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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">bytestring-0.9.2.1: Fast, packed, strict and lazy byte arrays with a list interface</p></div><div id="content"><div id="module-header"><table class="info"><tr><th>Portability</th><td>portable</td></tr><tr><th>Stability</th><td>experimental</td></tr><tr><th>Maintainer</th><td>dons@galois.com</td></tr><tr><th>Safe Haskell</th><td>Trustworthy</td></tr></table><p class="caption">Data.ByteString.Lazy</p></div><div id="table-of-contents"><p class="caption">Contents</p><ul><li><a href="#g:1">The <code>ByteString</code> type
</a></li><li><a href="#g:2">Introducing and eliminating <code><a href="Data-ByteString-Lazy.html#t:ByteString">ByteString</a></code>s
</a></li><li><a href="#g:3">Basic interface
</a></li><li><a href="#g:4">Transforming ByteStrings
</a></li><li><a href="#g:5">Reducing <code><a href="Data-ByteString-Lazy.html#t:ByteString">ByteString</a></code>s (folds)
</a><ul><li><a href="#g:6">Special folds
</a></li></ul></li><li><a href="#g:7">Building ByteStrings
</a><ul><li><a href="#g:8">Scans
</a></li><li><a href="#g:9">Accumulating maps
</a></li><li><a href="#g:10">Infinite ByteStrings
</a></li><li><a href="#g:11">Unfolding ByteStrings
</a></li></ul></li><li><a href="#g:12">Substrings
</a><ul><li><a href="#g:13">Breaking strings
</a></li><li><a href="#g:14">Breaking into many substrings
</a></li></ul></li><li><a href="#g:15">Predicates
</a><ul><li><a href="#g:16">Search for arbitrary substrings
</a></li></ul></li><li><a href="#g:17">Searching ByteStrings
</a><ul><li><a href="#g:18">Searching by equality
</a></li><li><a href="#g:19">Searching with a predicate
</a></li></ul></li><li><a href="#g:20">Indexing ByteStrings
</a></li><li><a href="#g:21">Zipping and unzipping ByteStrings
</a></li><li><a href="#g:22">Ordered ByteStrings
</a></li><li><a href="#g:23">Low level conversions
</a><ul><li><a href="#g:24">Copying ByteStrings
</a></li></ul></li><li><a href="#g:25">I/O with <code><a href="Data-ByteString-Lazy.html#t:ByteString">ByteString</a></code>s
</a><ul><li><a href="#g:26">Standard input and output
</a></li><li><a href="#g:27">Files
</a></li><li><a href="#g:28">I/O with Handles
</a></li></ul></li></ul></div><div id="description"><p class="caption">Description</p><div class="doc"><p>A time and space-efficient implementation of lazy byte vectors
using lists of packed <code><a href="../base-4.5.1.0/Data-Word.html#t:Word8">Word8</a></code> arrays, suitable for high performance
use, both in terms of large data quantities, or high speed
requirements. Byte vectors are encoded as lazy lists of strict <code><a href="../base-4.5.1.0/Data-Word.html#t:Word8">Word8</a></code>
arrays of bytes. They provide a means to manipulate large byte vectors
without requiring the entire vector be resident in memory.
</p><p>Some operations, such as concat, append, reverse and cons, have
better complexity than their <a href="Data-ByteString.html">Data.ByteString</a> equivalents, due to
optimisations resulting from the list spine structure. And for other
operations lazy ByteStrings are usually within a few percent of
strict ones, but with better heap usage. For data larger than the
available memory, or if you have tight memory constraints, this
module will be the only option. The default chunk size is 64k, which
should be good in most circumstances. For people with large L2
caches, you may want to increase this to fit your cache.
</p><p>This module is intended to be imported <code>qualified</code>, to avoid name
clashes with <a href="../base-4.5.1.0/Prelude.html">Prelude</a> functions. eg.
</p><pre> import qualified Data.ByteString.Lazy as B
</pre><p>Original GHC implementation by Bryan O'Sullivan.
Rewritten to use <code><a href="Data-Array-Unboxed.html#t:UArray">UArray</a></code> by Simon Marlow.
Rewritten to support slices and use <code><a href="../base-4.5.1.0/Foreign-ForeignPtr.html#t:ForeignPtr">ForeignPtr</a></code>
by David Roundy.
Polished and extended by Don Stewart.
Lazy variant by Duncan Coutts and Don Stewart.
</p></div></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"><span class="keyword">data</span> <a href="#t:ByteString">ByteString</a> </li><li class="src short"><a href="#v:empty">empty</a> :: <a href="Data-ByteString-Lazy.html#t:ByteString">ByteString</a></li><li class="src short"><a href="#v:singleton">singleton</a> :: <a href="../base-4.5.1.0/Data-Word.html#t:Word8">Word8</a> -> <a href="Data-ByteString-Lazy.html#t:ByteString">ByteString</a></li><li class="src short"><a href="#v:pack">pack</a> :: [<a href="../base-4.5.1.0/Data-Word.html#t:Word8">Word8</a>] -> <a href="Data-ByteString-Lazy.html#t:ByteString">ByteString</a></li><li class="src short"><a href="#v:unpack">unpack</a> :: <a href="Data-ByteString-Lazy.html#t:ByteString">ByteString</a> -> [<a href="../base-4.5.1.0/Data-Word.html#t:Word8">Word8</a>]</li><li class="src short"><a href="#v:fromChunks">fromChunks</a> :: [<a href="Data-ByteString.html#t:ByteString">ByteString</a>] -> <a href="Data-ByteString-Lazy.html#t:ByteString">ByteString</a></li><li class="src short"><a href="#v:toChunks">toChunks</a> :: <a href="Data-ByteString-Lazy.html#t:ByteString">ByteString</a> -> [<a href="Data-ByteString.html#t:ByteString">ByteString</a>]</li><li class="src short"><a href="#v:cons">cons</a> :: <a href="../base-4.5.1.0/Data-Word.html#t:Word8">Word8</a> -> <a href="Data-ByteString-Lazy.html#t:ByteString">ByteString</a> -> <a href="Data-ByteString-Lazy.html#t:ByteString">ByteString</a></li><li class="src short"><a href="#v:cons-39-">cons'</a> :: <a href="../base-4.5.1.0/Data-Word.html#t:Word8">Word8</a> -> <a href="Data-ByteString-Lazy.html#t:ByteString">ByteString</a> -> <a href="Data-ByteString-Lazy.html#t:ByteString">ByteString</a></li><li class="src short"><a href="#v:snoc">snoc</a> :: <a href="Data-ByteString-Lazy.html#t:ByteString">ByteString</a> -> <a href="../base-4.5.1.0/Data-Word.html#t:Word8">Word8</a> -> <a href="Data-ByteString-Lazy.html#t:ByteString">ByteString</a></li><li class="src short"><a href="#v:append">append</a> :: <a href="Data-ByteString-Lazy.html#t:ByteString">ByteString</a> -> <a href="Data-ByteString-Lazy.html#t:ByteString">ByteString</a> -> <a href="Data-ByteString-Lazy.html#t:ByteString">ByteString</a></li><li class="src short"><a href="#v:head">head</a> :: <a href="Data-ByteString-Lazy.html#t:ByteString">ByteString</a> -> <a href="../base-4.5.1.0/Data-Word.html#t:Word8">Word8</a></li><li class="src short"><a href="#v:uncons">uncons</a> :: <a href="Data-ByteString-Lazy.html#t:ByteString">ByteString</a> -> <a href="../base-4.5.1.0/Data-Maybe.html#t:Maybe">Maybe</a> (<a href="../base-4.5.1.0/Data-Word.html#t:Word8">Word8</a>, <a href="Data-ByteString-Lazy.html#t:ByteString">ByteString</a>)</li><li class="src short"><a href="#v:last">last</a> :: <a href="Data-ByteString-Lazy.html#t:ByteString">ByteString</a> -> <a href="../base-4.5.1.0/Data-Word.html#t:Word8">Word8</a></li><li class="src short"><a href="#v:tail">tail</a> :: <a href="Data-ByteString-Lazy.html#t:ByteString">ByteString</a> -> <a href="Data-ByteString-Lazy.html#t:ByteString">ByteString</a></li><li class="src short"><a href="#v:init">init</a> :: <a href="Data-ByteString-Lazy.html#t:ByteString">ByteString</a> -> <a href="Data-ByteString-Lazy.html#t:ByteString">ByteString</a></li><li class="src short"><a href="#v:null">null</a> :: <a href="Data-ByteString-Lazy.html#t:ByteString">ByteString</a> -> <a href="../base-4.5.1.0/Data-Bool.html#t:Bool">Bool</a></li><li class="src short"><a href="#v:length">length</a> :: <a href="Data-ByteString-Lazy.html#t:ByteString">ByteString</a> -> <a href="../base-4.5.1.0/Data-Int.html#t:Int64">Int64</a></li><li class="src short"><a href="#v:map">map</a> :: (<a href="../base-4.5.1.0/Data-Word.html#t:Word8">Word8</a> -> <a href="../base-4.5.1.0/Data-Word.html#t:Word8">Word8</a>) -> <a href="Data-ByteString-Lazy.html#t:ByteString">ByteString</a> -> <a href="Data-ByteString-Lazy.html#t:ByteString">ByteString</a></li><li class="src short"><a href="#v:reverse">reverse</a> :: <a href="Data-ByteString-Lazy.html#t:ByteString">ByteString</a> -> <a href="Data-ByteString-Lazy.html#t:ByteString">ByteString</a></li><li class="src short"><a href="#v:intersperse">intersperse</a> :: <a href="../base-4.5.1.0/Data-Word.html#t:Word8">Word8</a> -> <a href="Data-ByteString-Lazy.html#t:ByteString">ByteString</a> -> <a href="Data-ByteString-Lazy.html#t:ByteString">ByteString</a></li><li class="src short"><a href="#v:intercalate">intercalate</a> :: <a href="Data-ByteString-Lazy.html#t:ByteString">ByteString</a> -> [<a href="Data-ByteString-Lazy.html#t:ByteString">ByteString</a>] -> <a href="Data-ByteString-Lazy.html#t:ByteString">ByteString</a></li><li class="src short"><a href="#v:transpose">transpose</a> :: [<a href="Data-ByteString-Lazy.html#t:ByteString">ByteString</a>] -> [<a href="Data-ByteString-Lazy.html#t:ByteString">ByteString</a>]</li><li class="src short"><a href="#v:foldl">foldl</a> :: (a -> <a href="../base-4.5.1.0/Data-Word.html#t:Word8">Word8</a> -> a) -> a -> <a href="Data-ByteString-Lazy.html#t:ByteString">ByteString</a> -> a</li><li class="src short"><a href="#v:foldl-39-">foldl'</a> :: (a -> <a href="../base-4.5.1.0/Data-Word.html#t:Word8">Word8</a> -> a) -> a -> <a href="Data-ByteString-Lazy.html#t:ByteString">ByteString</a> -> a</li><li class="src short"><a href="#v:foldl1">foldl1</a> :: (<a href="../base-4.5.1.0/Data-Word.html#t:Word8">Word8</a> -> <a href="../base-4.5.1.0/Data-Word.html#t:Word8">Word8</a> -> <a href="../base-4.5.1.0/Data-Word.html#t:Word8">Word8</a>) -> <a href="Data-ByteString-Lazy.html#t:ByteString">ByteString</a> -> <a href="../base-4.5.1.0/Data-Word.html#t:Word8">Word8</a></li><li class="src short"><a href="#v:foldl1-39-">foldl1'</a> :: (<a href="../base-4.5.1.0/Data-Word.html#t:Word8">Word8</a> -> <a href="../base-4.5.1.0/Data-Word.html#t:Word8">Word8</a> -> <a href="../base-4.5.1.0/Data-Word.html#t:Word8">Word8</a>) -> <a href="Data-ByteString-Lazy.html#t:ByteString">ByteString</a> -> <a href="../base-4.5.1.0/Data-Word.html#t:Word8">Word8</a></li><li class="src short"><a href="#v:foldr">foldr</a> :: (<a href="../base-4.5.1.0/Data-Word.html#t:Word8">Word8</a> -> a -> a) -> a -> <a href="Data-ByteString-Lazy.html#t:ByteString">ByteString</a> -> a</li><li class="src short"><a href="#v:foldr1">foldr1</a> :: (<a href="../base-4.5.1.0/Data-Word.html#t:Word8">Word8</a> -> <a href="../base-4.5.1.0/Data-Word.html#t:Word8">Word8</a> -> <a href="../base-4.5.1.0/Data-Word.html#t:Word8">Word8</a>) -> <a href="Data-ByteString-Lazy.html#t:ByteString">ByteString</a> -> <a href="../base-4.5.1.0/Data-Word.html#t:Word8">Word8</a></li><li class="src short"><a href="#v:concat">concat</a> :: [<a href="Data-ByteString-Lazy.html#t:ByteString">ByteString</a>] -> <a href="Data-ByteString-Lazy.html#t:ByteString">ByteString</a></li><li class="src short"><a href="#v:concatMap">concatMap</a> :: (<a href="../base-4.5.1.0/Data-Word.html#t:Word8">Word8</a> -> <a href="Data-ByteString-Lazy.html#t:ByteString">ByteString</a>) -> <a href="Data-ByteString-Lazy.html#t:ByteString">ByteString</a> -> <a href="Data-ByteString-Lazy.html#t:ByteString">ByteString</a></li><li class="src short"><a href="#v:any">any</a> :: (<a href="../base-4.5.1.0/Data-Word.html#t:Word8">Word8</a> -> <a href="../base-4.5.1.0/Data-Bool.html#t:Bool">Bool</a>) -> <a href="Data-ByteString-Lazy.html#t:ByteString">ByteString</a> -> <a href="../base-4.5.1.0/Data-Bool.html#t:Bool">Bool</a></li><li class="src short"><a href="#v:all">all</a> :: (<a href="../base-4.5.1.0/Data-Word.html#t:Word8">Word8</a> -> <a href="../base-4.5.1.0/Data-Bool.html#t:Bool">Bool</a>) -> <a href="Data-ByteString-Lazy.html#t:ByteString">ByteString</a> -> <a href="../base-4.5.1.0/Data-Bool.html#t:Bool">Bool</a></li><li class="src short"><a href="#v:maximum">maximum</a> :: <a href="Data-ByteString-Lazy.html#t:ByteString">ByteString</a> -> <a href="../base-4.5.1.0/Data-Word.html#t:Word8">Word8</a></li><li class="src short"><a href="#v:minimum">minimum</a> :: <a href="Data-ByteString-Lazy.html#t:ByteString">ByteString</a> -> <a href="../base-4.5.1.0/Data-Word.html#t:Word8">Word8</a></li><li class="src short"><a href="#v:scanl">scanl</a> :: (<a href="../base-4.5.1.0/Data-Word.html#t:Word8">Word8</a> -> <a href="../base-4.5.1.0/Data-Word.html#t:Word8">Word8</a> -> <a href="../base-4.5.1.0/Data-Word.html#t:Word8">Word8</a>) -> <a href="../base-4.5.1.0/Data-Word.html#t:Word8">Word8</a> -> <a href="Data-ByteString-Lazy.html#t:ByteString">ByteString</a> -> <a href="Data-ByteString-Lazy.html#t:ByteString">ByteString</a></li><li class="src short"><a href="#v:mapAccumL">mapAccumL</a> :: (acc -> <a href="../base-4.5.1.0/Data-Word.html#t:Word8">Word8</a> -> (acc, <a href="../base-4.5.1.0/Data-Word.html#t:Word8">Word8</a>)) -> acc -> <a href="Data-ByteString-Lazy.html#t:ByteString">ByteString</a> -> (acc, <a href="Data-ByteString-Lazy.html#t:ByteString">ByteString</a>)</li><li class="src short"><a href="#v:mapAccumR">mapAccumR</a> :: (acc -> <a href="../base-4.5.1.0/Data-Word.html#t:Word8">Word8</a> -> (acc, <a href="../base-4.5.1.0/Data-Word.html#t:Word8">Word8</a>)) -> acc -> <a href="Data-ByteString-Lazy.html#t:ByteString">ByteString</a> -> (acc, <a href="Data-ByteString-Lazy.html#t:ByteString">ByteString</a>)</li><li class="src short"><a href="#v:repeat">repeat</a> :: <a href="../base-4.5.1.0/Data-Word.html#t:Word8">Word8</a> -> <a href="Data-ByteString-Lazy.html#t:ByteString">ByteString</a></li><li class="src short"><a href="#v:replicate">replicate</a> :: <a href="../base-4.5.1.0/Data-Int.html#t:Int64">Int64</a> -> <a href="../base-4.5.1.0/Data-Word.html#t:Word8">Word8</a> -> <a href="Data-ByteString-Lazy.html#t:ByteString">ByteString</a></li><li class="src short"><a href="#v:cycle">cycle</a> :: <a href="Data-ByteString-Lazy.html#t:ByteString">ByteString</a> -> <a href="Data-ByteString-Lazy.html#t:ByteString">ByteString</a></li><li class="src short"><a href="#v:iterate">iterate</a> :: (<a href="../base-4.5.1.0/Data-Word.html#t:Word8">Word8</a> -> <a href="../base-4.5.1.0/Data-Word.html#t:Word8">Word8</a>) -> <a href="../base-4.5.1.0/Data-Word.html#t:Word8">Word8</a> -> <a href="Data-ByteString-Lazy.html#t:ByteString">ByteString</a></li><li class="src short"><a href="#v:unfoldr">unfoldr</a> :: (a -> <a href="../base-4.5.1.0/Data-Maybe.html#t:Maybe">Maybe</a> (<a href="../base-4.5.1.0/Data-Word.html#t:Word8">Word8</a>, a)) -> a -> <a href="Data-ByteString-Lazy.html#t:ByteString">ByteString</a></li><li class="src short"><a href="#v:take">take</a> :: <a href="../base-4.5.1.0/Data-Int.html#t:Int64">Int64</a> -> <a href="Data-ByteString-Lazy.html#t:ByteString">ByteString</a> -> <a href="Data-ByteString-Lazy.html#t:ByteString">ByteString</a></li><li class="src short"><a href="#v:drop">drop</a> :: <a href="../base-4.5.1.0/Data-Int.html#t:Int64">Int64</a> -> <a href="Data-ByteString-Lazy.html#t:ByteString">ByteString</a> -> <a href="Data-ByteString-Lazy.html#t:ByteString">ByteString</a></li><li class="src short"><a href="#v:splitAt">splitAt</a> :: <a href="../base-4.5.1.0/Data-Int.html#t:Int64">Int64</a> -> <a href="Data-ByteString-Lazy.html#t:ByteString">ByteString</a> -> (<a href="Data-ByteString-Lazy.html#t:ByteString">ByteString</a>, <a href="Data-ByteString-Lazy.html#t:ByteString">ByteString</a>)</li><li class="src short"><a href="#v:takeWhile">takeWhile</a> :: (<a href="../base-4.5.1.0/Data-Word.html#t:Word8">Word8</a> -> <a href="../base-4.5.1.0/Data-Bool.html#t:Bool">Bool</a>) -> <a href="Data-ByteString-Lazy.html#t:ByteString">ByteString</a> -> <a href="Data-ByteString-Lazy.html#t:ByteString">ByteString</a></li><li class="src short"><a href="#v:dropWhile">dropWhile</a> :: (<a href="../base-4.5.1.0/Data-Word.html#t:Word8">Word8</a> -> <a href="../base-4.5.1.0/Data-Bool.html#t:Bool">Bool</a>) -> <a href="Data-ByteString-Lazy.html#t:ByteString">ByteString</a> -> <a href="Data-ByteString-Lazy.html#t:ByteString">ByteString</a></li><li class="src short"><a href="#v:span">span</a> :: (<a href="../base-4.5.1.0/Data-Word.html#t:Word8">Word8</a> -> <a href="../base-4.5.1.0/Data-Bool.html#t:Bool">Bool</a>) -> <a href="Data-ByteString-Lazy.html#t:ByteString">ByteString</a> -> (<a href="Data-ByteString-Lazy.html#t:ByteString">ByteString</a>, <a href="Data-ByteString-Lazy.html#t:ByteString">ByteString</a>)</li><li class="src short"><a href="#v:break">break</a> :: (<a href="../base-4.5.1.0/Data-Word.html#t:Word8">Word8</a> -> <a href="../base-4.5.1.0/Data-Bool.html#t:Bool">Bool</a>) -> <a href="Data-ByteString-Lazy.html#t:ByteString">ByteString</a> -> (<a href="Data-ByteString-Lazy.html#t:ByteString">ByteString</a>, <a href="Data-ByteString-Lazy.html#t:ByteString">ByteString</a>)</li><li class="src short"><a href="#v:group">group</a> :: <a href="Data-ByteString-Lazy.html#t:ByteString">ByteString</a> -> [<a href="Data-ByteString-Lazy.html#t:ByteString">ByteString</a>]</li><li class="src short"><a href="#v:groupBy">groupBy</a> :: (<a href="../base-4.5.1.0/Data-Word.html#t:Word8">Word8</a> -> <a href="../base-4.5.1.0/Data-Word.html#t:Word8">Word8</a> -> <a href="../base-4.5.1.0/Data-Bool.html#t:Bool">Bool</a>) -> <a href="Data-ByteString-Lazy.html#t:ByteString">ByteString</a> -> [<a href="Data-ByteString-Lazy.html#t:ByteString">ByteString</a>]</li><li class="src short"><a href="#v:inits">inits</a> :: <a href="Data-ByteString-Lazy.html#t:ByteString">ByteString</a> -> [<a href="Data-ByteString-Lazy.html#t:ByteString">ByteString</a>]</li><li class="src short"><a href="#v:tails">tails</a> :: <a href="Data-ByteString-Lazy.html#t:ByteString">ByteString</a> -> [<a href="Data-ByteString-Lazy.html#t:ByteString">ByteString</a>]</li><li class="src short"><a href="#v:split">split</a> :: <a href="../base-4.5.1.0/Data-Word.html#t:Word8">Word8</a> -> <a href="Data-ByteString-Lazy.html#t:ByteString">ByteString</a> -> [<a href="Data-ByteString-Lazy.html#t:ByteString">ByteString</a>]</li><li class="src short"><a href="#v:splitWith">splitWith</a> :: (<a href="../base-4.5.1.0/Data-Word.html#t:Word8">Word8</a> -> <a href="../base-4.5.1.0/Data-Bool.html#t:Bool">Bool</a>) -> <a href="Data-ByteString-Lazy.html#t:ByteString">ByteString</a> -> [<a href="Data-ByteString-Lazy.html#t:ByteString">ByteString</a>]</li><li class="src short"><a href="#v:isPrefixOf">isPrefixOf</a> :: <a href="Data-ByteString-Lazy.html#t:ByteString">ByteString</a> -> <a href="Data-ByteString-Lazy.html#t:ByteString">ByteString</a> -> <a href="../base-4.5.1.0/Data-Bool.html#t:Bool">Bool</a></li><li class="src short"><a href="#v:isSuffixOf">isSuffixOf</a> :: <a href="Data-ByteString-Lazy.html#t:ByteString">ByteString</a> -> <a href="Data-ByteString-Lazy.html#t:ByteString">ByteString</a> -> <a href="../base-4.5.1.0/Data-Bool.html#t:Bool">Bool</a></li><li class="src short"><a href="#v:elem">elem</a> :: <a href="../base-4.5.1.0/Data-Word.html#t:Word8">Word8</a> -> <a href="Data-ByteString-Lazy.html#t:ByteString">ByteString</a> -> <a href="../base-4.5.1.0/Data-Bool.html#t:Bool">Bool</a></li><li class="src short"><a href="#v:notElem">notElem</a> :: <a href="../base-4.5.1.0/Data-Word.html#t:Word8">Word8</a> -> <a href="Data-ByteString-Lazy.html#t:ByteString">ByteString</a> -> <a href="../base-4.5.1.0/Data-Bool.html#t:Bool">Bool</a></li><li class="src short"><a href="#v:find">find</a> :: (<a href="../base-4.5.1.0/Data-Word.html#t:Word8">Word8</a> -> <a href="../base-4.5.1.0/Data-Bool.html#t:Bool">Bool</a>) -> <a href="Data-ByteString-Lazy.html#t:ByteString">ByteString</a> -> <a href="../base-4.5.1.0/Data-Maybe.html#t:Maybe">Maybe</a> <a href="../base-4.5.1.0/Data-Word.html#t:Word8">Word8</a></li><li class="src short"><a href="#v:filter">filter</a> :: (<a href="../base-4.5.1.0/Data-Word.html#t:Word8">Word8</a> -> <a href="../base-4.5.1.0/Data-Bool.html#t:Bool">Bool</a>) -> <a href="Data-ByteString-Lazy.html#t:ByteString">ByteString</a> -> <a href="Data-ByteString-Lazy.html#t:ByteString">ByteString</a></li><li class="src short"><a href="#v:partition">partition</a> :: (<a href="../base-4.5.1.0/Data-Word.html#t:Word8">Word8</a> -> <a href="../base-4.5.1.0/Data-Bool.html#t:Bool">Bool</a>) -> <a href="Data-ByteString-Lazy.html#t:ByteString">ByteString</a> -> (<a href="Data-ByteString-Lazy.html#t:ByteString">ByteString</a>, <a href="Data-ByteString-Lazy.html#t:ByteString">ByteString</a>)</li><li class="src short"><a href="#v:index">index</a> :: <a href="Data-ByteString-Lazy.html#t:ByteString">ByteString</a> -> <a href="../base-4.5.1.0/Data-Int.html#t:Int64">Int64</a> -> <a href="../base-4.5.1.0/Data-Word.html#t:Word8">Word8</a></li><li class="src short"><a href="#v:elemIndex">elemIndex</a> :: <a href="../base-4.5.1.0/Data-Word.html#t:Word8">Word8</a> -> <a href="Data-ByteString-Lazy.html#t:ByteString">ByteString</a> -> <a href="../base-4.5.1.0/Data-Maybe.html#t:Maybe">Maybe</a> <a href="../base-4.5.1.0/Data-Int.html#t:Int64">Int64</a></li><li class="src short"><a href="#v:elemIndices">elemIndices</a> :: <a href="../base-4.5.1.0/Data-Word.html#t:Word8">Word8</a> -> <a href="Data-ByteString-Lazy.html#t:ByteString">ByteString</a> -> [<a href="../base-4.5.1.0/Data-Int.html#t:Int64">Int64</a>]</li><li class="src short"><a href="#v:findIndex">findIndex</a> :: (<a href="../base-4.5.1.0/Data-Word.html#t:Word8">Word8</a> -> <a href="../base-4.5.1.0/Data-Bool.html#t:Bool">Bool</a>) -> <a href="Data-ByteString-Lazy.html#t:ByteString">ByteString</a> -> <a href="../base-4.5.1.0/Data-Maybe.html#t:Maybe">Maybe</a> <a href="../base-4.5.1.0/Data-Int.html#t:Int64">Int64</a></li><li class="src short"><a href="#v:findIndices">findIndices</a> :: (<a href="../base-4.5.1.0/Data-Word.html#t:Word8">Word8</a> -> <a href="../base-4.5.1.0/Data-Bool.html#t:Bool">Bool</a>) -> <a href="Data-ByteString-Lazy.html#t:ByteString">ByteString</a> -> [<a href="../base-4.5.1.0/Data-Int.html#t:Int64">Int64</a>]</li><li class="src short"><a href="#v:count">count</a> :: <a href="../base-4.5.1.0/Data-Word.html#t:Word8">Word8</a> -> <a href="Data-ByteString-Lazy.html#t:ByteString">ByteString</a> -> <a href="../base-4.5.1.0/Data-Int.html#t:Int64">Int64</a></li><li class="src short"><a href="#v:zip">zip</a> :: <a href="Data-ByteString-Lazy.html#t:ByteString">ByteString</a> -> <a href="Data-ByteString-Lazy.html#t:ByteString">ByteString</a> -> [(<a href="../base-4.5.1.0/Data-Word.html#t:Word8">Word8</a>, <a href="../base-4.5.1.0/Data-Word.html#t:Word8">Word8</a>)]</li><li class="src short"><a href="#v:zipWith">zipWith</a> :: (<a href="../base-4.5.1.0/Data-Word.html#t:Word8">Word8</a> -> <a href="../base-4.5.1.0/Data-Word.html#t:Word8">Word8</a> -> a) -> <a href="Data-ByteString-Lazy.html#t:ByteString">ByteString</a> -> <a href="Data-ByteString-Lazy.html#t:ByteString">ByteString</a> -> [a]</li><li class="src short"><a href="#v:unzip">unzip</a> :: [(<a href="../base-4.5.1.0/Data-Word.html#t:Word8">Word8</a>, <a href="../base-4.5.1.0/Data-Word.html#t:Word8">Word8</a>)] -> (<a href="Data-ByteString-Lazy.html#t:ByteString">ByteString</a>, <a href="Data-ByteString-Lazy.html#t:ByteString">ByteString</a>)</li><li class="src short"><a href="#v:copy">copy</a> :: <a href="Data-ByteString-Lazy.html#t:ByteString">ByteString</a> -> <a href="Data-ByteString-Lazy.html#t:ByteString">ByteString</a></li><li class="src short"><a href="#v:getContents">getContents</a> :: <a href="../base-4.5.1.0/System-IO.html#t:IO">IO</a> <a href="Data-ByteString-Lazy.html#t:ByteString">ByteString</a></li><li class="src short"><a href="#v:putStr">putStr</a> :: <a href="Data-ByteString-Lazy.html#t:ByteString">ByteString</a> -> <a href="../base-4.5.1.0/System-IO.html#t:IO">IO</a> <a href="../ghc-prim-0.2.0.0/GHC-Tuple.html#t:-40--41-">()</a></li><li class="src short"><a href="#v:putStrLn">putStrLn</a> :: <a href="Data-ByteString-Lazy.html#t:ByteString">ByteString</a> -> <a href="../base-4.5.1.0/System-IO.html#t:IO">IO</a> <a href="../ghc-prim-0.2.0.0/GHC-Tuple.html#t:-40--41-">()</a></li><li class="src short"><a href="#v:interact">interact</a> :: (<a href="Data-ByteString-Lazy.html#t:ByteString">ByteString</a> -> <a href="Data-ByteString-Lazy.html#t:ByteString">ByteString</a>) -> <a href="../base-4.5.1.0/System-IO.html#t:IO">IO</a> <a href="../ghc-prim-0.2.0.0/GHC-Tuple.html#t:-40--41-">()</a></li><li class="src short"><a href="#v:readFile">readFile</a> :: <a href="../base-4.5.1.0/System-IO.html#t:FilePath">FilePath</a> -> <a href="../base-4.5.1.0/System-IO.html#t:IO">IO</a> <a href="Data-ByteString-Lazy.html#t:ByteString">ByteString</a></li><li class="src short"><a href="#v:writeFile">writeFile</a> :: <a href="../base-4.5.1.0/System-IO.html#t:FilePath">FilePath</a> -> <a href="Data-ByteString-Lazy.html#t:ByteString">ByteString</a> -> <a href="../base-4.5.1.0/System-IO.html#t:IO">IO</a> <a href="../ghc-prim-0.2.0.0/GHC-Tuple.html#t:-40--41-">()</a></li><li class="src short"><a href="#v:appendFile">appendFile</a> :: <a href="../base-4.5.1.0/System-IO.html#t:FilePath">FilePath</a> -> <a href="Data-ByteString-Lazy.html#t:ByteString">ByteString</a> -> <a href="../base-4.5.1.0/System-IO.html#t:IO">IO</a> <a href="../ghc-prim-0.2.0.0/GHC-Tuple.html#t:-40--41-">()</a></li><li class="src short"><a href="#v:hGetContents">hGetContents</a> :: <a href="../base-4.5.1.0/GHC-IO-Handle.html#t:Handle">Handle</a> -> <a href="../base-4.5.1.0/System-IO.html#t:IO">IO</a> <a href="Data-ByteString-Lazy.html#t:ByteString">ByteString</a></li><li class="src short"><a href="#v:hGet">hGet</a> :: <a href="../base-4.5.1.0/GHC-IO-Handle.html#t:Handle">Handle</a> -> <a href="../base-4.5.1.0/Data-Int.html#t:Int">Int</a> -> <a href="../base-4.5.1.0/System-IO.html#t:IO">IO</a> <a href="Data-ByteString-Lazy.html#t:ByteString">ByteString</a></li><li class="src short"><a href="#v:hGetNonBlocking">hGetNonBlocking</a> :: <a href="../base-4.5.1.0/GHC-IO-Handle.html#t:Handle">Handle</a> -> <a href="../base-4.5.1.0/Data-Int.html#t:Int">Int</a> -> <a href="../base-4.5.1.0/System-IO.html#t:IO">IO</a> <a href="Data-ByteString-Lazy.html#t:ByteString">ByteString</a></li><li class="src short"><a href="#v:hPut">hPut</a> :: <a href="../base-4.5.1.0/GHC-IO-Handle.html#t:Handle">Handle</a> -> <a href="Data-ByteString-Lazy.html#t:ByteString">ByteString</a> -> <a href="../base-4.5.1.0/System-IO.html#t:IO">IO</a> <a href="../ghc-prim-0.2.0.0/GHC-Tuple.html#t:-40--41-">()</a></li><li class="src short"><a href="#v:hPutNonBlocking">hPutNonBlocking</a> :: <a href="../base-4.5.1.0/GHC-IO-Handle.html#t:Handle">Handle</a> -> <a href="Data-ByteString-Lazy.html#t:ByteString">ByteString</a> -> <a href="../base-4.5.1.0/System-IO.html#t:IO">IO</a> <a href="Data-ByteString-Lazy.html#t:ByteString">ByteString</a></li><li class="src short"><a href="#v:hPutStr">hPutStr</a> :: <a href="../base-4.5.1.0/GHC-IO-Handle.html#t:Handle">Handle</a> -> <a href="Data-ByteString-Lazy.html#t:ByteString">ByteString</a> -> <a href="../base-4.5.1.0/System-IO.html#t:IO">IO</a> <a href="../ghc-prim-0.2.0.0/GHC-Tuple.html#t:-40--41-">()</a></li></ul></div><div id="interface"><h1 id="g:1">The <code>ByteString</code> type
</h1><div class="top"><p class="src"><span class="keyword">data</span> <a name="t:ByteString" class="def">ByteString</a> </p><div class="doc"><p>A space-efficient representation of a Word8 vector, supporting many
efficient operations. A <code><a href="Data-ByteString-Lazy.html#t:ByteString">ByteString</a></code> contains 8-bit characters only.
</p><p>Instances of Eq, Ord, Read, Show, Data, Typeable
</p></div><div class="subs instances"><p id="control.i:ByteString" class="caption collapser" onclick="toggleSection('i:ByteString')">Instances</p><div id="section.i:ByteString" class="show"><table><tr><td class="src"><a href="../base-4.5.1.0/Data-Eq.html#t:Eq">Eq</a> <a href="Data-ByteString-Lazy.html#t:ByteString">ByteString</a></td><td class="doc empty"> </td></tr><tr><td class="src"><a href="../base-4.5.1.0/Data-Data.html#t:Data">Data</a> <a href="Data-ByteString-Lazy.html#t:ByteString">ByteString</a></td><td class="doc empty"> </td></tr><tr><td class="src"><a href="../base-4.5.1.0/Data-Ord.html#t:Ord">Ord</a> <a href="Data-ByteString-Lazy.html#t:ByteString">ByteString</a></td><td class="doc empty"> </td></tr><tr><td class="src"><a href="../base-4.5.1.0/Text-Read.html#t:Read">Read</a> <a href="Data-ByteString-Lazy.html#t:ByteString">ByteString</a></td><td class="doc empty"> </td></tr><tr><td class="src"><a href="../base-4.5.1.0/Text-Show.html#t:Show">Show</a> <a href="Data-ByteString-Lazy.html#t:ByteString">ByteString</a></td><td class="doc empty"> </td></tr><tr><td class="src"><a href="../base-4.5.1.0/Data-Typeable-Internal.html#t:Typeable">Typeable</a> <a href="Data-ByteString-Lazy.html#t:ByteString">ByteString</a></td><td class="doc empty"> </td></tr><tr><td class="src"><a href="../base-4.5.1.0/Data-String.html#t:IsString">IsString</a> <a href="Data-ByteString-Lazy.html#t:ByteString">ByteString</a></td><td class="doc empty"> </td></tr><tr><td class="src"><a href="../base-4.5.1.0/Data-Monoid.html#t:Monoid">Monoid</a> <a href="Data-ByteString-Lazy.html#t:ByteString">ByteString</a></td><td class="doc empty"> </td></tr></table></div></div></div><h1 id="g:2">Introducing and eliminating <code><a href="Data-ByteString-Lazy.html#t:ByteString">ByteString</a></code>s
</h1><div class="top"><p class="src"><a name="v:empty" class="def">empty</a> :: <a href="Data-ByteString-Lazy.html#t:ByteString">ByteString</a></p><div class="doc"><p><em>O(1)</em> The empty <code><a href="Data-ByteString-Lazy.html#t:ByteString">ByteString</a></code>
</p></div></div><div class="top"><p class="src"><a name="v:singleton" class="def">singleton</a> :: <a href="../base-4.5.1.0/Data-Word.html#t:Word8">Word8</a> -> <a href="Data-ByteString-Lazy.html#t:ByteString">ByteString</a></p><div class="doc"><p><em>O(1)</em> Convert a <code><a href="../base-4.5.1.0/Data-Word.html#t:Word8">Word8</a></code> into a <code><a href="Data-ByteString-Lazy.html#t:ByteString">ByteString</a></code>
</p></div></div><div class="top"><p class="src"><a name="v:pack" class="def">pack</a> :: [<a href="../base-4.5.1.0/Data-Word.html#t:Word8">Word8</a>] -> <a href="Data-ByteString-Lazy.html#t:ByteString">ByteString</a></p><div class="doc"><p><em>O(n)</em> Convert a '[Word8]' into a <code><a href="Data-ByteString-Lazy.html#t:ByteString">ByteString</a></code>.
</p></div></div><div class="top"><p class="src"><a name="v:unpack" class="def">unpack</a> :: <a href="Data-ByteString-Lazy.html#t:ByteString">ByteString</a> -> [<a href="../base-4.5.1.0/Data-Word.html#t:Word8">Word8</a>]</p><div class="doc"><p><em>O(n)</em> Converts a <code><a href="Data-ByteString-Lazy.html#t:ByteString">ByteString</a></code> to a '[Word8]'.
</p></div></div><div class="top"><p class="src"><a name="v:fromChunks" class="def">fromChunks</a> :: [<a href="Data-ByteString.html#t:ByteString">ByteString</a>] -> <a href="Data-ByteString-Lazy.html#t:ByteString">ByteString</a></p><div class="doc"><p><em>O(c)</em> Convert a list of strict <code><a href="Data-ByteString-Lazy.html#t:ByteString">ByteString</a></code> into a lazy <code><a href="Data-ByteString-Lazy.html#t:ByteString">ByteString</a></code>
</p></div></div><div class="top"><p class="src"><a name="v:toChunks" class="def">toChunks</a> :: <a href="Data-ByteString-Lazy.html#t:ByteString">ByteString</a> -> [<a href="Data-ByteString.html#t:ByteString">ByteString</a>]</p><div class="doc"><p><em>O(n)</em> Convert a lazy <code><a href="Data-ByteString-Lazy.html#t:ByteString">ByteString</a></code> into a list of strict <code><a href="Data-ByteString-Lazy.html#t:ByteString">ByteString</a></code>
</p></div></div><h1 id="g:3">Basic interface
</h1><div class="top"><p class="src"><a name="v:cons" class="def">cons</a> :: <a href="../base-4.5.1.0/Data-Word.html#t:Word8">Word8</a> -> <a href="Data-ByteString-Lazy.html#t:ByteString">ByteString</a> -> <a href="Data-ByteString-Lazy.html#t:ByteString">ByteString</a></p><div class="doc"><p><em>O(1)</em> <code><a href="Data-ByteString-Lazy.html#v:cons">cons</a></code> is analogous to '(:)' for lists.
</p></div></div><div class="top"><p class="src"><a name="v:cons-39-" class="def">cons'</a> :: <a href="../base-4.5.1.0/Data-Word.html#t:Word8">Word8</a> -> <a href="Data-ByteString-Lazy.html#t:ByteString">ByteString</a> -> <a href="Data-ByteString-Lazy.html#t:ByteString">ByteString</a></p><div class="doc"><p><em>O(1)</em> Unlike <code><a href="Data-ByteString-Lazy.html#v:cons">cons</a></code>, 'cons\'' is
strict in the ByteString that we are consing onto. More precisely, it forces
the head and the first chunk. It does this because, for space efficiency, it
may coalesce the new byte onto the first 'chunk' rather than starting a
new 'chunk'.
</p><p>So that means you can't use a lazy recursive contruction like this:
</p><pre> let xs = cons\' c xs in xs
</pre><p>You can however use <code><a href="Data-ByteString-Lazy.html#v:cons">cons</a></code>, as well as <code><a href="Data-ByteString-Lazy.html#v:repeat">repeat</a></code> and <code><a href="Data-ByteString-Lazy.html#v:cycle">cycle</a></code>, to build
infinite lazy ByteStrings.
</p></div></div><div class="top"><p class="src"><a name="v:snoc" class="def">snoc</a> :: <a href="Data-ByteString-Lazy.html#t:ByteString">ByteString</a> -> <a href="../base-4.5.1.0/Data-Word.html#t:Word8">Word8</a> -> <a href="Data-ByteString-Lazy.html#t:ByteString">ByteString</a></p><div class="doc"><p><em>O(n\</em>c)/ Append a byte to the end of a <code><a href="Data-ByteString-Lazy.html#t:ByteString">ByteString</a></code>
</p></div></div><div class="top"><p class="src"><a name="v:append" class="def">append</a> :: <a href="Data-ByteString-Lazy.html#t:ByteString">ByteString</a> -> <a href="Data-ByteString-Lazy.html#t:ByteString">ByteString</a> -> <a href="Data-ByteString-Lazy.html#t:ByteString">ByteString</a></p><div class="doc"><p><em>O(n\</em>c)/ Append two ByteStrings
</p></div></div><div class="top"><p class="src"><a name="v:head" class="def">head</a> :: <a href="Data-ByteString-Lazy.html#t:ByteString">ByteString</a> -> <a href="../base-4.5.1.0/Data-Word.html#t:Word8">Word8</a></p><div class="doc"><p><em>O(1)</em> Extract the first element of a ByteString, which must be non-empty.
</p></div></div><div class="top"><p class="src"><a name="v:uncons" class="def">uncons</a> :: <a href="Data-ByteString-Lazy.html#t:ByteString">ByteString</a> -> <a href="../base-4.5.1.0/Data-Maybe.html#t:Maybe">Maybe</a> (<a href="../base-4.5.1.0/Data-Word.html#t:Word8">Word8</a>, <a href="Data-ByteString-Lazy.html#t:ByteString">ByteString</a>)</p><div class="doc"><p><em>O(1)</em> Extract the head and tail of a ByteString, returning Nothing
if it is empty.
</p></div></div><div class="top"><p class="src"><a name="v:last" class="def">last</a> :: <a href="Data-ByteString-Lazy.html#t:ByteString">ByteString</a> -> <a href="../base-4.5.1.0/Data-Word.html#t:Word8">Word8</a></p><div class="doc"><p><em>O(n\</em>c)/ Extract the last element of a ByteString, 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 href="Data-ByteString-Lazy.html#t:ByteString">ByteString</a> -> <a href="Data-ByteString-Lazy.html#t:ByteString">ByteString</a></p><div class="doc"><p><em>O(1)</em> Extract the elements after the head of a ByteString, which must be
non-empty.
</p></div></div><div class="top"><p class="src"><a name="v:init" class="def">init</a> :: <a href="Data-ByteString-Lazy.html#t:ByteString">ByteString</a> -> <a href="Data-ByteString-Lazy.html#t:ByteString">ByteString</a></p><div class="doc"><p><em>O(n\</em>c)/ Return all the elements of a <code><a href="Data-ByteString-Lazy.html#t:ByteString">ByteString</a></code> except the last one.
</p></div></div><div class="top"><p class="src"><a name="v:null" class="def">null</a> :: <a href="Data-ByteString-Lazy.html#t:ByteString">ByteString</a> -> <a href="../base-4.5.1.0/Data-Bool.html#t:Bool">Bool</a></p><div class="doc"><p><em>O(1)</em> Test whether a ByteString is empty.
</p></div></div><div class="top"><p class="src"><a name="v:length" class="def">length</a> :: <a href="Data-ByteString-Lazy.html#t:ByteString">ByteString</a> -> <a href="../base-4.5.1.0/Data-Int.html#t:Int64">Int64</a></p><div class="doc"><p><em>O(n\</em>c)/ <code><a href="Data-ByteString-Lazy.html#v:length">length</a></code> returns the length of a ByteString as an <code><a href="../base-4.5.1.0/Data-Int.html#t:Int64">Int64</a></code>
</p></div></div><h1 id="g:4">Transforming ByteStrings
</h1><div class="top"><p class="src"><a name="v:map" class="def">map</a> :: (<a href="../base-4.5.1.0/Data-Word.html#t:Word8">Word8</a> -> <a href="../base-4.5.1.0/Data-Word.html#t:Word8">Word8</a>) -> <a href="Data-ByteString-Lazy.html#t:ByteString">ByteString</a> -> <a href="Data-ByteString-Lazy.html#t:ByteString">ByteString</a></p><div class="doc"><p><em>O(n)</em> <code><a href="Data-ByteString-Lazy.html#v:map">map</a></code> <code>f xs</code> is the ByteString obtained by applying <code>f</code> to each
element of <code>xs</code>.
</p></div></div><div class="top"><p class="src"><a name="v:reverse" class="def">reverse</a> :: <a href="Data-ByteString-Lazy.html#t:ByteString">ByteString</a> -> <a href="Data-ByteString-Lazy.html#t:ByteString">ByteString</a></p><div class="doc"><p><em>O(n)</em> <code><a href="Data-ByteString-Lazy.html#v:reverse">reverse</a></code> <code>xs</code> returns the elements of <code>xs</code> in reverse order.
</p></div></div><div class="top"><p class="src"><a name="v:intersperse" class="def">intersperse</a> :: <a href="../base-4.5.1.0/Data-Word.html#t:Word8">Word8</a> -> <a href="Data-ByteString-Lazy.html#t:ByteString">ByteString</a> -> <a href="Data-ByteString-Lazy.html#t:ByteString">ByteString</a></p><div class="doc"><p>The <code><a href="Data-ByteString-Lazy.html#v:intersperse">intersperse</a></code> function takes a <code><a href="../base-4.5.1.0/Data-Word.html#t:Word8">Word8</a></code> and a <code><a href="Data-ByteString-Lazy.html#t:ByteString">ByteString</a></code> and
`intersperses' that byte between the elements of the <code><a href="Data-ByteString-Lazy.html#t:ByteString">ByteString</a></code>.
It is analogous to the intersperse function on Lists.
</p></div></div><div class="top"><p class="src"><a name="v:intercalate" class="def">intercalate</a> :: <a href="Data-ByteString-Lazy.html#t:ByteString">ByteString</a> -> [<a href="Data-ByteString-Lazy.html#t:ByteString">ByteString</a>] -> <a href="Data-ByteString-Lazy.html#t:ByteString">ByteString</a></p><div class="doc"><p><em>O(n)</em> The <code><a href="Data-ByteString-Lazy.html#v:intercalate">intercalate</a></code> function takes a <code><a href="Data-ByteString-Lazy.html#t:ByteString">ByteString</a></code> and a list of
<code><a href="Data-ByteString-Lazy.html#t:ByteString">ByteString</a></code>s and concatenates the list after interspersing the first
argument between each element of the list.
</p></div></div><div class="top"><p class="src"><a name="v:transpose" class="def">transpose</a> :: [<a href="Data-ByteString-Lazy.html#t:ByteString">ByteString</a>] -> [<a href="Data-ByteString-Lazy.html#t:ByteString">ByteString</a>]</p><div class="doc"><p>The <code><a href="Data-ByteString-Lazy.html#v:transpose">transpose</a></code> function transposes the rows and columns of its
<code><a href="Data-ByteString-Lazy.html#t:ByteString">ByteString</a></code> argument.
</p></div></div><h1 id="g:5">Reducing <code><a href="Data-ByteString-Lazy.html#t:ByteString">ByteString</a></code>s (folds)
</h1><div class="top"><p class="src"><a name="v:foldl" class="def">foldl</a> :: (a -> <a href="../base-4.5.1.0/Data-Word.html#t:Word8">Word8</a> -> a) -> a -> <a href="Data-ByteString-Lazy.html#t:ByteString">ByteString</a> -> a</p><div class="doc"><p><code><a href="Data-ByteString-Lazy.html#v:foldl">foldl</a></code>, applied to a binary operator, a starting value (typically
the left-identity of the operator), and a ByteString, reduces the
ByteString using the binary operator, from left to right.
</p></div></div><div class="top"><p class="src"><a name="v:foldl-39-" class="def">foldl'</a> :: (a -> <a href="../base-4.5.1.0/Data-Word.html#t:Word8">Word8</a> -> a) -> a -> <a href="Data-ByteString-Lazy.html#t:ByteString">ByteString</a> -> a</p><div class="doc"><p>'foldl\'' is like <code><a href="Data-ByteString-Lazy.html#v:foldl">foldl</a></code>, but strict in the accumulator.
</p></div></div><div class="top"><p class="src"><a name="v:foldl1" class="def">foldl1</a> :: (<a href="../base-4.5.1.0/Data-Word.html#t:Word8">Word8</a> -> <a href="../base-4.5.1.0/Data-Word.html#t:Word8">Word8</a> -> <a href="../base-4.5.1.0/Data-Word.html#t:Word8">Word8</a>) -> <a href="Data-ByteString-Lazy.html#t:ByteString">ByteString</a> -> <a href="../base-4.5.1.0/Data-Word.html#t:Word8">Word8</a></p><div class="doc"><p><code><a href="Data-ByteString-Lazy.html#v:foldl1">foldl1</a></code> is a variant of <code><a href="Data-ByteString-Lazy.html#v:foldl">foldl</a></code> that has no starting value
argument, and thus must be applied to non-empty <code>ByteStrings</code>.
This function is subject to array fusion.
</p></div></div><div class="top"><p class="src"><a name="v:foldl1-39-" class="def">foldl1'</a> :: (<a href="../base-4.5.1.0/Data-Word.html#t:Word8">Word8</a> -> <a href="../base-4.5.1.0/Data-Word.html#t:Word8">Word8</a> -> <a href="../base-4.5.1.0/Data-Word.html#t:Word8">Word8</a>) -> <a href="Data-ByteString-Lazy.html#t:ByteString">ByteString</a> -> <a href="../base-4.5.1.0/Data-Word.html#t:Word8">Word8</a></p><div class="doc"><p>'foldl1\'' is like <code><a href="Data-ByteString-Lazy.html#v:foldl1">foldl1</a></code>, but strict in the accumulator.
</p></div></div><div class="top"><p class="src"><a name="v:foldr" class="def">foldr</a> :: (<a href="../base-4.5.1.0/Data-Word.html#t:Word8">Word8</a> -> a -> a) -> a -> <a href="Data-ByteString-Lazy.html#t:ByteString">ByteString</a> -> a</p><div class="doc"><p><code><a href="Data-ByteString-Lazy.html#v:foldr">foldr</a></code>, applied to a binary operator, a starting value
(typically the right-identity of the operator), and a ByteString,
reduces the ByteString using the binary operator, from right to left.
</p></div></div><div class="top"><p class="src"><a name="v:foldr1" class="def">foldr1</a> :: (<a href="../base-4.5.1.0/Data-Word.html#t:Word8">Word8</a> -> <a href="../base-4.5.1.0/Data-Word.html#t:Word8">Word8</a> -> <a href="../base-4.5.1.0/Data-Word.html#t:Word8">Word8</a>) -> <a href="Data-ByteString-Lazy.html#t:ByteString">ByteString</a> -> <a href="../base-4.5.1.0/Data-Word.html#t:Word8">Word8</a></p><div class="doc"><p><code><a href="Data-ByteString-Lazy.html#v:foldr1">foldr1</a></code> is a variant of <code><a href="Data-ByteString-Lazy.html#v:foldr">foldr</a></code> that has no starting value argument,
and thus must be applied to non-empty <code><a href="Data-ByteString-Lazy.html#t:ByteString">ByteString</a></code>s
</p></div></div><h2 id="g:6">Special folds
</h2><div class="top"><p class="src"><a name="v:concat" class="def">concat</a> :: [<a href="Data-ByteString-Lazy.html#t:ByteString">ByteString</a>] -> <a href="Data-ByteString-Lazy.html#t:ByteString">ByteString</a></p><div class="doc"><p><em>O(n)</em> Concatenate a list of ByteStrings.
</p></div></div><div class="top"><p class="src"><a name="v:concatMap" class="def">concatMap</a> :: (<a href="../base-4.5.1.0/Data-Word.html#t:Word8">Word8</a> -> <a href="Data-ByteString-Lazy.html#t:ByteString">ByteString</a>) -> <a href="Data-ByteString-Lazy.html#t:ByteString">ByteString</a> -> <a href="Data-ByteString-Lazy.html#t:ByteString">ByteString</a></p><div class="doc"><p>Map a function over a <code><a href="Data-ByteString-Lazy.html#t:ByteString">ByteString</a></code> and concatenate the results
</p></div></div><div class="top"><p class="src"><a name="v:any" class="def">any</a> :: (<a href="../base-4.5.1.0/Data-Word.html#t:Word8">Word8</a> -> <a href="../base-4.5.1.0/Data-Bool.html#t:Bool">Bool</a>) -> <a href="Data-ByteString-Lazy.html#t:ByteString">ByteString</a> -> <a href="../base-4.5.1.0/Data-Bool.html#t:Bool">Bool</a></p><div class="doc"><p><em>O(n)</em> Applied to a predicate and a ByteString, <code><a href="Data-ByteString-Lazy.html#v:any">any</a></code> determines if
any element of the <code><a href="Data-ByteString-Lazy.html#t:ByteString">ByteString</a></code> satisfies the predicate.
</p></div></div><div class="top"><p class="src"><a name="v:all" class="def">all</a> :: (<a href="../base-4.5.1.0/Data-Word.html#t:Word8">Word8</a> -> <a href="../base-4.5.1.0/Data-Bool.html#t:Bool">Bool</a>) -> <a href="Data-ByteString-Lazy.html#t:ByteString">ByteString</a> -> <a href="../base-4.5.1.0/Data-Bool.html#t:Bool">Bool</a></p><div class="doc"><p><em>O(n)</em> Applied to a predicate and a <code><a href="Data-ByteString-Lazy.html#t:ByteString">ByteString</a></code>, <code><a href="Data-ByteString-Lazy.html#v:all">all</a></code> determines
if all elements of the <code><a href="Data-ByteString-Lazy.html#t:ByteString">ByteString</a></code> satisfy the predicate.
</p></div></div><div class="top"><p class="src"><a name="v:maximum" class="def">maximum</a> :: <a href="Data-ByteString-Lazy.html#t:ByteString">ByteString</a> -> <a href="../base-4.5.1.0/Data-Word.html#t:Word8">Word8</a></p><div class="doc"><p><em>O(n)</em> <code><a href="Data-ByteString-Lazy.html#v:maximum">maximum</a></code> returns the maximum value from a <code><a href="Data-ByteString-Lazy.html#t:ByteString">ByteString</a></code>
</p></div></div><div class="top"><p class="src"><a name="v:minimum" class="def">minimum</a> :: <a href="Data-ByteString-Lazy.html#t:ByteString">ByteString</a> -> <a href="../base-4.5.1.0/Data-Word.html#t:Word8">Word8</a></p><div class="doc"><p><em>O(n)</em> <code><a href="Data-ByteString-Lazy.html#v:minimum">minimum</a></code> returns the minimum value from a <code><a href="Data-ByteString-Lazy.html#t:ByteString">ByteString</a></code>
</p></div></div><h1 id="g:7">Building ByteStrings
</h1><h2 id="g:8">Scans
</h2><div class="top"><p class="src"><a name="v:scanl" class="def">scanl</a> :: (<a href="../base-4.5.1.0/Data-Word.html#t:Word8">Word8</a> -> <a href="../base-4.5.1.0/Data-Word.html#t:Word8">Word8</a> -> <a href="../base-4.5.1.0/Data-Word.html#t:Word8">Word8</a>) -> <a href="../base-4.5.1.0/Data-Word.html#t:Word8">Word8</a> -> <a href="Data-ByteString-Lazy.html#t:ByteString">ByteString</a> -> <a href="Data-ByteString-Lazy.html#t:ByteString">ByteString</a></p><div class="doc"><p><code><a href="Data-ByteString-Lazy.html#v:scanl">scanl</a></code> is similar to <code><a href="Data-ByteString-Lazy.html#v:foldl">foldl</a></code>, but returns a list of successive
reduced values from the left. This function will fuse.
</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><h2 id="g:9">Accumulating maps
</h2><div class="top"><p class="src"><a name="v:mapAccumL" class="def">mapAccumL</a> :: (acc -> <a href="../base-4.5.1.0/Data-Word.html#t:Word8">Word8</a> -> (acc, <a href="../base-4.5.1.0/Data-Word.html#t:Word8">Word8</a>)) -> acc -> <a href="Data-ByteString-Lazy.html#t:ByteString">ByteString</a> -> (acc, <a href="Data-ByteString-Lazy.html#t:ByteString">ByteString</a>)</p><div class="doc"><p>The <code><a href="Data-ByteString-Lazy.html#v:mapAccumL">mapAccumL</a></code> function behaves like a combination of <code><a href="Data-ByteString-Lazy.html#v:map">map</a></code> and
<code><a href="Data-ByteString-Lazy.html#v:foldl">foldl</a></code>; it applies a function to each element of a ByteString,
passing an accumulating parameter from left to right, and returning a
final value of this accumulator together with the new ByteString.
</p></div></div><div class="top"><p class="src"><a name="v:mapAccumR" class="def">mapAccumR</a> :: (acc -> <a href="../base-4.5.1.0/Data-Word.html#t:Word8">Word8</a> -> (acc, <a href="../base-4.5.1.0/Data-Word.html#t:Word8">Word8</a>)) -> acc -> <a href="Data-ByteString-Lazy.html#t:ByteString">ByteString</a> -> (acc, <a href="Data-ByteString-Lazy.html#t:ByteString">ByteString</a>)</p><div class="doc"><p>The <code><a href="Data-ByteString-Lazy.html#v:mapAccumR">mapAccumR</a></code> function behaves like a combination of <code><a href="Data-ByteString-Lazy.html#v:map">map</a></code> and
<code><a href="Data-ByteString-Lazy.html#v:foldr">foldr</a></code>; it applies a function to each element of a ByteString,
passing an accumulating parameter from right to left, and returning a
final value of this accumulator together with the new ByteString.
</p></div></div><h2 id="g:10">Infinite ByteStrings
</h2><div class="top"><p class="src"><a name="v:repeat" class="def">repeat</a> :: <a href="../base-4.5.1.0/Data-Word.html#t:Word8">Word8</a> -> <a href="Data-ByteString-Lazy.html#t:ByteString">ByteString</a></p><div class="doc"><p><code><code><a href="Data-ByteString-Lazy.html#v:repeat">repeat</a></code> x</code> is an infinite ByteString, 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="../base-4.5.1.0/Data-Int.html#t:Int64">Int64</a> -> <a href="../base-4.5.1.0/Data-Word.html#t:Word8">Word8</a> -> <a href="Data-ByteString-Lazy.html#t:ByteString">ByteString</a></p><div class="doc"><p><em>O(n)</em> <code><code><a href="Data-ByteString-Lazy.html#v:replicate">replicate</a></code> n x</code> is a ByteString of length <code>n</code> with <code>x</code>
the value of every element.
</p></div></div><div class="top"><p class="src"><a name="v:cycle" class="def">cycle</a> :: <a href="Data-ByteString-Lazy.html#t:ByteString">ByteString</a> -> <a href="Data-ByteString-Lazy.html#t:ByteString">ByteString</a></p><div class="doc"><p><code><a href="Data-ByteString-Lazy.html#v:cycle">cycle</a></code> ties a finite ByteString into a circular one, or equivalently,
the infinite repetition of the original ByteString.
</p></div></div><div class="top"><p class="src"><a name="v:iterate" class="def">iterate</a> :: (<a href="../base-4.5.1.0/Data-Word.html#t:Word8">Word8</a> -> <a href="../base-4.5.1.0/Data-Word.html#t:Word8">Word8</a>) -> <a href="../base-4.5.1.0/Data-Word.html#t:Word8">Word8</a> -> <a href="Data-ByteString-Lazy.html#t:ByteString">ByteString</a></p><div class="doc"><p><code><code><a href="Data-ByteString-Lazy.html#v:iterate">iterate</a></code> f x</code> returns an infinite ByteString 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><h2 id="g:11">Unfolding ByteStrings
</h2><div class="top"><p class="src"><a name="v:unfoldr" class="def">unfoldr</a> :: (a -> <a href="../base-4.5.1.0/Data-Maybe.html#t:Maybe">Maybe</a> (<a href="../base-4.5.1.0/Data-Word.html#t:Word8">Word8</a>, a)) -> a -> <a href="Data-ByteString-Lazy.html#t:ByteString">ByteString</a></p><div class="doc"><p><em>O(n)</em> The <code><a href="Data-ByteString-Lazy.html#v:unfoldr">unfoldr</a></code> function is analogous to the List 'unfoldr'.
<code><a href="Data-ByteString-Lazy.html#v:unfoldr">unfoldr</a></code> builds a ByteString from a seed value. The function takes
the element and returns <code><a href="../base-4.5.1.0/Data-Maybe.html#v:Nothing">Nothing</a></code> if it is done producing the
ByteString or returns <code><a href="../base-4.5.1.0/Data-Maybe.html#v:Just">Just</a></code> <code>(a,b)</code>, in which case, <code>a</code> is a
prepending to the ByteString and <code>b</code> is used as the next element in a
recursive call.
</p></div></div><h1 id="g:12">Substrings
</h1><h2 id="g:13">Breaking strings
</h2><div class="top"><p class="src"><a name="v:take" class="def">take</a> :: <a href="../base-4.5.1.0/Data-Int.html#t:Int64">Int64</a> -> <a href="Data-ByteString-Lazy.html#t:ByteString">ByteString</a> -> <a href="Data-ByteString-Lazy.html#t:ByteString">ByteString</a></p><div class="doc"><p><em>O(n\</em>c)/ <code><a href="Data-ByteString-Lazy.html#v:take">take</a></code> <code>n</code>, applied to a ByteString <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="Data-ByteString-Lazy.html#v:length">length</a></code> xs</code>.
</p></div></div><div class="top"><p class="src"><a name="v:drop" class="def">drop</a> :: <a href="../base-4.5.1.0/Data-Int.html#t:Int64">Int64</a> -> <a href="Data-ByteString-Lazy.html#t:ByteString">ByteString</a> -> <a href="Data-ByteString-Lazy.html#t:ByteString">ByteString</a></p><div class="doc"><p><em>O(n\</em>c)/ <code><a href="Data-ByteString-Lazy.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="Data-ByteString-Lazy.html#v:length">length</a></code> xs</code>.
</p></div></div><div class="top"><p class="src"><a name="v:splitAt" class="def">splitAt</a> :: <a href="../base-4.5.1.0/Data-Int.html#t:Int64">Int64</a> -> <a href="Data-ByteString-Lazy.html#t:ByteString">ByteString</a> -> (<a href="Data-ByteString-Lazy.html#t:ByteString">ByteString</a>, <a href="Data-ByteString-Lazy.html#t:ByteString">ByteString</a>)</p><div class="doc"><p><em>O(n\</em>c)/ <code><a href="Data-ByteString-Lazy.html#v:splitAt">splitAt</a></code> <code>n xs</code> is equivalent to <code>(<code><a href="Data-ByteString-Lazy.html#v:take">take</a></code> n xs, <code><a href="Data-ByteString-Lazy.html#v:drop">drop</a></code> n xs)</code>.
</p></div></div><div class="top"><p class="src"><a name="v:takeWhile" class="def">takeWhile</a> :: (<a href="../base-4.5.1.0/Data-Word.html#t:Word8">Word8</a> -> <a href="../base-4.5.1.0/Data-Bool.html#t:Bool">Bool</a>) -> <a href="Data-ByteString-Lazy.html#t:ByteString">ByteString</a> -> <a href="Data-ByteString-Lazy.html#t:ByteString">ByteString</a></p><div class="doc"><p><code><a href="Data-ByteString-Lazy.html#v:takeWhile">takeWhile</a></code>, applied to a predicate <code>p</code> and a ByteString <code>xs</code>,
returns the longest prefix (possibly empty) of <code>xs</code> of elements that
satisfy <code>p</code>.
</p></div></div><div class="top"><p class="src"><a name="v:dropWhile" class="def">dropWhile</a> :: (<a href="../base-4.5.1.0/Data-Word.html#t:Word8">Word8</a> -> <a href="../base-4.5.1.0/Data-Bool.html#t:Bool">Bool</a>) -> <a href="Data-ByteString-Lazy.html#t:ByteString">ByteString</a> -> <a href="Data-ByteString-Lazy.html#t:ByteString">ByteString</a></p><div class="doc"><p><code><a href="Data-ByteString-Lazy.html#v:dropWhile">dropWhile</a></code> <code>p xs</code> returns the suffix remaining after <code><a href="Data-ByteString-Lazy.html#v:takeWhile">takeWhile</a></code> <code>p xs</code>.
</p></div></div><div class="top"><p class="src"><a name="v:span" class="def">span</a> :: (<a href="../base-4.5.1.0/Data-Word.html#t:Word8">Word8</a> -> <a href="../base-4.5.1.0/Data-Bool.html#t:Bool">Bool</a>) -> <a href="Data-ByteString-Lazy.html#t:ByteString">ByteString</a> -> (<a href="Data-ByteString-Lazy.html#t:ByteString">ByteString</a>, <a href="Data-ByteString-Lazy.html#t:ByteString">ByteString</a>)</p><div class="doc"><p><code><a href="Data-ByteString-Lazy.html#v:span">span</a></code> <code>p xs</code> breaks the ByteString into two segments. It is
equivalent to <code>(<code><a href="Data-ByteString-Lazy.html#v:takeWhile">takeWhile</a></code> p xs, <code><a href="Data-ByteString-Lazy.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 href="../base-4.5.1.0/Data-Word.html#t:Word8">Word8</a> -> <a href="../base-4.5.1.0/Data-Bool.html#t:Bool">Bool</a>) -> <a href="Data-ByteString-Lazy.html#t:ByteString">ByteString</a> -> (<a href="Data-ByteString-Lazy.html#t:ByteString">ByteString</a>, <a href="Data-ByteString-Lazy.html#t:ByteString">ByteString</a>)</p><div class="doc"><p><code><a href="Data-ByteString-Lazy.html#v:break">break</a></code> <code>p</code> is equivalent to <code><code><a href="Data-ByteString-Lazy.html#v:span">span</a></code> (<code><a href="../base-4.5.1.0/Data-Bool.html#v:not">not</a></code> . p)</code>.
</p></div></div><div class="top"><p class="src"><a name="v:group" class="def">group</a> :: <a href="Data-ByteString-Lazy.html#t:ByteString">ByteString</a> -> [<a href="Data-ByteString-Lazy.html#t:ByteString">ByteString</a>]</p><div class="doc"><p>The <code><a href="Data-ByteString-Lazy.html#v:group">group</a></code> function takes a ByteString and returns a list of
ByteStrings 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="Data-ByteString-Lazy.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 href="../base-4.5.1.0/Data-Word.html#t:Word8">Word8</a> -> <a href="../base-4.5.1.0/Data-Word.html#t:Word8">Word8</a> -> <a href="../base-4.5.1.0/Data-Bool.html#t:Bool">Bool</a>) -> <a href="Data-ByteString-Lazy.html#t:ByteString">ByteString</a> -> [<a href="Data-ByteString-Lazy.html#t:ByteString">ByteString</a>]</p><div class="doc"><p>The <code><a href="Data-ByteString-Lazy.html#v:groupBy">groupBy</a></code> function is the non-overloaded version of <code><a href="Data-ByteString-Lazy.html#v:group">group</a></code>.
</p></div></div><div class="top"><p class="src"><a name="v:inits" class="def">inits</a> :: <a href="Data-ByteString-Lazy.html#t:ByteString">ByteString</a> -> [<a href="Data-ByteString-Lazy.html#t:ByteString">ByteString</a>]</p><div class="doc"><p><em>O(n)</em> Return all initial segments of the given <code><a href="Data-ByteString-Lazy.html#t:ByteString">ByteString</a></code>, shortest first.
</p></div></div><div class="top"><p class="src"><a name="v:tails" class="def">tails</a> :: <a href="Data-ByteString-Lazy.html#t:ByteString">ByteString</a> -> [<a href="Data-ByteString-Lazy.html#t:ByteString">ByteString</a>]</p><div class="doc"><p><em>O(n)</em> Return all final segments of the given <code><a href="Data-ByteString-Lazy.html#t:ByteString">ByteString</a></code>, longest first.
</p></div></div><h2 id="g:14">Breaking into many substrings
</h2><div class="top"><p class="src"><a name="v:split" class="def">split</a> :: <a href="../base-4.5.1.0/Data-Word.html#t:Word8">Word8</a> -> <a href="Data-ByteString-Lazy.html#t:ByteString">ByteString</a> -> [<a href="Data-ByteString-Lazy.html#t:ByteString">ByteString</a>]</p><div class="doc"><p><em>O(n)</em> Break a <code><a href="Data-ByteString-Lazy.html#t:ByteString">ByteString</a></code> into pieces separated by the byte
argument, consuming the delimiter. I.e.
</p><pre> split '\n' "a\nb\nd\ne" == ["a","b","d","e"]
split 'a' "aXaXaXa" == ["","X","X","X",""]
split 'x' "x" == ["",""]
</pre><p>and
</p><pre> intercalate [c] . split c == id
split == splitWith . (==)
</pre><p>As for all splitting functions in this library, this function does
not copy the substrings, it just constructs new <code>ByteStrings</code> that
are slices of the original.
</p></div></div><div class="top"><p class="src"><a name="v:splitWith" class="def">splitWith</a> :: (<a href="../base-4.5.1.0/Data-Word.html#t:Word8">Word8</a> -> <a href="../base-4.5.1.0/Data-Bool.html#t:Bool">Bool</a>) -> <a href="Data-ByteString-Lazy.html#t:ByteString">ByteString</a> -> [<a href="Data-ByteString-Lazy.html#t:ByteString">ByteString</a>]</p><div class="doc"><p><em>O(n)</em> Splits a <code><a href="Data-ByteString-Lazy.html#t:ByteString">ByteString</a></code> into components delimited by
separators, where the predicate returns True for a separator element.
The resulting components do not contain the separators. Two adjacent
separators result in an empty component in the output. eg.
</p><pre> splitWith (=='a') "aabbaca" == ["","","bb","c",""]
splitWith (=='a') [] == []
</pre></div></div><h1 id="g:15">Predicates
</h1><div class="top"><p class="src"><a name="v:isPrefixOf" class="def">isPrefixOf</a> :: <a href="Data-ByteString-Lazy.html#t:ByteString">ByteString</a> -> <a href="Data-ByteString-Lazy.html#t:ByteString">ByteString</a> -> <a href="../base-4.5.1.0/Data-Bool.html#t:Bool">Bool</a></p><div class="doc"><p><em>O(n)</em> The <code><a href="Data-ByteString-Lazy.html#v:isPrefixOf">isPrefixOf</a></code> function takes two ByteStrings and returns <code><a href="../base-4.5.1.0/Data-Bool.html#v:True">True</a></code>
iff the first 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="Data-ByteString-Lazy.html#t:ByteString">ByteString</a> -> <a href="Data-ByteString-Lazy.html#t:ByteString">ByteString</a> -> <a href="../base-4.5.1.0/Data-Bool.html#t:Bool">Bool</a></p><div class="doc"><p><em>O(n)</em> The <code><a href="Data-ByteString-Lazy.html#v:isSuffixOf">isSuffixOf</a></code> function takes two ByteStrings and returns <code><a href="../base-4.5.1.0/Data-Bool.html#v:True">True</a></code>
iff the first is a suffix of the second.
</p><p>The following holds:
</p><pre> isSuffixOf x y == reverse x `isPrefixOf` reverse y
</pre></div></div><h2 id="g:16">Search for arbitrary substrings
</h2><h1 id="g:17">Searching ByteStrings
</h1><h2 id="g:18">Searching by equality
</h2><div class="top"><p class="src"><a name="v:elem" class="def">elem</a> :: <a href="../base-4.5.1.0/Data-Word.html#t:Word8">Word8</a> -> <a href="Data-ByteString-Lazy.html#t:ByteString">ByteString</a> -> <a href="../base-4.5.1.0/Data-Bool.html#t:Bool">Bool</a></p><div class="doc"><p><em>O(n)</em> <code><a href="Data-ByteString-Lazy.html#v:elem">elem</a></code> is the <code><a href="Data-ByteString-Lazy.html#t:ByteString">ByteString</a></code> membership predicate.
</p></div></div><div class="top"><p class="src"><a name="v:notElem" class="def">notElem</a> :: <a href="../base-4.5.1.0/Data-Word.html#t:Word8">Word8</a> -> <a href="Data-ByteString-Lazy.html#t:ByteString">ByteString</a> -> <a href="../base-4.5.1.0/Data-Bool.html#t:Bool">Bool</a></p><div class="doc"><p><em>O(n)</em> <code><a href="Data-ByteString-Lazy.html#v:notElem">notElem</a></code> is the inverse of <code><a href="Data-ByteString-Lazy.html#v:elem">elem</a></code>
</p></div></div><h2 id="g:19">Searching with a predicate
</h2><div class="top"><p class="src"><a name="v:find" class="def">find</a> :: (<a href="../base-4.5.1.0/Data-Word.html#t:Word8">Word8</a> -> <a href="../base-4.5.1.0/Data-Bool.html#t:Bool">Bool</a>) -> <a href="Data-ByteString-Lazy.html#t:ByteString">ByteString</a> -> <a href="../base-4.5.1.0/Data-Maybe.html#t:Maybe">Maybe</a> <a href="../base-4.5.1.0/Data-Word.html#t:Word8">Word8</a></p><div class="doc"><p><em>O(n)</em> The <code><a href="Data-ByteString-Lazy.html#v:find">find</a></code> function takes a predicate and a ByteString,
and returns the first element in matching the predicate, or <code><a href="../base-4.5.1.0/Data-Maybe.html#v:Nothing">Nothing</a></code>
if there is no such element.
</p><pre> find f p = case findIndex f p of Just n -> Just (p ! n) ; _ -> Nothing
</pre></div></div><div class="top"><p class="src"><a name="v:filter" class="def">filter</a> :: (<a href="../base-4.5.1.0/Data-Word.html#t:Word8">Word8</a> -> <a href="../base-4.5.1.0/Data-Bool.html#t:Bool">Bool</a>) -> <a href="Data-ByteString-Lazy.html#t:ByteString">ByteString</a> -> <a href="Data-ByteString-Lazy.html#t:ByteString">ByteString</a></p><div class="doc"><p><em>O(n)</em> <code><a href="Data-ByteString-Lazy.html#v:filter">filter</a></code>, applied to a predicate and a ByteString,
returns a ByteString containing those characters that satisfy the
predicate.
</p></div></div><div class="top"><p class="src"><a name="v:partition" class="def">partition</a> :: (<a href="../base-4.5.1.0/Data-Word.html#t:Word8">Word8</a> -> <a href="../base-4.5.1.0/Data-Bool.html#t:Bool">Bool</a>) -> <a href="Data-ByteString-Lazy.html#t:ByteString">ByteString</a> -> (<a href="Data-ByteString-Lazy.html#t:ByteString">ByteString</a>, <a href="Data-ByteString-Lazy.html#t:ByteString">ByteString</a>)</p><div class="doc"><p><em>O(n)</em> The <code><a href="Data-ByteString-Lazy.html#v:partition">partition</a></code> function takes a predicate a ByteString and returns
the pair of ByteStrings with elements which do and do not satisfy the
predicate, respectively; i.e.,
</p><pre> partition p bs == (filter p xs, filter (not . p) xs)
</pre></div></div><h1 id="g:20">Indexing ByteStrings
</h1><div class="top"><p class="src"><a name="v:index" class="def">index</a> :: <a href="Data-ByteString-Lazy.html#t:ByteString">ByteString</a> -> <a href="../base-4.5.1.0/Data-Int.html#t:Int64">Int64</a> -> <a href="../base-4.5.1.0/Data-Word.html#t:Word8">Word8</a></p><div class="doc"><p><em>O(c)</em> <code><a href="Data-ByteString-Lazy.html#t:ByteString">ByteString</a></code> index (subscript) operator, starting from 0.
</p></div></div><div class="top"><p class="src"><a name="v:elemIndex" class="def">elemIndex</a> :: <a href="../base-4.5.1.0/Data-Word.html#t:Word8">Word8</a> -> <a href="Data-ByteString-Lazy.html#t:ByteString">ByteString</a> -> <a href="../base-4.5.1.0/Data-Maybe.html#t:Maybe">Maybe</a> <a href="../base-4.5.1.0/Data-Int.html#t:Int64">Int64</a></p><div class="doc"><p><em>O(n)</em> The <code><a href="Data-ByteString-Lazy.html#v:elemIndex">elemIndex</a></code> function returns the index of the first
element in the given <code><a href="Data-ByteString-Lazy.html#t:ByteString">ByteString</a></code> which is equal to the query
element, or <code><a href="../base-4.5.1.0/Data-Maybe.html#v:Nothing">Nothing</a></code> if there is no such element.
This implementation uses memchr(3).
</p></div></div><div class="top"><p class="src"><a name="v:elemIndices" class="def">elemIndices</a> :: <a href="../base-4.5.1.0/Data-Word.html#t:Word8">Word8</a> -> <a href="Data-ByteString-Lazy.html#t:ByteString">ByteString</a> -> [<a href="../base-4.5.1.0/Data-Int.html#t:Int64">Int64</a>]</p><div class="doc"><p><em>O(n)</em> The <code><a href="Data-ByteString-Lazy.html#v:elemIndices">elemIndices</a></code> function extends <code><a href="Data-ByteString-Lazy.html#v:elemIndex">elemIndex</a></code>, by returning
the indices of all elements equal to the query element, in ascending order.
This implementation uses memchr(3).
</p></div></div><div class="top"><p class="src"><a name="v:findIndex" class="def">findIndex</a> :: (<a href="../base-4.5.1.0/Data-Word.html#t:Word8">Word8</a> -> <a href="../base-4.5.1.0/Data-Bool.html#t:Bool">Bool</a>) -> <a href="Data-ByteString-Lazy.html#t:ByteString">ByteString</a> -> <a href="../base-4.5.1.0/Data-Maybe.html#t:Maybe">Maybe</a> <a href="../base-4.5.1.0/Data-Int.html#t:Int64">Int64</a></p><div class="doc"><p>The <code><a href="Data-ByteString-Lazy.html#v:findIndex">findIndex</a></code> function takes a predicate and a <code><a href="Data-ByteString-Lazy.html#t:ByteString">ByteString</a></code> and
returns the index of the first element in the ByteString
satisfying the predicate.
</p></div></div><div class="top"><p class="src"><a name="v:findIndices" class="def">findIndices</a> :: (<a href="../base-4.5.1.0/Data-Word.html#t:Word8">Word8</a> -> <a href="../base-4.5.1.0/Data-Bool.html#t:Bool">Bool</a>) -> <a href="Data-ByteString-Lazy.html#t:ByteString">ByteString</a> -> [<a href="../base-4.5.1.0/Data-Int.html#t:Int64">Int64</a>]</p><div class="doc"><p>The <code><a href="Data-ByteString-Lazy.html#v:findIndices">findIndices</a></code> function extends <code><a href="Data-ByteString-Lazy.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:count" class="def">count</a> :: <a href="../base-4.5.1.0/Data-Word.html#t:Word8">Word8</a> -> <a href="Data-ByteString-Lazy.html#t:ByteString">ByteString</a> -> <a href="../base-4.5.1.0/Data-Int.html#t:Int64">Int64</a></p><div class="doc"><p>count returns the number of times its argument appears in the ByteString
</p><pre> count = length . elemIndices
</pre><p>But more efficiently than using length on the intermediate list.
</p></div></div><h1 id="g:21">Zipping and unzipping ByteStrings
</h1><div class="top"><p class="src"><a name="v:zip" class="def">zip</a> :: <a href="Data-ByteString-Lazy.html#t:ByteString">ByteString</a> -> <a href="Data-ByteString-Lazy.html#t:ByteString">ByteString</a> -> [(<a href="../base-4.5.1.0/Data-Word.html#t:Word8">Word8</a>, <a href="../base-4.5.1.0/Data-Word.html#t:Word8">Word8</a>)]</p><div class="doc"><p><em>O(n)</em> <code><a href="Data-ByteString-Lazy.html#v:zip">zip</a></code> takes two ByteStrings and returns a list of
corresponding pairs of bytes. If one input ByteString is short,
excess elements of the longer ByteString are discarded. This is
equivalent to a pair of <code><a href="Data-ByteString-Lazy.html#v:unpack">unpack</a></code> operations.
</p></div></div><div class="top"><p class="src"><a name="v:zipWith" class="def">zipWith</a> :: (<a href="../base-4.5.1.0/Data-Word.html#t:Word8">Word8</a> -> <a href="../base-4.5.1.0/Data-Word.html#t:Word8">Word8</a> -> a) -> <a href="Data-ByteString-Lazy.html#t:ByteString">ByteString</a> -> <a href="Data-ByteString-Lazy.html#t:ByteString">ByteString</a> -> [a]</p><div class="doc"><p><code><a href="Data-ByteString-Lazy.html#v:zipWith">zipWith</a></code> generalises <code><a href="Data-ByteString-Lazy.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="Data-ByteString-Lazy.html#v:zipWith">zipWith</a></code> (+)</code> is applied to two ByteStrings to produce the list of
corresponding sums.
</p></div></div><div class="top"><p class="src"><a name="v:unzip" class="def">unzip</a> :: [(<a href="../base-4.5.1.0/Data-Word.html#t:Word8">Word8</a>, <a href="../base-4.5.1.0/Data-Word.html#t:Word8">Word8</a>)] -> (<a href="Data-ByteString-Lazy.html#t:ByteString">ByteString</a>, <a href="Data-ByteString-Lazy.html#t:ByteString">ByteString</a>)</p><div class="doc"><p><em>O(n)</em> <code><a href="Data-ByteString-Lazy.html#v:unzip">unzip</a></code> transforms a list of pairs of bytes into a pair of
ByteStrings. Note that this performs two <code><a href="Data-ByteString-Lazy.html#v:pack">pack</a></code> operations.
</p></div></div><h1 id="g:22">Ordered ByteStrings
</h1><h1 id="g:23">Low level conversions
</h1><h2 id="g:24">Copying ByteStrings
</h2><div class="top"><p class="src"><a name="v:copy" class="def">copy</a> :: <a href="Data-ByteString-Lazy.html#t:ByteString">ByteString</a> -> <a href="Data-ByteString-Lazy.html#t:ByteString">ByteString</a></p><div class="doc"><p><em>O(n)</em> Make a copy of the <code><a href="Data-ByteString-Lazy.html#t:ByteString">ByteString</a></code> with its own storage.
This is mainly useful to allow the rest of the data pointed
to by the <code><a href="Data-ByteString-Lazy.html#t:ByteString">ByteString</a></code> to be garbage collected, for example
if a large string has been read in, and only a small part of it
is needed in the rest of the program.
</p></div></div><h1 id="g:25">I/O with <code><a href="Data-ByteString-Lazy.html#t:ByteString">ByteString</a></code>s
</h1><h2 id="g:26">Standard input and output
</h2><div class="top"><p class="src"><a name="v:getContents" class="def">getContents</a> :: <a href="../base-4.5.1.0/System-IO.html#t:IO">IO</a> <a href="Data-ByteString-Lazy.html#t:ByteString">ByteString</a></p><div class="doc"><p>getContents. Equivalent to hGetContents stdin. Will read <em>lazily</em>
</p></div></div><div class="top"><p class="src"><a name="v:putStr" class="def">putStr</a> :: <a href="Data-ByteString-Lazy.html#t:ByteString">ByteString</a> -> <a href="../base-4.5.1.0/System-IO.html#t:IO">IO</a> <a href="../ghc-prim-0.2.0.0/GHC-Tuple.html#t:-40--41-">()</a></p><div class="doc"><p>Write a ByteString to stdout
</p></div></div><div class="top"><p class="src"><a name="v:putStrLn" class="def">putStrLn</a> :: <a href="Data-ByteString-Lazy.html#t:ByteString">ByteString</a> -> <a href="../base-4.5.1.0/System-IO.html#t:IO">IO</a> <a href="../ghc-prim-0.2.0.0/GHC-Tuple.html#t:-40--41-">()</a></p><div class="doc"><div class="warning"><p>Deprecated: Use Data.ByteString.Lazy.Char8.putStrLn instead. (Functions that rely on ASCII encodings belong in Data.ByteString.Lazy.Char8)</p></div><p>Write a ByteString to stdout, appending a newline byte
</p></div></div><div class="top"><p class="src"><a name="v:interact" class="def">interact</a> :: (<a href="Data-ByteString-Lazy.html#t:ByteString">ByteString</a> -> <a href="Data-ByteString-Lazy.html#t:ByteString">ByteString</a>) -> <a href="../base-4.5.1.0/System-IO.html#t:IO">IO</a> <a href="../ghc-prim-0.2.0.0/GHC-Tuple.html#t:-40--41-">()</a></p><div class="doc"><p>The interact function takes a function of type <code>ByteString -> ByteString</code>
as its argument. The entire input from the standard input device is passed
to this function as its argument, and the resulting string is output on the
standard output device.
</p></div></div><h2 id="g:27">Files
</h2><div class="top"><p class="src"><a name="v:readFile" class="def">readFile</a> :: <a href="../base-4.5.1.0/System-IO.html#t:FilePath">FilePath</a> -> <a href="../base-4.5.1.0/System-IO.html#t:IO">IO</a> <a href="Data-ByteString-Lazy.html#t:ByteString">ByteString</a></p><div class="doc"><p>Read an entire file <em>lazily</em> into a <code><a href="Data-ByteString-Lazy.html#t:ByteString">ByteString</a></code>.
The Handle will be held open until EOF is encountered.
</p></div></div><div class="top"><p class="src"><a name="v:writeFile" class="def">writeFile</a> :: <a href="../base-4.5.1.0/System-IO.html#t:FilePath">FilePath</a> -> <a href="Data-ByteString-Lazy.html#t:ByteString">ByteString</a> -> <a href="../base-4.5.1.0/System-IO.html#t:IO">IO</a> <a href="../ghc-prim-0.2.0.0/GHC-Tuple.html#t:-40--41-">()</a></p><div class="doc"><p>Write a <code><a href="Data-ByteString-Lazy.html#t:ByteString">ByteString</a></code> to a file.
</p></div></div><div class="top"><p class="src"><a name="v:appendFile" class="def">appendFile</a> :: <a href="../base-4.5.1.0/System-IO.html#t:FilePath">FilePath</a> -> <a href="Data-ByteString-Lazy.html#t:ByteString">ByteString</a> -> <a href="../base-4.5.1.0/System-IO.html#t:IO">IO</a> <a href="../ghc-prim-0.2.0.0/GHC-Tuple.html#t:-40--41-">()</a></p><div class="doc"><p>Append a <code><a href="Data-ByteString-Lazy.html#t:ByteString">ByteString</a></code> to a file.
</p></div></div><h2 id="g:28">I/O with Handles
</h2><div class="top"><p class="src"><a name="v:hGetContents" class="def">hGetContents</a> :: <a href="../base-4.5.1.0/GHC-IO-Handle.html#t:Handle">Handle</a> -> <a href="../base-4.5.1.0/System-IO.html#t:IO">IO</a> <a href="Data-ByteString-Lazy.html#t:ByteString">ByteString</a></p><div class="doc"><p>Read entire handle contents <em>lazily</em> into a <code><a href="Data-ByteString-Lazy.html#t:ByteString">ByteString</a></code>. Chunks
are read on demand, using the default chunk size.
</p><p>Once EOF is encountered, the Handle is closed.
</p><p>Note: the <code><a href="../base-4.5.1.0/GHC-IO-Handle.html#t:Handle">Handle</a></code> should be placed in binary mode with
<code><a href="../base-4.5.1.0/System-IO.html#v:hSetBinaryMode">hSetBinaryMode</a></code> for <code><a href="Data-ByteString-Lazy.html#v:hGetContents">hGetContents</a></code> to
work correctly.
</p></div></div><div class="top"><p class="src"><a name="v:hGet" class="def">hGet</a> :: <a href="../base-4.5.1.0/GHC-IO-Handle.html#t:Handle">Handle</a> -> <a href="../base-4.5.1.0/Data-Int.html#t:Int">Int</a> -> <a href="../base-4.5.1.0/System-IO.html#t:IO">IO</a> <a href="Data-ByteString-Lazy.html#t:ByteString">ByteString</a></p><div class="doc"><p>Read <code>n</code> bytes into a <code><a href="Data-ByteString-Lazy.html#t:ByteString">ByteString</a></code>, directly from the specified <code><a href="../base-4.5.1.0/GHC-IO-Handle.html#t:Handle">Handle</a></code>.
</p></div></div><div class="top"><p class="src"><a name="v:hGetNonBlocking" class="def">hGetNonBlocking</a> :: <a href="../base-4.5.1.0/GHC-IO-Handle.html#t:Handle">Handle</a> -> <a href="../base-4.5.1.0/Data-Int.html#t:Int">Int</a> -> <a href="../base-4.5.1.0/System-IO.html#t:IO">IO</a> <a href="Data-ByteString-Lazy.html#t:ByteString">ByteString</a></p><div class="doc"><p>hGetNonBlocking is similar to <code><a href="Data-ByteString-Lazy.html#v:hGet">hGet</a></code>, except that it will never block
waiting for data to become available, instead it returns only whatever data
is available. If there is no data available to be read, <code><a href="Data-ByteString-Lazy.html#v:hGetNonBlocking">hGetNonBlocking</a></code>
returns <code><a href="Data-ByteString-Lazy.html#v:empty">empty</a></code>.
</p><p>Note: on Windows and with Haskell implementation other than GHC, this
function does not work correctly; it behaves identically to <code><a href="Data-ByteString-Lazy.html#v:hGet">hGet</a></code>.
</p></div></div><div class="top"><p class="src"><a name="v:hPut" class="def">hPut</a> :: <a href="../base-4.5.1.0/GHC-IO-Handle.html#t:Handle">Handle</a> -> <a href="Data-ByteString-Lazy.html#t:ByteString">ByteString</a> -> <a href="../base-4.5.1.0/System-IO.html#t:IO">IO</a> <a href="../ghc-prim-0.2.0.0/GHC-Tuple.html#t:-40--41-">()</a></p><div class="doc"><p>Outputs a <code><a href="Data-ByteString-Lazy.html#t:ByteString">ByteString</a></code> to the specified <code><a href="../base-4.5.1.0/GHC-IO-Handle.html#t:Handle">Handle</a></code>.
</p></div></div><div class="top"><p class="src"><a name="v:hPutNonBlocking" class="def">hPutNonBlocking</a> :: <a href="../base-4.5.1.0/GHC-IO-Handle.html#t:Handle">Handle</a> -> <a href="Data-ByteString-Lazy.html#t:ByteString">ByteString</a> -> <a href="../base-4.5.1.0/System-IO.html#t:IO">IO</a> <a href="Data-ByteString-Lazy.html#t:ByteString">ByteString</a></p><div class="doc"><p>Similar to <code><a href="Data-ByteString-Lazy.html#v:hPut">hPut</a></code> except that it will never block. Instead it returns
any tail that did not get written. This tail may be <code><a href="Data-ByteString-Lazy.html#v:empty">empty</a></code> in the case that
the whole string was written, or the whole original string if nothing was
written. Partial writes are also possible.
</p><p>Note: on Windows and with Haskell implementation other than GHC, this
function does not work correctly; it behaves identically to <code><a href="Data-ByteString-Lazy.html#v:hPut">hPut</a></code>.
</p></div></div><div class="top"><p class="src"><a name="v:hPutStr" class="def">hPutStr</a> :: <a href="../base-4.5.1.0/GHC-IO-Handle.html#t:Handle">Handle</a> -> <a href="Data-ByteString-Lazy.html#t:ByteString">ByteString</a> -> <a href="../base-4.5.1.0/System-IO.html#t:IO">IO</a> <a href="../ghc-prim-0.2.0.0/GHC-Tuple.html#t:-40--41-">()</a></p><div class="doc"><p>A synonym for <code>hPut</code>, for compatibility
</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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