hs-varid'>eq</span> <span class='hs-varid'>y</span> <span class='hs-varid'>xs</span>
<a name="line-346"></a><span class='hs-cpp'>#endif</span>
<a name="line-347"></a>
<a name="line-348"></a>
<a name="line-349"></a><span class='hs-comment'>-- | 'delete' @x@ removes the first occurrence of @x@ from its list argument.</span>
<a name="line-350"></a><span class='hs-comment'>-- For example,</span>
<a name="line-351"></a><span class='hs-comment'>--</span>
<a name="line-352"></a><span class='hs-comment'>-- > delete 'a' "banana" == "bnana"</span>
<a name="line-353"></a><span class='hs-comment'>--</span>
<a name="line-354"></a><span class='hs-comment'>-- It is a special case of 'deleteBy', which allows the programmer to</span>
<a name="line-355"></a><span class='hs-comment'>-- supply their own equality test.</span>
<a name="line-356"></a>
<a name="line-357"></a><a name="delete"></a><span class='hs-definition'>delete</span> <span class='hs-keyglyph'>::</span> <span class='hs-layout'>(</span><span class='hs-conid'>Eq</span> <span class='hs-varid'>a</span><span class='hs-layout'>)</span> <span class='hs-keyglyph'>=></span> <span class='hs-varid'>a</span> <span class='hs-keyglyph'>-></span> <span class='hs-keyglyph'>[</span><span class='hs-varid'>a</span><span class='hs-keyglyph'>]</span> <span class='hs-keyglyph'>-></span> <span class='hs-keyglyph'>[</span><span class='hs-varid'>a</span><span class='hs-keyglyph'>]</span>
<a name="line-358"></a><span class='hs-definition'>delete</span> <span class='hs-keyglyph'>=</span> <span class='hs-varid'>deleteBy</span> <span class='hs-layout'>(</span><span class='hs-varop'>==</span><span class='hs-layout'>)</span>
<a name="line-359"></a>
<a name="line-360"></a><a name="deleteBy"></a><span class='hs-comment'>-- | The 'deleteBy' function behaves like 'delete', but takes a</span>
<a name="line-361"></a><span class='hs-comment'>-- user-supplied equality predicate.</span>
<a name="line-362"></a><span class='hs-definition'>deleteBy</span> <span class='hs-keyglyph'>::</span> <span class='hs-layout'>(</span><span class='hs-varid'>a</span> <span class='hs-keyglyph'>-></span> <span class='hs-varid'>a</span> <span class='hs-keyglyph'>-></span> <span class='hs-conid'>Bool</span><span class='hs-layout'>)</span> <span class='hs-keyglyph'>-></span> <span class='hs-varid'>a</span> <span class='hs-keyglyph'>-></span> <span class='hs-keyglyph'>[</span><span class='hs-varid'>a</span><span class='hs-keyglyph'>]</span> <span class='hs-keyglyph'>-></span> <span class='hs-keyglyph'>[</span><span class='hs-varid'>a</span><span class='hs-keyglyph'>]</span>
<a name="line-363"></a><span class='hs-definition'>deleteBy</span> <span class='hs-keyword'>_</span> <span class='hs-keyword'>_</span> <span class='hs-conid'>[]</span> <span class='hs-keyglyph'>=</span> <span class='hs-conid'>[]</span>
<a name="line-364"></a><span class='hs-definition'>deleteBy</span> <span class='hs-varid'>eq</span> <span class='hs-varid'>x</span> <span class='hs-layout'>(</span><span class='hs-varid'>y</span><span class='hs-conop'>:</span><span class='hs-varid'>ys</span><span class='hs-layout'>)</span> <span class='hs-keyglyph'>=</span> <span class='hs-keyword'>if</span> <span class='hs-varid'>x</span> <span class='hs-varop'>`eq`</span> <span class='hs-varid'>y</span> <span class='hs-keyword'>then</span> <span class='hs-varid'>ys</span> <span class='hs-keyword'>else</span> <span class='hs-varid'>y</span> <span class='hs-conop'>:</span> <span class='hs-varid'>deleteBy</span> <span class='hs-varid'>eq</span> <span class='hs-varid'>x</span> <span class='hs-varid'>ys</span>
<a name="line-365"></a>
<a name="line-366"></a><span class='hs-comment'>-- | The '\\' function is list difference ((non-associative).</span>
<a name="line-367"></a><span class='hs-comment'>-- In the result of @xs@ '\\' @ys@, the first occurrence of each element of</span>
<a name="line-368"></a><span class='hs-comment'>-- @ys@ in turn (if any) has been removed from @xs@. Thus</span>
<a name="line-369"></a><span class='hs-comment'>--</span>
<a name="line-370"></a><span class='hs-comment'>-- > (xs ++ ys) \\ xs == ys.</span>
<a name="line-371"></a><span class='hs-comment'>--</span>
<a name="line-372"></a><span class='hs-comment'>-- It is a special case of 'deleteFirstsBy', which allows the programmer</span>
<a name="line-373"></a><span class='hs-comment'>-- to supply their own equality test.</span>
<a name="line-374"></a>
<a name="line-375"></a><a name="\\"></a><span class='hs-layout'>(</span><span class='hs-varop'>\\</span><span class='hs-layout'>)</span> <span class='hs-keyglyph'>::</span> <span class='hs-layout'>(</span><span class='hs-conid'>Eq</span> <span class='hs-varid'>a</span><span class='hs-layout'>)</span> <span class='hs-keyglyph'>=></span> <span class='hs-keyglyph'>[</span><span class='hs-varid'>a</span><span class='hs-keyglyph'>]</span> <span class='hs-keyglyph'>-></span> <span class='hs-keyglyph'>[</span><span class='hs-varid'>a</span><span class='hs-keyglyph'>]</span> <span class='hs-keyglyph'>-></span> <span class='hs-keyglyph'>[</span><span class='hs-varid'>a</span><span class='hs-keyglyph'>]</span>
<a name="line-376"></a><span class='hs-layout'>(</span><span class='hs-varop'>\\</span><span class='hs-layout'>)</span> <span class='hs-keyglyph'>=</span> <span class='hs-varid'>foldl</span> <span class='hs-layout'>(</span><span class='hs-varid'>flip</span> <span class='hs-varid'>delete</span><span class='hs-layout'>)</span>
<a name="line-377"></a>
<a name="line-378"></a><span class='hs-comment'>-- | The 'union' function returns the list union of the two lists.</span>
<a name="line-379"></a><span class='hs-comment'>-- For example,</span>
<a name="line-380"></a><span class='hs-comment'>--</span>
<a name="line-381"></a><span class='hs-comment'>-- > "dog" `union` "cow" == "dogcw"</span>
<a name="line-382"></a><span class='hs-comment'>--</span>
<a name="line-383"></a><span class='hs-comment'>-- Duplicates, and elements of the first list, are removed from the</span>
<a name="line-384"></a><span class='hs-comment'>-- the second list, but if the first list contains duplicates, so will</span>
<a name="line-385"></a><span class='hs-comment'>-- the result.</span>
<a name="line-386"></a><span class='hs-comment'>-- It is a special case of 'unionBy', which allows the programmer to supply</span>
<a name="line-387"></a><span class='hs-comment'>-- their own equality test.</span>
<a name="line-388"></a>
<a name="line-389"></a><a name="union"></a><span class='hs-definition'>union</span> <span class='hs-keyglyph'>::</span> <span class='hs-layout'>(</span><span class='hs-conid'>Eq</span> <span class='hs-varid'>a</span><span class='hs-layout'>)</span> <span class='hs-keyglyph'>=></span> <span class='hs-keyglyph'>[</span><span class='hs-varid'>a</span><span class='hs-keyglyph'>]</span> <span class='hs-keyglyph'>-></span> <span class='hs-keyglyph'>[</span><span class='hs-varid'>a</span><span class='hs-keyglyph'>]</span> <span class='hs-keyglyph'>-></span> <span class='hs-keyglyph'>[</span><span class='hs-varid'>a</span><span class='hs-keyglyph'>]</span>
<a name="line-390"></a><span class='hs-definition'>union</span> <span class='hs-keyglyph'>=</span> <span class='hs-varid'>unionBy</span> <span class='hs-layout'>(</span><span class='hs-varop'>==</span><span class='hs-layout'>)</span>
<a name="line-391"></a>
<a name="line-392"></a><a name="unionBy"></a><span class='hs-comment'>-- | The 'unionBy' function is the non-overloaded version of 'union'.</span>
<a name="line-393"></a><span class='hs-definition'>unionBy</span> <span class='hs-keyglyph'>::</span> <span class='hs-layout'>(</span><span class='hs-varid'>a</span> <span class='hs-keyglyph'>-></span> <span class='hs-varid'>a</span> <span class='hs-keyglyph'>-></span> <span class='hs-conid'>Bool</span><span class='hs-layout'>)</span> <span class='hs-keyglyph'>-></span> <span class='hs-keyglyph'>[</span><span class='hs-varid'>a</span><span class='hs-keyglyph'>]</span> <span class='hs-keyglyph'>-></span> <span class='hs-keyglyph'>[</span><span class='hs-varid'>a</span><span class='hs-keyglyph'>]</span> <span class='hs-keyglyph'>-></span> <span class='hs-keyglyph'>[</span><span class='hs-varid'>a</span><span class='hs-keyglyph'>]</span>
<a name="line-394"></a><span class='hs-definition'>unionBy</span> <span class='hs-varid'>eq</span> <span class='hs-varid'>xs</span> <span class='hs-varid'>ys</span> <span class='hs-keyglyph'>=</span> <span class='hs-varid'>xs</span> <span class='hs-varop'>++</span> <span class='hs-varid'>foldl</span> <span class='hs-layout'>(</span><span class='hs-varid'>flip</span> <span class='hs-layout'>(</span><span class='hs-varid'>deleteBy</span> <span class='hs-varid'>eq</span><span class='hs-layout'>)</span><span class='hs-layout'>)</span> <span class='hs-layout'>(</span><span class='hs-varid'>nubBy</span> <span class='hs-varid'>eq</span> <span class='hs-varid'>ys</span><span class='hs-layout'>)</span> <span class='hs-varid'>xs</span>
<a name="line-395"></a>
<a name="line-396"></a><span class='hs-comment'>-- | The 'intersect' function takes the list intersection of two lists.</span>
<a name="line-397"></a><span class='hs-comment'>-- For example,</span>
<a name="line-398"></a><span class='hs-comment'>--</span>
<a name="line-399"></a><span class='hs-comment'>-- > [1,2,3,4] `intersect` [2,4,6,8] == [2,4]</span>
<a name="line-400"></a><span class='hs-comment'>--</span>
<a name="line-401"></a><span class='hs-comment'>-- If the first list contains duplicates, so will the result.</span>
<a name="line-402"></a><span class='hs-comment'>--</span>
<a name="line-403"></a><span class='hs-comment'>-- > [1,2,2,3,4] `intersect` [6,4,4,2] == [2,2,4]</span>
<a name="line-404"></a><span class='hs-comment'>--</span>
<a name="line-405"></a><span class='hs-comment'>-- It is a special case of 'intersectBy', which allows the programmer to</span>
<a name="line-406"></a><span class='hs-comment'>-- supply their own equality test.</span>
<a name="line-407"></a>
<a name="line-408"></a><a name="intersect"></a><span class='hs-definition'>intersect</span> <span class='hs-keyglyph'>::</span> <span class='hs-layout'>(</span><span class='hs-conid'>Eq</span> <span class='hs-varid'>a</span><span class='hs-layout'>)</span> <span class='hs-keyglyph'>=></span> <span class='hs-keyglyph'>[</span><span class='hs-varid'>a</span><span class='hs-keyglyph'>]</span> <span class='hs-keyglyph'>-></span> <span class='hs-keyglyph'>[</span><span class='hs-varid'>a</span><span class='hs-keyglyph'>]</span> <span class='hs-keyglyph'>-></span> <span class='hs-keyglyph'>[</span><span class='hs-varid'>a</span><span class='hs-keyglyph'>]</span>
<a name="line-409"></a><span class='hs-definition'>intersect</span> <span class='hs-keyglyph'>=</span> <span class='hs-varid'>intersectBy</span> <span class='hs-layout'>(</span><span class='hs-varop'>==</span><span class='hs-layout'>)</span>
<a name="line-410"></a>
<a name="line-411"></a><a name="intersectBy"></a><span class='hs-comment'>-- | The 'intersectBy' function is the non-overloaded version of 'intersect'.</span>
<a name="line-412"></a><span class='hs-definition'>intersectBy</span> <span class='hs-keyglyph'>::</span> <span class='hs-layout'>(</span><span class='hs-varid'>a</span> <span class='hs-keyglyph'>-></span> <span class='hs-varid'>a</span> <span class='hs-keyglyph'>-></span> <span class='hs-conid'>Bool</span><span class='hs-layout'>)</span> <span class='hs-keyglyph'>-></span> <span class='hs-keyglyph'>[</span><span class='hs-varid'>a</span><span class='hs-keyglyph'>]</span> <span class='hs-keyglyph'>-></span> <span class='hs-keyglyph'>[</span><span class='hs-varid'>a</span><span class='hs-keyglyph'>]</span> <span class='hs-keyglyph'>-></span> <span class='hs-keyglyph'>[</span><span class='hs-varid'>a</span><span class='hs-keyglyph'>]</span>
<a name="line-413"></a><span class='hs-definition'>intersectBy</span> <span class='hs-varid'>eq</span> <span class='hs-varid'>xs</span> <span class='hs-varid'>ys</span> <span class='hs-keyglyph'>=</span> <span class='hs-keyglyph'>[</span><span class='hs-varid'>x</span> <span class='hs-keyglyph'>|</span> <span class='hs-varid'>x</span> <span class='hs-keyglyph'><-</span> <span class='hs-varid'>xs</span><span class='hs-layout'>,</span> <span class='hs-varid'>any</span> <span class='hs-layout'>(</span><span class='hs-varid'>eq</span> <span class='hs-varid'>x</span><span class='hs-layout'>)</span> <span class='hs-varid'>ys</span><span class='hs-keyglyph'>]</span>
<a name="line-414"></a>
<a name="line-415"></a><span class='hs-comment'>-- | The 'intersperse' function takes an element and a list and</span>
<a name="line-416"></a><span class='hs-comment'>-- \`intersperses\' that element between the elements of the list.</span>
<a name="line-417"></a><span class='hs-comment'>-- For example,</span>
<a name="line-418"></a><span class='hs-comment'>--</span>
<a name="line-419"></a><span class='hs-comment'>-- > intersperse ',' "abcde" == "a,b,c,d,e"</span>
<a name="line-420"></a>
<a name="line-421"></a><a name="intersperse"></a><span class='hs-definition'>intersperse</span> <span class='hs-keyglyph'>::</span> <span class='hs-varid'>a</span> <span class='hs-keyglyph'>-></span> <span class='hs-keyglyph'>[</span><span class='hs-varid'>a</span><span class='hs-keyglyph'>]</span> <span class='hs-keyglyph'>-></span> <span class='hs-keyglyph'>[</span><span class='hs-varid'>a</span><span class='hs-keyglyph'>]</span>
<a name="line-422"></a><span class='hs-definition'>intersperse</span> <span class='hs-keyword'>_</span> <span class='hs-conid'>[]</span> <span class='hs-keyglyph'>=</span> <span class='hs-conid'>[]</span>
<a name="line-423"></a><span class='hs-definition'>intersperse</span> <span class='hs-keyword'>_</span> <span class='hs-keyglyph'>[</span><span class='hs-varid'>x</span><span class='hs-keyglyph'>]</span> <span class='hs-keyglyph'>=</span> <span class='hs-keyglyph'>[</span><span class='hs-varid'>x</span><span class='hs-keyglyph'>]</span>
<a name="line-424"></a><span class='hs-definition'>intersperse</span> <span class='hs-varid'>sep</span> <span class='hs-layout'>(</span><span class='hs-varid'>x</span><span class='hs-conop'>:</span><span class='hs-varid'>xs</span><span class='hs-layout'>)</span> <span class='hs-keyglyph'>=</span> <span class='hs-varid'>x</span> <span class='hs-conop'>:</span> <span class='hs-varid'>sep</span> <span class='hs-conop'>:</span> <span class='hs-varid'>intersperse</span> <span class='hs-varid'>sep</span> <span class='hs-varid'>xs</span>
<a name="line-425"></a>
<a name="line-426"></a><a name="intercalate"></a><span class='hs-comment'>-- | 'intercalate' @xs xss@ is equivalent to @('concat' ('intersperse' xs xss))@.</span>
<a name="line-427"></a><span class='hs-comment'>-- It inserts the list @xs@ in between the lists in @xss@ and concatenates the</span>
<a name="line-428"></a><span class='hs-comment'>-- result.</span>
<a name="line-429"></a><span class='hs-definition'>intercalate</span> <span class='hs-keyglyph'>::</span> <span class='hs-keyglyph'>[</span><span class='hs-varid'>a</span><span class='hs-keyglyph'>]</span> <span class='hs-keyglyph'>-></span> <span class='hs-keyglyph'>[</span><span class='hs-keyglyph'>[</span><span class='hs-varid'>a</span><span class='hs-keyglyph'>]</span><span class='hs-keyglyph'>]</span> <span class='hs-keyglyph'>-></span> <span class='hs-keyglyph'>[</span><span class='hs-varid'>a</span><span class='hs-keyglyph'>]</span>
<a name="line-430"></a><span class='hs-definition'>intercalate</span> <span class='hs-varid'>xs</span> <span class='hs-varid'>xss</span> <span class='hs-keyglyph'>=</span> <span class='hs-varid'>concat</span> <span class='hs-layout'>(</span><span class='hs-varid'>intersperse</span> <span class='hs-varid'>xs</span> <span class='hs-varid'>xss</span><span class='hs-layout'>)</span>
<a name="line-431"></a>
<a name="line-432"></a><span class='hs-comment'>-- | The 'transpose' function transposes the rows and columns of its argument.</span>
<a name="line-433"></a><span class='hs-comment'>-- For example,</span>
<a name="line-434"></a><span class='hs-comment'>--</span>
<a name="line-435"></a><span class='hs-comment'>-- > transpose [[1,2,3],[4,5,6]] == [[1,4],[2,5],[3,6]]</span>
<a name="line-436"></a>
<a name="line-437"></a><a name="transpose"></a><span class='hs-definition'>transpose</span> <span class='hs-keyglyph'>::</span> <span class='hs-keyglyph'>[</span><span class='hs-keyglyph'>[</span><span class='hs-varid'>a</span><span class='hs-keyglyph'>]</span><span class='hs-keyglyph'>]</span> <span class='hs-keyglyph'>-></span> <span class='hs-keyglyph'>[</span><span class='hs-keyglyph'>[</span><span class='hs-varid'>a</span><span class='hs-keyglyph'>]</span><span class='hs-keyglyph'>]</span>
<a name="line-438"></a><span class='hs-definition'>transpose</span> <span class='hs-conid'>[]</span> <span class='hs-keyglyph'>=</span> <span class='hs-conid'>[]</span>
<a name="line-439"></a><span class='hs-definition'>transpose</span> <span class='hs-layout'>(</span><span class='hs-conid'>[]</span> <span class='hs-conop'>:</span> <span class='hs-varid'>xss</span><span class='hs-layout'>)</span> <span class='hs-keyglyph'>=</span> <span class='hs-varid'>transpose</span> <span class='hs-varid'>xss</span>
<a name="line-440"></a><span class='hs-definition'>transpose</span> <span class='hs-layout'>(</span><span class='hs-layout'>(</span><span class='hs-varid'>x</span><span class='hs-conop'>:</span><span class='hs-varid'>xs</span><span class='hs-layout'>)</span> <span class='hs-conop'>:</span> <span class='hs-varid'>xss</span><span class='hs-layout'>)</span> <span class='hs-keyglyph'>=</span> <span class='hs-layout'>(</span><span class='hs-varid'>x</span> <span class='hs-conop'>:</span> <span class='hs-keyglyph'>[</span><span class='hs-varid'>h</span> <span class='hs-keyglyph'>|</span> <span class='hs-layout'>(</span><span class='hs-varid'>h</span><span class='hs-conop'>:</span><span class='hs-keyword'>_</span><span class='hs-layout'>)</span> <span class='hs-keyglyph'><-</span> <span class='hs-varid'>xss</span><span class='hs-keyglyph'>]</span><span class='hs-layout'>)</span> <span class='hs-conop'>:</span> <span class='hs-varid'>transpose</span> <span class='hs-layout'>(</span><span class='hs-varid'>xs</span> <span class='hs-conop'>:</span> <span class='hs-keyglyph'>[</span> <span class='hs-varid'>t</span> <span class='hs-keyglyph'>|</span> <span class='hs-layout'>(</span><span class='hs-keyword'>_</span><span class='hs-conop'>:</span><span class='hs-varid'>t</span><span class='hs-layout'>)</span> <span class='hs-keyglyph'><-</span> <span class='hs-varid'>xss</span><span class='hs-keyglyph'>]</span><span class='hs-layout'>)</span>
<a name="line-441"></a>
<a name="line-442"></a>
<a name="line-443"></a><span class='hs-comment'>-- | The 'partition' function takes a predicate a list and returns</span>
<a name="line-444"></a><span class='hs-comment'>-- the pair of lists of elements which do and do not satisfy the</span>
<a name="line-445"></a><span class='hs-comment'>-- predicate, respectively; i.e.,</span>
<a name="line-446"></a><span class='hs-comment'>--</span>
<a name="line-447"></a><span class='hs-comment'>-- > partition p xs == (filter p xs, filter (not . p) xs)</span>
<a name="line-448"></a>
<a name="line-449"></a><a name="partition"></a><span class='hs-definition'>partition</span> <span class='hs-keyglyph'>::</span> <span class='hs-layout'>(</span><span class='hs-varid'>a</span> <span class='hs-keyglyph'>-></span> <span class='hs-conid'>Bool</span><span class='hs-layout'>)</span> <span class='hs-keyglyph'>-></span> <span class='hs-keyglyph'>[</span><span class='hs-varid'>a</span><span class='hs-keyglyph'>]</span> <span class='hs-keyglyph'>-></span> <span class='hs-layout'>(</span><span class='hs-keyglyph'>[</span><span class='hs-varid'>a</span><span class='hs-keyglyph'>]</span><span class='hs-layout'>,</span><span class='hs-keyglyph'>[</span><span class='hs-varid'>a</span><span class='hs-keyglyph'>]</span><span class='hs-layout'>)</span>
<a name="line-450"></a><span class='hs-comment'>{-# INLINE partition #-}</span>
<a name="line-451"></a><span class='hs-definition'>partition</span> <span class='hs-varid'>p</span> <span class='hs-varid'>xs</span> <span class='hs-keyglyph'>=</span> <span class='hs-varid'>foldr</span> <span class='hs-layout'>(</span><span class='hs-varid'>select</span> <span class='hs-varid'>p</span><span class='hs-layout'>)</span> <span class='hs-layout'>(</span><span class='hs-conid'>[]</span><span class='hs-layout'>,</span><span class='hs-conid'>[]</span><span class='hs-layout'>)</span> <span class='hs-varid'>xs</span>
<a name="line-452"></a>
<a name="line-453"></a><a name="select"></a><span class='hs-definition'>select</span> <span class='hs-keyglyph'>::</span> <span class='hs-layout'>(</span><span class='hs-varid'>a</span> <span class='hs-keyglyph'>-></span> <span class='hs-conid'>Bool</span><span class='hs-layout'>)</span> <span class='hs-keyglyph'>-></span> <span class='hs-varid'>a</span> <span class='hs-keyglyph'>-></span> <span class='hs-layout'>(</span><span class='hs-keyglyph'>[</span><span class='hs-varid'>a</span><span class='hs-keyglyph'>]</span><span class='hs-layout'>,</span> <span class='hs-keyglyph'>[</span><span class='hs-varid'>a</span><span class='hs-keyglyph'>]</span><span class='hs-layout'>)</span> <span class='hs-keyglyph'>-></span> <span class='hs-layout'>(</span><span class='hs-keyglyph'>[</span><span class='hs-varid'>a</span><span class='hs-keyglyph'>]</span><span class='hs-layout'>,</span> <span class='hs-keyglyph'>[</span><span class='hs-varid'>a</span><span class='hs-keyglyph'>]</span><span class='hs-layout'>)</span>
<a name="line-454"></a><span class='hs-definition'>select</span> <span class='hs-varid'>p</span> <span class='hs-varid'>x</span> <span class='hs-keyglyph'>~</span><span class='hs-layout'>(</span><span class='hs-varid'>ts</span><span class='hs-layout'>,</span><span class='hs-varid'>fs</span><span class='hs-layout'>)</span> <span class='hs-keyglyph'>|</span> <span class='hs-varid'>p</span> <span class='hs-varid'>x</span> <span class='hs-keyglyph'>=</span> <span class='hs-layout'>(</span><span class='hs-varid'>x</span><span class='hs-conop'>:</span><span class='hs-varid'>ts</span><span class='hs-layout'>,</span><span class='hs-varid'>fs</span><span class='hs-layout'>)</span>
<a name="line-455"></a> <span class='hs-keyglyph'>|</span> <span class='hs-varid'>otherwise</span> <span class='hs-keyglyph'>=</span> <span class='hs-layout'>(</span><span class='hs-varid'>ts</span><span class='hs-layout'>,</span> <span class='hs-varid'>x</span><span class='hs-conop'>:</span><span class='hs-varid'>fs</span><span class='hs-layout'>)</span>
<a name="line-456"></a>
<a name="line-457"></a><a name="mapAccumL"></a><span class='hs-comment'>-- | The 'mapAccumL' function behaves like a combination of 'map' and</span>
<a name="line-458"></a><span class='hs-comment'>-- 'foldl'; it applies a function to each element of a list, passing</span>
<a name="line-459"></a><span class='hs-comment'>-- an accumulating parameter from left to right, and returning a final</span>
<a name="line-460"></a><span class='hs-comment'>-- value of this accumulator together with the new list.</span>
<a name="line-461"></a><span class='hs-definition'>mapAccumL</span> <span class='hs-keyglyph'>::</span> <span class='hs-layout'>(</span><span class='hs-varid'>acc</span> <span class='hs-keyglyph'>-></span> <span class='hs-varid'>x</span> <span class='hs-keyglyph'>-></span> <span class='hs-layout'>(</span><span class='hs-varid'>acc</span><span class='hs-layout'>,</span> <span class='hs-varid'>y</span><span class='hs-layout'>)</span><span class='hs-layout'>)</span> <span class='hs-comment'>-- Function of elt of input list</span>
<a name="line-462"></a> <span class='hs-comment'>-- and accumulator, returning new</span>
<a name="line-463"></a> <span class='hs-comment'>-- accumulator and elt of result list</span>
<a name="line-464"></a> <span class='hs-keyglyph'>-></span> <span class='hs-varid'>acc</span> <span class='hs-comment'>-- Initial accumulator </span>
<a name="line-465"></a> <span class='hs-keyglyph'>-></span> <span class='hs-keyglyph'>[</span><span class='hs-varid'>x</span><span class='hs-keyglyph'>]</span> <span class='hs-comment'>-- Input list</span>
<a name="line-466"></a> <span class='hs-keyglyph'>-></span> <span class='hs-layout'>(</span><span class='hs-varid'>acc</span><span class='hs-layout'>,</span> <span class='hs-keyglyph'>[</span><span class='hs-varid'>y</span><span class='hs-keyglyph'>]</span><span class='hs-layout'>)</span> <span class='hs-comment'>-- Final accumulator and result list</span>
<a name="line-467"></a><span class='hs-definition'>mapAccumL</span> <span class='hs-keyword'>_</span> <span class='hs-varid'>s</span> <span class='hs-conid'>[]</span> <span class='hs-keyglyph'>=</span> <span class='hs-layout'>(</span><span class='hs-varid'>s</span><span class='hs-layout'>,</span> <span class='hs-conid'>[]</span><span class='hs-layout'>)</span>
<a name="line-468"></a><span class='hs-definition'>mapAccumL</span> <span class='hs-varid'>f</span> <span class='hs-varid'>s</span> <span class='hs-layout'>(</span><span class='hs-varid'>x</span><span class='hs-conop'>:</span><span class='hs-varid'>xs</span><span class='hs-layout'>)</span> <span class='hs-keyglyph'>=</span> <span class='hs-layout'>(</span><span class='hs-varid'>s''</span><span class='hs-layout'>,</span><span class='hs-varid'>y</span><span class='hs-conop'>:</span><span class='hs-varid'>ys</span><span class='hs-layout'>)</span>
<a name="line-469"></a> <span class='hs-keyword'>where</span> <span class='hs-layout'>(</span><span class='hs-varid'>s'</span><span class='hs-layout'>,</span> <span class='hs-varid'>y</span> <span class='hs-layout'>)</span> <span class='hs-keyglyph'>=</span> <span class='hs-varid'>f</span> <span class='hs-varid'>s</span> <span class='hs-varid'>x</span>
<a name="line-470"></a> <span class='hs-layout'>(</span><span class='hs-varid'>s''</span><span class='hs-layout'>,</span><span class='hs-varid'>ys</span><span class='hs-layout'>)</span> <span class='hs-keyglyph'>=</span> <span class='hs-varid'>mapAccumL</span> <span class='hs-varid'>f</span> <span class='hs-varid'>s'</span> <span class='hs-varid'>xs</span>
<a name="line-471"></a>
<a name="line-472"></a><a name="mapAccumR"></a><span class='hs-comment'>-- | The 'mapAccumR' function behaves like a combination of 'map' and</span>
<a name="line-473"></a><span class='hs-comment'>-- 'foldr'; it applies a function to each element of a list, passing</span>
<a name="line-474"></a><span class='hs-comment'>-- an accumulating parameter from right to left, and returning a final</span>
<a name="line-475"></a><span class='hs-comment'>-- value of this accumulator together with the new list.</span>
<a name="line-476"></a><span class='hs-definition'>mapAccumR</span> <span class='hs-keyglyph'>::</span> <span class='hs-layout'>(</span><span class='hs-varid'>acc</span> <span class='hs-keyglyph'>-></span> <span class='hs-varid'>x</span> <span class='hs-keyglyph'>-></span> <span class='hs-layout'>(</span><span class='hs-varid'>acc</span><span class='hs-layout'>,</span> <span class='hs-varid'>y</span><span class='hs-layout'>)</span><span class='hs-layout'>)</span> <span class='hs-comment'>-- Function of elt of input list</span>
<a name="line-477"></a> <span class='hs-comment'>-- and accumulator, returning new</span>
<a name="line-478"></a> <span class='hs-comment'>-- accumulator and elt of result list</span>
<a name="line-479"></a> <span class='hs-keyglyph'>-></span> <span class='hs-varid'>acc</span> <span class='hs-comment'>-- Initial accumulator</span>
<a name="line-480"></a> <span class='hs-keyglyph'>-></span> <span class='hs-keyglyph'>[</span><span class='hs-varid'>x</span><span class='hs-keyglyph'>]</span> <span class='hs-comment'>-- Input list</span>
<a name="line-481"></a> <span class='hs-keyglyph'>-></span> <span class='hs-layout'>(</span><span class='hs-varid'>acc</span><span class='hs-layout'>,</span> <span class='hs-keyglyph'>[</span><span class='hs-varid'>y</span><span class='hs-keyglyph'>]</span><span class='hs-layout'>)</span> <span class='hs-comment'>-- Final accumulator and result list</span>
<a name="line-482"></a><span class='hs-definition'>mapAccumR</span> <span class='hs-keyword'>_</span> <span class='hs-varid'>s</span> <span class='hs-conid'>[]</span> <span class='hs-keyglyph'>=</span> <span class='hs-layout'>(</span><span class='hs-varid'>s</span><span class='hs-layout'>,</span> <span class='hs-conid'>[]</span><span class='hs-layout'>)</span>
<a name="line-483"></a><span class='hs-definition'>mapAccumR</span> <span class='hs-varid'>f</span> <span class='hs-varid'>s</span> <span class='hs-layout'>(</span><span class='hs-varid'>x</span><span class='hs-conop'>:</span><span class='hs-varid'>xs</span><span class='hs-layout'>)</span> <span class='hs-keyglyph'>=</span> <span class='hs-layout'>(</span><span class='hs-varid'>s''</span><span class='hs-layout'>,</span> <span class='hs-varid'>y</span><span class='hs-conop'>:</span><span class='hs-varid'>ys</span><span class='hs-layout'>)</span>
<a name="line-484"></a> <span class='hs-keyword'>where</span> <span class='hs-layout'>(</span><span class='hs-varid'>s''</span><span class='hs-layout'>,</span><span class='hs-varid'>y</span> <span class='hs-layout'>)</span> <span class='hs-keyglyph'>=</span> <span class='hs-varid'>f</span> <span class='hs-varid'>s'</span> <span class='hs-varid'>x</span>
<a name="line-485"></a> <span class='hs-layout'>(</span><span class='hs-varid'>s'</span><span class='hs-layout'>,</span> <span class='hs-varid'>ys</span><span class='hs-layout'>)</span> <span class='hs-keyglyph'>=</span> <span class='hs-varid'>mapAccumR</span> <span class='hs-varid'>f</span> <span class='hs-varid'>s</span> <span class='hs-varid'>xs</span>
<a name="line-486"></a>
<a name="line-487"></a><a name="insert"></a><span class='hs-comment'>-- | The 'insert' function takes an element and a list and inserts the</span>
<a name="line-488"></a><span class='hs-comment'>-- element into the list at the last position where it is still less</span>
<a name="line-489"></a><span class='hs-comment'>-- than or equal to the next element. In particular, if the list</span>
<a name="line-490"></a><span class='hs-comment'>-- is sorted before the call, the result will also be sorted.</span>
<a name="line-491"></a><span class='hs-comment'>-- It is a special case of 'insertBy', which allows the programmer to</span>
<a name="line-492"></a><span class='hs-comment'>-- supply their own comparison function.</span>
<a name="line-493"></a><span class='hs-definition'>insert</span> <span class='hs-keyglyph'>::</span> <span class='hs-conid'>Ord</span> <span class='hs-varid'>a</span> <span class='hs-keyglyph'>=></span> <span class='hs-varid'>a</span> <span class='hs-keyglyph'>-></span> <span class='hs-keyglyph'>[</span><span class='hs-varid'>a</span><span class='hs-keyglyph'>]</span> <span class='hs-keyglyph'>-></span> <span class='hs-keyglyph'>[</span><span class='hs-varid'>a</span><span class='hs-keyglyph'>]</span>
<a name="line-494"></a><span class='hs-definition'>insert</span> <span class='hs-varid'>e</span> <span class='hs-varid'>ls</span> <span class='hs-keyglyph'>=</span> <span class='hs-varid'>insertBy</span> <span class='hs-layout'>(</span><span class='hs-varid'>compare</span><span class='hs-layout'>)</span> <span class='hs-varid'>e</span> <span class='hs-varid'>ls</span>
<a name="line-495"></a>
<a name="line-496"></a><a name="insertBy"></a><span class='hs-comment'>-- | The non-overloaded version of 'insert'.</span>
<a name="line-497"></a><span class='hs-definition'>insertBy</span> <span class='hs-keyglyph'>::</span> <span class='hs-layout'>(</span><span class='hs-varid'>a</span> <span class='hs-keyglyph'>-></span> <span class='hs-varid'>a</span> <span class='hs-keyglyph'>-></span> <span class='hs-conid'>Ordering</span><span class='hs-layout'>)</span> <span class='hs-keyglyph'>-></span> <span class='hs-varid'>a</span> <span class='hs-keyglyph'>-></span> <span class='hs-keyglyph'>[</span><span class='hs-varid'>a</span><span class='hs-keyglyph'>]</span> <span class='hs-keyglyph'>-></span> <span class='hs-keyglyph'>[</span><span class='hs-varid'>a</span><span class='hs-keyglyph'>]</span>
<a name="line-498"></a><span class='hs-definition'>insertBy</span> <span class='hs-keyword'>_</span> <span class='hs-varid'>x</span> <span class='hs-conid'>[]</span> <span class='hs-keyglyph'>=</span> <span class='hs-keyglyph'>[</span><span class='hs-varid'>x</span><span class='hs-keyglyph'>]</span>
<a name="line-499"></a><span class='hs-definition'>insertBy</span> <span class='hs-varid'>cmp</span> <span class='hs-varid'>x</span> <span class='hs-varid'>ys</span><span class='hs-keyglyph'>@</span><span class='hs-layout'>(</span><span class='hs-varid'>y</span><span class='hs-conop'>:</span><span class='hs-varid'>ys'</span><span class='hs-layout'>)</span>
<a name="line-500"></a> <span class='hs-keyglyph'>=</span> <span class='hs-keyword'>case</span> <span class='hs-varid'>cmp</span> <span class='hs-varid'>x</span> <span class='hs-varid'>y</span> <span class='hs-keyword'>of</span>
<a name="line-501"></a> <span class='hs-conid'>GT</span> <span class='hs-keyglyph'>-></span> <span class='hs-varid'>y</span> <span class='hs-conop'>:</span> <span class='hs-varid'>insertBy</span> <span class='hs-varid'>cmp</span> <span class='hs-varid'>x</span> <span class='hs-varid'>ys'</span>
<a name="line-502"></a> <span class='hs-keyword'>_</span> <span class='hs-keyglyph'>-></span> <span class='hs-varid'>x</span> <span class='hs-conop'>:</span> <span class='hs-varid'>ys</span>
<a name="line-503"></a>
<a name="line-504"></a><span class='hs-cpp'>#ifdef __GLASGOW_HASKELL__</span>
<a name="line-505"></a>
<a name="line-506"></a><a name="maximum"></a><span class='hs-comment'>-- | 'maximum' returns the maximum value from a list,</span>
<a name="line-507"></a><span class='hs-comment'>-- which must be non-empty, finite, and of an ordered type.</span>
<a name="line-508"></a><span class='hs-comment'>-- It is a special case of 'Data.List.maximumBy', which allows the</span>
<a name="line-509"></a><span class='hs-comment'>-- programmer to supply their own comparison function.</span>
<a name="line-510"></a><span class='hs-definition'>maximum</span> <span class='hs-keyglyph'>::</span> <span class='hs-layout'>(</span><span class='hs-conid'>Ord</span> <span class='hs-varid'>a</span><span class='hs-layout'>)</span> <span class='hs-keyglyph'>=></span> <span class='hs-keyglyph'>[</span><span class='hs-varid'>a</span><span class='hs-keyglyph'>]</span> <span class='hs-keyglyph'>-></span> <span class='hs-varid'>a</span>
<a name="line-511"></a><span class='hs-definition'>maximum</span> <span class='hs-conid'>[]</span> <span class='hs-keyglyph'>=</span> <span class='hs-varid'>errorEmptyList</span> <span class='hs-str'>"maximum"</span>
<a name="line-512"></a><span class='hs-definition'>maximum</span> <span class='hs-varid'>xs</span> <span class='hs-keyglyph'>=</span> <span class='hs-varid'>foldl1</span> <span class='hs-varid'>max</span> <span class='hs-varid'>xs</span>
<a name="line-513"></a>
<a name="line-514"></a><span class='hs-comment'>{-# RULES
<a name="line-515"></a> "maximumInt" maximum = (strictMaximum :: [Int] -> Int);
<a name="line-516"></a> "maximumInteger" maximum = (strictMaximum :: [Integer] -> Integer)
<a name="line-517"></a> #-}</span>
<a name="line-518"></a>
<a name="line-519"></a><a name="strictMaximum"></a><span class='hs-comment'>-- We can't make the overloaded version of maximum strict without</span>
<a name="line-520"></a><span class='hs-comment'>-- changing its semantics (max might not be strict), but we can for</span>
<a name="line-521"></a><span class='hs-comment'>-- the version specialised to 'Int'.</span>
<a name="line-522"></a><span class='hs-definition'>strictMaximum</span> <span class='hs-keyglyph'>::</span> <span class='hs-layout'>(</span><span class='hs-conid'>Ord</span> <span class='hs-varid'>a</span><span class='hs-layout'>)</span> <span class='hs-keyglyph'>=></span> <span class='hs-keyglyph'>[</span><span class='hs-varid'>a</span><span class='hs-keyglyph'>]</span> <span class='hs-keyglyph'>-></span> <span class='hs-varid'>a</span>
<a name="line-523"></a><span class='hs-definition'>strictMaximum</span> <span class='hs-conid'>[]</span> <span class='hs-keyglyph'>=</span> <span class='hs-varid'>errorEmptyList</span> <span class='hs-str'>"maximum"</span>
<a name="line-524"></a><span class='hs-definition'>strictMaximum</span> <span class='hs-varid'>xs</span> <span class='hs-keyglyph'>=</span> <span class='hs-varid'>foldl1'</span> <span class='hs-varid'>max</span> <span class='hs-varid'>xs</span>
<a name="line-525"></a>
<a name="line-526"></a><a name="minimum"></a><span class='hs-comment'>-- | 'minimum' returns the minimum value from a list,</span>
<a name="line-527"></a><span class='hs-comment'>-- which must be non-empty, finite, and of an ordered type.</span>
<a name="line-528"></a><span class='hs-comment'>-- It is a special case of 'Data.List.minimumBy', which allows the</span>
<a name="line-529"></a><span class='hs-comment'>-- programmer to supply their own comparison function.</span>
<a name="line-530"></a><span class='hs-definition'>minimum</span> <span class='hs-keyglyph'>::</span> <span class='hs-layout'>(</span><span class='hs-conid'>Ord</span> <span class='hs-varid'>a</span><span class='hs-layout'>)</span> <span class='hs-keyglyph'>=></span> <span class='hs-keyglyph'>[</span><span class='hs-varid'>a</span><span class='hs-keyglyph'>]</span> <span class='hs-keyglyph'>-></span> <span class='hs-varid'>a</span>
<a name="line-531"></a><span class='hs-definition'>minimum</span> <span class='hs-conid'>[]</span> <span class='hs-keyglyph'>=</span> <span class='hs-varid'>errorEmptyList</span> <span class='hs-str'>"minimum"</span>
<a name="line-532"></a><span class='hs-definition'>minimum</span> <span class='hs-varid'>xs</span> <span class='hs-keyglyph'>=</span> <span class='hs-varid'>foldl1</span> <span class='hs-varid'>min</span> <span class='hs-varid'>xs</span>
<a name="line-533"></a>
<a name="line-534"></a><span class='hs-comment'>{-# RULES
<a name="line-535"></a> "minimumInt" minimum = (strictMinimum :: [Int] -> Int);
<a name="line-536"></a> "minimumInteger" minimum = (strictMinimum :: [Integer] -> Integer)
<a name="line-537"></a> #-}</span>
<a name="line-538"></a>
<a name="line-539"></a><a name="strictMinimum"></a><span class='hs-definition'>strictMinimum</span> <span class='hs-keyglyph'>::</span> <span class='hs-layout'>(</span><span class='hs-conid'>Ord</span> <span class='hs-varid'>a</span><span class='hs-layout'>)</span> <span class='hs-keyglyph'>=></span> <span class='hs-keyglyph'>[</span><span class='hs-varid'>a</span><span class='hs-keyglyph'>]</span> <span class='hs-keyglyph'>-></span> <span class='hs-varid'>a</span>
<a name="line-540"></a><span class='hs-definition'>strictMinimum</span> <span class='hs-conid'>[]</span> <span class='hs-keyglyph'>=</span> <span class='hs-varid'>errorEmptyList</span> <span class='hs-str'>"minimum"</span>
<a name="line-541"></a><span class='hs-definition'>strictMinimum</span> <span class='hs-varid'>xs</span> <span class='hs-keyglyph'>=</span> <span class='hs-varid'>foldl1'</span> <span class='hs-varid'>min</span> <span class='hs-varid'>xs</span>
<a name="line-542"></a>
<a name="line-543"></a><span class='hs-cpp'>#endif /* __GLASGOW_HASKELL__ */</span>
<a name="line-544"></a>
<a name="line-545"></a><a name="maximumBy"></a><span class='hs-comment'>-- | The 'maximumBy' function takes a comparison function and a list</span>
<a name="line-546"></a><span class='hs-comment'>-- and returns the greatest element of the list by the comparison function.</span>
<a name="line-547"></a><span class='hs-comment'>-- The list must be finite and non-empty.</span>
<a name="line-548"></a><span class='hs-definition'>maximumBy</span> <span class='hs-keyglyph'>::</span> <span class='hs-layout'>(</span><span class='hs-varid'>a</span> <span class='hs-keyglyph'>-></span> <span class='hs-varid'>a</span> <span class='hs-keyglyph'>-></span> <span class='hs-conid'>Ordering</span><span class='hs-layout'>)</span> <span class='hs-keyglyph'>-></span> <span class='hs-keyglyph'>[</span><span class='hs-varid'>a</span><span class='hs-keyglyph'>]</span> <span class='hs-keyglyph'>-></span> <span class='hs-varid'>a</span>
<a name="line-549"></a><span class='hs-definition'>maximumBy</span> <span class='hs-keyword'>_</span> <span class='hs-conid'>[]</span> <span class='hs-keyglyph'>=</span> <span class='hs-varid'>error</span> <span class='hs-str'>"List.maximumBy: empty list"</span>
<a name="line-550"></a><span class='hs-definition'>maximumBy</span> <span class='hs-varid'>cmp</span> <span class='hs-varid'>xs</span> <span class='hs-keyglyph'>=</span> <span class='hs-varid'>foldl1</span> <span class='hs-varid'>maxBy</span> <span class='hs-varid'>xs</span>
<a name="line-551"></a> <span class='hs-keyword'>where</span>
<a name="line-552"></a> <span class='hs-varid'>maxBy</span> <span class='hs-varid'>x</span> <span class='hs-varid'>y</span> <span class='hs-keyglyph'>=</span> <span class='hs-keyword'>case</span> <span class='hs-varid'>cmp</span> <span class='hs-varid'>x</span> <span class='hs-varid'>y</span> <span class='hs-keyword'>of</span>
<a name="line-553"></a> <span class='hs-conid'>GT</span> <span class='hs-keyglyph'>-></span> <span class='hs-varid'>x</span>
<a name="line-554"></a> <span class='hs-keyword'>_</span> <span class='hs-keyglyph'>-></span> <span class='hs-varid'>y</span>
<a name="line-555"></a>
<a name="line-556"></a><a name="minimumBy"></a><span class='hs-comment'>-- | The 'minimumBy' function takes a comparison function and a list</span>
<a name="line-557"></a><span class='hs-comment'>-- and returns the least element of the list by the comparison function.</span>
<a name="line-558"></a><span class='hs-comment'>-- The list must be finite and non-empty.</span>
<a name="line-559"></a><span class='hs-definition'>minimumBy</span> <span class='hs-keyglyph'>::</span> <span class='hs-layout'>(</span><span class='hs-varid'>a</span> <span class='hs-keyglyph'>-></span> <span class='hs-varid'>a</span> <span class='hs-keyglyph'>-></span> <span class='hs-conid'>Ordering</span><span class='hs-layout'>)</span> <span class='hs-keyglyph'>-></span> <span class='hs-keyglyph'>[</span><span class='hs-varid'>a</span><span class='hs-keyglyph'>]</span> <span class='hs-keyglyph'>-></span> <span class='hs-varid'>a</span>
<a name="line-560"></a><span class='hs-definition'>minimumBy</span> <span class='hs-keyword'>_</span> <span class='hs-conid'>[]</span> <span class='hs-keyglyph'>=</span> <span class='hs-varid'>error</span> <span class='hs-str'>"List.minimumBy: empty list"</span>
<a name="line-561"></a><span class='hs-definition'>minimumBy</span> <span class='hs-varid'>cmp</span> <span class='hs-varid'>xs</span> <span class='hs-keyglyph'>=</span> <span class='hs-varid'>foldl1</span> <span class='hs-varid'>minBy</span> <span class='hs-varid'>xs</span>
<a name="line-562"></a> <span class='hs-keyword'>where</span>
<a name="line-563"></a> <span class='hs-varid'>minBy</span> <span class='hs-varid'>x</span> <span class='hs-varid'>y</span> <span class='hs-keyglyph'>=</span> <span class='hs-keyword'>case</span> <span class='hs-varid'>cmp</span> <span class='hs-varid'>x</span> <span class='hs-varid'>y</span> <span class='hs-keyword'>of</span>
<a name="line-564"></a> <span class='hs-conid'>GT</span> <span class='hs-keyglyph'>-></span> <span class='hs-varid'>y</span>
<a name="line-565"></a> <span class='hs-keyword'>_</span> <span class='hs-keyglyph'>-></span> <span class='hs-varid'>x</span>
<a name="line-566"></a>
<a name="line-567"></a><a name="genericLength"></a><span class='hs-comment'>-- | The 'genericLength' function is an overloaded version of 'length'. In</span>
<a name="line-568"></a><span class='hs-comment'>-- particular, instead of returning an 'Int', it returns any type which is</span>
<a name="line-569"></a><span class='hs-comment'>-- an instance of 'Num'. It is, however, less efficient than 'length'.</span>
<a name="line-570"></a><span class='hs-definition'>genericLength</span> <span class='hs-keyglyph'>::</span> <span class='hs-layout'>(</span><span class='hs-conid'>Num</span> <span class='hs-varid'>i</span><span class='hs-layout'>)</span> <span class='hs-keyglyph'>=></span> <span class='hs-keyglyph'>[</span><span class='hs-varid'>b</span><span class='hs-keyglyph'>]</span> <span class='hs-keyglyph'>-></span> <span class='hs-varid'>i</span>
<a name="line-571"></a><span class='hs-definition'>genericLength</span> <span class='hs-conid'>[]</span> <span class='hs-keyglyph'>=</span> <span class='hs-num'>0</span>
<a name="line-572"></a><span class='hs-definition'>genericLength</span> <span class='hs-layout'>(</span><span class='hs-keyword'>_</span><span class='hs-conop'>:</span><span class='hs-varid'>l</span><span class='hs-layout'>)</span> <span class='hs-keyglyph'>=</span> <span class='hs-num'>1</span> <span class='hs-varop'>+</span> <span class='hs-varid'>genericLength</span> <span class='hs-varid'>l</span>
<a name="line-573"></a>
<a name="line-574"></a><span class='hs-comment'>{-# RULES
<a name="line-575"></a> "genericLengthInt" genericLength = (strictGenericLength :: [a] -> Int);
<a name="line-576"></a> "genericLengthInteger" genericLength = (strictGenericLength :: [a] -> Integer);
<a name="line-577"></a> #-}</span>
<a name="line-578"></a>
<a name="line-579"></a><a name="strictGenericLength"></a><span class='hs-definition'>strictGenericLength</span> <span class='hs-keyglyph'>::</span> <span class='hs-layout'>(</span><span class='hs-conid'>Num</span> <span class='hs-varid'>i</span><span class='hs-layout'>)</span> <span class='hs-keyglyph'>=></span> <span class='hs-keyglyph'>[</span><span class='hs-varid'>b</span><span class='hs-keyglyph'>]</span> <span class='hs-keyglyph'>-></span> <span class='hs-varid'>i</span>
<a name="line-580"></a><span class='hs-definition'>strictGenericLength</span> <span class='hs-varid'>l</span> <span class='hs-keyglyph'>=</span> <span class='hs-varid'>gl</span> <span class='hs-varid'>l</span> <span class='hs-num'>0</span>
<a name="line-581"></a> <span class='hs-keyword'>where</span>
<a name="line-582"></a> <span class='hs-varid'>gl</span> <span class='hs-conid'>[]</span> <span class='hs-varid'>a</span> <span class='hs-keyglyph'>=</span> <span class='hs-varid'>a</span>
<a name="line-583"></a> <span class='hs-varid'>gl</span> <span class='hs-layout'>(</span><span class='hs-keyword'>_</span><span class='hs-conop'>:</span><span class='hs-varid'>xs</span><span class='hs-layout'>)</span> <span class='hs-varid'>a</span> <span class='hs-keyglyph'>=</span> <span class='hs-keyword'>let</span> <span class='hs-varid'>a'</span> <span class='hs-keyglyph'>=</span> <span class='hs-varid'>a</span> <span class='hs-varop'>+</span> <span class='hs-num'>1</span> <span class='hs-keyword'>in</span> <span class='hs-varid'>a'</span> <span class='hs-varop'>`seq`</span> <span class='hs-varid'>gl</span> <span class='hs-varid'>xs</span> <span class='hs-varid'>a'</span>
<a name="line-584"></a>
<a name="line-585"></a><a name="genericTake"></a><span class='hs-comment'>-- | The 'genericTake' function is an overloaded version of 'take', which</span>
<a name="line-586"></a><span class='hs-comment'>-- accepts any 'Integral' value as the number of elements to take.</span>
<a name="line-587"></a><span class='hs-definition'>genericTake</span> <span class='hs-keyglyph'>::</span> <span class='hs-layout'>(</span><span class='hs-conid'>Integral</span> <span class='hs-varid'>i</span><span class='hs-layout'>)</span> <span class='hs-keyglyph'>=></span> <span class='hs-varid'>i</span> <span class='hs-keyglyph'>-></span> <span class='hs-keyglyph'>[</span><span class='hs-varid'>a</span><span class='hs-keyglyph'>]</span> <span class='hs-keyglyph'>-></span> <span class='hs-keyglyph'>[</span><span class='hs-varid'>a</span><span class='hs-keyglyph'>]</span>
<a name="line-588"></a><span class='hs-definition'>genericTake</span> <span class='hs-varid'>n</span> <span class='hs-keyword'>_</span> <span class='hs-keyglyph'>|</span> <span class='hs-varid'>n</span> <span class='hs-varop'><=</span> <span class='hs-num'>0</span> <span class='hs-keyglyph'>=</span> <span class='hs-conid'>[]</span>
<a name="line-589"></a><span class='hs-definition'>genericTake</span> <span class='hs-keyword'>_</span> <span class='hs-conid'>[]</span> <span class='hs-keyglyph'>=</span> <span class='hs-conid'>[]</span>
<a name="line-590"></a><span class='hs-definition'>genericTake</span> <span class='hs-varid'>n</span> <span class='hs-layout'>(</span><span class='hs-varid'>x</span><span class='hs-conop'>:</span><span class='hs-varid'>xs</span><span class='hs-layout'>)</span> <span class='hs-keyglyph'>=</span> <span class='hs-varid'>x</span> <span class='hs-conop'>:</span> <span class='hs-varid'>genericTake</span> <span class='hs-layout'>(</span><span class='hs-varid'>n</span><span class='hs-comment'>-</span><span class='hs-num'>1</span><span class='hs-layout'>)</span> <span class='hs-varid'>xs</span>
<a name="line-591"></a>
<a name="line-592"></a><a name="genericDrop"></a><span class='hs-comment'>-- | The 'genericDrop' function is an overloaded version of 'drop', which</span>
<a name="line-593"></a><span class='hs-comment'>-- accepts any 'Integral' value as the number of elements to drop.</span>
<a name="line-594"></a><span class='hs-definition'>genericDrop</span> <span class='hs-keyglyph'>::</span> <span class='hs-layout'>(</span><span class='hs-conid'>Integral</span> <span class='hs-varid'>i</span><span class='hs-layout'>)</span> <span class='hs-keyglyph'>=></span> <span class='hs-varid'>i</span> <span class='hs-keyglyph'>-></span> <span class='hs-keyglyph'>[</span><span class='hs-varid'>a</span><span class='hs-keyglyph'>]</span> <span class='hs-keyglyph'>-></span> <span class='hs-keyglyph'>[</span><span class='hs-varid'>a</span><span class='hs-keyglyph'>]</span>
<a name="line-595"></a><span class='hs-definition'>genericDrop</span> <span class='hs-varid'>n</span> <span class='hs-varid'>xs</span> <span class='hs-keyglyph'>|</span> <span class='hs-varid'>n</span> <span class='hs-varop'><=</span> <span class='hs-num'>0</span> <span class='hs-keyglyph'>=</span> <span class='hs-varid'>xs</span>
<a name="line-596"></a><span class='hs-definition'>genericDrop</span> <span class='hs-keyword'>_</span> <span class='hs-conid'>[]</span> <span class='hs-keyglyph'>=</span> <span class='hs-conid'>[]</span>
<a name="line-597"></a><span class='hs-definition'>genericDrop</span> <span class='hs-varid'>n</span> <span class='hs-layout'>(</span><span class='hs-keyword'>_</span><span class='hs-conop'>:</span><span class='hs-varid'>xs</span><span class='hs-layout'>)</span> <span class='hs-keyglyph'>=</span> <span class='hs-varid'>genericDrop</span> <span class='hs-layout'>(</span><span class='hs-varid'>n</span><span class='hs-comment'>-</span><span class='hs-num'>1</span><span class='hs-layout'>)</span> <span class='hs-varid'>xs</span>
<a name="line-598"></a>
<a name="line-599"></a>
<a name="line-600"></a><a name="genericSplitAt"></a><span class='hs-comment'>-- | The 'genericSplitAt' function is an overloaded version of 'splitAt', which</span>
<a name="line-601"></a><span class='hs-comment'>-- accepts any 'Integral' value as the position at which to split.</span>
<a name="line-602"></a><span class='hs-definition'>genericSplitAt</span> <span class='hs-keyglyph'>::</span> <span class='hs-layout'>(</span><span class='hs-conid'>Integral</span> <span class='hs-varid'>i</span><span class='hs-layout'>)</span> <span class='hs-keyglyph'>=></span> <span class='hs-varid'>i</span> <span class='hs-keyglyph'>-></span> <span class='hs-keyglyph'>[</span><span class='hs-varid'>b</span><span class='hs-keyglyph'>]</span> <span class='hs-keyglyph'>-></span> <span class='hs-layout'>(</span><span class='hs-keyglyph'>[</span><span class='hs-varid'>b</span><span class='hs-keyglyph'>]</span><span class='hs-layout'>,</span><span class='hs-keyglyph'>[</span><span class='hs-varid'>b</span><span class='hs-keyglyph'>]</span><span class='hs-layout'>)</span>
<a name="line-603"></a><span class='hs-definition'>genericSplitAt</span> <span class='hs-varid'>n</span> <span class='hs-varid'>xs</span> <span class='hs-keyglyph'>|</span> <span class='hs-varid'>n</span> <span class='hs-varop'><=</span> <span class='hs-num'>0</span> <span class='hs-keyglyph'>=</span> <span class='hs-layout'>(</span><span class='hs-conid'>[]</span><span class='hs-layout'>,</span><span class='hs-varid'>xs</span><span class='hs-layout'>)</span>
<a name="line-604"></a><span class='hs-definition'>genericSplitAt</span> <span class='hs-keyword'>_</span> <span class='hs-conid'>[]</span> <span class='hs-keyglyph'>=</span> <span class='hs-layout'>(</span><span class='hs-conid'>[]</span><span class='hs-layout'>,</span><span class='hs-conid'>[]</span><span class='hs-layout'>)</span>
<a name="line-605"></a><span class='hs-definition'>genericSplitAt</span> <span class='hs-varid'>n</span> <span class='hs-layout'>(</span><span class='hs-varid'>x</span><span class='hs-conop'>:</span><span class='hs-varid'>xs</span><span class='hs-layout'>)</span> <span class='hs-keyglyph'>=</span> <span class='hs-layout'>(</span><span class='hs-varid'>x</span><span class='hs-conop'>:</span><span class='hs-varid'>xs'</span><span class='hs-layout'>,</span><span class='hs-varid'>xs''</span><span class='hs-layout'>)</span> <span class='hs-keyword'>where</span>
<a name="line-606"></a> <span class='hs-layout'>(</span><span class='hs-varid'>xs'</span><span class='hs-layout'>,</span><span class='hs-varid'>xs''</span><span class='hs-layout'>)</span> <span class='hs-keyglyph'>=</span> <span class='hs-varid'>genericSplitAt</span> <span class='hs-layout'>(</span><span class='hs-varid'>n</span><span class='hs-comment'>-</span><span class='hs-num'>1</span><span class='hs-layout'>)</span> <span class='hs-varid'>xs</span>
<a name="line-607"></a>
<a name="line-608"></a><a name="genericIndex"></a><span class='hs-comment'>-- | The 'genericIndex' function is an overloaded version of '!!', which</span>
<a name="line-609"></a><span class='hs-comment'>-- accepts any 'Integral' value as the index.</span>
<a name="line-610"></a><span class='hs-definition'>genericIndex</span> <span class='hs-keyglyph'>::</span> <span class='hs-layout'>(</span><span class='hs-conid'>Integral</span> <span class='hs-varid'>a</span><span class='hs-layout'>)</span> <span class='hs-keyglyph'>=></span> <span class='hs-keyglyph'>[</span><span class='hs-varid'>b</span><span class='hs-keyglyph'>]</span> <span class='hs-keyglyph'>-></span> <span class='hs-varid'>a</span> <span class='hs-keyglyph'>-></span> <span class='hs-varid'>b</span>
<a name="line-611"></a><span class='hs-definition'>genericIndex</span> <span class='hs-layout'>(</span><span class='hs-varid'>x</span><span class='hs-conop'>:</span><span class='hs-keyword'>_</span><span class='hs-layout'>)</span> <span class='hs-num'>0</span> <span class='hs-keyglyph'>=</span> <span class='hs-varid'>x</span>
<a name="line-612"></a><span class='hs-definition'>genericIndex</span> <span class='hs-layout'>(</span><span class='hs-keyword'>_</span><span class='hs-conop'>:</span><span class='hs-varid'>xs</span><span class='hs-layout'>)</span> <span class='hs-varid'>n</span>
<a name="line-613"></a> <span class='hs-keyglyph'>|</span> <span class='hs-varid'>n</span> <span class='hs-varop'>></span> <span class='hs-num'>0</span> <span class='hs-keyglyph'>=</span> <span class='hs-varid'>genericIndex</span> <span class='hs-varid'>xs</span> <span class='hs-layout'>(</span><span class='hs-varid'>n</span><span class='hs-comment'>-</span><span class='hs-num'>1</span><span class='hs-layout'>)</span>
<a name="line-614"></a> <span class='hs-keyglyph'>|</span> <span class='hs-varid'>otherwise</span> <span class='hs-keyglyph'>=</span> <span class='hs-varid'>error</span> <span class='hs-str'>"List.genericIndex: negative argument."</span>
<a name="line-615"></a><span class='hs-definition'>genericIndex</span> <span class='hs-keyword'>_</span> <span class='hs-keyword'>_</span> <span class='hs-keyglyph'>=</span> <span class='hs-varid'>error</span> <span class='hs-str'>"List.genericIndex: index too large."</span>
<a name="line-616"></a>
<a name="line-617"></a><a name="genericReplicate"></a><span class='hs-comment'>-- | The 'genericReplicate' function is an overloaded version of 'replicate',</span>
<a name="line-618"></a><span class='hs-comment'>-- which accepts any 'Integral' value as the number of repetitions to make.</span>
<a name="line-619"></a><span class='hs-definition'>genericReplicate</span> <span class='hs-keyglyph'>::</span> <span class='hs-layout'>(</span><span class='hs-conid'>Integral</span> <span class='hs-varid'>i</span><span class='hs-layout'>)</span> <span class='hs-keyglyph'>=></span> <span class='hs-varid'>i</span> <span class='hs-keyglyph'>-></span> <span class='hs-varid'>a</span> <span class='hs-keyglyph'>-></span> <span class='hs-keyglyph'>[</span><span class='hs-varid'>a</span><span class='hs-keyglyph'>]</span>
<a name="line-620"></a><span class='hs-definition'>genericReplicate</span> <span class='hs-varid'>n</span> <span class='hs-varid'>x</span> <span class='hs-keyglyph'>=</span> <span class='hs-varid'>genericTake</span> <span class='hs-varid'>n</span> <span class='hs-layout'>(</span><span class='hs-varid'>repeat</span> <span class='hs-varid'>x</span><span class='hs-layout'>)</span>
<a name="line-621"></a>
<a name="line-622"></a><a name="zip4"></a><span class='hs-comment'>-- | The 'zip4' function takes four lists and returns a list of</span>
<a name="line-623"></a><span class='hs-comment'>-- quadruples, analogous to 'zip'.</span>
<a name="line-624"></a><span class='hs-definition'>zip4</span> <span class='hs-keyglyph'>::</span> <span class='hs-keyglyph'>[</span><span class='hs-varid'>a</span><span class='hs-keyglyph'>]</span> <span class='hs-keyglyph'>-></span> <span class='hs-keyglyph'>[</span><span class='hs-varid'>b</span><span class='hs-keyglyph'>]</span> <span class='hs-keyglyph'>-></span> <span class='hs-keyglyph'>[</span><span class='hs-varid'>c</span><span class='hs-keyglyph'>]</span> <span class='hs-keyglyph'>-></span> <span class='hs-keyglyph'>[</span><span class='hs-varid'>d</span><span class='hs-keyglyph'>]</span> <span class='hs-keyglyph'>-></span> <span class='hs-keyglyph'>[</span><span class='hs-layout'>(</span><span class='hs-varid'>a</span><span class='hs-layout'>,</span><span class='hs-varid'>b</span><span class='hs-layout'>,</span><span class='hs-varid'>c</span><span class='hs-layout'>,</span><span class='hs-varid'>d</span><span class='hs-layout'>)</span><span class='hs-keyglyph'>]</span>
<a name="line-625"></a><span class='hs-definition'>zip4</span> <span class='hs-keyglyph'>=</span> <span class='hs-varid'>zipWith4</span> <span class='hs-conid'>(,,,)</span>
<a name="line-626"></a>
<a name="line-627"></a><a name="zip5"></a><span class='hs-comment'>-- | The 'zip5' function takes five lists and returns a list of</span>
<a name="line-628"></a><span class='hs-comment'>-- five-tuples, analogous to 'zip'.</span>
<a name="line-629"></a><span class='hs-definition'>zip5</span> <span class='hs-keyglyph'>::</span> <span class='hs-keyglyph'>[</span><span class='hs-varid'>a</span><span class='hs-keyglyph'>]</span> <span class='hs-keyglyph'>-></span> <span class='hs-keyglyph'>[</span><span class='hs-varid'>b</span><span class='hs-keyglyph'>]</span> <span class='hs-keyglyph'>-></span> <span class='hs-keyglyph'>[</span><span class='hs-varid'>c</span><span class='hs-keyglyph'>]</span> <span class='hs-keyglyph'>-></span> <span class='hs-keyglyph'>[</span><span class='hs-varid'>d</span><span class='hs-keyglyph'>]</span> <span class='hs-keyglyph'>-></span> <span class='hs-keyglyph'>[</span><span class='hs-varid'>e</span><span class='hs-keyglyph'>]</span> <span class='hs-keyglyph'>-></span> <span class='hs-keyglyph'>[</span><span class='hs-layout'>(</span><span class='hs-varid'>a</span><span class='hs-layout'>,</span><span class='hs-varid'>b</span><span class='hs-layout'>,</span><span class='hs-varid'>c</span><span class='hs-layout'>,</span><span class='hs-varid'>d</span><span class='hs-layout'>,</span><span class='hs-varid'>e</span><span class='hs-layout'>)</span><span class='hs-keyglyph'>]</span>
<a name="line-630"></a><span class='hs-definition'>zip5</span> <span class='hs-keyglyph'>=</span> <span class='hs-varid'>zipWith5</span> <span class='hs-conid'>(,,,,)</span>
<a name="line-631"></a>
<a name="line-632"></a><a name="zip6"></a><span class='hs-comment'>-- | The 'zip6' function takes six lists and returns a list of six-tuples,</span>
<a name="line-633"></a><span class='hs-comment'>-- analogous to 'zip'.</span>
<a name="line-634"></a><span class='hs-definition'>zip6</span> <span class='hs-keyglyph'>::</span> <span class='hs-keyglyph'>[</span><span class='hs-varid'>a</span><span class='hs-keyglyph'>]</span> <span class='hs-keyglyph'>-></span> <span class='hs-keyglyph'>[</span><span class='hs-varid'>b</span><span class='hs-keyglyph'>]</span> <span class='hs-keyglyph'>-></span> <span class='hs-keyglyph'>[</span><span class='hs-varid'>c</span><span class='hs-keyglyph'>]</span> <span class='hs-keyglyph'>-></span> <span class='hs-keyglyph'>[</span><span class='hs-varid'>d</span><span class='hs-keyglyph'>]</span> <span class='hs-keyglyph'>-></span> <span class='hs-keyglyph'>[</span><span class='hs-varid'>e</span><span class='hs-keyglyph'>]</span> <span class='hs-keyglyph'>-></span> <span class='hs-keyglyph'>[</span><span class='hs-varid'>f</span><span class='hs-keyglyph'>]</span> <span class='hs-keyglyph'>-></span>
<a name="line-635"></a> <span class='hs-keyglyph'>[</span><span class='hs-layout'>(</span><span class='hs-varid'>a</span><span class='hs-layout'>,</span><span class='hs-varid'>b</span><span class='hs-layout'>,</span><span class='hs-varid'>c</span><span class='hs-layout'>,</span><span class='hs-varid'>d</span><span class='hs-layout'>,</span><span class='hs-varid'>e</span><span class='hs-layout'>,</span><span class='hs-varid'>f</span><span class='hs-layout'>)</span><span class='hs-keyglyph'>]</span>
<a name="line-636"></a><span class='hs-definition'>zip6</span> <span class='hs-keyglyph'>=</span> <span class='hs-varid'>zipWith6</span> <span class='hs-conid'>(,,,,,)</span>
<a name="line-637"></a>
<a name="line-638"></a><a name="zip7"></a><span class='hs-comment'>-- | The 'zip7' function takes seven lists and returns a list of</span>
<a name="line-639"></a><span class='hs-comment'>-- seven-tuples, analogous to 'zip'.</span>
<a name="line-640"></a><span class='hs-definition'>zip7</span> <span class='hs-keyglyph'>::</span> <span class='hs-keyglyph'>[</span><span class='hs-varid'>a</span><span class='hs-keyglyph'>]</span> <span class='hs-keyglyph'>-></span> <span class='hs-keyglyph'>[</span><span class='hs-varid'>b</span><span class='hs-keyglyph'>]</span> <span class='hs-keyglyph'>-></span> <span class='hs-keyglyph'>[</span><span class='hs-varid'>c</span><span class='hs-keyglyph'>]</span> <span class='hs-keyglyph'>-></span> <span class='hs-keyglyph'>[</span><span class='hs-varid'>d</span><span class='hs-keyglyph'>]</span> <span class='hs-keyglyph'>-></span> <span class='hs-keyglyph'>[</span><span class='hs-varid'>e</span><span class='hs-keyglyph'>]</span> <span class='hs-keyglyph'>-></span> <span class='hs-keyglyph'>[</span><span class='hs-varid'>f</span><span class='hs-keyglyph'>]</span> <span class='hs-keyglyph'>-></span>
<a name="line-641"></a> <span class='hs-keyglyph'>[</span><span class='hs-varid'>g</span><span class='hs-keyglyph'>]</span> <span class='hs-keyglyph'>-></span> <span class='hs-keyglyph'>[</span><span class='hs-layout'>(</span><span class='hs-varid'>a</span><span class='hs-layout'>,</span><span class='hs-varid'>b</span><span class='hs-layout'>,</span><span class='hs-varid'>c</span><span class='hs-layout'>,</span><span class='hs-varid'>d</span><span class='hs-layout'>,</span><span class='hs-varid'>e</span><span class='hs-layout'>,</span><span class='hs-varid'>f</span><span class='hs-layout'>,</span><span class='hs-varid'>g</span><span class='hs-layout'>)</span><span class='hs-keyglyph'>]</span>
<a name="line-642"></a><span class='hs-definition'>zip7</span> <span class='hs-keyglyph'>=</span> <span class='hs-varid'>zipWith7</span> <span class='hs-conid'>(,,,,,,)</span>
<a name="line-643"></a>
<a name="line-644"></a><a name="zipWith4"></a><span class='hs-comment'>-- | The 'zipWith4' function takes a function which combines four</span>
<a name="line-645"></a><span class='hs-comment'>-- elements, as well as four lists and returns a list of their point-wise</span>
<a name="line-646"></a><span class='hs-comment'>-- combination, analogous to 'zipWith'.</span>
<a name="line-647"></a><span class='hs-definition'>zipWith4</span> <span class='hs-keyglyph'>::</span> <span class='hs-layout'>(</span><span class='hs-varid'>a</span><span class='hs-keyglyph'>-></span><span class='hs-varid'>b</span><span class='hs-keyglyph'>-></span><span class='hs-varid'>c</span><span class='hs-keyglyph'>-></span><span class='hs-varid'>d</span><span class='hs-keyglyph'>-></span><span class='hs-varid'>e</span><span class='hs-layout'>)</span> <span class='hs-keyglyph'>-></span> <span class='hs-keyglyph'>[</span><span class='hs-varid'>a</span><span class='hs-keyglyph'>]</span><span class='hs-keyglyph'>-></span><span class='hs-keyglyph'>[</span><span class='hs-varid'>b</span><span class='hs-keyglyph'>]</span><span class='hs-keyglyph'>-></span><span class='hs-keyglyph'>[</span><span class='hs-varid'>c</span><span class='hs-keyglyph'>]</span><span class='hs-keyglyph'>-></span><span class='hs-keyglyph'>[</span><span class='hs-varid'>d</span><span class='hs-keyglyph'>]</span><span class='hs-keyglyph'>-></span><span class='hs-keyglyph'>[</span><span class='hs-varid'>e</span><span class='hs-keyglyph'>]</span>
<a name="line-648"></a><span class='hs-definition'>zipWith4</span> <span class='hs-varid'>z</span> <span class='hs-layout'>(</span><span class='hs-varid'>a</span><span class='hs-conop'>:</span><span class='hs-keyword'>as</span><span class='hs-layout'>)</span> <span class='hs-layout'>(</span><span class='hs-varid'>b</span><span class='hs-conop'>:</span><span class='hs-varid'>bs</span><span class='hs-layout'>)</span> <span class='hs-layout'>(</span><span class='hs-varid'>c</span><span class='hs-conop'>:</span><span class='hs-varid'>cs</span><span class='hs-layout'>)</span> <span class='hs-layout'>(</span><span class='hs-varid'>d</span><span class='hs-conop'>:</span><span class='hs-varid'>ds</span><span class='hs-layout'>)</span>
<a name="line-649"></a> <span class='hs-keyglyph'>=</span> <span class='hs-varid'>z</span> <span class='hs-varid'>a</span> <span class='hs-varid'>b</span> <span class='hs-varid'>c</span> <span class='hs-varid'>d</span> <span class='hs-conop'>:</span> <span class='hs-varid'>zipWith4</span> <span class='hs-varid'>z</span> <span class='hs-keyword'>as</span> <span class='hs-varid'>bs</span> <span class='hs-varid'>cs</span> <span class='hs-varid'>ds</span>
<a name="line-650"></a><span class='hs-definition'>zipWith4</span> <span class='hs-keyword'>_</span> <span class='hs-keyword'>_</span> <span class='hs-keyword'>_</span> <span class='hs-keyword'>_</span> <span class='hs-keyword'>_</span> <span class='hs-keyglyph'>=</span> <span class='hs-conid'>[]</span>
<a name="line-651"></a>
<a name="line-652"></a><a name="zipWith5"></a><span class='hs-comment'>-- | The 'zipWith5' function takes a function which combines five</span>
<a name="line-653"></a><span class='hs-comment'>-- elements, as well as five lists and returns a list of their point-wise</span>
<a name="line-654"></a><span class='hs-comment'>-- combination, analogous to 'zipWith'.</span>
<a name="line-655"></a><span class='hs-definition'>zipWith5</span> <span class='hs-keyglyph'>::</span> <span class='hs-layout'>(</span><span class='hs-varid'>a</span><span class='hs-keyglyph'>-></span><span class='hs-varid'>b</span><span class='hs-keyglyph'>-></span><span class='hs-varid'>c</span><span class='hs-keyglyph'>-></span><span class='hs-varid'>d</span><span class='hs-keyglyph'>-></span><span class='hs-varid'>e</span><span class='hs-keyglyph'>-></span><span class='hs-varid'>f</span><span class='hs-layout'>)</span> <span class='hs-keyglyph'>-></span>
<a name="line-656"></a> <span class='hs-keyglyph'>[</span><span class='hs-varid'>a</span><span class='hs-keyglyph'>]</span><span class='hs-keyglyph'>-></span><span class='hs-keyglyph'>[</span><span class='hs-varid'>b</span><span class='hs-keyglyph'>]</span><span class='hs-keyglyph'>-></span><span class='hs-keyglyph'>[</span><span class='hs-varid'>c</span><span class='hs-keyglyph'>]</span><span class='hs-keyglyph'>-></span><span class='hs-keyglyph'>[</span><span class='hs-varid'>d</span><span class='hs-keyglyph'>]</span><span class='hs-keyglyph'>-></span><span class='hs-keyglyph'>[</span><span class='hs-varid'>e</span><span class='hs-keyglyph'>]</span><span class='hs-keyglyph'>-></span><span class='hs-keyglyph'>[</span><span class='hs-varid'>f</span><span class='hs-keyglyph'>]</span>
<a name="line-657"></a><span class='hs-definition'>zipWith5</span> <span class='hs-varid'>z</span> <span class='hs-layout'>(</span><span class='hs-varid'>a</span><span class='hs-conop'>:</span><span class='hs-keyword'>as</span><span class='hs-layout'>)</span> <span class='hs-layout'>(</span><span class='hs-varid'>b</span><span class='hs-conop'>:</span><span class='hs-varid'>bs</span><span class='hs-layout'>)</span> <span class='hs-layout'>(</span><span class='hs-varid'>c</span><span class='hs-conop'>:</span><span class='hs-varid'>cs</span><span class='hs-layout'>)</span> <span class='hs-layout'>(</span><span class='hs-varid'>d</span><span class='hs-conop'>:</span><span class='hs-varid'>ds</span><span class='hs-layout'>)</span> <span class='hs-layout'>(</span><span class='hs-varid'>e</span><span class='hs-conop'>:</span><span class='hs-varid'>es</span><span class='hs-layout'>)</span>
<a name="line-658"></a> <span class='hs-keyglyph'>=</span> <span class='hs-varid'>z</span> <span class='hs-varid'>a</span> <span class='hs-varid'>b</span> <span class='hs-varid'>c</span> <span class='hs-varid'>d</span> <span class='hs-varid'>e</span> <span class='hs-conop'>:</span> <span class='hs-varid'>zipWith5</span> <span class='hs-varid'>z</span> <span class='hs-keyword'>as</span> <span class='hs-varid'>bs</span> <span class='hs-varid'>cs</span> <span class='hs-varid'>ds</span> <span class='hs-varid'>es</span>
<a name="line-659"></a><span class='hs-definition'>zipWith5</span> <span class='hs-keyword'>_</span> <span class='hs-keyword'>_</span> <span class='hs-keyword'>_</span> <span class='hs-keyword'>_</span> <span class='hs-keyword'>_</span> <span class='hs-keyword'>_</span> <span class='hs-keyglyph'>=</span> <span class='hs-conid'>[]</span>
<a name="line-660"></a>
<a name="line-661"></a><a name="zipWith6"></a><span class='hs-comment'>-- | The 'zipWith6' function takes a function which combines six</span>
<a name="line-662"></a><span class='hs-comment'>-- elements, as well as six lists and returns a list of their point-wise</span>
<a name="line-663"></a><span class='hs-comment'>-- combination, analogous to 'zipWith'.</span>
<a name="line-664"></a><span class='hs-definition'>zipWith6</span> <span class='hs-keyglyph'>::</span> <span class='hs-layout'>(</span><span class='hs-varid'>a</span><span class='hs-keyglyph'>-></span><span class='hs-varid'>b</span><span class='hs-keyglyph'>-></span><span class='hs-varid'>c</span><span class='hs-keyglyph'>-></span><span class='hs-varid'>d</span><span class='hs-keyglyph'>-></span><span class='hs-varid'>e</span><span class='hs-keyglyph'>-></span><span class='hs-varid'>f</span><span class='hs-keyglyph'>-></span><span class='hs-varid'>g</span><span class='hs-layout'>)</span> <span class='hs-keyglyph'>-></span>
<a name="line-665"></a> <span class='hs-keyglyph'>[</span><span class='hs-varid'>a</span><span class='hs-keyglyph'>]</span><span class='hs-keyglyph'>-></span><span class='hs-keyglyph'>[</span><span class='hs-varid'>b</span><span class='hs-keyglyph'>]</span><span class='hs-keyglyph'>-></span><span class='hs-keyglyph'>[</span><span class='hs-varid'>c</span><span class='hs-keyglyph'>]</span><span class='hs-keyglyph'>-></span><span class='hs-keyglyph'>[</span><span class='hs-varid'>d</span><span class='hs-keyglyph'>]</span><span class='hs-keyglyph'>-></span><span class='hs-keyglyph'>[</span><span class='hs-varid'>e</span><span class='hs-keyglyph'>]</span><span class='hs-keyglyph'>-></span><span class='hs-keyglyph'>[</span><span class='hs-varid'>f</span><span class='hs-keyglyph'>]</span><span class='hs-keyglyph'>-></span><span class='hs-keyglyph'>[</span><span class='hs-varid'>g</span><span class='hs-keyglyph'>]</span>
<a name="line-666"></a><span class='hs-definition'>zipWith6</span> <span class='hs-varid'>z</span> <span class='hs-layout'>(</span><span class='hs-varid'>a</span><span class='hs-conop'>:</span><span class='hs-keyword'>as</span><span class='hs-layout'>)</span> <span class='hs-layout'>(</span><span class='hs-varid'>b</span><span class='hs-conop'>:</span><span class='hs-varid'>bs</span><span class='hs-layout'>)</span> <span class='hs-layout'>(</span><span class='hs-varid'>c</span><span class='hs-conop'>:</span><span class='hs-varid'>cs</span><span class='hs-layout'>)</span> <span class='hs-layout'>(</span><span class='hs-varid'>d</span><span class='hs-conop'>:</span><span class='hs-varid'>ds</span><span class='hs-layout'>)</span> <span class='hs-layout'>(</span><span class='hs-varid'>e</span><span class='hs-conop'>:</span><span class='hs-varid'>es</span><span class='hs-layout'>)</span> <span class='hs-layout'>(</span><span class='hs-varid'>f</span><span class='hs-conop'>:</span><span class='hs-varid'>fs</span><span class='hs-layout'>)</span>
<a name="line-667"></a> <span class='hs-keyglyph'>=</span> <span class='hs-varid'>z</span> <span class='hs-varid'>a</span> <span class='hs-varid'>b</span> <span class='hs-varid'>c</span> <span class='hs-varid'>d</span> <span class='hs-varid'>e</span> <span class='hs-varid'>f</span> <span class='hs-conop'>:</span> <span class='hs-varid'>zipWith6</span> <span class='hs-varid'>z</span> <span class='hs-keyword'>as</span> <span class='hs-varid'>bs</span> <span class='hs-varid'>cs</span> <span class='hs-varid'>ds</span> <span class='hs-varid'>es</span> <span class='hs-varid'>fs</span>
<a name="line-668"></a><span class='hs-definition'>zipWith6</span> <span class='hs-keyword'>_</span> <span class='hs-keyword'>_</span> <span class='hs-keyword'>_</span> <span class='hs-keyword'>_</span> <span class='hs-keyword'>_</span> <span class='hs-keyword'>_</span> <span class='hs-keyword'>_</span> <span class='hs-keyglyph'>=</span> <span class='hs-conid'>[]</span>
<a name="line-669"></a>
<a name="line-670"></a><a name="zipWith7"></a><span class='hs-comment'>-- | The 'zipWith7' function takes a function which combines seven</span>
<a name="line-671"></a><span class='hs-comment'>-- elements, as well as seven lists and returns a list of their point-wise</span>
<a name="line-672"></a><span class='hs-comment'>-- combination, analogous to 'zipWith'.</span>
<a name="line-673"></a><span class='hs-definition'>zipWith7</span> <span class='hs-keyglyph'>::</span> <span class='hs-layout'>(</span><span class='hs-varid'>a</span><span class='hs-keyglyph'>-></span><span class='hs-varid'>b</span><span class='hs-keyglyph'>-></span><span class='hs-varid'>c</span><span class='hs-keyglyph'>-></span><span class='hs-varid'>d</span><span class='hs-keyglyph'>-></span><span class='hs-varid'>e</span><span class='hs-keyglyph'>-></span><span class='hs-varid'>f</span><span class='hs-keyglyph'>-></span><span class='hs-varid'>g</span><span class='hs-keyglyph'>-></span><span class='hs-varid'>h</span><span class='hs-layout'>)</span> <span class='hs-keyglyph'>-></span>
<a name="line-674"></a> <span class='hs-keyglyph'>[</span><span class='hs-varid'>a</span><span class='hs-keyglyph'>]</span><span class='hs-keyglyph'>-></span><span class='hs-keyglyph'>[</span><span class='hs-varid'>b</span><span class='hs-keyglyph'>]</span><span class='hs-keyglyph'>-></span><span class='hs-keyglyph'>[</span><span class='hs-varid'>c</span><span class='hs-keyglyph'>]</span><span class='hs-keyglyph'>-></span><span class='hs-keyglyph'>[</span><span class='hs-varid'>d</span><span class='hs-keyglyph'>]</span><span class='hs-keyglyph'>-></span><span class='hs-keyglyph'>[</span><span class='hs-varid'>e</span><span class='hs-keyglyph'>]</span><span class='hs-keyglyph'>-></span><span class='hs-keyglyph'>[</span><span class='hs-varid'>f</span><span class='hs-keyglyph'>]</span><span class='hs-keyglyph'>-></span><span class='hs-keyglyph'>[</span><span class='hs-varid'>g</span><span class='hs-keyglyph'>]</span><span class='hs-keyglyph'>-></span><span class='hs-keyglyph'>[</span><span class='hs-varid'>h</span><span class='hs-keyglyph'>]</span>
<a name="line-675"></a><span class='hs-definition'>zipWith7</span> <span class='hs-varid'>z</span> <span class='hs-layout'>(</span><span class='hs-varid'>a</span><span class='hs-conop'>:</span><span class='hs-keyword'>as</span><span class='hs-layout'>)</span> <span class='hs-layout'>(</span><span class='hs-varid'>b</span><span class='hs-conop'>:</span><span class='hs-varid'>bs</span><span class='hs-layout'>)</span> <span class='hs-layout'>(</span><span class='hs-varid'>c</span><span class='hs-conop'>:</span><span class='hs-varid'>cs</span><span class='hs-layout'>)</span> <span class='hs-layout'>(</span><span class='hs-varid'>d</span><span class='hs-conop'>:</span><span class='hs-varid'>ds</span><span class='hs-layout'>)</span> <span class='hs-layout'>(</span><span class='hs-varid'>e</span><span class='hs-conop'>:</span><span class='hs-varid'>es</span><span class='hs-layout'>)</span> <span class='hs-layout'>(</span><span class='hs-varid'>f</span><span class='hs-conop'>:</span><span class='hs-varid'>fs</span><span class='hs-layout'>)</span> <span class='hs-layout'>(</span><span class='hs-varid'>g</span><span class='hs-conop'>:</span><span class='hs-varid'>gs</span><span class='hs-layout'>)</span>
<a name="line-676"></a> <span class='hs-keyglyph'>=</span> <span class='hs-varid'>z</span> <span class='hs-varid'>a</span> <span class='hs-varid'>b</span> <span class='hs-varid'>c</span> <span class='hs-varid'>d</span> <span class='hs-varid'>e</span> <span class='hs-varid'>f</span> <span class='hs-varid'>g</span> <span class='hs-conop'>:</span> <span class='hs-varid'>zipWith7</span> <span class='hs-varid'>z</span> <span class='hs-keyword'>as</span> <span class='hs-varid'>bs</span> <span class='hs-varid'>cs</span> <span class='hs-varid'>ds</span> <span class='hs-varid'>es</span> <span class='hs-varid'>fs</span> <span class='hs-varid'>gs</span>
<a name="line-677"></a><span class='hs-definition'>zipWith7</span> <span class='hs-keyword'>_</span> <span class='hs-keyword'>_</span> <span class='hs-keyword'>_</span> <span class='hs-keyword'>_</span> <span class='hs-keyword'>_</span> <span class='hs-keyword'>_</span> <span class='hs-keyword'>_</span> <span class='hs-keyword'>_</span> <span class='hs-keyglyph'>=</span> <span class='hs-conid'>[]</span>
<a name="line-678"></a>
<a name="line-679"></a><a name="unzip4"></a><span class='hs-comment'>-- | The 'unzip4' function takes a list of quadruples and returns four</span>
<a name="line-680"></a><span class='hs-comment'>-- lists, analogous to 'unzip'.</span>
<a name="line-681"></a><span class='hs-definition'>unzip4</span> <span class='hs-keyglyph'>::</span> <span class='hs-keyglyph'>[</span><span class='hs-layout'>(</span><span class='hs-varid'>a</span><span class='hs-layout'>,</span><span class='hs-varid'>b</span><span class='hs-layout'>,</span><span class='hs-varid'>c</span><span class='hs-layout'>,</span><span class='hs-varid'>d</span><span class='hs-layout'>)</span><span class='hs-keyglyph'>]</span> <span class='hs-keyglyph'>-></span> <span class='hs-layout'>(</span><span class='hs-keyglyph'>[</span><span class='hs-varid'>a</span><span class='hs-keyglyph'>]</span><span class='hs-layout'>,</span><span class='hs-keyglyph'>[</span><span class='hs-varid'>b</span><span class='hs-keyglyph'>]</span><span class='hs-layout'>,</span><span class='hs-keyglyph'>[</span><span class='hs-varid'>c</span><span class='hs-keyglyph'>]</span><span class='hs-layout'>,</span><span class='hs-keyglyph'>[</span><span class='hs-varid'>d</span><span class='hs-keyglyph'>]</span><span class='hs-layout'>)</span>
<a name="line-682"></a><span class='hs-definition'>unzip4</span> <span class='hs-keyglyph'>=</span> <span class='hs-varid'>foldr</span> <span class='hs-layout'>(</span><span class='hs-keyglyph'>\</span><span class='hs-layout'>(</span><span class='hs-varid'>a</span><span class='hs-layout'>,</span><span class='hs-varid'>b</span><span class='hs-layout'>,</span><span class='hs-varid'>c</span><span class='hs-layout'>,</span><span class='hs-varid'>d</span><span class='hs-layout'>)</span> <span class='hs-keyglyph'>~</span><span class='hs-layout'>(</span><span class='hs-keyword'>as</span><span class='hs-layout'>,</span><span class='hs-varid'>bs</span><span class='hs-layout'>,</span><span class='hs-varid'>cs</span><span class='hs-layout'>,</span><span class='hs-varid'>ds</span><span class='hs-layout'>)</span> <span class='hs-keyglyph'>-></span>
<a name="line-683"></a> <span class='hs-layout'>(</span><span class='hs-varid'>a</span><span class='hs-conop'>:</span><span class='hs-keyword'>as</span><span class='hs-layout'>,</span><span class='hs-varid'>b</span><span class='hs-conop'>:</span><span class='hs-varid'>bs</span><span class='hs-layout'>,</span><span class='hs-varid'>c</span><span class='hs-conop'>:</span><span class='hs-varid'>cs</span><span class='hs-layout'>,</span><span class='hs-varid'>d</span><span class='hs-conop'>:</span><span class='hs-varid'>ds</span><span class='hs-layout'>)</span><span class='hs-layout'>)</span>
<a name="line-684"></a> <span class='hs-layout'>(</span><span class='hs-conid'>[]</span><span class='hs-layout'>,</span><span class='hs-conid'>[]</span><span class='hs-layout'>,</span><span class='hs-conid'>[]</span><span class='hs-layout'>,</span><span class='hs-conid'>[]</span><span class='hs-layout'>)</span>
<a name="line-685"></a>
<a name="line-686"></a><a name="unzip5"></a><span class='hs-comment'>-- | The 'unzip5' function takes a list of five-tuples and returns five</span>
<a name="line-687"></a><span class='hs-comment'>-- lists, analogous to 'unzip'.</span>
<a name="line-688"></a><span class='hs-definition'>unzip5</span> <span class='hs-keyglyph'>::</span> <span class='hs-keyglyph'>[</span><span class='hs-layout'>(</span><span class='hs-varid'>a</span><span class='hs-layout'>,</span><span class='hs-varid'>b</span><span class='hs-layout'>,</span><span class='hs-varid'>c</span><span class='hs-layout'>,</span><span class='hs-varid'>d</span><span class='hs-layout'>,</span><span class='hs-varid'>e</span><span class='hs-layout'>)</span><span class='hs-keyglyph'>]</span> <span class='hs-keyglyph'>-></span> <span class='hs-layout'>(</span><span class='hs-keyglyph'>[</span><span class='hs-varid'>a</span><span class='hs-keyglyph'>]</span><span class='hs-layout'>,</span><span class='hs-keyglyph'>[</span><span class='hs-varid'>b</span><span class='hs-keyglyph'>]</span><span class='hs-layout'>,</span><span class='hs-keyglyph'>[</span><span class='hs-varid'>c</span><span class='hs-keyglyph'>]</span><span class='hs-layout'>,</span><span class='hs-keyglyph'>[</span><span class='hs-varid'>d</span><span class='hs-keyglyph'>]</span><span class='hs-layout'>,</span><span class='hs-keyglyph'>[</span><span class='hs-varid'>e</span><span class='hs-keyglyph'>]</span><span class='hs-layout'>)</span>
<a name="line-689"></a><span class='hs-definition'>unzip5</span> <span class='hs-keyglyph'>=</span> <span class='hs-varid'>foldr</span> <span class='hs-layout'>(</span><span class='hs-keyglyph'>\</span><span class='hs-layout'>(</span><span class='hs-varid'>a</span><span class='hs-layout'>,</span><span class='hs-varid'>b</span><span class='hs-layout'>,</span><span class='hs-varid'>c</span><span class='hs-layout'>,</span><span class='hs-varid'>d</span><span class='hs-layout'>,</span><span class='hs-varid'>e</span><span class='hs-layout'>)</span> <span class='hs-keyglyph'>~</span><span class='hs-layout'>(</span><span class='hs-keyword'>as</span><span class='hs-layout'>,</span><span class='hs-varid'>bs</span><span class='hs-layout'>,</span><span class='hs-varid'>cs</span><span class='hs-layout'>,</span><span class='hs-varid'>ds</span><span class='hs-layout'>,</span><span class='hs-varid'>es</span><span class='hs-layout'>)</span> <span class='hs-keyglyph'>-></span>
<a name="line-690"></a> <span class='hs-layout'>(</span><span class='hs-varid'>a</span><span class='hs-conop'>:</span><span class='hs-keyword'>as</span><span class='hs-layout'>,</span><span class='hs-varid'>b</span><span class='hs-conop'>:</span><span class='hs-varid'>bs</span><span class='hs-layout'>,</span><span class='hs-varid'>c</span><span class='hs-conop'>:</span><span class='hs-varid'>cs</span><span class='hs-layout'>,</span><span class='hs-varid'>d</span><span class='hs-conop'>:</span><span class='hs-varid'>ds</span><span class='hs-layout'>,</span><span class='hs-varid'>e</span><span class='hs-conop'>:</span><span class='hs-varid'>es</span><span class='hs-layout'>)</span><span class='hs-layout'>)</span>
<a name="line-691"></a> <span class='hs-layout'>(</span><span class='hs-conid'>[]</span><span class='hs-layout'>,</span><span class='hs-conid'>[]</span><span class='hs-layout'>,</span><span class='hs-conid'>[]</span><span class='hs-layout'>,</span><span class='hs-conid'>[]</span><span class='hs-layout'>,</span><span class='hs-conid'>[]</span><span class='hs-layout'>)</span>
<a name="line-692"></a>
<a name="line-693"></a><a name="unzip6"></a><span class='hs-comment'>-- | The 'unzip6' function takes a list of six-tuples and returns six</span>
<a name="line-694"></a><span class='hs-comment'>-- lists, analogous to 'unzip'.</span>
<a name="line-695"></a><span class='hs-definition'>unzip6</span> <span class='hs-keyglyph'>::</span> <span class='hs-keyglyph'>[</span><span class='hs-layout'>(</span><span class='hs-varid'>a</span><span class='hs-layout'>,</span><span class='hs-varid'>b</span><span class='hs-layout'>,</span><span class='hs-varid'>c</span><span class='hs-layout'>,</span><span class='hs-varid'>d</span><span class='hs-layout'>,</span><span class='hs-varid'>e</span><span class='hs-layout'>,</span><span class='hs-varid'>f</span><span class='hs-layout'>)</span><span class='hs-keyglyph'>]</span> <span class='hs-keyglyph'>-></span> <span class='hs-layout'>(</span><span class='hs-keyglyph'>[</span><span class='hs-varid'>a</span><span class='hs-keyglyph'>]</span><span class='hs-layout'>,</span><span class='hs-keyglyph'>[</span><span class='hs-varid'>b</span><span class='hs-keyglyph'>]</span><span class='hs-layout'>,</span><span class='hs-keyglyph'>[</span><span class='hs-varid'>c</span><span class='hs-keyglyph'>]</span><span class='hs-layout'>,</span><span class='hs-keyglyph'>[</span><span class='hs-varid'>d</span><span class='hs-keyglyph'>]</span><span class='hs-layout'>,</span><span class='hs-keyglyph'>[</span><span class='hs-varid'>e</span><span class='hs-keyglyph'>]</span><span class='hs-layout'>,</span><span class='hs-keyglyph'>[</span><span class='hs-varid'>f</span><span class='hs-keyglyph'>]</span><span class='hs-layout'>)</span>
<a name="line-696"></a><span class='hs-definition'>unzip6</span> <span class='hs-keyglyph'>=</span> <span class='hs-varid'>foldr</span> <span class='hs-layout'>(</span><span class='hs-keyglyph'>\</span><span class='hs-layout'>(</span><span class='hs-varid'>a</span><span class='hs-layout'>,</span><span class='hs-varid'>b</span><span class='hs-layout'>,</span><span class='hs-varid'>c</span><span class='hs-layout'>,</span><span class='hs-varid'>d</span><span class='hs-layout'>,</span><span class='hs-varid'>e</span><span class='hs-layout'>,</span><span class='hs-varid'>f</span><span class='hs-layout'>)</span> <span class='hs-keyglyph'>~</span><span class='hs-layout'>(</span><span class='hs-keyword'>as</span><span class='hs-layout'>,</span><span class='hs-varid'>bs</span><span class='hs-layout'>,</span><span class='hs-varid'>cs</span><span class='hs-layout'>,</span><span class='hs-varid'>ds</span><span class='hs-layout'>,</span><span class='hs-varid'>es</span><span class='hs-layout'>,</span><span class='hs-varid'>fs</span><span class='hs-layout'>)</span> <span class='hs-keyglyph'>-></span>
<a name="line-697"></a> <span class='hs-layout'>(</span><span class='hs-varid'>a</span><span class='hs-conop'>:</span><span class='hs-keyword'>as</span><span class='hs-layout'>,</span><span class='hs-varid'>b</span><span class='hs-conop'>:</span><span class='hs-varid'>bs</span><span class='hs-layout'>,</span><span class='hs-varid'>c</span><span class='hs-conop'>:</span><span class='hs-varid'>cs</span><span class='hs-layout'>,</span><span class='hs-varid'>d</span><span class='hs-conop'>:</span><span class='hs-varid'>ds</span><span class='hs-layout'>,</span><span class='hs-varid'>e</span><span class='hs-conop'>:</span><span class='hs-varid'>es</span><span class='hs-layout'>,</span><span class='hs-varid'>f</span><span class='hs-conop'>:</span><span class='hs-varid'>fs</span><span class='hs-layout'>)</span><span class='hs-layout'>)</span>
<a name="line-698"></a> <span class='hs-layout'>(</span><span class='hs-conid'>[]</span><span class='hs-layout'>,</span><span class='hs-conid'>[]</span><span class='hs-layout'>,</span><span class='hs-conid'>[]</span><span class='hs-layout'>,</span><span class='hs-conid'>[]</span><span class='hs-layout'>,</span><span class='hs-conid'>[]</span><span class='hs-layout'>,</span><span class='hs-conid'>[]</span><span class='hs-layout'>)</span>
<a name="line-699"></a>
<a name="line-700"></a><a name="unzip7"></a><span class='hs-comment'>-- | The 'unzip7' function takes a list of seven-tuples and returns</span>
<a name="line-701"></a><span class='hs-comment'>-- seven lists, analogous to 'unzip'.</span>
<a name="line-702"></a><span class='hs-definition'>unzip7</span> <span class='hs-keyglyph'>::</span> <span class='hs-keyglyph'>[</span><span class='hs-layout'>(</span><span class='hs-varid'>a</span><span class='hs-layout'>,</span><span class='hs-varid'>b</span><span class='hs-layout'>,</span><span class='hs-varid'>c</span><span class='hs-layout'>,</span><span class='hs-varid'>d</span><span class='hs-layout'>,</span><span class='hs-varid'>e</span><span class='hs-layout'>,</span><span class='hs-varid'>f</span><span class='hs-layout'>,</span><span class='hs-varid'>g</span><span class='hs-layout'>)</span><span class='hs-keyglyph'>]</span> <span class='hs-keyglyph'>-></span> <span class='hs-layout'>(</span><span class='hs-keyglyph'>[</span><span class='hs-varid'>a</span><span class='hs-keyglyph'>]</span><span class='hs-layout'>,</span><span class='hs-keyglyph'>[</span><span class='hs-varid'>b</span><span class='hs-keyglyph'>]</span><span class='hs-layout'>,</span><span class='hs-keyglyph'>[</span><span class='hs-varid'>c</span><span class='hs-keyglyph'>]</span><span class='hs-layout'>,</span><span class='hs-keyglyph'>[</span><span class='hs-varid'>d</span><span class='hs-keyglyph'>]</span><span class='hs-layout'>,</span><span class='hs-keyglyph'>[</span><span class='hs-varid'>e</span><span class='hs-keyglyph'>]</span><span class='hs-layout'>,</span><span class='hs-keyglyph'>[</span><span class='hs-varid'>f</span><span class='hs-keyglyph'>]</span><span class='hs-layout'>,</span><span class='hs-keyglyph'>[</span><span class='hs-varid'>g</span><span class='hs-keyglyph'>]</span><span class='hs-layout'>)</span>
<a name="line-703"></a><span class='hs-definition'>unzip7</span> <span class='hs-keyglyph'>=</span> <span class='hs-varid'>foldr</span> <span class='hs-layout'>(</span><span class='hs-keyglyph'>\</span><span class='hs-layout'>(</span><span class='hs-varid'>a</span><span class='hs-layout'>,</span><span class='hs-varid'>b</span><span class='hs-layout'>,</span><span class='hs-varid'>c</span><span class='hs-layout'>,</span><span class='hs-varid'>d</span><span class='hs-layout'>,</span><span class='hs-varid'>e</span><span class='hs-layout'>,</span><span class='hs-varid'>f</span><span class='hs-layout'>,</span><span class='hs-varid'>g</span><span class='hs-layout'>)</span> <span class='hs-keyglyph'>~</span><span class='hs-layout'>(</span><span class='hs-keyword'>as</span><span class='hs-layout'>,</span><span class='hs-varid'>bs</span><span class='hs-layout'>,</span><span class='hs-varid'>cs</span><span class='hs-layout'>,</span><span class='hs-varid'>ds</span><span class='hs-layout'>,</span><span class='hs-varid'>es</span><span class='hs-layout'>,</span><span class='hs-varid'>fs</span><span class='hs-layout'>,</span><span class='hs-varid'>gs</span><span class='hs-layout'>)</span> <span class='hs-keyglyph'>-></span>
<a name="line-704"></a> <span class='hs-layout'>(</span><span class='hs-varid'>a</span><span class='hs-conop'>:</span><span class='hs-keyword'>as</span><span class='hs-layout'>,</span><span class='hs-varid'>b</span><span class='hs-conop'>:</span><span class='hs-varid'>bs</span><span class='hs-layout'>,</span><span class='hs-varid'>c</span><span class='hs-conop'>:</span><span class='hs-varid'>cs</span><span class='hs-layout'>,</span><span class='hs-varid'>d</span><span class='hs-conop'>:</span><span class='hs-varid'>ds</span><span class='hs-layout'>,</span><span class='hs-varid'>e</span><span class='hs-conop'>:</span><span class='hs-varid'>es</span><span class='hs-layout'>,</span><span class='hs-varid'>f</span><span class='hs-conop'>:</span><span class='hs-varid'>fs</span><span class='hs-layout'>,</span><span class='hs-varid'>g</span><span class='hs-conop'>:</span><span class='hs-varid'>gs</span><span class='hs-layout'>)</span><span class='hs-layout'>)</span>
<a name="line-705"></a> <span class='hs-layout'>(</span><span class='hs-conid'>[]</span><span class='hs-layout'>,</span><span class='hs-conid'>[]</span><span class='hs-layout'>,</span><span class='hs-conid'>[]</span><span class='hs-layout'>,</span><span class='hs-conid'>[]</span><span class='hs-layout'>,</span><span class='hs-conid'>[]</span><span class='hs-layout'>,</span><span class='hs-conid'>[]</span><span class='hs-layout'>,</span><span class='hs-conid'>[]</span><span class='hs-layout'>)</span>
<a name="line-706"></a>
<a name="line-707"></a>
<a name="line-708"></a><a name="deleteFirstsBy"></a><span class='hs-comment'>-- | The 'deleteFirstsBy' function takes a predicate and two lists and</span>
<a name="line-709"></a><span class='hs-comment'>-- returns the first list with the first occurrence of each element of</span>
<a name="line-710"></a><span class='hs-comment'>-- the second list removed.</span>
<a name="line-711"></a><span class='hs-definition'>deleteFirstsBy</span> <span class='hs-keyglyph'>::</span> <span class='hs-layout'>(</span><span class='hs-varid'>a</span> <span class='hs-keyglyph'>-></span> <span class='hs-varid'>a</span> <span class='hs-keyglyph'>-></span> <span class='hs-conid'>Bool</span><span class='hs-layout'>)</span> <span class='hs-keyglyph'>-></span> <span class='hs-keyglyph'>[</span><span class='hs-varid'>a</span><span class='hs-keyglyph'>]</span> <span class='hs-keyglyph'>-></span> <span class='hs-keyglyph'>[</span><span class='hs-varid'>a</span><span class='hs-keyglyph'>]</span> <span class='hs-keyglyph'>-></span> <span class='hs-keyglyph'>[</span><span class='hs-varid'>a</span><span class='hs-keyglyph'>]</span>
<a name="line-712"></a><span class='hs-definition'>deleteFirstsBy</span> <span class='hs-varid'>eq</span> <span class='hs-keyglyph'>=</span> <span class='hs-varid'>foldl</span> <span class='hs-layout'>(</span><span class='hs-varid'>flip</span> <span class='hs-layout'>(</span><span class='hs-varid'>deleteBy</span> <span class='hs-varid'>eq</span><span class='hs-layout'>)</span><span class='hs-layout'>)</span>
<a name="line-713"></a>
<a name="line-714"></a><a name="group"></a><span class='hs-comment'>-- | The 'group' function takes a list and returns a list of lists such</span>
<a name="line-715"></a><span class='hs-comment'>-- that the concatenation of the result is equal to the argument. Moreover,</span>
<a name="line-716"></a><span class='hs-comment'>-- each sublist in the result contains only equal elements. For example,</span>
<a name="line-717"></a><span class='hs-comment'>--</span>
<a name="line-718"></a><span class='hs-comment'>-- > group "Mississippi" = ["M","i","ss","i","ss","i","pp","i"]</span>
<a name="line-719"></a><span class='hs-comment'>--</span>
<a name="line-720"></a><span class='hs-comment'>-- It is a special case of 'groupBy', which allows the programmer to supply</span>
<a name="line-721"></a><span class='hs-comment'>-- their own equality test.</span>
<a name="line-722"></a><span class='hs-definition'>group</span> <span class='hs-keyglyph'>::</span> <span class='hs-conid'>Eq</span> <span class='hs-varid'>a</span> <span class='hs-keyglyph'>=></span> <span class='hs-keyglyph'>[</span><span class='hs-varid'>a</span><span class='hs-keyglyph'>]</span> <span class='hs-keyglyph'>-></span> <span class='hs-keyglyph'>[</span><span class='hs-keyglyph'>[</span><span class='hs-varid'>a</span><span class='hs-keyglyph'>]</span><span class='hs-keyglyph'>]</span>
<a name="line-723"></a><span class='hs-definition'>group</span> <span class='hs-keyglyph'>=</span> <span class='hs-varid'>groupBy</span> <span class='hs-layout'>(</span><span class='hs-varop'>==</span><span class='hs-layout'>)</span>
<a name="line-724"></a>
<a name="line-725"></a><a name="groupBy"></a><span class='hs-comment'>-- | The 'groupBy' function is the non-overloaded version of 'group'.</span>
<a name="line-726"></a><span class='hs-definition'>groupBy</span> <span class='hs-keyglyph'>::</span> <span class='hs-layout'>(</span><span class='hs-varid'>a</span> <span class='hs-keyglyph'>-></span> <span class='hs-varid'>a</span> <span class='hs-keyglyph'>-></span> <span class='hs-conid'>Bool</span><span class='hs-layout'>)</span> <span class='hs-keyglyph'>-></span> <span class='hs-keyglyph'>[</span><span class='hs-varid'>a</span><span class='hs-keyglyph'>]</span> <span class='hs-keyglyph'>-></span> <span class='hs-keyglyph'>[</span><span class='hs-keyglyph'>[</span><span class='hs-varid'>a</span><span class='hs-keyglyph'>]</span><span class='hs-keyglyph'>]</span>
<a name="line-727"></a><span class='hs-definition'>groupBy</span> <span class='hs-keyword'>_</span> <span class='hs-conid'>[]</span> <span class='hs-keyglyph'>=</span> <span class='hs-conid'>[]</span>
<a name="line-728"></a><span class='hs-definition'>groupBy</span> <span class='hs-varid'>eq</span> <span class='hs-layout'>(</span><span class='hs-varid'>x</span><span class='hs-conop'>:</span><span class='hs-varid'>xs</span><span class='hs-layout'>)</span> <span class='hs-keyglyph'>=</span> <span class='hs-layout'>(</span><span class='hs-varid'>x</span><span class='hs-conop'>:</span><span class='hs-varid'>ys</span><span class='hs-layout'>)</span> <span class='hs-conop'>:</span> <span class='hs-varid'>groupBy</span> <span class='hs-varid'>eq</span> <span class='hs-varid'>zs</span>
<a name="line-729"></a> <span class='hs-keyword'>where</span> <span class='hs-layout'>(</span><span class='hs-varid'>ys</span><span class='hs-layout'>,</span><span class='hs-varid'>zs</span><span class='hs-layout'>)</span> <span class='hs-keyglyph'>=</span> <span class='hs-varid'>span</span> <span class='hs-layout'>(</span><span class='hs-varid'>eq</span> <span class='hs-varid'>x</span><span class='hs-layout'>)</span> <span class='hs-varid'>xs</span>
<a name="line-730"></a>
<a name="line-731"></a><a name="inits"></a><span class='hs-comment'>-- | The 'inits' function returns all initial segments of the argument,</span>
<a name="line-732"></a><span class='hs-comment'>-- shortest first. For example,</span>
<a name="line-733"></a><span class='hs-comment'>--</span>
<a name="line-734"></a><span class='hs-comment'>-- > inits "abc" == ["","a","ab","abc"]</span>
<a name="line-735"></a><span class='hs-comment'>--</span>
<a name="line-736"></a><span class='hs-definition'>inits</span> <span class='hs-keyglyph'>::</span> <span class='hs-keyglyph'>[</span><span class='hs-varid'>a</span><span class='hs-keyglyph'>]</span> <span class='hs-keyglyph'>-></span> <span class='hs-keyglyph'>[</span><span class='hs-keyglyph'>[</span><span class='hs-varid'>a</span><span class='hs-keyglyph'>]</span><span class='hs-keyglyph'>]</span>
<a name="line-737"></a><span class='hs-definition'>inits</span> <span class='hs-conid'>[]</span> <span class='hs-keyglyph'>=</span> <span class='hs-keyglyph'>[</span><span class='hs-conid'>[]</span><span class='hs-keyglyph'>]</span>
<a name="line-738"></a><span class='hs-definition'>inits</span> <span class='hs-layout'>(</span><span class='hs-varid'>x</span><span class='hs-conop'>:</span><span class='hs-varid'>xs</span><span class='hs-layout'>)</span> <span class='hs-keyglyph'>=</span> <span class='hs-keyglyph'>[</span><span class='hs-conid'>[]</span><span class='hs-keyglyph'>]</span> <span class='hs-varop'>++</span> <span class='hs-varid'>map</span> <span class='hs-layout'>(</span><span class='hs-varid'>x</span><span class='hs-conop'>:</span><span class='hs-layout'>)</span> <span class='hs-layout'>(</span><span class='hs-varid'>inits</span> <span class='hs-varid'>xs</span><span class='hs-layout'>)</span>
<a name="line-739"></a>
<a name="line-740"></a><a name="tails"></a><span class='hs-comment'>-- | The 'tails' function returns all final segments of the argument,</span>
<a name="line-741"></a><span class='hs-comment'>-- longest first. For example,</span>
<a name="line-742"></a><span class='hs-comment'>--</span>
<a name="line-743"></a><span class='hs-comment'>-- > tails "abc" == ["abc", "bc", "c",""]</span>
<a name="line-744"></a><span class='hs-comment'>--</span>
<a name="line-745"></a><span class='hs-definition'>tails</span> <span class='hs-keyglyph'>::</span> <span class='hs-keyglyph'>[</span><span class='hs-varid'>a</span><span class='hs-keyglyph'>]</span> <span class='hs-keyglyph'>-></span> <span class='hs-keyglyph'>[</span><span class='hs-keyglyph'>[</span><span class='hs-varid'>a</span><span class='hs-keyglyph'>]</span><span class='hs-keyglyph'>]</span>
<a name="line-746"></a><span class='hs-definition'>tails</span> <span class='hs-conid'>[]</span> <span class='hs-keyglyph'>=</span> <span class='hs-keyglyph'>[</span><span class='hs-conid'>[]</span><span class='hs-keyglyph'>]</span>
<a name="line-747"></a><span class='hs-definition'>tails</span> <span class='hs-varid'>xxs</span><span class='hs-keyglyph'>@</span><span class='hs-layout'>(</span><span class='hs-keyword'>_</span><span class='hs-conop'>:</span><span class='hs-varid'>xs</span><span class='hs-layout'>)</span> <span class='hs-keyglyph'>=</span> <span class='hs-varid'>xxs</span> <span class='hs-conop'>:</span> <span class='hs-varid'>tails</span> <span class='hs-varid'>xs</span>
<a name="line-748"></a>
<a name="line-749"></a>
<a name="line-750"></a><a name="subsequences"></a><span class='hs-comment'>-- | The 'subsequences' function returns the list of all subsequences of the argument.</span>
<a name="line-751"></a><span class='hs-comment'>--</span>
<a name="line-752"></a><span class='hs-comment'>-- > subsequences "abc" == ["","a","b","ab","c","ac","bc","abc"]</span>
<a name="line-753"></a><span class='hs-definition'>subsequences</span> <span class='hs-keyglyph'>::</span> <span class='hs-keyglyph'>[</span><span class='hs-varid'>a</span><span class='hs-keyglyph'>]</span> <span class='hs-keyglyph'>-></span> <span class='hs-keyglyph'>[</span><span class='hs-keyglyph'>[</span><span class='hs-varid'>a</span><span class='hs-keyglyph'>]</span><span class='hs-keyglyph'>]</span>
<a name="line-754"></a><span class='hs-definition'>subsequences</span> <span class='hs-varid'>xs</span> <span class='hs-keyglyph'>=</span> <span class='hs-conid'>[]</span> <span class='hs-conop'>:</span> <span class='hs-varid'>nonEmptySubsequences</span> <span class='hs-varid'>xs</span>
<a name="line-755"></a>
<a name="line-756"></a><a name="nonEmptySubsequences"></a><span class='hs-comment'>-- | The 'nonEmptySubsequences' function returns the list of all subsequences of the argument,</span>
<a name="line-757"></a><span class='hs-comment'>-- except for the empty list.</span>
<a name="line-758"></a><span class='hs-comment'>--</span>
<a name="line-759"></a><span class='hs-comment'>-- > nonEmptySubsequences "abc" == ["a","b","ab","c","ac","bc","abc"]</span>
<a name="line-760"></a><span class='hs-definition'>nonEmptySubsequences</span> <span class='hs-keyglyph'>::</span> <span class='hs-keyglyph'>[</span><span class='hs-varid'>a</span><span class='hs-keyglyph'>]</span> <span class='hs-keyglyph'>-></span> <span class='hs-keyglyph'>[</span><span class='hs-keyglyph'>[</span><span class='hs-varid'>a</span><span class='hs-keyglyph'>]</span><span class='hs-keyglyph'>]</span>
<a name="line-761"></a><span class='hs-definition'>nonEmptySubsequences</span> <span class='hs-conid'>[]</span> <span class='hs-keyglyph'>=</span> <span class='hs-conid'>[]</span>
<a name="line-762"></a><span class='hs-definition'>nonEmptySubsequences</span> <span class='hs-layout'>(</span><span class='hs-varid'>x</span><span class='hs-conop'>:</span><span class='hs-varid'>xs</span><span class='hs-layout'>)</span> <span class='hs-keyglyph'>=</span> <span class='hs-keyglyph'>[</span><span class='hs-varid'>x</span><span class='hs-keyglyph'>]</span> <span class='hs-conop'>:</span> <span class='hs-varid'>foldr</span> <span class='hs-varid'>f</span> <span class='hs-conid'>[]</span> <span class='hs-layout'>(</span><span class='hs-varid'>nonEmptySubsequences</span> <span class='hs-varid'>xs</span><span class='hs-layout'>)</span>
<a name="line-763"></a> <span class='hs-keyword'>where</span> <span class='hs-varid'>f</span> <span class='hs-varid'>ys</span> <span class='hs-varid'>r</span> <span class='hs-keyglyph'>=</span> <span class='hs-varid'>ys</span> <span class='hs-conop'>:</span> <span class='hs-layout'>(</span><span class='hs-varid'>x</span> <span class='hs-conop'>:</span> <span class='hs-varid'>ys</span><span class='hs-layout'>)</span> <span class='hs-conop'>:</span> <span class='hs-varid'>r</span>
<a name="line-764"></a>
<a name="line-765"></a>
<a name="line-766"></a><a name="permutations"></a><span class='hs-comment'>-- | The 'permutations' function returns the list of all permutations of the argument.</span>
<a name="line-767"></a><span class='hs-comment'>--</span>
<a name="line-768"></a><span class='hs-comment'>-- > permutations "abc" == ["abc","bac","cba","bca","cab","acb"]</span>
<a name="line-769"></a><span class='hs-definition'>permutations</span> <span class='hs-keyglyph'>::</span> <span class='hs-keyglyph'>[</span><span class='hs-varid'>a</span><span class='hs-keyglyph'>]</span> <span class='hs-keyglyph'>-></span> <span class='hs-keyglyph'>[</span><span class='hs-keyglyph'>[</span><span class='hs-varid'>a</span><span class='hs-keyglyph'>]</span><span class='hs-keyglyph'>]</span>
<a name="line-770"></a><span class='hs-definition'>permutations</span> <span class='hs-varid'>xs0</span> <span class='hs-keyglyph'>=</span> <span class='hs-varid'>xs0</span> <span class='hs-conop'>:</span> <span class='hs-varid'>perms</span> <span class='hs-varid'>xs0</span> <span class='hs-conid'>[]</span>
<a name="line-771"></a> <span class='hs-keyword'>where</span>
<a name="line-772"></a> <span class='hs-varid'>perms</span> <span class='hs-conid'>[]</span> <span class='hs-keyword'>_</span> <span class='hs-keyglyph'>=</span> <span class='hs-conid'>[]</span>
<a name="line-773"></a> <span class='hs-varid'>perms</span> <span class='hs-layout'>(</span><span class='hs-varid'>t</span><span class='hs-conop'>:</span><span class='hs-varid'>ts</span><span class='hs-layout'>)</span> <span class='hs-varid'>is</span> <span class='hs-keyglyph'>=</span> <span class='hs-varid'>foldr</span> <span class='hs-varid'>interleave</span> <span class='hs-layout'>(</span><span class='hs-varid'>perms</span> <span class='hs-varid'>ts</span> <span class='hs-layout'>(</span><span class='hs-varid'>t</span><span class='hs-conop'>:</span><span class='hs-varid'>is</span><span class='hs-layout'>)</span><span class='hs-layout'>)</span> <span class='hs-layout'>(</span><span class='hs-varid'>permutations</span> <span class='hs-varid'>is</span><span class='hs-layout'>)</span>
<a name="line-774"></a> <span class='hs-keyword'>where</span> <span class='hs-varid'>interleave</span> <span class='hs-varid'>xs</span> <span class='hs-varid'>r</span> <span class='hs-keyglyph'>=</span> <span class='hs-keyword'>let</span> <span class='hs-layout'>(</span><span class='hs-keyword'>_</span><span class='hs-layout'>,</span><span class='hs-varid'>zs</span><span class='hs-layout'>)</span> <span class='hs-keyglyph'>=</span> <span class='hs-varid'>interleave'</span> <span class='hs-varid'>id</span> <span class='hs-varid'>xs</span> <span class='hs-varid'>r</span> <span class='hs-keyword'>in</span> <span class='hs-varid'>zs</span>
<a name="line-775"></a> <span class='hs-varid'>interleave'</span> <span class='hs-keyword'>_</span> <span class='hs-conid'>[]</span> <span class='hs-varid'>r</span> <span class='hs-keyglyph'>=</span> <span class='hs-layout'>(</span><span class='hs-varid'>ts</span><span class='hs-layout'>,</span> <span class='hs-varid'>r</span><span class='hs-layout'>)</span>
<a name="line-776"></a> <span class='hs-varid'>interleave'</span> <span class='hs-varid'>f</span> <span class='hs-layout'>(</span><span class='hs-varid'>y</span><span class='hs-conop'>:</span><span class='hs-varid'>ys</span><span class='hs-layout'>)</span> <span class='hs-varid'>r</span> <span class='hs-keyglyph'>=</span> <span class='hs-keyword'>let</span> <span class='hs-layout'>(</span><span class='hs-varid'>us</span><span class='hs-layout'>,</span><span class='hs-varid'>zs</span><span class='hs-layout'>)</span> <span class='hs-keyglyph'>=</span> <span class='hs-varid'>interleave'</span> <span class='hs-layout'>(</span><span class='hs-varid'>f</span> <span class='hs-varop'>.</span> <span class='hs-layout'>(</span><span class='hs-varid'>y</span><span class='hs-conop'>:</span><span class='hs-layout'>)</span><span class='hs-layout'>)</span> <span class='hs-varid'>ys</span> <span class='hs-varid'>r</span>
<a name="line-777"></a> <span class='hs-keyword'>in</span> <span class='hs-layout'>(</span><span class='hs-varid'>y</span><span class='hs-conop'>:</span><span class='hs-varid'>us</span><span class='hs-layout'>,</span> <span class='hs-varid'>f</span> <span class='hs-layout'>(</span><span class='hs-varid'>t</span><span class='hs-conop'>:</span><span class='hs-varid'>y</span><span class='hs-conop'>:</span><span class='hs-varid'>us</span><span class='hs-layout'>)</span> <span class='hs-conop'>:</span> <span class='hs-varid'>zs</span><span class='hs-layout'>)</span>
<a name="line-778"></a>
<a name="line-779"></a>
<a name="line-780"></a><span class='hs-comment'>------------------------------------------------------------------------------</span>
<a name="line-781"></a><span class='hs-comment'>-- Quick Sort algorithm taken from HBC's QSort library.</span>
<a name="line-782"></a>
<a name="line-783"></a><a name="sort"></a><span class='hs-comment'>-- | The 'sort' function implements a stable sorting algorithm.</span>
<a name="line-784"></a><span class='hs-comment'>-- It is a special case of 'sortBy', which allows the programmer to supply</span>
<a name="line-785"></a><span class='hs-comment'>-- their own comparison function.</span>
<a name="line-786"></a><span class='hs-definition'>sort</span> <span class='hs-keyglyph'>::</span> <span class='hs-layout'>(</span><span class='hs-conid'>Ord</span> <span class='hs-varid'>a</span><span class='hs-layout'>)</span> <span class='hs-keyglyph'>=></span> <span class='hs-keyglyph'>[</span><span class='hs-varid'>a</span><span class='hs-keyglyph'>]</span> <span class='hs-keyglyph'>-></span> <span class='hs-keyglyph'>[</span><span class='hs-varid'>a</span><span class='hs-keyglyph'>]</span>
<a name="line-787"></a>
<a name="line-788"></a><a name="sortBy"></a><span class='hs-comment'>-- | The 'sortBy' function is the non-overloaded version of 'sort'.</span>
<a name="line-789"></a><span class='hs-definition'>sortBy</span> <span class='hs-keyglyph'>::</span> <span class='hs-layout'>(</span><span class='hs-varid'>a</span> <span class='hs-keyglyph'>-></span> <span class='hs-varid'>a</span> <span class='hs-keyglyph'>-></span> <span class='hs-conid'>Ordering</span><span class='hs-layout'>)</span> <span class='hs-keyglyph'>-></span> <span class='hs-keyglyph'>[</span><span class='hs-varid'>a</span><span class='hs-keyglyph'>]</span> <span class='hs-keyglyph'>-></span> <span class='hs-keyglyph'>[</span><span class='hs-varid'>a</span><span class='hs-keyglyph'>]</span>
<a name="line-790"></a>
<a name="line-791"></a><span class='hs-cpp'>#ifdef USE_REPORT_PRELUDE</span>
<a name="line-792"></a><span class='hs-definition'>sort</span> <span class='hs-keyglyph'>=</span> <span class='hs-varid'>sortBy</span> <span class='hs-varid'>compare</span>
<a name="line-793"></a><span class='hs-definition'>sortBy</span> <span class='hs-varid'>cmp</span> <span class='hs-keyglyph'>=</span> <span class='hs-varid'>foldr</span> <span class='hs-layout'>(</span><span class='hs-varid'>insertBy</span> <span class='hs-varid'>cmp</span><span class='hs-layout'>)</span> <span class='hs-conid'>[]</span>
<a name="line-794"></a><span class='hs-cpp'>#else</span>
<a name="line-795"></a>
<a name="line-796"></a><span class='hs-comment'>{-
<a name="line-797"></a>GHC's mergesort replaced by a better implementation, 24/12/2009.
<a name="line-798"></a>This code originally contributed to the nhc12 compiler by Thomas Nordin
<a name="line-799"></a>in 2002. Rumoured to have been based on code by Lennart Augustsson, e.g.
<a name="line-800"></a> <a href="http://www.mail-archive.com/haskell@haskell.org/msg01822.html">http://www.mail-archive.com/haskell@haskell.org/msg01822.html</a>
<a name="line-801"></a>and possibly to bear similarities to a 1982 paper by Richard O'Keefe:
<a name="line-802"></a>"A smooth applicative merge sort".
<a name="line-803"></a>
<a name="line-804"></a>Benchmarks show it to be often 2x the speed of the previous implementation.
<a name="line-805"></a>Fixes ticket <a href="http://hackage.haskell.org/trac/ghc/ticket/2143">http://hackage.haskell.org/trac/ghc/ticket/2143</a>
<a name="line-806"></a>-}</span>
<a name="line-807"></a>
<a name="line-808"></a><span class='hs-definition'>sort</span> <span class='hs-keyglyph'>=</span> <span class='hs-varid'>sortBy</span> <span class='hs-varid'>compare</span>
<a name="line-809"></a><span class='hs-definition'>sortBy</span> <span class='hs-varid'>cmp</span> <span class='hs-keyglyph'>=</span> <span class='hs-varid'>mergeAll</span> <span class='hs-varop'>.</span> <span class='hs-varid'>sequences</span>
<a name="line-810"></a> <span class='hs-keyword'>where</span>
<a name="line-811"></a> <span class='hs-varid'>sequences</span> <span class='hs-layout'>(</span><span class='hs-varid'>a</span><span class='hs-conop'>:</span><span class='hs-varid'>b</span><span class='hs-conop'>:</span><span class='hs-varid'>xs</span><span class='hs-layout'>)</span>
<a name="line-812"></a> <span class='hs-keyglyph'>|</span> <span class='hs-varid'>a</span> <span class='hs-varop'>`cmp`</span> <span class='hs-varid'>b</span> <span class='hs-varop'>==</span> <span class='hs-conid'>GT</span> <span class='hs-keyglyph'>=</span> <span class='hs-varid'>descending</span> <span class='hs-varid'>b</span> <span class='hs-keyglyph'>[</span><span class='hs-varid'>a</span><span class='hs-keyglyph'>]</span> <span class='hs-varid'>xs</span>
<a name="line-813"></a> <span class='hs-keyglyph'>|</span> <span class='hs-varid'>otherwise</span> <span class='hs-keyglyph'>=</span> <span class='hs-varid'>ascending</span> <span class='hs-varid'>b</span> <span class='hs-layout'>(</span><span class='hs-varid'>a</span><span class='hs-conop'>:</span><span class='hs-layout'>)</span> <span class='hs-varid'>xs</span>
<a name="line-814"></a> <span class='hs-varid'>sequences</span> <span class='hs-varid'>xs</span> <span class='hs-keyglyph'>=</span> <span class='hs-keyglyph'>[</span><span class='hs-varid'>xs</span><span class='hs-keyglyph'>]</span>
<a name="line-815"></a>
<a name="line-816"></a> <span class='hs-varid'>descending</span> <span class='hs-varid'>a</span> <span class='hs-keyword'>as</span> <span class='hs-layout'>(</span><span class='hs-varid'>b</span><span class='hs-conop'>:</span><span class='hs-varid'>bs</span><span class='hs-layout'>)</span>
<a name="line-817"></a> <span class='hs-keyglyph'>|</span> <span class='hs-varid'>a</span> <span class='hs-varop'>`cmp`</span> <span class='hs-varid'>b</span> <span class='hs-varop'>==</span> <span class='hs-conid'>GT</span> <span class='hs-keyglyph'>=</span> <span class='hs-varid'>descending</span> <span class='hs-varid'>b</span> <span class='hs-layout'>(</span><span class='hs-varid'>a</span><span class='hs-conop'>:</span><span class='hs-keyword'>as</span><span class='hs-layout'>)</span> <span class='hs-varid'>bs</span>
<a name="line-818"></a> <span class='hs-varid'>descending</span> <span class='hs-varid'>a</span> <span class='hs-keyword'>as</span> <span class='hs-varid'>bs</span> <span class='hs-keyglyph'>=</span> <span class='hs-layout'>(</span><span class='hs-varid'>a</span><span class='hs-conop'>:</span><span class='hs-keyword'>as</span><span class='hs-layout'>)</span><span class='hs-conop'>:</span> <span class='hs-varid'>sequences</span> <span class='hs-varid'>bs</span>
<a name="line-819"></a>
<a name="line-820"></a> <span class='hs-varid'>ascending</span> <span class='hs-varid'>a</span> <span class='hs-keyword'>as</span> <span class='hs-layout'>(</span><span class='hs-varid'>b</span><span class='hs-conop'>:</span><span class='hs-varid'>bs</span><span class='hs-layout'>)</span>
<a name="line-821"></a> <span class='hs-keyglyph'>|</span> <span class='hs-varid'>a</span> <span class='hs-varop'>`cmp`</span> <span class='hs-varid'>b</span> <span class='hs-varop'>/=</span> <span class='hs-conid'>GT</span> <span class='hs-keyglyph'>=</span> <span class='hs-varid'>ascending</span> <span class='hs-varid'>b</span> <span class='hs-layout'>(</span><span class='hs-keyglyph'>\</span><span class='hs-varid'>ys</span> <span class='hs-keyglyph'>-></span> <span class='hs-keyword'>as</span> <span class='hs-layout'>(</span><span class='hs-varid'>a</span><span class='hs-conop'>:</span><span class='hs-varid'>ys</span><span class='hs-layout'>)</span><span class='hs-layout'>)</span> <span class='hs-varid'>bs</span>
<a name="line-822"></a> <span class='hs-varid'>ascending</span> <span class='hs-varid'>a</span> <span class='hs-keyword'>as</span> <span class='hs-varid'>bs</span> <span class='hs-keyglyph'>=</span> <span class='hs-keyword'>as</span> <span class='hs-keyglyph'>[</span><span class='hs-varid'>a</span><span class='hs-keyglyph'>]</span><span class='hs-conop'>:</span> <span class='hs-varid'>sequences</span> <span class='hs-varid'>bs</span>
<a name="line-823"></a>
<a name="line-824"></a> <span class='hs-varid'>mergeAll</span> <span class='hs-keyglyph'>[</span><span class='hs-varid'>x</span><span class='hs-keyglyph'>]</span> <span class='hs-keyglyph'>=</span> <span class='hs-varid'>x</span>
<a name="line-825"></a> <span class='hs-varid'>mergeAll</span> <span class='hs-varid'>xs</span> <span class='hs-keyglyph'>=</span> <span class='hs-varid'>mergeAll</span> <span class='hs-layout'>(</span><span class='hs-varid'>mergePairs</span> <span class='hs-varid'>xs</span><span class='hs-layout'>)</span>
<a name="line-826"></a>
<a name="line-827"></a> <span class='hs-varid'>mergePairs</span> <span class='hs-layout'>(</span><span class='hs-varid'>a</span><span class='hs-conop'>:</span><span class='hs-varid'>b</span><span class='hs-conop'>:</span><span class='hs-varid'>xs</span><span class='hs-layout'>)</span> <span class='hs-keyglyph'>=</span> <span class='hs-varid'>merge</span> <span class='hs-varid'>a</span> <span class='hs-varid'>b</span><span class='hs-conop'>:</span> <span class='hs-varid'>mergePairs</span> <span class='hs-varid'>xs</span>
<a name="line-828"></a> <span class='hs-varid'>mergePairs</span> <span class='hs-varid'>xs</span> <span class='hs-keyglyph'>=</span> <span class='hs-varid'>xs</span>
<a name="line-829"></a>
<a name="line-830"></a> <span class='hs-varid'>merge</span> <span class='hs-keyword'>as</span><span class='hs-keyglyph'>@</span><span class='hs-layout'>(</span><span class='hs-varid'>a</span><span class='hs-conop'>:</span><span class='hs-varid'>as'</span><span class='hs-layout'>)</span> <span class='hs-varid'>bs</span><span class='hs-keyglyph'>@</span><span class='hs-layout'>(</span><span class='hs-varid'>b</span><span class='hs-conop'>:</span><span class='hs-varid'>bs'</span><span class='hs-layout'>)</span>
<a name="line-831"></a> <span class='hs-keyglyph'>|</span> <span class='hs-varid'>a</span> <span class='hs-varop'>`cmp`</span> <span class='hs-varid'>b</span> <span class='hs-varop'>==</span> <span class='hs-conid'>GT</span> <span class='hs-keyglyph'>=</span> <span class='hs-varid'>b</span><span class='hs-conop'>:</span><span class='hs-varid'>merge</span> <span class='hs-keyword'>as</span> <span class='hs-varid'>bs'</span>
<a name="line-832"></a> <span class='hs-keyglyph'>|</span> <span class='hs-varid'>otherwise</span> <span class='hs-keyglyph'>=</span> <span class='hs-varid'>a</span><span class='hs-conop'>:</span><span class='hs-varid'>merge</span> <span class='hs-varid'>as'</span> <span class='hs-varid'>bs</span>
<a name="line-833"></a> <span class='hs-varid'>merge</span> <span class='hs-conid'>[]</span> <span class='hs-varid'>bs</span> <span class='hs-keyglyph'>=</span> <span class='hs-varid'>bs</span>
<a name="line-834"></a> <span class='hs-varid'>merge</span> <span class='hs-keyword'>as</span> <span class='hs-conid'>[]</span> <span class='hs-keyglyph'>=</span> <span class='hs-keyword'>as</span>
<a name="line-835"></a>
<a name="line-836"></a><span class='hs-comment'>{-
<a name="line-837"></a>sortBy cmp l = mergesort cmp l
<a name="line-838"></a>sort l = mergesort compare l
<a name="line-839"></a>
<a name="line-840"></a>Quicksort replaced by mergesort, 14/5/2002.
<a name="line-841"></a>
<a name="line-842"></a>From: Ian Lynagh <igloo@earth.li>
<a name="line-843"></a>
<a name="line-844"></a>I am curious as to why the List.sort implementation in GHC is a
<a name="line-845"></a>quicksort algorithm rather than an algorithm that guarantees n log n
<a name="line-846"></a>time in the worst case? I have attached a mergesort implementation along
<a name="line-847"></a>with a few scripts to time it's performance, the results of which are
<a name="line-848"></a>shown below (* means it didn't finish successfully - in all cases this
<a name="line-849"></a>was due to a stack overflow).
<a name="line-850"></a>
<a name="line-851"></a>If I heap profile the random_list case with only 10000 then I see
<a name="line-852"></a>random_list peaks at using about 2.5M of memory, whereas in the same
<a name="line-853"></a>program using List.sort it uses only 100k.
<a name="line-854"></a>
<a name="line-855"></a>Input style Input length Sort data Sort alg User time
<a name="line-856"></a>stdin 10000 random_list sort 2.82
<a name="line-857"></a>stdin 10000 random_list mergesort 2.96
<a name="line-858"></a>stdin 10000 sorted sort 31.37
<a name="line-859"></a>stdin 10000 sorted mergesort 1.90
<a name="line-860"></a>stdin 10000 revsorted sort 31.21
<a name="line-861"></a>stdin 10000 revsorted mergesort 1.88
<a name="line-862"></a>stdin 100000 random_list sort *
<a name="line-863"></a>stdin 100000 random_list mergesort *
<a name="line-864"></a>stdin 100000 sorted sort *
<a name="line-865"></a>stdin 100000 sorted mergesort *
<a name="line-866"></a>stdin 100000 revsorted sort *
<a name="line-867"></a>stdin 100000 revsorted mergesort *
<a name="line-868"></a>func 10000 random_list sort 0.31
<a name="line-869"></a>func 10000 random_list mergesort 0.91
<a name="line-870"></a>func 10000 sorted sort 19.09
<a name="line-871"></a>func 10000 sorted mergesort 0.15
<a name="line-872"></a>func 10000 revsorted sort 19.17
<a name="line-873"></a>func 10000 revsorted mergesort 0.16
<a name="line-874"></a>func 100000 random_list sort 3.85
<a name="line-875"></a>func 100000 random_list mergesort *
<a name="line-876"></a>func 100000 sorted sort 5831.47
<a name="line-877"></a>func 100000 sorted mergesort 2.23
<a name="line-878"></a>func 100000 revsorted sort 5872.34
<a name="line-879"></a>func 100000 revsorted mergesort 2.24
<a name="line-880"></a>
<a name="line-881"></a>mergesort :: (a -> a -> Ordering) -> [a] -> [a]
<a name="line-882"></a>mergesort cmp = mergesort' cmp . map wrap
<a name="line-883"></a>
<a name="line-884"></a>mergesort' :: (a -> a -> Ordering) -> [[a]] -> [a]
<a name="line-885"></a>mergesort' _ [] = []
<a name="line-886"></a>mergesort' _ [xs] = xs
<a name="line-887"></a>mergesort' cmp xss = mergesort' cmp (merge_pairs cmp xss)
<a name="line-888"></a>
<a name="line-889"></a>merge_pairs :: (a -> a -> Ordering) -> [[a]] -> [[a]]
<a name="line-890"></a>merge_pairs _ [] = []
<a name="line-891"></a>merge_pairs _ [xs] = [xs]
<a name="line-892"></a>merge_pairs cmp (xs:ys:xss) = merge cmp xs ys : merge_pairs cmp xss
<a name="line-893"></a>
<a name="line-894"></a>merge :: (a -> a -> Ordering) -> [a] -> [a] -> [a]
<a name="line-895"></a>merge _ [] ys = ys
<a name="line-896"></a>merge _ xs [] = xs
<a name="line-897"></a>merge cmp (x:xs) (y:ys)
<a name="line-898"></a> = case x `cmp` y of
<a name="line-899"></a> GT -> y : merge cmp (x:xs) ys
<a name="line-900"></a> _ -> x : merge cmp xs (y:ys)
<a name="line-901"></a>
<a name="line-902"></a>wrap :: a -> [a]
<a name="line-903"></a>wrap x = [x]
<a name="line-904"></a>
<a name="line-905"></a>
<a name="line-906"></a>
<a name="line-907"></a>OLDER: qsort version
<a name="line-908"></a>
<a name="line-909"></a>-- qsort is stable and does not concatenate.
<a name="line-910"></a>qsort :: (a -> a -> Ordering) -> [a] -> [a] -> [a]
<a name="line-911"></a>qsort _ [] r = r
<a name="line-912"></a>qsort _ [x] r = x:r
<a name="line-913"></a>qsort cmp (x:xs) r = qpart cmp x xs [] [] r
<a name="line-914"></a>
<a name="line-915"></a>-- qpart partitions and sorts the sublists
<a name="line-916"></a>qpart :: (a -> a -> Ordering) -> a -> [a] -> [a] -> [a] -> [a] -> [a]
<a name="line-917"></a>qpart cmp x [] rlt rge r =
<a name="line-918"></a> -- rlt and rge are in reverse order and must be sorted with an
<a name="line-919"></a> -- anti-stable sorting
<a name="line-920"></a> rqsort cmp rlt (x:rqsort cmp rge r)
<a name="line-921"></a>qpart cmp x (y:ys) rlt rge r =
<a name="line-922"></a> case cmp x y of
<a name="line-923"></a> GT -> qpart cmp x ys (y:rlt) rge r
<a name="line-924"></a> _ -> qpart cmp x ys rlt (y:rge) r
<a name="line-925"></a>
<a name="line-926"></a>-- rqsort is as qsort but anti-stable, i.e. reverses equal elements
<a name="line-927"></a>rqsort :: (a -> a -> Ordering) -> [a] -> [a] -> [a]
<a name="line-928"></a>rqsort _ [] r = r
<a name="line-929"></a>rqsort _ [x] r = x:r
<a name="line-930"></a>rqsort cmp (x:xs) r = rqpart cmp x xs [] [] r
<a name="line-931"></a>
<a name="line-932"></a>rqpart :: (a -> a -> Ordering) -> a -> [a] -> [a] -> [a] -> [a] -> [a]
<a name="line-933"></a>rqpart cmp x [] rle rgt r =
<a name="line-934"></a> qsort cmp rle (x:qsort cmp rgt r)
<a name="line-935"></a>rqpart cmp x (y:ys) rle rgt r =
<a name="line-936"></a> case cmp y x of
<a name="line-937"></a> GT -> rqpart cmp x ys rle (y:rgt) r
<a name="line-938"></a> _ -> rqpart cmp x ys (y:rle) rgt r
<a name="line-939"></a>-}</span>
<a name="line-940"></a>
<a name="line-941"></a><span class='hs-cpp'>#endif /* USE_REPORT_PRELUDE */</span>
<a name="line-942"></a>
<a name="line-943"></a><a name="unfoldr"></a><span class='hs-comment'>-- | The 'unfoldr' function is a \`dual\' to 'foldr': while 'foldr'</span>
<a name="line-944"></a><span class='hs-comment'>-- reduces a list to a summary value, 'unfoldr' builds a list from</span>
<a name="line-945"></a><span class='hs-comment'>-- a seed value. The function takes the element and returns 'Nothing'</span>
<a name="line-946"></a><span class='hs-comment'>-- if it is done producing the list or returns 'Just' @(a,b)@, in which</span>
<a name="line-947"></a><span class='hs-comment'>-- case, @a@ is a prepended to the list and @b@ is used as the next</span>
<a name="line-948"></a><span class='hs-comment'>-- element in a recursive call. For example,</span>
<a name="line-949"></a><span class='hs-comment'>--</span>
<a name="line-950"></a><span class='hs-comment'>-- > iterate f == unfoldr (\x -> Just (x, f x))</span>
<a name="line-951"></a><span class='hs-comment'>--</span>
<a name="line-952"></a><span class='hs-comment'>-- In some cases, 'unfoldr' can undo a 'foldr' operation:</span>
<a name="line-953"></a><span class='hs-comment'>--</span>
<a name="line-954"></a><span class='hs-comment'>-- > unfoldr f' (foldr f z xs) == xs</span>
<a name="line-955"></a><span class='hs-comment'>--</span>
<a name="line-956"></a><span class='hs-comment'>-- if the following holds:</span>
<a name="line-957"></a><span class='hs-comment'>--</span>
<a name="line-958"></a><span class='hs-comment'>-- > f' (f x y) = Just (x,y)</span>
<a name="line-959"></a><span class='hs-comment'>-- > f' z = Nothing</span>
<a name="line-960"></a><span class='hs-comment'>--</span>
<a name="line-961"></a><span class='hs-comment'>-- A simple use of unfoldr:</span>
<a name="line-962"></a><span class='hs-comment'>--</span>
<a name="line-963"></a><span class='hs-comment'>-- > unfoldr (\b -> if b == 0 then Nothing else Just (b, b-1)) 10</span>
<a name="line-964"></a><span class='hs-comment'>-- > [10,9,8,7,6,5,4,3,2,1]</span>
<a name="line-965"></a><span class='hs-comment'>--</span>
<a name="line-966"></a><span class='hs-definition'>unfoldr</span> <span class='hs-keyglyph'>::</span> <span class='hs-layout'>(</span><span class='hs-varid'>b</span> <span class='hs-keyglyph'>-></span> <span class='hs-conid'>Maybe</span> <span class='hs-layout'>(</span><span class='hs-varid'>a</span><span class='hs-layout'>,</span> <span class='hs-varid'>b</span><span class='hs-layout'>)</span><span class='hs-layout'>)</span> <span class='hs-keyglyph'>-></span> <span class='hs-varid'>b</span> <span class='hs-keyglyph'>-></span> <span class='hs-keyglyph'>[</span><span class='hs-varid'>a</span><span class='hs-keyglyph'>]</span>
<a name="line-967"></a><span class='hs-definition'>unfoldr</span> <span class='hs-varid'>f</span> <span class='hs-varid'>b</span> <span class='hs-keyglyph'>=</span>
<a name="line-968"></a> <span class='hs-keyword'>case</span> <span class='hs-varid'>f</span> <span class='hs-varid'>b</span> <span class='hs-keyword'>of</span>
<a name="line-969"></a> <span class='hs-conid'>Just</span> <span class='hs-layout'>(</span><span class='hs-varid'>a</span><span class='hs-layout'>,</span><span class='hs-varid'>new_b</span><span class='hs-layout'>)</span> <span class='hs-keyglyph'>-></span> <span class='hs-varid'>a</span> <span class='hs-conop'>:</span> <span class='hs-varid'>unfoldr</span> <span class='hs-varid'>f</span> <span class='hs-varid'>new_b</span>
<a name="line-970"></a> <span class='hs-conid'>Nothing</span> <span class='hs-keyglyph'>-></span> <span class='hs-conid'>[]</span>
<a name="line-971"></a>
<a name="line-972"></a><span class='hs-comment'>-- -----------------------------------------------------------------------------</span>
<a name="line-973"></a>
<a name="line-974"></a><a name="foldl'"></a><span class='hs-comment'>-- | A strict version of 'foldl'.</span>
<a name="line-975"></a><span class='hs-definition'>foldl'</span> <span class='hs-keyglyph'>::</span> <span class='hs-layout'>(</span><span class='hs-varid'>a</span> <span class='hs-keyglyph'>-></span> <span class='hs-varid'>b</span> <span class='hs-keyglyph'>-></span> <span class='hs-varid'>a</span><span class='hs-layout'>)</span> <span class='hs-keyglyph'>-></span> <span class='hs-varid'>a</span> <span class='hs-keyglyph'>-></span> <span class='hs-keyglyph'>[</span><span class='hs-varid'>b</span><span class='hs-keyglyph'>]</span> <span class='hs-keyglyph'>-></span> <span class='hs-varid'>a</span>
<a name="line-976"></a><span class='hs-cpp'>#ifdef __GLASGOW_HASKELL__</span>
<a name="line-977"></a><span class='hs-definition'>foldl'</span> <span class='hs-varid'>f</span> <span class='hs-varid'>z0</span> <span class='hs-varid'>xs0</span> <span class='hs-keyglyph'>=</span> <span class='hs-varid'>lgo</span> <span class='hs-varid'>z0</span> <span class='hs-varid'>xs0</span>
<a name="line-978"></a> <span class='hs-keyword'>where</span> <span class='hs-varid'>lgo</span> <span class='hs-varid'>z</span> <span class='hs-conid'>[]</span> <span class='hs-keyglyph'>=</span> <span class='hs-varid'>z</span>
<a name="line-979"></a> <span class='hs-varid'>lgo</span> <span class='hs-varid'>z</span> <span class='hs-layout'>(</span><span class='hs-varid'>x</span><span class='hs-conop'>:</span><span class='hs-varid'>xs</span><span class='hs-layout'>)</span> <span class='hs-keyglyph'>=</span> <span class='hs-keyword'>let</span> <span class='hs-varid'>z'</span> <span class='hs-keyglyph'>=</span> <span class='hs-varid'>f</span> <span class='hs-varid'>z</span> <span class='hs-varid'>x</span> <span class='hs-keyword'>in</span> <span class='hs-varid'>z'</span> <span class='hs-varop'>`seq`</span> <span class='hs-varid'>lgo</span> <span class='hs-varid'>z'</span> <span class='hs-varid'>xs</span>
<a name="line-980"></a><span class='hs-cpp'>#else</span>
<a name="line-981"></a><span class='hs-definition'>foldl'</span> <span class='hs-varid'>f</span> <span class='hs-varid'>a</span> <span class='hs-conid'>[]</span> <span class='hs-keyglyph'>=</span> <span class='hs-varid'>a</span>
<a name="line-982"></a><span class='hs-definition'>foldl'</span> <span class='hs-varid'>f</span> <span class='hs-varid'>a</span> <span class='hs-layout'>(</span><span class='hs-varid'>x</span><span class='hs-conop'>:</span><span class='hs-varid'>xs</span><span class='hs-layout'>)</span> <span class='hs-keyglyph'>=</span> <span class='hs-keyword'>let</span> <span class='hs-varid'>a'</span> <span class='hs-keyglyph'>=</span> <span class='hs-varid'>f</span> <span class='hs-varid'>a</span> <span class='hs-varid'>x</span> <span class='hs-keyword'>in</span> <span class='hs-varid'>a'</span> <span class='hs-varop'>`seq`</span> <span class='hs-varid'>foldl'</span> <span class='hs-varid'>f</span> <span class='hs-varid'>a'</span> <span class='hs-varid'>xs</span>
<a name="line-983"></a><span class='hs-cpp'>#endif</span>
<a name="line-984"></a>
<a name="line-985"></a><span class='hs-cpp'>#ifdef __GLASGOW_HASKELL__</span>
<a name="line-986"></a><a name="foldl1"></a><span class='hs-comment'>-- | 'foldl1' is a variant of 'foldl' that has no starting value argument,</span>
<a name="line-987"></a><span class='hs-comment'>-- and thus must be applied to non-empty lists.</span>
<a name="line-988"></a><span class='hs-definition'>foldl1</span> <span class='hs-keyglyph'>::</span> <span class='hs-layout'>(</span><span class='hs-varid'>a</span> <span class='hs-keyglyph'>-></span> <span class='hs-varid'>a</span> <span class='hs-keyglyph'>-></span> <span class='hs-varid'>a</span><span class='hs-layout'>)</span> <span class='hs-keyglyph'>-></span> <span class='hs-keyglyph'>[</span><span class='hs-varid'>a</span><span class='hs-keyglyph'>]</span> <span class='hs-keyglyph'>-></span> <span class='hs-varid'>a</span>
<a name="line-989"></a><span class='hs-definition'>foldl1</span> <span class='hs-varid'>f</span> <span class='hs-layout'>(</span><span class='hs-varid'>x</span><span class='hs-conop'>:</span><span class='hs-varid'>xs</span><span class='hs-layout'>)</span> <span class='hs-keyglyph'>=</span> <span class='hs-varid'>foldl</span> <span class='hs-varid'>f</span> <span class='hs-varid'>x</span> <span class='hs-varid'>xs</span>
<a name="line-990"></a><span class='hs-definition'>foldl1</span> <span class='hs-keyword'>_</span> <span class='hs-conid'>[]</span> <span class='hs-keyglyph'>=</span> <span class='hs-varid'>errorEmptyList</span> <span class='hs-str'>"foldl1"</span>
<a name="line-991"></a><span class='hs-cpp'>#endif /* __GLASGOW_HASKELL__ */</span>
<a name="line-992"></a>
<a name="line-993"></a><a name="foldl1'"></a><span class='hs-comment'>-- | A strict version of 'foldl1'</span>
<a name="line-994"></a><span class='hs-definition'>foldl1'</span> <span class='hs-keyglyph'>::</span> <span class='hs-layout'>(</span><span class='hs-varid'>a</span> <span class='hs-keyglyph'>-></span> <span class='hs-varid'>a</span> <span class='hs-keyglyph'>-></span> <span class='hs-varid'>a</span><span class='hs-layout'>)</span> <span class='hs-keyglyph'>-></span> <span class='hs-keyglyph'>[</span><span class='hs-varid'>a</span><span class='hs-keyglyph'>]</span> <span class='hs-keyglyph'>-></span> <span class='hs-varid'>a</span>
<a name="line-995"></a><span class='hs-definition'>foldl1'</span> <span class='hs-varid'>f</span> <span class='hs-layout'>(</span><span class='hs-varid'>x</span><span class='hs-conop'>:</span><span class='hs-varid'>xs</span><span class='hs-layout'>)</span> <span class='hs-keyglyph'>=</span> <span class='hs-varid'>foldl'</span> <span class='hs-varid'>f</span> <span class='hs-varid'>x</span> <span class='hs-varid'>xs</span>
<a name="line-996"></a><span class='hs-definition'>foldl1'</span> <span class='hs-keyword'>_</span> <span class='hs-conid'>[]</span> <span class='hs-keyglyph'>=</span> <span class='hs-varid'>errorEmptyList</span> <span class='hs-str'>"foldl1'"</span>
<a name="line-997"></a>
<a name="line-998"></a><span class='hs-cpp'>#ifdef __GLASGOW_HASKELL__</span>
<a name="line-999"></a><span class='hs-comment'>-- -----------------------------------------------------------------------------</span>
<a name="line-1000"></a><span class='hs-comment'>-- List sum and product</span>
<a name="line-1001"></a>
<a name="line-1002"></a><a name="sum"></a><span class='hs-comment'>{-# SPECIALISE sum :: [Int] -> Int #-}</span>
<a name="line-1003"></a><span class='hs-comment'>{-# SPECIALISE sum :: [Integer] -> Integer #-}</span>
<a name="line-1004"></a><span class='hs-comment'>{-# SPECIALISE product :: [Int] -> Int #-}</span>
<a name="line-1005"></a><span class='hs-comment'>{-# SPECIALISE product :: [Integer] -> Integer #-}</span>
<a name="line-1006"></a><span class='hs-comment'>-- | The 'sum' function computes the sum of a finite list of numbers.</span>
<a name="line-1007"></a><span class='hs-definition'>sum</span> <span class='hs-keyglyph'>::</span> <span class='hs-layout'>(</span><span class='hs-conid'>Num</span> <span class='hs-varid'>a</span><span class='hs-layout'>)</span> <span class='hs-keyglyph'>=></span> <span class='hs-keyglyph'>[</span><span class='hs-varid'>a</span><span class='hs-keyglyph'>]</span> <span class='hs-keyglyph'>-></span> <span class='hs-varid'>a</span>
<a name="line-1008"></a><a name="product"></a><span class='hs-comment'>-- | The 'product' function computes the product of a finite list of numbers.</span>
<a name="line-1009"></a><span class='hs-definition'>product</span> <span class='hs-keyglyph'>::</span> <span class='hs-layout'>(</span><span class='hs-conid'>Num</span> <span class='hs-varid'>a</span><span class='hs-layout'>)</span> <span class='hs-keyglyph'>=></span> <span class='hs-keyglyph'>[</span><span class='hs-varid'>a</span><span class='hs-keyglyph'>]</span> <span class='hs-keyglyph'>-></span> <span class='hs-varid'>a</span>
<a name="line-1010"></a><span class='hs-cpp'>#ifdef USE_REPORT_PRELUDE</span>
<a name="line-1011"></a><span class='hs-definition'>sum</span> <span class='hs-keyglyph'>=</span> <span class='hs-varid'>foldl</span> <span class='hs-layout'>(</span><span class='hs-varop'>+</span><span class='hs-layout'>)</span> <span class='hs-num'>0</span>
<a name="line-1012"></a><span class='hs-definition'>product</span> <span class='hs-keyglyph'>=</span> <span class='hs-varid'>foldl</span> <span class='hs-layout'>(</span><span class='hs-varop'>*</span><span class='hs-layout'>)</span> <span class='hs-num'>1</span>
<a name="line-1013"></a><span class='hs-cpp'>#else</span>
<a name="line-1014"></a><span class='hs-definition'>sum</span> <span class='hs-varid'>l</span> <span class='hs-keyglyph'>=</span> <span class='hs-varid'>sum'</span> <span class='hs-varid'>l</span> <span class='hs-num'>0</span>
<a name="line-1015"></a> <span class='hs-keyword'>where</span>
<a name="line-1016"></a> <span class='hs-varid'>sum'</span> <span class='hs-conid'>[]</span> <span class='hs-varid'>a</span> <span class='hs-keyglyph'>=</span> <span class='hs-varid'>a</span>
<a name="line-1017"></a> <span class='hs-varid'>sum'</span> <span class='hs-layout'>(</span><span class='hs-varid'>x</span><span class='hs-conop'>:</span><span class='hs-varid'>xs</span><span class='hs-layout'>)</span> <span class='hs-varid'>a</span> <span class='hs-keyglyph'>=</span> <span class='hs-varid'>sum'</span> <span class='hs-varid'>xs</span> <span class='hs-layout'>(</span><span class='hs-varid'>a</span><span class='hs-varop'>+</span><span class='hs-varid'>x</span><span class='hs-layout'>)</span>
<a name="line-1018"></a><span class='hs-definition'>product</span> <span class='hs-varid'>l</span> <span class='hs-keyglyph'>=</span> <span class='hs-varid'>prod</span> <span class='hs-varid'>l</span> <span class='hs-num'>1</span>
<a name="line-1019"></a> <span class='hs-keyword'>where</span>
<a name="line-1020"></a> <span class='hs-varid'>prod</span> <span class='hs-conid'>[]</span> <span class='hs-varid'>a</span> <span class='hs-keyglyph'>=</span> <span class='hs-varid'>a</span>
<a name="line-1021"></a> <span class='hs-varid'>prod</span> <span class='hs-layout'>(</span><span class='hs-varid'>x</span><span class='hs-conop'>:</span><span class='hs-varid'>xs</span><span class='hs-layout'>)</span> <span class='hs-varid'>a</span> <span class='hs-keyglyph'>=</span> <span class='hs-varid'>prod</span> <span class='hs-varid'>xs</span> <span class='hs-layout'>(</span><span class='hs-varid'>a</span><span class='hs-varop'>*</span><span class='hs-varid'>x</span><span class='hs-layout'>)</span>
<a name="line-1022"></a><span class='hs-cpp'>#endif</span>
<a name="line-1023"></a>
<a name="line-1024"></a><span class='hs-comment'>-- -----------------------------------------------------------------------------</span>
<a name="line-1025"></a><span class='hs-comment'>-- Functions on strings</span>
<a name="line-1026"></a>
<a name="line-1027"></a><a name="lines"></a><span class='hs-comment'>-- | 'lines' breaks a string up into a list of strings at newline</span>
<a name="line-1028"></a><span class='hs-comment'>-- characters. The resulting strings do not contain newlines.</span>
<a name="line-1029"></a><span class='hs-definition'>lines</span> <span class='hs-keyglyph'>::</span> <span class='hs-conid'>String</span> <span class='hs-keyglyph'>-></span> <span class='hs-keyglyph'>[</span><span class='hs-conid'>String</span><span class='hs-keyglyph'>]</span>
<a name="line-1030"></a><span class='hs-definition'>lines</span> <span class='hs-str'>""</span> <span class='hs-keyglyph'>=</span> <span class='hs-conid'>[]</span>
<a name="line-1031"></a><span class='hs-cpp'>#ifdef __GLASGOW_HASKELL__</span>
<a name="line-1032"></a><span class='hs-comment'>-- Somehow GHC doesn't detect the selector thunks in the below code,</span>
<a name="line-1033"></a><span class='hs-comment'>-- so s' keeps a reference to the first line via the pair and we have</span>
<a name="line-1034"></a><span class='hs-comment'>-- a space leak (cf. #4334).</span>
<a name="line-1035"></a><span class='hs-comment'>-- So we need to make GHC see the selector thunks with a trick.</span>
<a name="line-1036"></a><span class='hs-definition'>lines</span> <span class='hs-varid'>s</span> <span class='hs-keyglyph'>=</span> <span class='hs-varid'>cons</span> <span class='hs-layout'>(</span><span class='hs-keyword'>case</span> <span class='hs-varid'>break</span> <span class='hs-layout'>(</span><span class='hs-varop'>==</span> <span class='hs-chr'>'\n'</span><span class='hs-layout'>)</span> <span class='hs-varid'>s</span> <span class='hs-keyword'>of</span>
<a name="line-1037"></a> <span class='hs-layout'>(</span><span class='hs-varid'>l</span><span class='hs-layout'>,</span> <span class='hs-varid'>s'</span><span class='hs-layout'>)</span> <span class='hs-keyglyph'>-></span> <span class='hs-layout'>(</span><span class='hs-varid'>l</span><span class='hs-layout'>,</span> <span class='hs-keyword'>case</span> <span class='hs-varid'>s'</span> <span class='hs-keyword'>of</span>
<a name="line-1038"></a> <span class='hs-conid'>[]</span> <span class='hs-keyglyph'>-></span> <span class='hs-conid'>[]</span>
<a name="line-1039"></a> <span class='hs-keyword'>_</span><span class='hs-conop'>:</span><span class='hs-varid'>s''</span> <span class='hs-keyglyph'>-></span> <span class='hs-varid'>lines</span> <span class='hs-varid'>s''</span><span class='hs-layout'>)</span><span class='hs-layout'>)</span>
<a name="line-1040"></a> <span class='hs-keyword'>where</span>
<a name="line-1041"></a> <span class='hs-varid'>cons</span> <span class='hs-keyglyph'>~</span><span class='hs-layout'>(</span><span class='hs-varid'>h</span><span class='hs-layout'>,</span> <span class='hs-varid'>t</span><span class='hs-layout'>)</span> <span class='hs-keyglyph'>=</span> <span class='hs-varid'>h</span> <span class='hs-conop'>:</span> <span class='hs-varid'>t</span>
<a name="line-1042"></a><span class='hs-cpp'>#else</span>
<a name="line-1043"></a><span class='hs-definition'>lines</span> <span class='hs-varid'>s</span> <span class='hs-keyglyph'>=</span> <span class='hs-keyword'>let</span> <span class='hs-layout'>(</span><span class='hs-varid'>l</span><span class='hs-layout'>,</span> <span class='hs-varid'>s'</span><span class='hs-layout'>)</span> <span class='hs-keyglyph'>=</span> <span class='hs-varid'>break</span> <span class='hs-layout'>(</span><span class='hs-varop'>==</span> <span class='hs-chr'>'\n'</span><span class='hs-layout'>)</span> <span class='hs-varid'>s</span>
<a name="line-1044"></a> <span class='hs-keyword'>in</span> <span class='hs-varid'>l</span> <span class='hs-conop'>:</span> <span class='hs-keyword'>case</span> <span class='hs-varid'>s'</span> <span class='hs-keyword'>of</span>
<a name="line-1045"></a> <span class='hs-conid'>[]</span> <span class='hs-keyglyph'>-></span> <span class='hs-conid'>[]</span>
<a name="line-1046"></a> <span class='hs-layout'>(</span><span class='hs-keyword'>_</span><span class='hs-conop'>:</span><span class='hs-varid'>s''</span><span class='hs-layout'>)</span> <span class='hs-keyglyph'>-></span> <span class='hs-varid'>lines</span> <span class='hs-varid'>s''</span>
<a name="line-1047"></a><span class='hs-cpp'>#endif</span>
<a name="line-1048"></a>
<a name="line-1049"></a><a name="unlines"></a><span class='hs-comment'>-- | 'unlines' is an inverse operation to 'lines'.</span>
<a name="line-1050"></a><span class='hs-comment'>-- It joins lines, after appending a terminating newline to each.</span>
<a name="line-1051"></a><span class='hs-definition'>unlines</span> <span class='hs-keyglyph'>::</span> <span class='hs-keyglyph'>[</span><span class='hs-conid'>String</span><span class='hs-keyglyph'>]</span> <span class='hs-keyglyph'>-></span> <span class='hs-conid'>String</span>
<a name="line-1052"></a><span class='hs-cpp'>#ifdef USE_REPORT_PRELUDE</span>
<a name="line-1053"></a><span class='hs-definition'>unlines</span> <span class='hs-keyglyph'>=</span> <span class='hs-varid'>concatMap</span> <span class='hs-layout'>(</span><span class='hs-varop'>++</span> <span class='hs-str'>"\n"</span><span class='hs-layout'>)</span>
<a name="line-1054"></a><span class='hs-cpp'>#else</span>
<a name="line-1055"></a><span class='hs-comment'>-- HBC version (stolen)</span>
<a name="line-1056"></a><span class='hs-comment'>-- here's a more efficient version</span>
<a name="line-1057"></a><span class='hs-definition'>unlines</span> <span class='hs-conid'>[]</span> <span class='hs-keyglyph'>=</span> <span class='hs-conid'>[]</span>
<a name="line-1058"></a><span class='hs-definition'>unlines</span> <span class='hs-layout'>(</span><span class='hs-varid'>l</span><span class='hs-conop'>:</span><span class='hs-varid'>ls</span><span class='hs-layout'>)</span> <span class='hs-keyglyph'>=</span> <span class='hs-varid'>l</span> <span class='hs-varop'>++</span> <span class='hs-chr'>'\n'</span> <span class='hs-conop'>:</span> <span class='hs-varid'>unlines</span> <span class='hs-varid'>ls</span>
<a name="line-1059"></a><span class='hs-cpp'>#endif</span>
<a name="line-1060"></a>
<a name="line-1061"></a><a name="words"></a><span class='hs-comment'>-- | 'words' breaks a string up into a list of words, which were delimited</span>
<a name="line-1062"></a><span class='hs-comment'>-- by white space.</span>
<a name="line-1063"></a><span class='hs-definition'>words</span> <span class='hs-keyglyph'>::</span> <span class='hs-conid'>String</span> <span class='hs-keyglyph'>-></span> <span class='hs-keyglyph'>[</span><span class='hs-conid'>String</span><span class='hs-keyglyph'>]</span>
<a name="line-1064"></a><span class='hs-definition'>words</span> <span class='hs-varid'>s</span> <span class='hs-keyglyph'>=</span> <span class='hs-keyword'>case</span> <span class='hs-varid'>dropWhile</span> <span class='hs-comment'>{-partain:Char.-}</span><span class='hs-varid'>isSpace</span> <span class='hs-varid'>s</span> <span class='hs-keyword'>of</span>
<a name="line-1065"></a> <span class='hs-str'>""</span> <span class='hs-keyglyph'>-></span> <span class='hs-conid'>[]</span>
<a name="line-1066"></a> <span class='hs-varid'>s'</span> <span class='hs-keyglyph'>-></span> <span class='hs-varid'>w</span> <span class='hs-conop'>:</span> <span class='hs-varid'>words</span> <span class='hs-varid'>s''</span>
<a name="line-1067"></a> <span class='hs-keyword'>where</span> <span class='hs-layout'>(</span><span class='hs-varid'>w</span><span class='hs-layout'>,</span> <span class='hs-varid'>s''</span><span class='hs-layout'>)</span> <span class='hs-keyglyph'>=</span>
<a name="line-1068"></a> <span class='hs-varid'>break</span> <span class='hs-comment'>{-partain:Char.-}</span><span class='hs-varid'>isSpace</span> <span class='hs-varid'>s'</span>
<a name="line-1069"></a>
<a name="line-1070"></a><a name="unwords"></a><span class='hs-comment'>-- | 'unwords' is an inverse operation to 'words'.</span>
<a name="line-1071"></a><span class='hs-comment'>-- It joins words with separating spaces.</span>
<a name="line-1072"></a><span class='hs-definition'>unwords</span> <span class='hs-keyglyph'>::</span> <span class='hs-keyglyph'>[</span><span class='hs-conid'>String</span><span class='hs-keyglyph'>]</span> <span class='hs-keyglyph'>-></span> <span class='hs-conid'>String</span>
<a name="line-1073"></a><span class='hs-cpp'>#ifdef USE_REPORT_PRELUDE</span>
<a name="line-1074"></a><span class='hs-definition'>unwords</span> <span class='hs-conid'>[]</span> <span class='hs-keyglyph'>=</span> <span class='hs-str'>""</span>
<a name="line-1075"></a><span class='hs-definition'>unwords</span> <span class='hs-varid'>ws</span> <span class='hs-keyglyph'>=</span> <span class='hs-varid'>foldr1</span> <span class='hs-layout'>(</span><span class='hs-keyglyph'>\</span><span class='hs-varid'>w</span> <span class='hs-varid'>s</span> <span class='hs-keyglyph'>-></span> <span class='hs-varid'>w</span> <span class='hs-varop'>++</span> <span class='hs-chr'>' '</span><span class='hs-conop'>:</span><span class='hs-varid'>s</span><span class='hs-layout'>)</span> <span class='hs-varid'>ws</span>
<a name="line-1076"></a><span class='hs-cpp'>#else</span>
<a name="line-1077"></a><span class='hs-comment'>-- HBC version (stolen)</span>
<a name="line-1078"></a><span class='hs-comment'>-- here's a more efficient version</span>
<a name="line-1079"></a><span class='hs-definition'>unwords</span> <span class='hs-conid'>[]</span> <span class='hs-keyglyph'>=</span> <span class='hs-str'>""</span>
<a name="line-1080"></a><span class='hs-definition'>unwords</span> <span class='hs-keyglyph'>[</span><span class='hs-varid'>w</span><span class='hs-keyglyph'>]</span> <span class='hs-keyglyph'>=</span> <span class='hs-varid'>w</span>
<a name="line-1081"></a><span class='hs-definition'>unwords</span> <span class='hs-layout'>(</span><span class='hs-varid'>w</span><span class='hs-conop'>:</span><span class='hs-varid'>ws</span><span class='hs-layout'>)</span> <span class='hs-keyglyph'>=</span> <span class='hs-varid'>w</span> <span class='hs-varop'>++</span> <span class='hs-chr'>' '</span> <span class='hs-conop'>:</span> <span class='hs-varid'>unwords</span> <span class='hs-varid'>ws</span>
<a name="line-1082"></a><span class='hs-cpp'>#endif</span>
<a name="line-1083"></a>
<a name="line-1084"></a><span class='hs-cpp'>#else /* !__GLASGOW_HASKELL__ */</span>
<a name="line-1085"></a>
<a name="line-1086"></a><a name="errorEmptyList"></a><span class='hs-definition'>errorEmptyList</span> <span class='hs-keyglyph'>::</span> <span class='hs-conid'>String</span> <span class='hs-keyglyph'>-></span> <span class='hs-varid'>a</span>
<a name="line-1087"></a><span class='hs-definition'>errorEmptyList</span> <span class='hs-varid'>fun</span> <span class='hs-keyglyph'>=</span>
<a name="line-1088"></a> <span class='hs-varid'>error</span> <span class='hs-layout'>(</span><span class='hs-str'>"Prelude."</span> <span class='hs-varop'>++</span> <span class='hs-varid'>fun</span> <span class='hs-varop'>++</span> <span class='hs-str'>": empty list"</span><span class='hs-layout'>)</span>
<a name="line-1089"></a>
<a name="line-1090"></a><span class='hs-cpp'>#endif /* !__GLASGOW_HASKELL__ */</span>
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