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</script></head><body><div id="package-header"><ul class="links" id="page-menu"><li><a href="index.html">Contents</a></li><li><a href="doc-index.html">Index</a></li></ul><p class="caption">haskell98-2.0.0.1: Compatibility with Haskell 98</p></div><div id="content"><div id="module-header"><table class="info"><tr><th>Safe Haskell</th><td>Safe</td></tr></table><p class="caption">List</p></div><div id="synopsis"><p id="control.syn" class="caption expander" onclick="toggleSection('syn')">Synopsis</p><ul id="section.syn" class="hide" onclick="toggleSection('syn')"><li class="src short"><a href="#v:elemIndex">elemIndex</a> :: <a href="Prelude.html#t:Eq">Eq</a> a => a -> [a] -> <a href="Prelude.html#t:Maybe">Maybe</a> <a href="Prelude.html#t:Int">Int</a></li><li class="src short"><a href="#v:elemIndices">elemIndices</a> :: <a href="Prelude.html#t:Eq">Eq</a> a => a -> [a] -> [<a href="Prelude.html#t:Int">Int</a>]</li><li class="src short"><a href="#v:find">find</a> :: (a -> <a href="Prelude.html#t:Bool">Bool</a>) -> [a] -> <a href="Prelude.html#t:Maybe">Maybe</a> a</li><li class="src short"><a href="#v:findIndex">findIndex</a> :: (a -> <a href="Prelude.html#t:Bool">Bool</a>) -> [a] -> <a href="Prelude.html#t:Maybe">Maybe</a> <a href="Prelude.html#t:Int">Int</a></li><li class="src short"><a href="#v:findIndices">findIndices</a> :: (a -> <a href="Prelude.html#t:Bool">Bool</a>) -> [a] -> [<a href="Prelude.html#t:Int">Int</a>]</li><li class="src short"><a href="#v:nub">nub</a> :: <a href="Prelude.html#t:Eq">Eq</a> a => [a] -> [a]</li><li class="src short"><a href="#v:nubBy">nubBy</a> :: (a -> a -> <a href="Prelude.html#t:Bool">Bool</a>) -> [a] -> [a]</li><li class="src short"><a href="#v:delete">delete</a> :: <a href="Prelude.html#t:Eq">Eq</a> a => a -> [a] -> [a]</li><li class="src short"><a href="#v:deleteBy">deleteBy</a> :: (a -> a -> <a href="Prelude.html#t:Bool">Bool</a>) -> a -> [a] -> [a]</li><li class="src short"><a href="#v:-92--92-">(\\)</a> :: <a href="Prelude.html#t:Eq">Eq</a> a => [a] -> [a] -> [a]</li><li class="src short"><a href="#v:deleteFirstsBy">deleteFirstsBy</a> :: (a -> a -> <a href="Prelude.html#t:Bool">Bool</a>) -> [a] -> [a] -> [a]</li><li class="src short"><a href="#v:union">union</a> :: <a href="Prelude.html#t:Eq">Eq</a> a => [a] -> [a] -> [a]</li><li class="src short"><a href="#v:unionBy">unionBy</a> :: (a -> a -> <a href="Prelude.html#t:Bool">Bool</a>) -> [a] -> [a] -> [a]</li><li class="src short"><a href="#v:intersect">intersect</a> :: <a href="Prelude.html#t:Eq">Eq</a> a => [a] -> [a] -> [a]</li><li class="src short"><a href="#v:intersectBy">intersectBy</a> :: (a -> a -> <a href="Prelude.html#t:Bool">Bool</a>) -> [a] -> [a] -> [a]</li><li class="src short"><a href="#v:intersperse">intersperse</a> :: a -> [a] -> [a]</li><li class="src short"><a href="#v:transpose">transpose</a> :: [[a]] -> [[a]]</li><li class="src short"><a href="#v:partition">partition</a> :: (a -> <a href="Prelude.html#t:Bool">Bool</a>) -> [a] -> ([a], [a])</li><li class="src short"><a href="#v:group">group</a> :: <a href="Prelude.html#t:Eq">Eq</a> a => [a] -> [[a]]</li><li class="src short"><a href="#v:groupBy">groupBy</a> :: (a -> a -> <a href="Prelude.html#t:Bool">Bool</a>) -> [a] -> [[a]]</li><li class="src short"><a href="#v:inits">inits</a> :: [a] -> [[a]]</li><li class="src short"><a href="#v:tails">tails</a> :: [a] -> [[a]]</li><li class="src short"><a href="#v:isPrefixOf">isPrefixOf</a> :: <a href="Prelude.html#t:Eq">Eq</a> a => [a] -> [a] -> <a href="Prelude.html#t:Bool">Bool</a></li><li class="src short"><a href="#v:isSuffixOf">isSuffixOf</a> :: <a href="Prelude.html#t:Eq">Eq</a> a => [a] -> [a] -> <a href="Prelude.html#t:Bool">Bool</a></li><li class="src short"><a href="#v:mapAccumL">mapAccumL</a> :: (acc -> x -> (acc, y)) -> acc -> [x] -> (acc, [y])</li><li class="src short"><a href="#v:mapAccumR">mapAccumR</a> :: (acc -> x -> (acc, y)) -> acc -> [x] -> (acc, [y])</li><li class="src short"><a href="#v:sort">sort</a> :: <a href="Prelude.html#t:Ord">Ord</a> a => [a] -> [a]</li><li class="src short"><a href="#v:sortBy">sortBy</a> :: (a -> a -> <a href="Prelude.html#t:Ordering">Ordering</a>) -> [a] -> [a]</li><li class="src short"><a href="#v:insert">insert</a> :: <a href="Prelude.html#t:Ord">Ord</a> a => a -> [a] -> [a]</li><li class="src short"><a href="#v:insertBy">insertBy</a> :: (a -> a -> <a href="Prelude.html#t:Ordering">Ordering</a>) -> a -> [a] -> [a]</li><li class="src short"><a href="#v:maximumBy">maximumBy</a> :: (a -> a -> <a href="Prelude.html#t:Ordering">Ordering</a>) -> [a] -> a</li><li class="src short"><a href="#v:minimumBy">minimumBy</a> :: (a -> a -> <a href="Prelude.html#t:Ordering">Ordering</a>) -> [a] -> a</li><li class="src short"><a href="#v:genericLength">genericLength</a> :: <a href="Prelude.html#t:Num">Num</a> i => [b] -> i</li><li class="src short"><a href="#v:genericTake">genericTake</a> :: <a href="Prelude.html#t:Integral">Integral</a> i => i -> [a] -> [a]</li><li class="src short"><a href="#v:genericDrop">genericDrop</a> :: <a href="Prelude.html#t:Integral">Integral</a> i => i -> [a] -> [a]</li><li class="src short"><a href="#v:genericSplitAt">genericSplitAt</a> :: <a href="Prelude.html#t:Integral">Integral</a> i => i -> [b] -> ([b], [b])</li><li class="src short"><a href="#v:genericIndex">genericIndex</a> :: <a href="Prelude.html#t:Integral">Integral</a> a => [b] -> a -> b</li><li class="src short"><a href="#v:genericReplicate">genericReplicate</a> :: <a href="Prelude.html#t:Integral">Integral</a> i => i -> a -> [a]</li><li class="src short"><a href="#v:zip4">zip4</a> :: [a] -> [b] -> [c] -> [d] -> [(a, b, c, d)]</li><li class="src short"><a href="#v:zip5">zip5</a> :: [a] -> [b] -> [c] -> [d] -> [e] -> [(a, b, c, d, e)]</li><li class="src short"><a href="#v:zip6">zip6</a> :: [a] -> [b] -> [c] -> [d] -> [e] -> [f] -> [(a, b, c, d, e, f)]</li><li class="src short"><a href="#v:zip7">zip7</a> :: [a] -> [b] -> [c] -> [d] -> [e] -> [f] -> [g] -> [(a, b, c, d, e, f, g)]</li><li class="src short"><a href="#v:zipWith4">zipWith4</a> :: (a -> b -> c -> d -> e) -> [a] -> [b] -> [c] -> [d] -> [e]</li><li class="src short"><a href="#v:zipWith5">zipWith5</a> :: (a -> b -> c -> d -> e -> f) -> [a] -> [b] -> [c] -> [d] -> [e] -> [f]</li><li class="src short"><a href="#v:zipWith6">zipWith6</a> :: (a -> b -> c -> d -> e -> f -> g) -> [a] -> [b] -> [c] -> [d] -> [e] -> [f] -> [g]</li><li class="src short"><a href="#v:zipWith7">zipWith7</a> :: (a -> b -> c -> d -> e -> f -> g -> h) -> [a] -> [b] -> [c] -> [d] -> [e] -> [f] -> [g] -> [h]</li><li class="src short"><a href="#v:unzip4">unzip4</a> :: [(a, b, c, d)] -> ([a], [b], [c], [d])</li><li class="src short"><a href="#v:unzip5">unzip5</a> :: [(a, b, c, d, e)] -> ([a], [b], [c], [d], [e])</li><li class="src short"><a href="#v:unzip6">unzip6</a> :: [(a, b, c, d, e, f)] -> ([a], [b], [c], [d], [e], [f])</li><li class="src short"><a href="#v:unzip7">unzip7</a> :: [(a, b, c, d, e, f, g)] -> ([a], [b], [c], [d], [e], [f], [g])</li><li class="src short"><a href="#v:unfoldr">unfoldr</a> :: (b -> <a href="Prelude.html#t:Maybe">Maybe</a> (a, b)) -> b -> [a]</li><li class="src short"><a href="#v:map">map</a> :: (a -> b) -> [a] -> [b]</li><li class="src short"><a href="#v:-43--43-">(++)</a> :: [a] -> [a] -> [a]</li><li class="src short"><a href="#v:concat">concat</a> :: [[a]] -> [a]</li><li class="src short"><a href="#v:filter">filter</a> :: (a -> <a href="Prelude.html#t:Bool">Bool</a>) -> [a] -> [a]</li><li class="src short"><a href="#v:head">head</a> :: [a] -> a</li><li class="src short"><a href="#v:last">last</a> :: [a] -> a</li><li class="src short"><a href="#v:tail">tail</a> :: [a] -> [a]</li><li class="src short"><a href="#v:init">init</a> :: [a] -> [a]</li><li class="src short"><a href="#v:null">null</a> :: [a] -> <a href="Prelude.html#t:Bool">Bool</a></li><li class="src short"><a href="#v:length">length</a> :: [a] -> <a href="Prelude.html#t:Int">Int</a></li><li class="src short"><a href="#v:-33--33-">(!!)</a> :: [a] -> <a href="Prelude.html#t:Int">Int</a> -> a</li><li class="src short"><a href="#v:foldl">foldl</a> :: (a -> b -> a) -> a -> [b] -> a</li><li class="src short"><a href="#v:foldl1">foldl1</a> :: (a -> a -> a) -> [a] -> a</li><li class="src short"><a href="#v:scanl">scanl</a> :: (a -> b -> a) -> a -> [b] -> [a]</li><li class="src short"><a href="#v:scanl1">scanl1</a> :: (a -> a -> a) -> [a] -> [a]</li><li class="src short"><a href="#v:foldr">foldr</a> :: (a -> b -> b) -> b -> [a] -> b</li><li class="src short"><a href="#v:foldr1">foldr1</a> :: (a -> a -> a) -> [a] -> a</li><li class="src short"><a href="#v:scanr">scanr</a> :: (a -> b -> b) -> b -> [a] -> [b]</li><li class="src short"><a href="#v:scanr1">scanr1</a> :: (a -> a -> a) -> [a] -> [a]</li><li class="src short"><a href="#v:iterate">iterate</a> :: (a -> a) -> a -> [a]</li><li class="src short"><a href="#v:repeat">repeat</a> :: a -> [a]</li><li class="src short"><a href="#v:replicate">replicate</a> :: <a href="Prelude.html#t:Int">Int</a> -> a -> [a]</li><li class="src short"><a href="#v:cycle">cycle</a> :: [a] -> [a]</li><li class="src short"><a href="#v:take">take</a> :: <a href="Prelude.html#t:Int">Int</a> -> [a] -> [a]</li><li class="src short"><a href="#v:drop">drop</a> :: <a href="Prelude.html#t:Int">Int</a> -> [a] -> [a]</li><li class="src short"><a href="#v:splitAt">splitAt</a> :: <a href="Prelude.html#t:Int">Int</a> -> [a] -> ([a], [a])</li><li class="src short"><a href="#v:takeWhile">takeWhile</a> :: (a -> <a href="Prelude.html#t:Bool">Bool</a>) -> [a] -> [a]</li><li class="src short"><a href="#v:dropWhile">dropWhile</a> :: (a -> <a href="Prelude.html#t:Bool">Bool</a>) -> [a] -> [a]</li><li class="src short"><a href="#v:span">span</a> :: (a -> <a href="Prelude.html#t:Bool">Bool</a>) -> [a] -> ([a], [a])</li><li class="src short"><a href="#v:break">break</a> :: (a -> <a href="Prelude.html#t:Bool">Bool</a>) -> [a] -> ([a], [a])</li><li class="src short"><a href="#v:lines">lines</a> :: <a href="Prelude.html#t:String">String</a> -> [<a href="Prelude.html#t:String">String</a>]</li><li class="src short"><a href="#v:words">words</a> :: <a href="Prelude.html#t:String">String</a> -> [<a href="Prelude.html#t:String">String</a>]</li><li class="src short"><a href="#v:unlines">unlines</a> :: [<a href="Prelude.html#t:String">String</a>] -> <a href="Prelude.html#t:String">String</a></li><li class="src short"><a href="#v:unwords">unwords</a> :: [<a href="Prelude.html#t:String">String</a>] -> <a href="Prelude.html#t:String">String</a></li><li class="src short"><a href="#v:reverse">reverse</a> :: [a] -> [a]</li><li class="src short"><a href="#v:and">and</a> :: [<a href="Prelude.html#t:Bool">Bool</a>] -> <a href="Prelude.html#t:Bool">Bool</a></li><li class="src short"><a href="#v:or">or</a> :: [<a href="Prelude.html#t:Bool">Bool</a>] -> <a href="Prelude.html#t:Bool">Bool</a></li><li class="src short"><a href="#v:any">any</a> :: (a -> <a href="Prelude.html#t:Bool">Bool</a>) -> [a] -> <a href="Prelude.html#t:Bool">Bool</a></li><li class="src short"><a href="#v:all">all</a> :: (a -> <a href="Prelude.html#t:Bool">Bool</a>) -> [a] -> <a href="Prelude.html#t:Bool">Bool</a></li><li class="src short"><a href="#v:elem">elem</a> :: <a href="Prelude.html#t:Eq">Eq</a> a => a -> [a] -> <a href="Prelude.html#t:Bool">Bool</a></li><li class="src short"><a href="#v:notElem">notElem</a> :: <a href="Prelude.html#t:Eq">Eq</a> a => a -> [a] -> <a href="Prelude.html#t:Bool">Bool</a></li><li class="src short"><a href="#v:lookup">lookup</a> :: <a href="Prelude.html#t:Eq">Eq</a> a => a -> [(a, b)] -> <a href="Prelude.html#t:Maybe">Maybe</a> b</li><li class="src short"><a href="#v:sum">sum</a> :: <a href="Prelude.html#t:Num">Num</a> a => [a] -> a</li><li class="src short"><a href="#v:product">product</a> :: <a href="Prelude.html#t:Num">Num</a> a => [a] -> a</li><li class="src short"><a href="#v:maximum">maximum</a> :: <a href="Prelude.html#t:Ord">Ord</a> a => [a] -> a</li><li class="src short"><a href="#v:minimum">minimum</a> :: <a href="Prelude.html#t:Ord">Ord</a> a => [a] -> a</li><li class="src short"><a href="#v:concatMap">concatMap</a> :: (a -> [b]) -> [a] -> [b]</li><li class="src short"><a href="#v:zip">zip</a> :: [a] -> [b] -> [(a, b)]</li><li class="src short"><a href="#v:zip3">zip3</a> :: [a] -> [b] -> [c] -> [(a, b, c)]</li><li class="src short"><a href="#v:zipWith">zipWith</a> :: (a -> b -> c) -> [a] -> [b] -> [c]</li><li class="src short"><a href="#v:zipWith3">zipWith3</a> :: (a -> b -> c -> d) -> [a] -> [b] -> [c] -> [d]</li><li class="src short"><a href="#v:unzip">unzip</a> :: [(a, b)] -> ([a], [b])</li><li class="src short"><a href="#v:unzip3">unzip3</a> :: [(a, b, c)] -> ([a], [b], [c])</li></ul></div><div id="interface"><h1>Documentation</h1><div class="top"><p class="src"><a name="v:elemIndex" class="def">elemIndex</a> :: <a href="Prelude.html#t:Eq">Eq</a> a => a -> [a] -> <a href="Prelude.html#t:Maybe">Maybe</a> <a href="Prelude.html#t:Int">Int</a><a href="../base-4.5.1.0/src/Data-List.html#elemIndex" class="link">Source</a></p><div class="doc"><p>The <code><a href="List.html#v:elemIndex">elemIndex</a></code> function returns the index of the first element
in the given list which is equal (by <code><a href="Prelude.html#v:-61--61-">==</a></code>) to the query element,
or <code><a href="Prelude.html#v:Nothing">Nothing</a></code> if there is no such element.
</p></div></div><div class="top"><p class="src"><a name="v:elemIndices" class="def">elemIndices</a> :: <a href="Prelude.html#t:Eq">Eq</a> a => a -> [a] -> [<a href="Prelude.html#t:Int">Int</a>]<a href="../base-4.5.1.0/src/Data-List.html#elemIndices" class="link">Source</a></p><div class="doc"><p>The <code><a href="List.html#v:elemIndices">elemIndices</a></code> function extends <code><a href="List.html#v:elemIndex">elemIndex</a></code>, by returning the
indices of all elements equal to the query element, in ascending order.
</p></div></div><div class="top"><p class="src"><a name="v:find" class="def">find</a> :: (a -> <a href="Prelude.html#t:Bool">Bool</a>) -> [a] -> <a href="Prelude.html#t:Maybe">Maybe</a> a<a href="../base-4.5.1.0/src/Data-List.html#find" class="link">Source</a></p><div class="doc"><p>The <code><a href="List.html#v:find">find</a></code> function takes a predicate and a list and returns the
first element in the list matching the predicate, or <code><a href="Prelude.html#v:Nothing">Nothing</a></code> if
there is no such element.
</p></div></div><div class="top"><p class="src"><a name="v:findIndex" class="def">findIndex</a> :: (a -> <a href="Prelude.html#t:Bool">Bool</a>) -> [a] -> <a href="Prelude.html#t:Maybe">Maybe</a> <a href="Prelude.html#t:Int">Int</a><a href="../base-4.5.1.0/src/Data-List.html#findIndex" class="link">Source</a></p><div class="doc"><p>The <code><a href="List.html#v:findIndex">findIndex</a></code> function takes a predicate and a list and returns
the index of the first element in the list satisfying the predicate,
or <code><a href="Prelude.html#v:Nothing">Nothing</a></code> if there is no such element.
</p></div></div><div class="top"><p class="src"><a name="v:findIndices" class="def">findIndices</a> :: (a -> <a href="Prelude.html#t:Bool">Bool</a>) -> [a] -> [<a href="Prelude.html#t:Int">Int</a>]<a href="../base-4.5.1.0/src/Data-List.html#findIndices" class="link">Source</a></p><div class="doc"><p>The <code><a href="List.html#v:findIndices">findIndices</a></code> function extends <code><a href="List.html#v:findIndex">findIndex</a></code>, by returning the
indices of all elements satisfying the predicate, in ascending order.
</p></div></div><div class="top"><p class="src"><a name="v:nub" class="def">nub</a> :: <a href="Prelude.html#t:Eq">Eq</a> a => [a] -> [a]<a href="../base-4.5.1.0/src/Data-List.html#nub" class="link">Source</a></p><div class="doc"><p><em>O(n^2)</em>. The <code><a href="List.html#v:nub">nub</a></code> function removes duplicate elements from a list.
In particular, it keeps only the first occurrence of each element.
(The name <code><a href="List.html#v:nub">nub</a></code> means `essence'.)
It is a special case of <code><a href="List.html#v:nubBy">nubBy</a></code>, which allows the programmer to supply
their own equality test.
</p></div></div><div class="top"><p class="src"><a name="v:nubBy" class="def">nubBy</a> :: (a -> a -> <a href="Prelude.html#t:Bool">Bool</a>) -> [a] -> [a]<a href="../base-4.5.1.0/src/Data-List.html#nubBy" class="link">Source</a></p><div class="doc"><p>The <code><a href="List.html#v:nubBy">nubBy</a></code> function behaves just like <code><a href="List.html#v:nub">nub</a></code>, except it uses a
user-supplied equality predicate instead of the overloaded <code><a href="Prelude.html#v:-61--61-">==</a></code>
function.
</p></div></div><div class="top"><p class="src"><a name="v:delete" class="def">delete</a> :: <a href="Prelude.html#t:Eq">Eq</a> a => a -> [a] -> [a]<a href="../base-4.5.1.0/src/Data-List.html#delete" class="link">Source</a></p><div class="doc"><p><code><a href="List.html#v:delete">delete</a></code> <code>x</code> removes the first occurrence of <code>x</code> from its list argument.
For example,
</p><pre> delete 'a' "banana" == "bnana"
</pre><p>It is a special case of <code><a href="List.html#v:deleteBy">deleteBy</a></code>, which allows the programmer to
supply their own equality test.
</p></div></div><div class="top"><p class="src"><a name="v:deleteBy" class="def">deleteBy</a> :: (a -> a -> <a href="Prelude.html#t:Bool">Bool</a>) -> a -> [a] -> [a]<a href="../base-4.5.1.0/src/Data-List.html#deleteBy" class="link">Source</a></p><div class="doc"><p>The <code><a href="List.html#v:deleteBy">deleteBy</a></code> function behaves like <code><a href="List.html#v:delete">delete</a></code>, but takes a
user-supplied equality predicate.
</p></div></div><div class="top"><p class="src"><a name="v:-92--92-" class="def">(\\)</a> :: <a href="Prelude.html#t:Eq">Eq</a> a => [a] -> [a] -> [a]<a href="../base-4.5.1.0/src/Data-List.html#%5C%5C" class="link">Source</a></p><div class="doc"><p>The <code><a href="List.html#v:-92--92-">\\</a></code> function is list difference (non-associative).
In the result of <code>xs</code> <code><a href="List.html#v:-92--92-">\\</a></code> <code>ys</code>, the first occurrence of each element of
<code>ys</code> in turn (if any) has been removed from <code>xs</code>. Thus
</p><pre> (xs ++ ys) \\ xs == ys.
</pre><p>It is a special case of <code><a href="List.html#v:deleteFirstsBy">deleteFirstsBy</a></code>, which allows the programmer
to supply their own equality test.
</p></div></div><div class="top"><p class="src"><a name="v:deleteFirstsBy" class="def">deleteFirstsBy</a> :: (a -> a -> <a href="Prelude.html#t:Bool">Bool</a>) -> [a] -> [a] -> [a]<a href="../base-4.5.1.0/src/Data-List.html#deleteFirstsBy" class="link">Source</a></p><div class="doc"><p>The <code><a href="List.html#v:deleteFirstsBy">deleteFirstsBy</a></code> function takes a predicate and two lists and
returns the first list with the first occurrence of each element of
the second list removed.
</p></div></div><div class="top"><p class="src"><a name="v:union" class="def">union</a> :: <a href="Prelude.html#t:Eq">Eq</a> a => [a] -> [a] -> [a]<a href="../base-4.5.1.0/src/Data-List.html#union" class="link">Source</a></p><div class="doc"><p>The <code><a href="List.html#v:union">union</a></code> function returns the list union of the two lists.
For example,
</p><pre> "dog" `union` "cow" == "dogcw"
</pre><p>Duplicates, and elements of the first list, are removed from the
the second list, but if the first list contains duplicates, so will
the result.
It is a special case of <code><a href="List.html#v:unionBy">unionBy</a></code>, which allows the programmer to supply
their own equality test.
</p></div></div><div class="top"><p class="src"><a name="v:unionBy" class="def">unionBy</a> :: (a -> a -> <a href="Prelude.html#t:Bool">Bool</a>) -> [a] -> [a] -> [a]<a href="../base-4.5.1.0/src/Data-List.html#unionBy" class="link">Source</a></p><div class="doc"><p>The <code><a href="List.html#v:unionBy">unionBy</a></code> function is the non-overloaded version of <code><a href="List.html#v:union">union</a></code>.
</p></div></div><div class="top"><p class="src"><a name="v:intersect" class="def">intersect</a> :: <a href="Prelude.html#t:Eq">Eq</a> a => [a] -> [a] -> [a]<a href="../base-4.5.1.0/src/Data-List.html#intersect" class="link">Source</a></p><div class="doc"><p>The <code><a href="List.html#v:intersect">intersect</a></code> function takes the list intersection of two lists.
For example,
</p><pre> [1,2,3,4] `intersect` [2,4,6,8] == [2,4]
</pre><p>If the first list contains duplicates, so will the result.
</p><pre> [1,2,2,3,4] `intersect` [6,4,4,2] == [2,2,4]
</pre><p>It is a special case of <code><a href="List.html#v:intersectBy">intersectBy</a></code>, which allows the programmer to
supply their own equality test.
</p></div></div><div class="top"><p class="src"><a name="v:intersectBy" class="def">intersectBy</a> :: (a -> a -> <a href="Prelude.html#t:Bool">Bool</a>) -> [a] -> [a] -> [a]<a href="../base-4.5.1.0/src/Data-List.html#intersectBy" class="link">Source</a></p><div class="doc"><p>The <code><a href="List.html#v:intersectBy">intersectBy</a></code> function is the non-overloaded version of <code><a href="List.html#v:intersect">intersect</a></code>.
</p></div></div><div class="top"><p class="src"><a name="v:intersperse" class="def">intersperse</a> :: a -> [a] -> [a]<a href="../base-4.5.1.0/src/Data-List.html#intersperse" class="link">Source</a></p><div class="doc"><p>The <code><a href="List.html#v:intersperse">intersperse</a></code> function takes an element and a list and
`intersperses' that element between the elements of the list.
For example,
</p><pre> intersperse ',' "abcde" == "a,b,c,d,e"
</pre></div></div><div class="top"><p class="src"><a name="v:transpose" class="def">transpose</a> :: [[a]] -> [[a]]<a href="../base-4.5.1.0/src/Data-List.html#transpose" class="link">Source</a></p><div class="doc"><p>The <code><a href="List.html#v:transpose">transpose</a></code> function transposes the rows and columns of its argument.
For example,
</p><pre> transpose [[1,2,3],[4,5,6]] == [[1,4],[2,5],[3,6]]
</pre></div></div><div class="top"><p class="src"><a name="v:partition" class="def">partition</a> :: (a -> <a href="Prelude.html#t:Bool">Bool</a>) -> [a] -> ([a], [a])<a href="../base-4.5.1.0/src/Data-List.html#partition" class="link">Source</a></p><div class="doc"><p>The <code><a href="List.html#v:partition">partition</a></code> function takes a predicate a list and returns
the pair of lists of elements which do and do not satisfy the
predicate, respectively; i.e.,
</p><pre> partition p xs == (filter p xs, filter (not . p) xs)
</pre></div></div><div class="top"><p class="src"><a name="v:group" class="def">group</a> :: <a href="Prelude.html#t:Eq">Eq</a> a => [a] -> [[a]]<a href="../base-4.5.1.0/src/Data-List.html#group" class="link">Source</a></p><div class="doc"><p>The <code><a href="List.html#v:group">group</a></code> function takes a list and returns a list of lists such
that the concatenation of the result is equal to the argument. Moreover,
each sublist in the result contains only equal elements. For example,
</p><pre> group "Mississippi" = ["M","i","ss","i","ss","i","pp","i"]
</pre><p>It is a special case of <code><a href="List.html#v:groupBy">groupBy</a></code>, which allows the programmer to supply
their own equality test.
</p></div></div><div class="top"><p class="src"><a name="v:groupBy" class="def">groupBy</a> :: (a -> a -> <a href="Prelude.html#t:Bool">Bool</a>) -> [a] -> [[a]]<a href="../base-4.5.1.0/src/Data-List.html#groupBy" class="link">Source</a></p><div class="doc"><p>The <code><a href="List.html#v:groupBy">groupBy</a></code> function is the non-overloaded version of <code><a href="List.html#v:group">group</a></code>.
</p></div></div><div class="top"><p class="src"><a name="v:inits" class="def">inits</a> :: [a] -> [[a]]<a href="../base-4.5.1.0/src/Data-List.html#inits" class="link">Source</a></p><div class="doc"><p>The <code><a href="List.html#v:inits">inits</a></code> function returns all initial segments of the argument,
shortest first. For example,
</p><pre> inits "abc" == ["","a","ab","abc"]
</pre><p>Note that <code><a href="List.html#v:inits">inits</a></code> has the following strictness property:
<code>inits _|_ = [] : _|_</code>
</p></div></div><div class="top"><p class="src"><a name="v:tails" class="def">tails</a> :: [a] -> [[a]]<a href="../base-4.5.1.0/src/Data-List.html#tails" class="link">Source</a></p><div class="doc"><p>The <code><a href="List.html#v:tails">tails</a></code> function returns all final segments of the argument,
longest first. For example,
</p><pre> tails "abc" == ["abc", "bc", "c",""]
</pre><p>Note that <code><a href="List.html#v:tails">tails</a></code> has the following strictness property:
<code>tails _|_ = _|_ : _|_</code>
</p></div></div><div class="top"><p class="src"><a name="v:isPrefixOf" class="def">isPrefixOf</a> :: <a href="Prelude.html#t:Eq">Eq</a> a => [a] -> [a] -> <a href="Prelude.html#t:Bool">Bool</a><a href="../base-4.5.1.0/src/Data-List.html#isPrefixOf" class="link">Source</a></p><div class="doc"><p>The <code><a href="List.html#v:isPrefixOf">isPrefixOf</a></code> function takes two lists and returns <code><a href="Prelude.html#v:True">True</a></code>
iff the first list is a prefix of the second.
</p></div></div><div class="top"><p class="src"><a name="v:isSuffixOf" class="def">isSuffixOf</a> :: <a href="Prelude.html#t:Eq">Eq</a> a => [a] -> [a] -> <a href="Prelude.html#t:Bool">Bool</a><a href="../base-4.5.1.0/src/Data-List.html#isSuffixOf" class="link">Source</a></p><div class="doc"><p>The <code><a href="List.html#v:isSuffixOf">isSuffixOf</a></code> function takes two lists and returns <code><a href="Prelude.html#v:True">True</a></code>
iff the first list is a suffix of the second.
Both lists must be finite.
</p></div></div><div class="top"><p class="src"><a name="v:mapAccumL" class="def">mapAccumL</a> :: (acc -> x -> (acc, y)) -> acc -> [x] -> (acc, [y])<a href="../base-4.5.1.0/src/Data-List.html#mapAccumL" class="link">Source</a></p><div class="doc"><p>The <code><a href="List.html#v:mapAccumL">mapAccumL</a></code> function behaves like a combination of <code><a href="List.html#v:map">map</a></code> and
<code><a href="List.html#v:foldl">foldl</a></code>; it applies a function to each element of a list, passing
an accumulating parameter from left to right, and returning a final
value of this accumulator together with the new list.
</p></div></div><div class="top"><p class="src"><a name="v:mapAccumR" class="def">mapAccumR</a> :: (acc -> x -> (acc, y)) -> acc -> [x] -> (acc, [y])<a href="../base-4.5.1.0/src/Data-List.html#mapAccumR" class="link">Source</a></p><div class="doc"><p>The <code><a href="List.html#v:mapAccumR">mapAccumR</a></code> function behaves like a combination of <code><a href="List.html#v:map">map</a></code> and
<code><a href="List.html#v:foldr">foldr</a></code>; it applies a function to each element of a list, passing
an accumulating parameter from right to left, and returning a final
value of this accumulator together with the new list.
</p></div></div><div class="top"><p class="src"><a name="v:sort" class="def">sort</a> :: <a href="Prelude.html#t:Ord">Ord</a> a => [a] -> [a]<a href="../base-4.5.1.0/src/Data-List.html#sort" class="link">Source</a></p><div class="doc"><p>The <code><a href="List.html#v:sort">sort</a></code> function implements a stable sorting algorithm.
It is a special case of <code><a href="List.html#v:sortBy">sortBy</a></code>, which allows the programmer to supply
their own comparison function.
</p></div></div><div class="top"><p class="src"><a name="v:sortBy" class="def">sortBy</a> :: (a -> a -> <a href="Prelude.html#t:Ordering">Ordering</a>) -> [a] -> [a]<a href="../base-4.5.1.0/src/Data-List.html#sortBy" class="link">Source</a></p><div class="doc"><p>The <code><a href="List.html#v:sortBy">sortBy</a></code> function is the non-overloaded version of <code><a href="List.html#v:sort">sort</a></code>.
</p></div></div><div class="top"><p class="src"><a name="v:insert" class="def">insert</a> :: <a href="Prelude.html#t:Ord">Ord</a> a => a -> [a] -> [a]<a href="../base-4.5.1.0/src/Data-List.html#insert" class="link">Source</a></p><div class="doc"><p>The <code><a href="List.html#v:insert">insert</a></code> function takes an element and a list and inserts the
element into the list at the last position where it is still less
than or equal to the next element. In particular, if the list
is sorted before the call, the result will also be sorted.
It is a special case of <code><a href="List.html#v:insertBy">insertBy</a></code>, which allows the programmer to
supply their own comparison function.
</p></div></div><div class="top"><p class="src"><a name="v:insertBy" class="def">insertBy</a> :: (a -> a -> <a href="Prelude.html#t:Ordering">Ordering</a>) -> a -> [a] -> [a]<a href="../base-4.5.1.0/src/Data-List.html#insertBy" class="link">Source</a></p><div class="doc"><p>The non-overloaded version of <code><a href="List.html#v:insert">insert</a></code>.
</p></div></div><div class="top"><p class="src"><a name="v:maximumBy" class="def">maximumBy</a> :: (a -> a -> <a href="Prelude.html#t:Ordering">Ordering</a>) -> [a] -> a<a href="../base-4.5.1.0/src/Data-List.html#maximumBy" class="link">Source</a></p><div class="doc"><p>The <code><a href="List.html#v:maximumBy">maximumBy</a></code> function takes a comparison function and a list
and returns the greatest element of the list by the comparison function.
The list must be finite and non-empty.
</p></div></div><div class="top"><p class="src"><a name="v:minimumBy" class="def">minimumBy</a> :: (a -> a -> <a href="Prelude.html#t:Ordering">Ordering</a>) -> [a] -> a<a href="../base-4.5.1.0/src/Data-List.html#minimumBy" class="link">Source</a></p><div class="doc"><p>The <code><a href="List.html#v:minimumBy">minimumBy</a></code> function takes a comparison function and a list
and returns the least element of the list by the comparison function.
The list must be finite and non-empty.
</p></div></div><div class="top"><p class="src"><a name="v:genericLength" class="def">genericLength</a> :: <a href="Prelude.html#t:Num">Num</a> i => [b] -> i<a href="../base-4.5.1.0/src/Data-List.html#genericLength" class="link">Source</a></p><div class="doc"><p>The <code><a href="List.html#v:genericLength">genericLength</a></code> function is an overloaded version of <code><a href="List.html#v:length">length</a></code>. In
particular, instead of returning an <code><a href="Prelude.html#t:Int">Int</a></code>, it returns any type which is
an instance of <code><a href="Prelude.html#t:Num">Num</a></code>. It is, however, less efficient than <code><a href="List.html#v:length">length</a></code>.
</p></div></div><div class="top"><p class="src"><a name="v:genericTake" class="def">genericTake</a> :: <a href="Prelude.html#t:Integral">Integral</a> i => i -> [a] -> [a]<a href="../base-4.5.1.0/src/Data-List.html#genericTake" class="link">Source</a></p><div class="doc"><p>The <code><a href="List.html#v:genericTake">genericTake</a></code> function is an overloaded version of <code><a href="List.html#v:take">take</a></code>, which
accepts any <code><a href="Prelude.html#t:Integral">Integral</a></code> value as the number of elements to take.
</p></div></div><div class="top"><p class="src"><a name="v:genericDrop" class="def">genericDrop</a> :: <a href="Prelude.html#t:Integral">Integral</a> i => i -> [a] -> [a]<a href="../base-4.5.1.0/src/Data-List.html#genericDrop" class="link">Source</a></p><div class="doc"><p>The <code><a href="List.html#v:genericDrop">genericDrop</a></code> function is an overloaded version of <code><a href="List.html#v:drop">drop</a></code>, which
accepts any <code><a href="Prelude.html#t:Integral">Integral</a></code> value as the number of elements to drop.
</p></div></div><div class="top"><p class="src"><a name="v:genericSplitAt" class="def">genericSplitAt</a> :: <a href="Prelude.html#t:Integral">Integral</a> i => i -> [b] -> ([b], [b])<a href="../base-4.5.1.0/src/Data-List.html#genericSplitAt" class="link">Source</a></p><div class="doc"><p>The <code><a href="List.html#v:genericSplitAt">genericSplitAt</a></code> function is an overloaded version of <code><a href="../base-4.5.1.0/Data-List.html#v:splitAt">splitAt</a></code>, which
accepts any <code><a href="Prelude.html#t:Integral">Integral</a></code> value as the position at which to split.
</p></div></div><div class="top"><p class="src"><a name="v:genericIndex" class="def">genericIndex</a> :: <a href="Prelude.html#t:Integral">Integral</a> a => [b] -> a -> b<a href="../base-4.5.1.0/src/Data-List.html#genericIndex" class="link">Source</a></p><div class="doc"><p>The <code><a href="List.html#v:genericIndex">genericIndex</a></code> function is an overloaded version of <code><a href="List.html#v:-33--33-">!!</a></code>, which
accepts any <code><a href="Prelude.html#t:Integral">Integral</a></code> value as the index.
</p></div></div><div class="top"><p class="src"><a name="v:genericReplicate" class="def">genericReplicate</a> :: <a href="Prelude.html#t:Integral">Integral</a> i => i -> a -> [a]<a href="../base-4.5.1.0/src/Data-List.html#genericReplicate" class="link">Source</a></p><div class="doc"><p>The <code><a href="List.html#v:genericReplicate">genericReplicate</a></code> function is an overloaded version of <code><a href="List.html#v:replicate">replicate</a></code>,
which accepts any <code><a href="Prelude.html#t:Integral">Integral</a></code> value as the number of repetitions to make.
</p></div></div><div class="top"><p class="src"><a name="v:zip4" class="def">zip4</a> :: [a] -> [b] -> [c] -> [d] -> [(a, b, c, d)]<a href="../base-4.5.1.0/src/Data-List.html#zip4" class="link">Source</a></p><div class="doc"><p>The <code><a href="List.html#v:zip4">zip4</a></code> function takes four lists and returns a list of
quadruples, analogous to <code><a href="List.html#v:zip">zip</a></code>.
</p></div></div><div class="top"><p class="src"><a name="v:zip5" class="def">zip5</a> :: [a] -> [b] -> [c] -> [d] -> [e] -> [(a, b, c, d, e)]<a href="../base-4.5.1.0/src/Data-List.html#zip5" class="link">Source</a></p><div class="doc"><p>The <code><a href="List.html#v:zip5">zip5</a></code> function takes five lists and returns a list of
five-tuples, analogous to <code><a href="List.html#v:zip">zip</a></code>.
</p></div></div><div class="top"><p class="src"><a name="v:zip6" class="def">zip6</a> :: [a] -> [b] -> [c] -> [d] -> [e] -> [f] -> [(a, b, c, d, e, f)]<a href="../base-4.5.1.0/src/Data-List.html#zip6" class="link">Source</a></p><div class="doc"><p>The <code><a href="List.html#v:zip6">zip6</a></code> function takes six lists and returns a list of six-tuples,
analogous to <code><a href="List.html#v:zip">zip</a></code>.
</p></div></div><div class="top"><p class="src"><a name="v:zip7" class="def">zip7</a> :: [a] -> [b] -> [c] -> [d] -> [e] -> [f] -> [g] -> [(a, b, c, d, e, f, g)]<a href="../base-4.5.1.0/src/Data-List.html#zip7" class="link">Source</a></p><div class="doc"><p>The <code><a href="List.html#v:zip7">zip7</a></code> function takes seven lists and returns a list of
seven-tuples, analogous to <code><a href="List.html#v:zip">zip</a></code>.
</p></div></div><div class="top"><p class="src"><a name="v:zipWith4" class="def">zipWith4</a> :: (a -> b -> c -> d -> e) -> [a] -> [b] -> [c] -> [d] -> [e]<a href="../base-4.5.1.0/src/Data-List.html#zipWith4" class="link">Source</a></p><div class="doc"><p>The <code><a href="List.html#v:zipWith4">zipWith4</a></code> function takes a function which combines four
elements, as well as four lists and returns a list of their point-wise
combination, analogous to <code><a href="List.html#v:zipWith">zipWith</a></code>.
</p></div></div><div class="top"><p class="src"><a name="v:zipWith5" class="def">zipWith5</a> :: (a -> b -> c -> d -> e -> f) -> [a] -> [b] -> [c] -> [d] -> [e] -> [f]<a href="../base-4.5.1.0/src/Data-List.html#zipWith5" class="link">Source</a></p><div class="doc"><p>The <code><a href="List.html#v:zipWith5">zipWith5</a></code> function takes a function which combines five
elements, as well as five lists and returns a list of their point-wise
combination, analogous to <code><a href="List.html#v:zipWith">zipWith</a></code>.
</p></div></div><div class="top"><p class="src"><a name="v:zipWith6" class="def">zipWith6</a> :: (a -> b -> c -> d -> e -> f -> g) -> [a] -> [b] -> [c] -> [d] -> [e] -> [f] -> [g]<a href="../base-4.5.1.0/src/Data-List.html#zipWith6" class="link">Source</a></p><div class="doc"><p>The <code><a href="List.html#v:zipWith6">zipWith6</a></code> function takes a function which combines six
elements, as well as six lists and returns a list of their point-wise
combination, analogous to <code><a href="List.html#v:zipWith">zipWith</a></code>.
</p></div></div><div class="top"><p class="src"><a name="v:zipWith7" class="def">zipWith7</a> :: (a -> b -> c -> d -> e -> f -> g -> h) -> [a] -> [b] -> [c] -> [d] -> [e] -> [f] -> [g] -> [h]<a href="../base-4.5.1.0/src/Data-List.html#zipWith7" class="link">Source</a></p><div class="doc"><p>The <code><a href="List.html#v:zipWith7">zipWith7</a></code> function takes a function which combines seven
elements, as well as seven lists and returns a list of their point-wise
combination, analogous to <code><a href="List.html#v:zipWith">zipWith</a></code>.
</p></div></div><div class="top"><p class="src"><a name="v:unzip4" class="def">unzip4</a> :: [(a, b, c, d)] -> ([a], [b], [c], [d])<a href="../base-4.5.1.0/src/Data-List.html#unzip4" class="link">Source</a></p><div class="doc"><p>The <code><a href="List.html#v:unzip4">unzip4</a></code> function takes a list of quadruples and returns four
lists, analogous to <code><a href="List.html#v:unzip">unzip</a></code>.
</p></div></div><div class="top"><p class="src"><a name="v:unzip5" class="def">unzip5</a> :: [(a, b, c, d, e)] -> ([a], [b], [c], [d], [e])<a href="../base-4.5.1.0/src/Data-List.html#unzip5" class="link">Source</a></p><div class="doc"><p>The <code><a href="List.html#v:unzip5">unzip5</a></code> function takes a list of five-tuples and returns five
lists, analogous to <code><a href="List.html#v:unzip">unzip</a></code>.
</p></div></div><div class="top"><p class="src"><a name="v:unzip6" class="def">unzip6</a> :: [(a, b, c, d, e, f)] -> ([a], [b], [c], [d], [e], [f])<a href="../base-4.5.1.0/src/Data-List.html#unzip6" class="link">Source</a></p><div class="doc"><p>The <code><a href="List.html#v:unzip6">unzip6</a></code> function takes a list of six-tuples and returns six
lists, analogous to <code><a href="List.html#v:unzip">unzip</a></code>.
</p></div></div><div class="top"><p class="src"><a name="v:unzip7" class="def">unzip7</a> :: [(a, b, c, d, e, f, g)] -> ([a], [b], [c], [d], [e], [f], [g])<a href="../base-4.5.1.0/src/Data-List.html#unzip7" class="link">Source</a></p><div class="doc"><p>The <code><a href="List.html#v:unzip7">unzip7</a></code> function takes a list of seven-tuples and returns
seven lists, analogous to <code><a href="List.html#v:unzip">unzip</a></code>.
</p></div></div><div class="top"><p class="src"><a name="v:unfoldr" class="def">unfoldr</a> :: (b -> <a href="Prelude.html#t:Maybe">Maybe</a> (a, b)) -> b -> [a]<a href="../base-4.5.1.0/src/Data-List.html#unfoldr" class="link">Source</a></p><div class="doc"><p>The <code><a href="List.html#v:unfoldr">unfoldr</a></code> function is a `dual' to <code><a href="List.html#v:foldr">foldr</a></code>: while <code><a href="List.html#v:foldr">foldr</a></code>
reduces a list to a summary value, <code><a href="List.html#v:unfoldr">unfoldr</a></code> builds a list from
a seed value. The function takes the element and returns <code><a href="Prelude.html#v:Nothing">Nothing</a></code>
if it is done producing the list or returns <code><a href="Prelude.html#v:Just">Just</a></code> <code>(a,b)</code>, in which
case, <code>a</code> is a prepended to the list and <code>b</code> is used as the next
element in a recursive call. For example,
</p><pre> iterate f == unfoldr (\x -> Just (x, f x))
</pre><p>In some cases, <code><a href="List.html#v:unfoldr">unfoldr</a></code> can undo a <code><a href="List.html#v:foldr">foldr</a></code> operation:
</p><pre> unfoldr f' (foldr f z xs) == xs
</pre><p>if the following holds:
</p><pre> f' (f x y) = Just (x,y)
f' z = Nothing
</pre><p>A simple use of unfoldr:
</p><pre> unfoldr (\b -> if b == 0 then Nothing else Just (b, b-1)) 10
[10,9,8,7,6,5,4,3,2,1]
</pre></div></div><div class="top"><p class="src"><a name="v:map" class="def">map</a> :: (a -> b) -> [a] -> [b]<a href="../base-4.5.1.0/src/GHC-Base.html#map" class="link">Source</a></p><div class="doc"><p><code><a href="List.html#v:map">map</a></code> <code>f xs</code> is the list obtained by applying <code>f</code> to each element
of <code>xs</code>, i.e.,
</p><pre> map f [x1, x2, ..., xn] == [f x1, f x2, ..., f xn]
map f [x1, x2, ...] == [f x1, f x2, ...]
</pre></div></div><div class="top"><p class="src"><a name="v:-43--43-" class="def">(++)</a> :: [a] -> [a] -> [a]<a href="../base-4.5.1.0/src/GHC-Base.html#%2B%2B" class="link">Source</a></p><div class="doc"><p>Append two lists, i.e.,
</p><pre> [x1, ..., xm] ++ [y1, ..., yn] == [x1, ..., xm, y1, ..., yn]
[x1, ..., xm] ++ [y1, ...] == [x1, ..., xm, y1, ...]
</pre><p>If the first list is not finite, the result is the first list.
</p></div></div><div class="top"><p class="src"><a name="v:concat" class="def">concat</a> :: [[a]] -> [a]<a href="../base-4.5.1.0/src/GHC-List.html#concat" class="link">Source</a></p><div class="doc"><p>Concatenate a list of lists.
</p></div></div><div class="top"><p class="src"><a name="v:filter" class="def">filter</a> :: (a -> <a href="Prelude.html#t:Bool">Bool</a>) -> [a] -> [a]<a href="../base-4.5.1.0/src/GHC-List.html#filter" class="link">Source</a></p><div class="doc"><p><code><a href="List.html#v:filter">filter</a></code>, applied to a predicate and a list, returns the list of
those elements that satisfy the predicate; i.e.,
</p><pre> filter p xs = [ x | x <- xs, p x]
</pre></div></div><div class="top"><p class="src"><a name="v:head" class="def">head</a> :: [a] -> a<a href="../base-4.5.1.0/src/GHC-List.html#head" class="link">Source</a></p><div class="doc"><p>Extract the first element of a list, which must be non-empty.
</p></div></div><div class="top"><p class="src"><a name="v:last" class="def">last</a> :: [a] -> a<a href="../base-4.5.1.0/src/GHC-List.html#last" class="link">Source</a></p><div class="doc"><p>Extract the last element of a list, which must be finite and non-empty.
</p></div></div><div class="top"><p class="src"><a name="v:tail" class="def">tail</a> :: [a] -> [a]<a href="../base-4.5.1.0/src/GHC-List.html#tail" class="link">Source</a></p><div class="doc"><p>Extract the elements after the head of a list, which must be non-empty.
</p></div></div><div class="top"><p class="src"><a name="v:init" class="def">init</a> :: [a] -> [a]<a href="../base-4.5.1.0/src/GHC-List.html#init" class="link">Source</a></p><div class="doc"><p>Return all the elements of a list except the last one.
The list must be non-empty.
</p></div></div><div class="top"><p class="src"><a name="v:null" class="def">null</a> :: [a] -> <a href="Prelude.html#t:Bool">Bool</a><a href="../base-4.5.1.0/src/GHC-List.html#null" class="link">Source</a></p><div class="doc"><p>Test whether a list is empty.
</p></div></div><div class="top"><p class="src"><a name="v:length" class="def">length</a> :: [a] -> <a href="Prelude.html#t:Int">Int</a><a href="../base-4.5.1.0/src/GHC-List.html#length" class="link">Source</a></p><div class="doc"><p><em>O(n)</em>. <code><a href="List.html#v:length">length</a></code> returns the length of a finite list as an <code><a href="Prelude.html#t:Int">Int</a></code>.
It is an instance of the more general <code><a href="../base-4.5.1.0/Data-List.html#v:genericLength">genericLength</a></code>,
the result type of which may be any kind of number.
</p></div></div><div class="top"><p class="src"><a name="v:-33--33-" class="def">(!!)</a> :: [a] -> <a href="Prelude.html#t:Int">Int</a> -> a<a href="../base-4.5.1.0/src/GHC-List.html#%21%21" class="link">Source</a></p><div class="doc"><p>List index (subscript) operator, starting from 0.
It is an instance of the more general <code><a href="../base-4.5.1.0/Data-List.html#v:genericIndex">genericIndex</a></code>,
which takes an index of any integral type.
</p></div></div><div class="top"><p class="src"><a name="v:foldl" class="def">foldl</a> :: (a -> b -> a) -> a -> [b] -> a<a href="../base-4.5.1.0/src/GHC-List.html#foldl" class="link">Source</a></p><div class="doc"><p><code><a href="List.html#v:foldl">foldl</a></code>, applied to a binary operator, a starting value (typically
the left-identity of the operator), and a list, reduces the list
using the binary operator, from left to right:
</p><pre> foldl f z [x1, x2, ..., xn] == (...((z `f` x1) `f` x2) `f`...) `f` xn
</pre><p>The list must be finite.
</p></div></div><div class="top"><p class="src"><a name="v:foldl1" class="def">foldl1</a> :: (a -> a -> a) -> [a] -> a<a href="../base-4.5.1.0/src/Data-List.html#foldl1" class="link">Source</a></p><div class="doc"><p><code><a href="List.html#v:foldl1">foldl1</a></code> is a variant of <code><a href="List.html#v:foldl">foldl</a></code> that has no starting value argument,
and thus must be applied to non-empty lists.
</p></div></div><div class="top"><p class="src"><a name="v:scanl" class="def">scanl</a> :: (a -> b -> a) -> a -> [b] -> [a]<a href="../base-4.5.1.0/src/GHC-List.html#scanl" class="link">Source</a></p><div class="doc"><p><code><a href="List.html#v:scanl">scanl</a></code> is similar to <code><a href="List.html#v:foldl">foldl</a></code>, but returns a list of successive
reduced values from the left:
</p><pre> scanl f z [x1, x2, ...] == [z, z `f` x1, (z `f` x1) `f` x2, ...]
</pre><p>Note that
</p><pre> last (scanl f z xs) == foldl f z xs.
</pre></div></div><div class="top"><p class="src"><a name="v:scanl1" class="def">scanl1</a> :: (a -> a -> a) -> [a] -> [a]<a href="../base-4.5.1.0/src/GHC-List.html#scanl1" class="link">Source</a></p><div class="doc"><p><code><a href="List.html#v:scanl1">scanl1</a></code> is a variant of <code><a href="List.html#v:scanl">scanl</a></code> that has no starting value argument:
</p><pre> scanl1 f [x1, x2, ...] == [x1, x1 `f` x2, ...]
</pre></div></div><div class="top"><p class="src"><a name="v:foldr" class="def">foldr</a> :: (a -> b -> b) -> b -> [a] -> b<a href="../base-4.5.1.0/src/GHC-Base.html#foldr" class="link">Source</a></p><div class="doc"><p><code><a href="List.html#v:foldr">foldr</a></code>, applied to a binary operator, a starting value (typically
the right-identity of the operator), and a list, reduces the list
using the binary operator, from right to left:
</p><pre> foldr f z [x1, x2, ..., xn] == x1 `f` (x2 `f` ... (xn `f` z)...)
</pre></div></div><div class="top"><p class="src"><a name="v:foldr1" class="def">foldr1</a> :: (a -> a -> a) -> [a] -> a<a href="../base-4.5.1.0/src/GHC-List.html#foldr1" class="link">Source</a></p><div class="doc"><p><code><a href="List.html#v:foldr1">foldr1</a></code> is a variant of <code><a href="List.html#v:foldr">foldr</a></code> that has no starting value argument,
and thus must be applied to non-empty lists.
</p></div></div><div class="top"><p class="src"><a name="v:scanr" class="def">scanr</a> :: (a -> b -> b) -> b -> [a] -> [b]<a href="../base-4.5.1.0/src/GHC-List.html#scanr" class="link">Source</a></p><div class="doc"><p><code><a href="List.html#v:scanr">scanr</a></code> is the right-to-left dual of <code><a href="List.html#v:scanl">scanl</a></code>.
Note that
</p><pre> head (scanr f z xs) == foldr f z xs.
</pre></div></div><div class="top"><p class="src"><a name="v:scanr1" class="def">scanr1</a> :: (a -> a -> a) -> [a] -> [a]<a href="../base-4.5.1.0/src/GHC-List.html#scanr1" class="link">Source</a></p><div class="doc"><p><code><a href="List.html#v:scanr1">scanr1</a></code> is a variant of <code><a href="List.html#v:scanr">scanr</a></code> that has no starting value argument.
</p></div></div><div class="top"><p class="src"><a name="v:iterate" class="def">iterate</a> :: (a -> a) -> a -> [a]<a href="../base-4.5.1.0/src/GHC-List.html#iterate" class="link">Source</a></p><div class="doc"><p><code><a href="List.html#v:iterate">iterate</a></code> <code>f x</code> returns an infinite list of repeated applications
of <code>f</code> to <code>x</code>:
</p><pre> iterate f x == [x, f x, f (f x), ...]
</pre></div></div><div class="top"><p class="src"><a name="v:repeat" class="def">repeat</a> :: a -> [a]<a href="../base-4.5.1.0/src/GHC-List.html#repeat" class="link">Source</a></p><div class="doc"><p><code><a href="List.html#v:repeat">repeat</a></code> <code>x</code> is an infinite list, with <code>x</code> the value of every element.
</p></div></div><div class="top"><p class="src"><a name="v:replicate" class="def">replicate</a> :: <a href="Prelude.html#t:Int">Int</a> -> a -> [a]<a href="../base-4.5.1.0/src/GHC-List.html#replicate" class="link">Source</a></p><div class="doc"><p><code><a href="List.html#v:replicate">replicate</a></code> <code>n x</code> is a list of length <code>n</code> with <code>x</code> the value of
every element.
It is an instance of the more general <code><a href="../base-4.5.1.0/Data-List.html#v:genericReplicate">genericReplicate</a></code>,
in which <code>n</code> may be of any integral type.
</p></div></div><div class="top"><p class="src"><a name="v:cycle" class="def">cycle</a> :: [a] -> [a]<a href="../base-4.5.1.0/src/GHC-List.html#cycle" class="link">Source</a></p><div class="doc"><p><code><a href="List.html#v:cycle">cycle</a></code> ties a finite list into a circular one, or equivalently,
the infinite repetition of the original list. It is the identity
on infinite lists.
</p></div></div><div class="top"><p class="src"><a name="v:take" class="def">take</a> :: <a href="Prelude.html#t:Int">Int</a> -> [a] -> [a]<a href="../base-4.5.1.0/src/GHC-List.html#take" class="link">Source</a></p><div class="doc"><p><code><a href="List.html#v:take">take</a></code> <code>n</code>, applied to a list <code>xs</code>, returns the prefix of <code>xs</code>
of length <code>n</code>, or <code>xs</code> itself if <code>n > <code><a href="List.html#v:length">length</a></code> xs</code>:
</p><pre> take 5 "Hello World!" == "Hello"
take 3 [1,2,3,4,5] == [1,2,3]
take 3 [1,2] == [1,2]
take 3 [] == []
take (-1) [1,2] == []
take 0 [1,2] == []
</pre><p>It is an instance of the more general <code><a href="../base-4.5.1.0/Data-List.html#v:genericTake">genericTake</a></code>,
in which <code>n</code> may be of any integral type.
</p></div></div><div class="top"><p class="src"><a name="v:drop" class="def">drop</a> :: <a href="Prelude.html#t:Int">Int</a> -> [a] -> [a]<a href="../base-4.5.1.0/src/GHC-List.html#drop" class="link">Source</a></p><div class="doc"><p><code><a href="List.html#v:drop">drop</a></code> <code>n xs</code> returns the suffix of <code>xs</code>
after the first <code>n</code> elements, or <code>[]</code> if <code>n > <code><a href="List.html#v:length">length</a></code> xs</code>:
</p><pre> drop 6 "Hello World!" == "World!"
drop 3 [1,2,3,4,5] == [4,5]
drop 3 [1,2] == []
drop 3 [] == []
drop (-1) [1,2] == [1,2]
drop 0 [1,2] == [1,2]
</pre><p>It is an instance of the more general <code><a href="../base-4.5.1.0/Data-List.html#v:genericDrop">genericDrop</a></code>,
in which <code>n</code> may be of any integral type.
</p></div></div><div class="top"><p class="src"><a name="v:splitAt" class="def">splitAt</a> :: <a href="Prelude.html#t:Int">Int</a> -> [a] -> ([a], [a])</p><div class="doc"><p><code><a href="List.html#v:splitAt">splitAt</a></code> <code>n xs</code> returns a tuple where first element is <code>xs</code> prefix of
length <code>n</code> and second element is the remainder of the list:
</p><pre> splitAt 6 "Hello World!" == ("Hello ","World!")
splitAt 3 [1,2,3,4,5] == ([1,2,3],[4,5])
splitAt 1 [1,2,3] == ([1],[2,3])
splitAt 3 [1,2,3] == ([1,2,3],[])
splitAt 4 [1,2,3] == ([1,2,3],[])
splitAt 0 [1,2,3] == ([],[1,2,3])
splitAt (-1) [1,2,3] == ([],[1,2,3])
</pre><p>It is equivalent to <code>(<code><a href="List.html#v:take">take</a></code> n xs, <code><a href="List.html#v:drop">drop</a></code> n xs)</code>.
<code><a href="List.html#v:splitAt">splitAt</a></code> is an instance of the more general <code><a href="List.html#v:genericSplitAt">genericSplitAt</a></code>,
in which <code>n</code> may be of any integral type.
</p></div></div><div class="top"><p class="src"><a name="v:takeWhile" class="def">takeWhile</a> :: (a -> <a href="Prelude.html#t:Bool">Bool</a>) -> [a] -> [a]<a href="../base-4.5.1.0/src/GHC-List.html#takeWhile" class="link">Source</a></p><div class="doc"><p><code><a href="List.html#v:takeWhile">takeWhile</a></code>, applied to a predicate <code>p</code> and a list <code>xs</code>, returns the
longest prefix (possibly empty) of <code>xs</code> of elements that satisfy <code>p</code>:
</p><pre> takeWhile (< 3) [1,2,3,4,1,2,3,4] == [1,2]
takeWhile (< 9) [1,2,3] == [1,2,3]
takeWhile (< 0) [1,2,3] == []
</pre></div></div><div class="top"><p class="src"><a name="v:dropWhile" class="def">dropWhile</a> :: (a -> <a href="Prelude.html#t:Bool">Bool</a>) -> [a] -> [a]<a href="../base-4.5.1.0/src/GHC-List.html#dropWhile" class="link">Source</a></p><div class="doc"><p><code><a href="List.html#v:dropWhile">dropWhile</a></code> <code>p xs</code> returns the suffix remaining after <code><a href="List.html#v:takeWhile">takeWhile</a></code> <code>p xs</code>:
</p><pre> dropWhile (< 3) [1,2,3,4,5,1,2,3] == [3,4,5,1,2,3]
dropWhile (< 9) [1,2,3] == []
dropWhile (< 0) [1,2,3] == [1,2,3]
</pre></div></div><div class="top"><p class="src"><a name="v:span" class="def">span</a> :: (a -> <a href="Prelude.html#t:Bool">Bool</a>) -> [a] -> ([a], [a])<a href="../base-4.5.1.0/src/GHC-List.html#span" class="link">Source</a></p><div class="doc"><p><code><a href="List.html#v:span">span</a></code>, applied to a predicate <code>p</code> and a list <code>xs</code>, returns a tuple where
first element is longest prefix (possibly empty) of <code>xs</code> of elements that
satisfy <code>p</code> and second element is the remainder of the list:
</p><pre> span (< 3) [1,2,3,4,1,2,3,4] == ([1,2],[3,4,1,2,3,4])
span (< 9) [1,2,3] == ([1,2,3],[])
span (< 0) [1,2,3] == ([],[1,2,3])
</pre><p><code><a href="List.html#v:span">span</a></code> <code>p xs</code> is equivalent to <code>(<code><a href="List.html#v:takeWhile">takeWhile</a></code> p xs, <code><a href="List.html#v:dropWhile">dropWhile</a></code> p xs)</code>
</p></div></div><div class="top"><p class="src"><a name="v:break" class="def">break</a> :: (a -> <a href="Prelude.html#t:Bool">Bool</a>) -> [a] -> ([a], [a])<a href="../base-4.5.1.0/src/GHC-List.html#break" class="link">Source</a></p><div class="doc"><p><code><a href="List.html#v:break">break</a></code>, applied to a predicate <code>p</code> and a list <code>xs</code>, returns a tuple where
first element is longest prefix (possibly empty) of <code>xs</code> of elements that
<em>do not satisfy</em> <code>p</code> and second element is the remainder of the list:
</p><pre> break (> 3) [1,2,3,4,1,2,3,4] == ([1,2,3],[4,1,2,3,4])
break (< 9) [1,2,3] == ([],[1,2,3])
break (> 9) [1,2,3] == ([1,2,3],[])
</pre><p><code><a href="List.html#v:break">break</a></code> <code>p</code> is equivalent to <code><code><a href="List.html#v:span">span</a></code> (<code><a href="Prelude.html#v:not">not</a></code> . p)</code>.
</p></div></div><div class="top"><p class="src"><a name="v:lines" class="def">lines</a> :: <a href="Prelude.html#t:String">String</a> -> [<a href="Prelude.html#t:String">String</a>]<a href="../base-4.5.1.0/src/Data-List.html#lines" class="link">Source</a></p><div class="doc"><p><code><a href="List.html#v:lines">lines</a></code> breaks a string up into a list of strings at newline
characters. The resulting strings do not contain newlines.
</p></div></div><div class="top"><p class="src"><a name="v:words" class="def">words</a> :: <a href="Prelude.html#t:String">String</a> -> [<a href="Prelude.html#t:String">String</a>]<a href="../base-4.5.1.0/src/Data-List.html#words" class="link">Source</a></p><div class="doc"><p><code><a href="List.html#v:words">words</a></code> breaks a string up into a list of words, which were delimited
by white space.
</p></div></div><div class="top"><p class="src"><a name="v:unlines" class="def">unlines</a> :: [<a href="Prelude.html#t:String">String</a>] -> <a href="Prelude.html#t:String">String</a><a href="../base-4.5.1.0/src/Data-List.html#unlines" class="link">Source</a></p><div class="doc"><p><code><a href="List.html#v:unlines">unlines</a></code> is an inverse operation to <code><a href="List.html#v:lines">lines</a></code>.
It joins lines, after appending a terminating newline to each.
</p></div></div><div class="top"><p class="src"><a name="v:unwords" class="def">unwords</a> :: [<a href="Prelude.html#t:String">String</a>] -> <a href="Prelude.html#t:String">String</a><a href="../base-4.5.1.0/src/Data-List.html#unwords" class="link">Source</a></p><div class="doc"><p><code><a href="List.html#v:unwords">unwords</a></code> is an inverse operation to <code><a href="List.html#v:words">words</a></code>.
It joins words with separating spaces.
</p></div></div><div class="top"><p class="src"><a name="v:reverse" class="def">reverse</a> :: [a] -> [a]<a href="../base-4.5.1.0/src/GHC-List.html#reverse" class="link">Source</a></p><div class="doc"><p><code><a href="List.html#v:reverse">reverse</a></code> <code>xs</code> returns the elements of <code>xs</code> in reverse order.
<code>xs</code> must be finite.
</p></div></div><div class="top"><p class="src"><a name="v:and" class="def">and</a> :: [<a href="Prelude.html#t:Bool">Bool</a>] -> <a href="Prelude.html#t:Bool">Bool</a><a href="../base-4.5.1.0/src/GHC-List.html#and" class="link">Source</a></p><div class="doc"><p><code><a href="List.html#v:and">and</a></code> returns the conjunction of a Boolean list. For the result to be
<code><a href="Prelude.html#v:True">True</a></code>, the list must be finite; <code><a href="Prelude.html#v:False">False</a></code>, however, results from a <code><a href="Prelude.html#v:False">False</a></code>
value at a finite index of a finite or infinite list.
</p></div></div><div class="top"><p class="src"><a name="v:or" class="def">or</a> :: [<a href="Prelude.html#t:Bool">Bool</a>] -> <a href="Prelude.html#t:Bool">Bool</a><a href="../base-4.5.1.0/src/GHC-List.html#or" class="link">Source</a></p><div class="doc"><p><code><a href="List.html#v:or">or</a></code> returns the disjunction of a Boolean list. For the result to be
<code><a href="Prelude.html#v:False">False</a></code>, the list must be finite; <code><a href="Prelude.html#v:True">True</a></code>, however, results from a <code><a href="Prelude.html#v:True">True</a></code>
value at a finite index of a finite or infinite list.
</p></div></div><div class="top"><p class="src"><a name="v:any" class="def">any</a> :: (a -> <a href="Prelude.html#t:Bool">Bool</a>) -> [a] -> <a href="Prelude.html#t:Bool">Bool</a><a href="../base-4.5.1.0/src/GHC-List.html#any" class="link">Source</a></p><div class="doc"><p>Applied to a predicate and a list, <code><a href="List.html#v:any">any</a></code> determines if any element
of the list satisfies the predicate. For the result to be
<code><a href="Prelude.html#v:False">False</a></code>, the list must be finite; <code><a href="Prelude.html#v:True">True</a></code>, however, results from a <code><a href="Prelude.html#v:True">True</a></code>
value for the predicate applied to an element at a finite index of a finite or infinite list.
</p></div></div><div class="top"><p class="src"><a name="v:all" class="def">all</a> :: (a -> <a href="Prelude.html#t:Bool">Bool</a>) -> [a] -> <a href="Prelude.html#t:Bool">Bool</a><a href="../base-4.5.1.0/src/GHC-List.html#all" class="link">Source</a></p><div class="doc"><p>Applied to a predicate and a list, <code><a href="List.html#v:all">all</a></code> determines if all elements
of the list satisfy the predicate. For the result to be
<code><a href="Prelude.html#v:True">True</a></code>, the list must be finite; <code><a href="Prelude.html#v:False">False</a></code>, however, results from a <code><a href="Prelude.html#v:False">False</a></code>
value for the predicate applied to an element at a finite index of a finite or infinite list.
</p></div></div><div class="top"><p class="src"><a name="v:elem" class="def">elem</a> :: <a href="Prelude.html#t:Eq">Eq</a> a => a -> [a] -> <a href="Prelude.html#t:Bool">Bool</a><a href="../base-4.5.1.0/src/GHC-List.html#elem" class="link">Source</a></p><div class="doc"><p><code><a href="List.html#v:elem">elem</a></code> is the list membership predicate, usually written in infix form,
e.g., <code>x `elem` xs</code>. For the result to be
<code><a href="Prelude.html#v:False">False</a></code>, the list must be finite; <code><a href="Prelude.html#v:True">True</a></code>, however, results from an element equal to <code>x</code> found at a finite index of a finite or infinite list.
</p></div></div><div class="top"><p class="src"><a name="v:notElem" class="def">notElem</a> :: <a href="Prelude.html#t:Eq">Eq</a> a => a -> [a] -> <a href="Prelude.html#t:Bool">Bool</a><a href="../base-4.5.1.0/src/GHC-List.html#notElem" class="link">Source</a></p><div class="doc"><p><code><a href="List.html#v:notElem">notElem</a></code> is the negation of <code><a href="List.html#v:elem">elem</a></code>.
</p></div></div><div class="top"><p class="src"><a name="v:lookup" class="def">lookup</a> :: <a href="Prelude.html#t:Eq">Eq</a> a => a -> [(a, b)] -> <a href="Prelude.html#t:Maybe">Maybe</a> b<a href="../base-4.5.1.0/src/GHC-List.html#lookup" class="link">Source</a></p><div class="doc"><p><code><a href="List.html#v:lookup">lookup</a></code> <code>key assocs</code> looks up a key in an association list.
</p></div></div><div class="top"><p class="src"><a name="v:sum" class="def">sum</a> :: <a href="Prelude.html#t:Num">Num</a> a => [a] -> a<a href="../base-4.5.1.0/src/Data-List.html#sum" class="link">Source</a></p><div class="doc"><p>The <code><a href="List.html#v:sum">sum</a></code> function computes the sum of a finite list of numbers.
</p></div></div><div class="top"><p class="src"><a name="v:product" class="def">product</a> :: <a href="Prelude.html#t:Num">Num</a> a => [a] -> a<a href="../base-4.5.1.0/src/Data-List.html#product" class="link">Source</a></p><div class="doc"><p>The <code><a href="List.html#v:product">product</a></code> function computes the product of a finite list of numbers.
</p></div></div><div class="top"><p class="src"><a name="v:maximum" class="def">maximum</a> :: <a href="Prelude.html#t:Ord">Ord</a> a => [a] -> a<a href="../base-4.5.1.0/src/Data-List.html#maximum" class="link">Source</a></p><div class="doc"><p><code><a href="List.html#v:maximum">maximum</a></code> returns the maximum value from a list,
which must be non-empty, finite, and of an ordered type.
It is a special case of <code><a href="List.html#v:maximumBy">maximumBy</a></code>, which allows the
programmer to supply their own comparison function.
</p></div></div><div class="top"><p class="src"><a name="v:minimum" class="def">minimum</a> :: <a href="Prelude.html#t:Ord">Ord</a> a => [a] -> a<a href="../base-4.5.1.0/src/Data-List.html#minimum" class="link">Source</a></p><div class="doc"><p><code><a href="List.html#v:minimum">minimum</a></code> returns the minimum value from a list,
which must be non-empty, finite, and of an ordered type.
It is a special case of <code><a href="List.html#v:minimumBy">minimumBy</a></code>, which allows the
programmer to supply their own comparison function.
</p></div></div><div class="top"><p class="src"><a name="v:concatMap" class="def">concatMap</a> :: (a -> [b]) -> [a] -> [b]<a href="../base-4.5.1.0/src/GHC-List.html#concatMap" class="link">Source</a></p><div class="doc"><p>Map a function over a list and concatenate the results.
</p></div></div><div class="top"><p class="src"><a name="v:zip" class="def">zip</a> :: [a] -> [b] -> [(a, b)]<a href="../base-4.5.1.0/src/GHC-List.html#zip" class="link">Source</a></p><div class="doc"><p><code><a href="List.html#v:zip">zip</a></code> takes two lists and returns a list of corresponding pairs.
If one input list is short, excess elements of the longer list are
discarded.
</p></div></div><div class="top"><p class="src"><a name="v:zip3" class="def">zip3</a> :: [a] -> [b] -> [c] -> [(a, b, c)]<a href="../base-4.5.1.0/src/GHC-List.html#zip3" class="link">Source</a></p><div class="doc"><p><code><a href="List.html#v:zip3">zip3</a></code> takes three lists and returns a list of triples, analogous to
<code><a href="List.html#v:zip">zip</a></code>.
</p></div></div><div class="top"><p class="src"><a name="v:zipWith" class="def">zipWith</a> :: (a -> b -> c) -> [a] -> [b] -> [c]<a href="../base-4.5.1.0/src/GHC-List.html#zipWith" class="link">Source</a></p><div class="doc"><p><code><a href="List.html#v:zipWith">zipWith</a></code> generalises <code><a href="List.html#v:zip">zip</a></code> by zipping with the function given
as the first argument, instead of a tupling function.
For example, <code><code><a href="List.html#v:zipWith">zipWith</a></code> (+)</code> is applied to two lists to produce the
list of corresponding sums.
</p></div></div><div class="top"><p class="src"><a name="v:zipWith3" class="def">zipWith3</a> :: (a -> b -> c -> d) -> [a] -> [b] -> [c] -> [d]<a href="../base-4.5.1.0/src/GHC-List.html#zipWith3" class="link">Source</a></p><div class="doc"><p>The <code><a href="List.html#v:zipWith3">zipWith3</a></code> function takes a function which combines three
elements, as well as three lists and returns a list of their point-wise
combination, analogous to <code><a href="List.html#v:zipWith">zipWith</a></code>.
</p></div></div><div class="top"><p class="src"><a name="v:unzip" class="def">unzip</a> :: [(a, b)] -> ([a], [b])<a href="../base-4.5.1.0/src/GHC-List.html#unzip" class="link">Source</a></p><div class="doc"><p><code><a href="List.html#v:unzip">unzip</a></code> transforms a list of pairs into a list of first components
and a list of second components.
</p></div></div><div class="top"><p class="src"><a name="v:unzip3" class="def">unzip3</a> :: [(a, b, c)] -> ([a], [b], [c])<a href="../base-4.5.1.0/src/GHC-List.html#unzip3" class="link">Source</a></p><div class="doc"><p>The <code><a href="List.html#v:unzip3">unzip3</a></code> function takes a list of triples and returns three
lists, analogous to <code><a href="List.html#v:unzip">unzip</a></code>.
</p></div></div></div></div><div id="footer"><p>Produced by <a href="http://www.haskell.org/haddock/">Haddock</a> version 2.11.0</p></div></body></html>
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