<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Strict//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-strict.dtd">
<html>
<head>
<!-- Generated by HsColour, http://www.cs.york.ac.uk/fp/darcs/hscolour/ -->
<title>Data/Conduit/List.hs</title>
<link type='text/css' rel='stylesheet' href='hscolour.css' />
</head>
<body>
<pre><a name="line-1"></a><span class='hs-comment'>{-# LANGUAGE FlexibleContexts #-}</span>
<a name="line-2"></a><span class='hs-comment'>-- | Higher-level functions to interact with the elements of a stream. Most of</span>
<a name="line-3"></a><span class='hs-comment'>-- these are based on list functions.</span>
<a name="line-4"></a><span class='hs-comment'>--</span>
<a name="line-5"></a><span class='hs-comment'>-- Note that these functions all deal with individual elements of a stream as a</span>
<a name="line-6"></a><span class='hs-comment'>-- sort of \"black box\", where there is no introspection of the contained</span>
<a name="line-7"></a><span class='hs-comment'>-- elements. Values such as @ByteString@ and @Text@ will likely need to be</span>
<a name="line-8"></a><span class='hs-comment'>-- treated specially to deal with their contents properly (@Word8@ and @Char@,</span>
<a name="line-9"></a><span class='hs-comment'>-- respectively). See the "Data.Conduit.Binary" and "Data.Conduit.Text"</span>
<a name="line-10"></a><span class='hs-comment'>-- modules.</span>
<a name="line-11"></a><span class='hs-keyword'>module</span> <span class='hs-conid'>Data</span><span class='hs-varop'>.</span><span class='hs-conid'>Conduit</span><span class='hs-varop'>.</span><span class='hs-conid'>List</span>
<a name="line-12"></a> <span class='hs-layout'>(</span> <span class='hs-comment'>-- * Sources</span>
<a name="line-13"></a> <span class='hs-varid'>sourceList</span>
<a name="line-14"></a> <span class='hs-layout'>,</span> <span class='hs-varid'>sourceNull</span>
<a name="line-15"></a> <span class='hs-comment'>-- * Sinks</span>
<a name="line-16"></a> <span class='hs-comment'>-- ** Pure</span>
<a name="line-17"></a> <span class='hs-layout'>,</span> <span class='hs-varid'>fold</span>
<a name="line-18"></a> <span class='hs-layout'>,</span> <span class='hs-varid'>take</span>
<a name="line-19"></a> <span class='hs-layout'>,</span> <span class='hs-varid'>drop</span>
<a name="line-20"></a> <span class='hs-layout'>,</span> <span class='hs-varid'>head</span>
<a name="line-21"></a> <span class='hs-layout'>,</span> <span class='hs-varid'>zip</span>
<a name="line-22"></a> <span class='hs-layout'>,</span> <span class='hs-varid'>peek</span>
<a name="line-23"></a> <span class='hs-layout'>,</span> <span class='hs-varid'>consume</span>
<a name="line-24"></a> <span class='hs-layout'>,</span> <span class='hs-varid'>sinkNull</span>
<a name="line-25"></a> <span class='hs-comment'>-- ** Monadic</span>
<a name="line-26"></a> <span class='hs-layout'>,</span> <span class='hs-varid'>foldM</span>
<a name="line-27"></a> <span class='hs-layout'>,</span> <span class='hs-varid'>mapM_</span>
<a name="line-28"></a> <span class='hs-comment'>-- Conduits</span>
<a name="line-29"></a> <span class='hs-comment'>-- ** Pure</span>
<a name="line-30"></a> <span class='hs-layout'>,</span> <span class='hs-varid'>map</span>
<a name="line-31"></a> <span class='hs-layout'>,</span> <span class='hs-varid'>concatMap</span>
<a name="line-32"></a> <span class='hs-layout'>,</span> <span class='hs-varid'>concatMapAccum</span>
<a name="line-33"></a> <span class='hs-layout'>,</span> <span class='hs-varid'>groupBy</span>
<a name="line-34"></a> <span class='hs-layout'>,</span> <span class='hs-varid'>isolate</span>
<a name="line-35"></a> <span class='hs-layout'>,</span> <span class='hs-varid'>filter</span>
<a name="line-36"></a> <span class='hs-comment'>-- ** Monadic</span>
<a name="line-37"></a> <span class='hs-layout'>,</span> <span class='hs-varid'>mapM</span>
<a name="line-38"></a> <span class='hs-layout'>,</span> <span class='hs-varid'>concatMapM</span>
<a name="line-39"></a> <span class='hs-layout'>,</span> <span class='hs-varid'>concatMapAccumM</span>
<a name="line-40"></a> <span class='hs-layout'>)</span> <span class='hs-keyword'>where</span>
<a name="line-41"></a>
<a name="line-42"></a><span class='hs-keyword'>import</span> <span class='hs-conid'>Prelude</span>
<a name="line-43"></a> <span class='hs-layout'>(</span> <span class='hs-layout'>(</span><span class='hs-varop'>$</span><span class='hs-layout'>)</span><span class='hs-layout'>,</span> <span class='hs-varid'>return</span><span class='hs-layout'>,</span> <span class='hs-layout'>(</span><span class='hs-varop'>==</span><span class='hs-layout'>)</span><span class='hs-layout'>,</span> <span class='hs-layout'>(</span><span class='hs-comment'>-</span><span class='hs-layout'>)</span><span class='hs-layout'>,</span> <span class='hs-conid'>Int</span>
<a name="line-44"></a> <span class='hs-layout'>,</span> <span class='hs-layout'>(</span><span class='hs-varop'>.</span><span class='hs-layout'>)</span><span class='hs-layout'>,</span> <span class='hs-varid'>id</span><span class='hs-layout'>,</span> <span class='hs-conid'>Maybe</span> <span class='hs-layout'>(</span><span class='hs-keyglyph'>..</span><span class='hs-layout'>)</span><span class='hs-layout'>,</span> <span class='hs-varid'>fmap</span><span class='hs-layout'>,</span> <span class='hs-conid'>Monad</span>
<a name="line-45"></a> <span class='hs-layout'>,</span> <span class='hs-conid'>Bool</span> <span class='hs-layout'>(</span><span class='hs-keyglyph'>..</span><span class='hs-layout'>)</span>
<a name="line-46"></a> <span class='hs-layout'>,</span> <span class='hs-layout'>(</span><span class='hs-varop'>>></span><span class='hs-layout'>)</span>
<a name="line-47"></a> <span class='hs-layout'>)</span>
<a name="line-48"></a><span class='hs-keyword'>import</span> <span class='hs-keyword'>qualified</span> <span class='hs-conid'>Prelude</span>
<a name="line-49"></a><span class='hs-keyword'>import</span> <span class='hs-conid'>Data</span><span class='hs-varop'>.</span><span class='hs-conid'>Conduit</span>
<a name="line-50"></a><span class='hs-keyword'>import</span> <span class='hs-conid'>Control</span><span class='hs-varop'>.</span><span class='hs-conid'>Monad</span><span class='hs-varop'>.</span><span class='hs-conid'>Trans</span><span class='hs-varop'>.</span><span class='hs-conid'>Class</span> <span class='hs-layout'>(</span><span class='hs-varid'>lift</span><span class='hs-layout'>)</span>
<a name="line-51"></a><span class='hs-keyword'>import</span> <span class='hs-conid'>Data</span><span class='hs-varop'>.</span><span class='hs-conid'>Monoid</span> <span class='hs-layout'>(</span><span class='hs-varid'>mempty</span><span class='hs-layout'>)</span>
<a name="line-52"></a>
<a name="line-53"></a><a name="fold"></a><span class='hs-comment'>-- | A strict left fold.</span>
<a name="line-54"></a><span class='hs-comment'>--</span>
<a name="line-55"></a><span class='hs-comment'>-- Since 0.2.0</span>
<a name="line-56"></a><span class='hs-definition'>fold</span> <span class='hs-keyglyph'>::</span> <span class='hs-conid'>Resource</span> <span class='hs-varid'>m</span>
<a name="line-57"></a> <span class='hs-keyglyph'>=></span> <span class='hs-layout'>(</span><span class='hs-varid'>b</span> <span class='hs-keyglyph'>-></span> <span class='hs-varid'>a</span> <span class='hs-keyglyph'>-></span> <span class='hs-varid'>b</span><span class='hs-layout'>)</span>
<a name="line-58"></a> <span class='hs-keyglyph'>-></span> <span class='hs-varid'>b</span>
<a name="line-59"></a> <span class='hs-keyglyph'>-></span> <span class='hs-conid'>Sink</span> <span class='hs-varid'>a</span> <span class='hs-varid'>m</span> <span class='hs-varid'>b</span>
<a name="line-60"></a><span class='hs-definition'>fold</span> <span class='hs-varid'>f</span> <span class='hs-varid'>accum0</span> <span class='hs-keyglyph'>=</span> <span class='hs-varid'>sinkState</span>
<a name="line-61"></a> <span class='hs-varid'>accum0</span>
<a name="line-62"></a> <span class='hs-layout'>(</span><span class='hs-keyglyph'>\</span><span class='hs-varid'>accum</span> <span class='hs-varid'>input</span> <span class='hs-keyglyph'>-></span> <span class='hs-varid'>return</span> <span class='hs-layout'>(</span><span class='hs-conid'>StateProcessing</span> <span class='hs-varop'>$</span> <span class='hs-varid'>f</span> <span class='hs-varid'>accum</span> <span class='hs-varid'>input</span><span class='hs-layout'>)</span><span class='hs-layout'>)</span>
<a name="line-63"></a> <span class='hs-varid'>return</span>
<a name="line-64"></a>
<a name="line-65"></a><a name="foldM"></a><span class='hs-comment'>-- | A monadic strict left fold.</span>
<a name="line-66"></a><span class='hs-comment'>--</span>
<a name="line-67"></a><span class='hs-comment'>-- Since 0.2.0</span>
<a name="line-68"></a><span class='hs-definition'>foldM</span> <span class='hs-keyglyph'>::</span> <span class='hs-conid'>Resource</span> <span class='hs-varid'>m</span>
<a name="line-69"></a> <span class='hs-keyglyph'>=></span> <span class='hs-layout'>(</span><span class='hs-varid'>b</span> <span class='hs-keyglyph'>-></span> <span class='hs-varid'>a</span> <span class='hs-keyglyph'>-></span> <span class='hs-varid'>m</span> <span class='hs-varid'>b</span><span class='hs-layout'>)</span>
<a name="line-70"></a> <span class='hs-keyglyph'>-></span> <span class='hs-varid'>b</span>
<a name="line-71"></a> <span class='hs-keyglyph'>-></span> <span class='hs-conid'>Sink</span> <span class='hs-varid'>a</span> <span class='hs-varid'>m</span> <span class='hs-varid'>b</span>
<a name="line-72"></a><span class='hs-definition'>foldM</span> <span class='hs-varid'>f</span> <span class='hs-varid'>accum0</span> <span class='hs-keyglyph'>=</span> <span class='hs-varid'>sinkState</span>
<a name="line-73"></a> <span class='hs-varid'>accum0</span>
<a name="line-74"></a> <span class='hs-layout'>(</span><span class='hs-keyglyph'>\</span><span class='hs-varid'>accum</span> <span class='hs-varid'>input</span> <span class='hs-keyglyph'>-></span> <span class='hs-keyword'>do</span>
<a name="line-75"></a> <span class='hs-varid'>accum'</span> <span class='hs-keyglyph'><-</span> <span class='hs-varid'>lift</span> <span class='hs-varop'>$</span> <span class='hs-varid'>f</span> <span class='hs-varid'>accum</span> <span class='hs-varid'>input</span>
<a name="line-76"></a> <span class='hs-varid'>return</span> <span class='hs-varop'>$</span> <span class='hs-conid'>StateProcessing</span> <span class='hs-varid'>accum'</span>
<a name="line-77"></a> <span class='hs-layout'>)</span>
<a name="line-78"></a> <span class='hs-varid'>return</span>
<a name="line-79"></a>
<a name="line-80"></a><a name="mapM_"></a><span class='hs-comment'>-- | Apply the action to all values in the stream.</span>
<a name="line-81"></a><span class='hs-comment'>--</span>
<a name="line-82"></a><span class='hs-comment'>-- Since 0.2.0</span>
<a name="line-83"></a><span class='hs-definition'>mapM_</span> <span class='hs-keyglyph'>::</span> <span class='hs-conid'>Resource</span> <span class='hs-varid'>m</span>
<a name="line-84"></a> <span class='hs-keyglyph'>=></span> <span class='hs-layout'>(</span><span class='hs-varid'>a</span> <span class='hs-keyglyph'>-></span> <span class='hs-varid'>m</span> <span class='hs-conid'>()</span><span class='hs-layout'>)</span>
<a name="line-85"></a> <span class='hs-keyglyph'>-></span> <span class='hs-conid'>Sink</span> <span class='hs-varid'>a</span> <span class='hs-varid'>m</span> <span class='hs-conid'>()</span>
<a name="line-86"></a><span class='hs-definition'>mapM_</span> <span class='hs-varid'>f</span> <span class='hs-keyglyph'>=</span>
<a name="line-87"></a> <span class='hs-conid'>SinkData</span> <span class='hs-varid'>push</span> <span class='hs-varid'>close</span>
<a name="line-88"></a> <span class='hs-keyword'>where</span>
<a name="line-89"></a> <span class='hs-varid'>push</span> <span class='hs-varid'>input</span> <span class='hs-keyglyph'>=</span> <span class='hs-varid'>lift</span> <span class='hs-layout'>(</span><span class='hs-varid'>f</span> <span class='hs-varid'>input</span><span class='hs-layout'>)</span> <span class='hs-varop'>>></span> <span class='hs-varid'>return</span> <span class='hs-layout'>(</span><span class='hs-conid'>Processing</span> <span class='hs-varid'>push</span> <span class='hs-varid'>close</span><span class='hs-layout'>)</span>
<a name="line-90"></a> <span class='hs-varid'>close</span> <span class='hs-keyglyph'>=</span> <span class='hs-varid'>return</span> <span class='hs-conid'>()</span>
<a name="line-91"></a>
<a name="line-92"></a><a name="sourceList"></a><span class='hs-comment'>-- | Convert a list into a source.</span>
<a name="line-93"></a><span class='hs-comment'>--</span>
<a name="line-94"></a><span class='hs-comment'>-- Since 0.2.0</span>
<a name="line-95"></a><span class='hs-definition'>sourceList</span> <span class='hs-keyglyph'>::</span> <span class='hs-conid'>Resource</span> <span class='hs-varid'>m</span> <span class='hs-keyglyph'>=></span> <span class='hs-keyglyph'>[</span><span class='hs-varid'>a</span><span class='hs-keyglyph'>]</span> <span class='hs-keyglyph'>-></span> <span class='hs-conid'>Source</span> <span class='hs-varid'>m</span> <span class='hs-varid'>a</span>
<a name="line-96"></a><span class='hs-definition'>sourceList</span> <span class='hs-varid'>l0</span> <span class='hs-keyglyph'>=</span>
<a name="line-97"></a> <span class='hs-varid'>sourceState</span> <span class='hs-varid'>l0</span> <span class='hs-varid'>go</span>
<a name="line-98"></a> <span class='hs-keyword'>where</span>
<a name="line-99"></a> <span class='hs-varid'>go</span> <span class='hs-conid'>[]</span> <span class='hs-keyglyph'>=</span> <span class='hs-varid'>return</span> <span class='hs-conid'>StateClosed</span>
<a name="line-100"></a> <span class='hs-varid'>go</span> <span class='hs-layout'>(</span><span class='hs-varid'>x</span><span class='hs-conop'>:</span><span class='hs-varid'>xs</span><span class='hs-layout'>)</span> <span class='hs-keyglyph'>=</span> <span class='hs-varid'>return</span> <span class='hs-varop'>$</span> <span class='hs-conid'>StateOpen</span> <span class='hs-varid'>xs</span> <span class='hs-varid'>x</span>
<a name="line-101"></a>
<a name="line-102"></a><a name="drop"></a><span class='hs-comment'>-- | Ignore a certain number of values in the stream. This function is</span>
<a name="line-103"></a><span class='hs-comment'>-- semantically equivalent to:</span>
<a name="line-104"></a><span class='hs-comment'>--</span>
<a name="line-105"></a><span class='hs-comment'>-- > drop i = take i >> return ()</span>
<a name="line-106"></a><span class='hs-comment'>--</span>
<a name="line-107"></a><span class='hs-comment'>-- However, @drop@ is more efficient as it does not need to hold values in</span>
<a name="line-108"></a><span class='hs-comment'>-- memory.</span>
<a name="line-109"></a><span class='hs-comment'>--</span>
<a name="line-110"></a><span class='hs-comment'>-- Since 0.2.0</span>
<a name="line-111"></a><span class='hs-definition'>drop</span> <span class='hs-keyglyph'>::</span> <span class='hs-conid'>Resource</span> <span class='hs-varid'>m</span>
<a name="line-112"></a> <span class='hs-keyglyph'>=></span> <span class='hs-conid'>Int</span>
<a name="line-113"></a> <span class='hs-keyglyph'>-></span> <span class='hs-conid'>Sink</span> <span class='hs-varid'>a</span> <span class='hs-varid'>m</span> <span class='hs-conid'>()</span>
<a name="line-114"></a><span class='hs-definition'>drop</span> <span class='hs-varid'>count0</span> <span class='hs-keyglyph'>=</span> <span class='hs-varid'>sinkState</span>
<a name="line-115"></a> <span class='hs-varid'>count0</span>
<a name="line-116"></a> <span class='hs-varid'>push</span>
<a name="line-117"></a> <span class='hs-varid'>close</span>
<a name="line-118"></a> <span class='hs-keyword'>where</span>
<a name="line-119"></a> <span class='hs-varid'>push</span> <span class='hs-num'>0</span> <span class='hs-varid'>x</span> <span class='hs-keyglyph'>=</span> <span class='hs-varid'>return</span> <span class='hs-varop'>$</span> <span class='hs-conid'>StateDone</span> <span class='hs-layout'>(</span><span class='hs-conid'>Just</span> <span class='hs-varid'>x</span><span class='hs-layout'>)</span> <span class='hs-conid'>()</span>
<a name="line-120"></a> <span class='hs-varid'>push</span> <span class='hs-varid'>count</span> <span class='hs-keyword'>_</span> <span class='hs-keyglyph'>=</span> <span class='hs-keyword'>do</span>
<a name="line-121"></a> <span class='hs-keyword'>let</span> <span class='hs-varid'>count'</span> <span class='hs-keyglyph'>=</span> <span class='hs-varid'>count</span> <span class='hs-comment'>-</span> <span class='hs-num'>1</span>
<a name="line-122"></a> <span class='hs-varid'>return</span> <span class='hs-varop'>$</span> <span class='hs-keyword'>if</span> <span class='hs-varid'>count'</span> <span class='hs-varop'>==</span> <span class='hs-num'>0</span>
<a name="line-123"></a> <span class='hs-keyword'>then</span> <span class='hs-conid'>StateDone</span> <span class='hs-conid'>Nothing</span> <span class='hs-conid'>()</span>
<a name="line-124"></a> <span class='hs-keyword'>else</span> <span class='hs-conid'>StateProcessing</span> <span class='hs-varid'>count'</span>
<a name="line-125"></a> <span class='hs-varid'>close</span> <span class='hs-keyword'>_</span> <span class='hs-keyglyph'>=</span> <span class='hs-varid'>return</span> <span class='hs-conid'>()</span>
<a name="line-126"></a>
<a name="line-127"></a><a name="take"></a><span class='hs-comment'>-- | Take some values from the stream and return as a list. If you want to</span>
<a name="line-128"></a><span class='hs-comment'>-- instead create a conduit that pipes data to another sink, see 'isolate'.</span>
<a name="line-129"></a><span class='hs-comment'>-- This function is semantically equivalent to:</span>
<a name="line-130"></a><span class='hs-comment'>--</span>
<a name="line-131"></a><span class='hs-comment'>-- > take i = isolate i =$ consume</span>
<a name="line-132"></a><span class='hs-comment'>--</span>
<a name="line-133"></a><span class='hs-comment'>-- Since 0.2.0</span>
<a name="line-134"></a><span class='hs-definition'>take</span> <span class='hs-keyglyph'>::</span> <span class='hs-conid'>Resource</span> <span class='hs-varid'>m</span>
<a name="line-135"></a> <span class='hs-keyglyph'>=></span> <span class='hs-conid'>Int</span>
<a name="line-136"></a> <span class='hs-keyglyph'>-></span> <span class='hs-conid'>Sink</span> <span class='hs-varid'>a</span> <span class='hs-varid'>m</span> <span class='hs-keyglyph'>[</span><span class='hs-varid'>a</span><span class='hs-keyglyph'>]</span>
<a name="line-137"></a><span class='hs-definition'>take</span> <span class='hs-varid'>count0</span> <span class='hs-keyglyph'>=</span> <span class='hs-varid'>sinkState</span>
<a name="line-138"></a> <span class='hs-layout'>(</span><span class='hs-varid'>count0</span><span class='hs-layout'>,</span> <span class='hs-varid'>id</span><span class='hs-layout'>)</span>
<a name="line-139"></a> <span class='hs-varid'>push</span>
<a name="line-140"></a> <span class='hs-varid'>close</span>
<a name="line-141"></a> <span class='hs-keyword'>where</span>
<a name="line-142"></a> <span class='hs-varid'>push</span> <span class='hs-layout'>(</span><span class='hs-num'>0</span><span class='hs-layout'>,</span> <span class='hs-varid'>front</span><span class='hs-layout'>)</span> <span class='hs-varid'>x</span> <span class='hs-keyglyph'>=</span> <span class='hs-varid'>return</span> <span class='hs-layout'>(</span><span class='hs-conid'>StateDone</span> <span class='hs-layout'>(</span><span class='hs-conid'>Just</span> <span class='hs-varid'>x</span><span class='hs-layout'>)</span> <span class='hs-layout'>(</span><span class='hs-varid'>front</span> <span class='hs-conid'>[]</span><span class='hs-layout'>)</span><span class='hs-layout'>)</span>
<a name="line-143"></a> <span class='hs-varid'>push</span> <span class='hs-layout'>(</span><span class='hs-varid'>count</span><span class='hs-layout'>,</span> <span class='hs-varid'>front</span><span class='hs-layout'>)</span> <span class='hs-varid'>x</span> <span class='hs-keyglyph'>=</span> <span class='hs-keyword'>do</span>
<a name="line-144"></a> <span class='hs-keyword'>let</span> <span class='hs-varid'>count'</span> <span class='hs-keyglyph'>=</span> <span class='hs-varid'>count</span> <span class='hs-comment'>-</span> <span class='hs-num'>1</span>
<a name="line-145"></a> <span class='hs-varid'>front'</span> <span class='hs-keyglyph'>=</span> <span class='hs-varid'>front</span> <span class='hs-varop'>.</span> <span class='hs-layout'>(</span><span class='hs-varid'>x</span><span class='hs-conop'>:</span><span class='hs-layout'>)</span>
<a name="line-146"></a> <span class='hs-varid'>return</span> <span class='hs-varop'>$</span> <span class='hs-keyword'>if</span> <span class='hs-varid'>count'</span> <span class='hs-varop'>==</span> <span class='hs-num'>0</span>
<a name="line-147"></a> <span class='hs-keyword'>then</span> <span class='hs-conid'>StateDone</span> <span class='hs-conid'>Nothing</span> <span class='hs-layout'>(</span><span class='hs-varid'>front'</span> <span class='hs-conid'>[]</span><span class='hs-layout'>)</span>
<a name="line-148"></a> <span class='hs-keyword'>else</span> <span class='hs-conid'>StateProcessing</span> <span class='hs-layout'>(</span><span class='hs-varid'>count'</span><span class='hs-layout'>,</span> <span class='hs-varid'>front'</span><span class='hs-layout'>)</span>
<a name="line-149"></a> <span class='hs-varid'>close</span> <span class='hs-layout'>(</span><span class='hs-keyword'>_</span><span class='hs-layout'>,</span> <span class='hs-varid'>front</span><span class='hs-layout'>)</span> <span class='hs-keyglyph'>=</span> <span class='hs-varid'>return</span> <span class='hs-varop'>$</span> <span class='hs-varid'>front</span> <span class='hs-conid'>[]</span>
<a name="line-150"></a>
<a name="line-151"></a><a name="head"></a><span class='hs-comment'>-- | Take a single value from the stream, if available.</span>
<a name="line-152"></a><span class='hs-comment'>--</span>
<a name="line-153"></a><span class='hs-comment'>-- Since 0.2.0</span>
<a name="line-154"></a><span class='hs-definition'>head</span> <span class='hs-keyglyph'>::</span> <span class='hs-conid'>Resource</span> <span class='hs-varid'>m</span> <span class='hs-keyglyph'>=></span> <span class='hs-conid'>Sink</span> <span class='hs-varid'>a</span> <span class='hs-varid'>m</span> <span class='hs-layout'>(</span><span class='hs-conid'>Maybe</span> <span class='hs-varid'>a</span><span class='hs-layout'>)</span>
<a name="line-155"></a><span class='hs-definition'>head</span> <span class='hs-keyglyph'>=</span>
<a name="line-156"></a> <span class='hs-conid'>SinkData</span> <span class='hs-varid'>push</span> <span class='hs-varid'>close</span>
<a name="line-157"></a> <span class='hs-keyword'>where</span>
<a name="line-158"></a> <span class='hs-varid'>push</span> <span class='hs-varid'>x</span> <span class='hs-keyglyph'>=</span> <span class='hs-varid'>return</span> <span class='hs-varop'>$</span> <span class='hs-conid'>Done</span> <span class='hs-conid'>Nothing</span> <span class='hs-layout'>(</span><span class='hs-conid'>Just</span> <span class='hs-varid'>x</span><span class='hs-layout'>)</span>
<a name="line-159"></a> <span class='hs-varid'>close</span> <span class='hs-keyglyph'>=</span> <span class='hs-varid'>return</span> <span class='hs-conid'>Nothing</span>
<a name="line-160"></a>
<a name="line-161"></a><a name="peek"></a><span class='hs-comment'>-- | Look at the next value in the stream, if available. This function will not</span>
<a name="line-162"></a><span class='hs-comment'>-- change the state of the stream.</span>
<a name="line-163"></a><span class='hs-comment'>--</span>
<a name="line-164"></a><span class='hs-comment'>-- Since 0.2.0</span>
<a name="line-165"></a><span class='hs-definition'>peek</span> <span class='hs-keyglyph'>::</span> <span class='hs-conid'>Resource</span> <span class='hs-varid'>m</span> <span class='hs-keyglyph'>=></span> <span class='hs-conid'>Sink</span> <span class='hs-varid'>a</span> <span class='hs-varid'>m</span> <span class='hs-layout'>(</span><span class='hs-conid'>Maybe</span> <span class='hs-varid'>a</span><span class='hs-layout'>)</span>
<a name="line-166"></a><span class='hs-definition'>peek</span> <span class='hs-keyglyph'>=</span>
<a name="line-167"></a> <span class='hs-conid'>SinkData</span> <span class='hs-varid'>push</span> <span class='hs-varid'>close</span>
<a name="line-168"></a> <span class='hs-keyword'>where</span>
<a name="line-169"></a> <span class='hs-varid'>push</span> <span class='hs-varid'>x</span> <span class='hs-keyglyph'>=</span> <span class='hs-varid'>return</span> <span class='hs-varop'>$</span> <span class='hs-conid'>Done</span> <span class='hs-layout'>(</span><span class='hs-conid'>Just</span> <span class='hs-varid'>x</span><span class='hs-layout'>)</span> <span class='hs-layout'>(</span><span class='hs-conid'>Just</span> <span class='hs-varid'>x</span><span class='hs-layout'>)</span>
<a name="line-170"></a> <span class='hs-varid'>close</span> <span class='hs-keyglyph'>=</span> <span class='hs-varid'>return</span> <span class='hs-conid'>Nothing</span>
<a name="line-171"></a>
<a name="line-172"></a><a name="map"></a><span class='hs-comment'>-- | Apply a transformation to all values in a stream.</span>
<a name="line-173"></a><span class='hs-comment'>--</span>
<a name="line-174"></a><span class='hs-comment'>-- Since 0.2.0</span>
<a name="line-175"></a><span class='hs-definition'>map</span> <span class='hs-keyglyph'>::</span> <span class='hs-conid'>Monad</span> <span class='hs-varid'>m</span> <span class='hs-keyglyph'>=></span> <span class='hs-layout'>(</span><span class='hs-varid'>a</span> <span class='hs-keyglyph'>-></span> <span class='hs-varid'>b</span><span class='hs-layout'>)</span> <span class='hs-keyglyph'>-></span> <span class='hs-conid'>Conduit</span> <span class='hs-varid'>a</span> <span class='hs-varid'>m</span> <span class='hs-varid'>b</span>
<a name="line-176"></a><span class='hs-definition'>map</span> <span class='hs-varid'>f</span> <span class='hs-keyglyph'>=</span>
<a name="line-177"></a> <span class='hs-varid'>conduit</span>
<a name="line-178"></a> <span class='hs-keyword'>where</span>
<a name="line-179"></a> <span class='hs-varid'>conduit</span> <span class='hs-keyglyph'>=</span> <span class='hs-conid'>Conduit</span> <span class='hs-varid'>push</span> <span class='hs-varid'>close</span>
<a name="line-180"></a> <span class='hs-varid'>push</span> <span class='hs-keyglyph'>=</span> <span class='hs-varid'>return</span> <span class='hs-varop'>.</span> <span class='hs-conid'>Producing</span> <span class='hs-varid'>conduit</span> <span class='hs-varop'>.</span> <span class='hs-varid'>return</span> <span class='hs-varop'>.</span> <span class='hs-varid'>f</span>
<a name="line-181"></a> <span class='hs-varid'>close</span> <span class='hs-keyglyph'>=</span> <span class='hs-varid'>return</span> <span class='hs-conid'>[]</span>
<a name="line-182"></a>
<a name="line-183"></a><a name="mapM"></a><span class='hs-comment'>-- | Apply a monadic transformation to all values in a stream.</span>
<a name="line-184"></a><span class='hs-comment'>--</span>
<a name="line-185"></a><span class='hs-comment'>-- If you do not need the transformed values, and instead just want the monadic</span>
<a name="line-186"></a><span class='hs-comment'>-- side-effects of running the action, see 'mapM_'.</span>
<a name="line-187"></a><span class='hs-comment'>--</span>
<a name="line-188"></a><span class='hs-comment'>-- Since 0.2.0</span>
<a name="line-189"></a><span class='hs-definition'>mapM</span> <span class='hs-keyglyph'>::</span> <span class='hs-conid'>Monad</span> <span class='hs-varid'>m</span> <span class='hs-keyglyph'>=></span> <span class='hs-layout'>(</span><span class='hs-varid'>a</span> <span class='hs-keyglyph'>-></span> <span class='hs-varid'>m</span> <span class='hs-varid'>b</span><span class='hs-layout'>)</span> <span class='hs-keyglyph'>-></span> <span class='hs-conid'>Conduit</span> <span class='hs-varid'>a</span> <span class='hs-varid'>m</span> <span class='hs-varid'>b</span>
<a name="line-190"></a><span class='hs-definition'>mapM</span> <span class='hs-varid'>f</span> <span class='hs-keyglyph'>=</span>
<a name="line-191"></a> <span class='hs-varid'>conduit</span>
<a name="line-192"></a> <span class='hs-keyword'>where</span>
<a name="line-193"></a> <span class='hs-varid'>conduit</span> <span class='hs-keyglyph'>=</span> <span class='hs-conid'>Conduit</span> <span class='hs-varid'>push</span> <span class='hs-varid'>close</span>
<a name="line-194"></a> <span class='hs-varid'>push</span> <span class='hs-keyglyph'>=</span> <span class='hs-varid'>fmap</span> <span class='hs-layout'>(</span><span class='hs-conid'>Producing</span> <span class='hs-varid'>conduit</span> <span class='hs-varop'>.</span> <span class='hs-varid'>return</span><span class='hs-layout'>)</span> <span class='hs-varop'>.</span> <span class='hs-varid'>lift</span> <span class='hs-varop'>.</span> <span class='hs-varid'>f</span>
<a name="line-195"></a> <span class='hs-varid'>close</span> <span class='hs-keyglyph'>=</span> <span class='hs-varid'>return</span> <span class='hs-conid'>[]</span>
<a name="line-196"></a>
<a name="line-197"></a><a name="concatMap"></a><span class='hs-comment'>-- | Apply a transformation to all values in a stream, concatenating the output</span>
<a name="line-198"></a><span class='hs-comment'>-- values.</span>
<a name="line-199"></a><span class='hs-comment'>--</span>
<a name="line-200"></a><span class='hs-comment'>-- Since 0.2.0</span>
<a name="line-201"></a><span class='hs-definition'>concatMap</span> <span class='hs-keyglyph'>::</span> <span class='hs-conid'>Monad</span> <span class='hs-varid'>m</span> <span class='hs-keyglyph'>=></span> <span class='hs-layout'>(</span><span class='hs-varid'>a</span> <span class='hs-keyglyph'>-></span> <span class='hs-keyglyph'>[</span><span class='hs-varid'>b</span><span class='hs-keyglyph'>]</span><span class='hs-layout'>)</span> <span class='hs-keyglyph'>-></span> <span class='hs-conid'>Conduit</span> <span class='hs-varid'>a</span> <span class='hs-varid'>m</span> <span class='hs-varid'>b</span>
<a name="line-202"></a><span class='hs-definition'>concatMap</span> <span class='hs-varid'>f</span> <span class='hs-keyglyph'>=</span>
<a name="line-203"></a> <span class='hs-varid'>conduit</span>
<a name="line-204"></a> <span class='hs-keyword'>where</span>
<a name="line-205"></a> <span class='hs-varid'>conduit</span> <span class='hs-keyglyph'>=</span> <span class='hs-conid'>Conduit</span> <span class='hs-varid'>push</span> <span class='hs-varid'>close</span>
<a name="line-206"></a> <span class='hs-varid'>push</span> <span class='hs-keyglyph'>=</span> <span class='hs-varid'>return</span> <span class='hs-varop'>.</span> <span class='hs-conid'>Producing</span> <span class='hs-varid'>conduit</span> <span class='hs-varop'>.</span> <span class='hs-varid'>f</span>
<a name="line-207"></a> <span class='hs-varid'>close</span> <span class='hs-keyglyph'>=</span> <span class='hs-varid'>return</span> <span class='hs-conid'>[]</span>
<a name="line-208"></a>
<a name="line-209"></a><a name="concatMapM"></a><span class='hs-comment'>-- | Apply a monadic transformation to all values in a stream, concatenating</span>
<a name="line-210"></a><span class='hs-comment'>-- the output values.</span>
<a name="line-211"></a><span class='hs-comment'>--</span>
<a name="line-212"></a><span class='hs-comment'>-- Since 0.2.0</span>
<a name="line-213"></a><span class='hs-definition'>concatMapM</span> <span class='hs-keyglyph'>::</span> <span class='hs-conid'>Monad</span> <span class='hs-varid'>m</span> <span class='hs-keyglyph'>=></span> <span class='hs-layout'>(</span><span class='hs-varid'>a</span> <span class='hs-keyglyph'>-></span> <span class='hs-varid'>m</span> <span class='hs-keyglyph'>[</span><span class='hs-varid'>b</span><span class='hs-keyglyph'>]</span><span class='hs-layout'>)</span> <span class='hs-keyglyph'>-></span> <span class='hs-conid'>Conduit</span> <span class='hs-varid'>a</span> <span class='hs-varid'>m</span> <span class='hs-varid'>b</span>
<a name="line-214"></a><span class='hs-definition'>concatMapM</span> <span class='hs-varid'>f</span> <span class='hs-keyglyph'>=</span>
<a name="line-215"></a> <span class='hs-varid'>conduit</span>
<a name="line-216"></a> <span class='hs-keyword'>where</span>
<a name="line-217"></a> <span class='hs-varid'>conduit</span> <span class='hs-keyglyph'>=</span> <span class='hs-conid'>Conduit</span> <span class='hs-varid'>push</span> <span class='hs-varid'>close</span>
<a name="line-218"></a> <span class='hs-varid'>push</span> <span class='hs-keyglyph'>=</span> <span class='hs-varid'>fmap</span> <span class='hs-layout'>(</span><span class='hs-conid'>Producing</span> <span class='hs-varid'>conduit</span><span class='hs-layout'>)</span> <span class='hs-varop'>.</span> <span class='hs-varid'>lift</span> <span class='hs-varop'>.</span> <span class='hs-varid'>f</span>
<a name="line-219"></a> <span class='hs-varid'>close</span> <span class='hs-keyglyph'>=</span> <span class='hs-varid'>return</span> <span class='hs-conid'>[]</span>
<a name="line-220"></a>
<a name="line-221"></a><a name="concatMapAccum"></a><span class='hs-comment'>-- | 'concatMap' with an accumulator.</span>
<a name="line-222"></a><span class='hs-comment'>--</span>
<a name="line-223"></a><span class='hs-comment'>-- Since 0.2.0</span>
<a name="line-224"></a><span class='hs-definition'>concatMapAccum</span> <span class='hs-keyglyph'>::</span> <span class='hs-conid'>Resource</span> <span class='hs-varid'>m</span> <span class='hs-keyglyph'>=></span> <span class='hs-layout'>(</span><span class='hs-varid'>a</span> <span class='hs-keyglyph'>-></span> <span class='hs-varid'>accum</span> <span class='hs-keyglyph'>-></span> <span class='hs-layout'>(</span><span class='hs-varid'>accum</span><span class='hs-layout'>,</span> <span class='hs-keyglyph'>[</span><span class='hs-varid'>b</span><span class='hs-keyglyph'>]</span><span class='hs-layout'>)</span><span class='hs-layout'>)</span> <span class='hs-keyglyph'>-></span> <span class='hs-varid'>accum</span> <span class='hs-keyglyph'>-></span> <span class='hs-conid'>Conduit</span> <span class='hs-varid'>a</span> <span class='hs-varid'>m</span> <span class='hs-varid'>b</span>
<a name="line-225"></a><span class='hs-definition'>concatMapAccum</span> <span class='hs-varid'>f</span> <span class='hs-varid'>accum</span> <span class='hs-keyglyph'>=</span> <span class='hs-varid'>conduitState</span> <span class='hs-varid'>accum</span> <span class='hs-varid'>push</span> <span class='hs-varid'>close</span>
<a name="line-226"></a> <span class='hs-keyword'>where</span>
<a name="line-227"></a> <span class='hs-varid'>push</span> <span class='hs-varid'>state</span> <span class='hs-varid'>input</span> <span class='hs-keyglyph'>=</span> <span class='hs-keyword'>let</span> <span class='hs-layout'>(</span><span class='hs-varid'>state'</span><span class='hs-layout'>,</span> <span class='hs-varid'>result</span><span class='hs-layout'>)</span> <span class='hs-keyglyph'>=</span> <span class='hs-varid'>f</span> <span class='hs-varid'>input</span> <span class='hs-varid'>state</span>
<a name="line-228"></a> <span class='hs-keyword'>in</span> <span class='hs-varid'>return</span> <span class='hs-varop'>$</span> <span class='hs-conid'>StateProducing</span> <span class='hs-varid'>state'</span> <span class='hs-varid'>result</span>
<a name="line-229"></a> <span class='hs-varid'>close</span> <span class='hs-keyword'>_</span> <span class='hs-keyglyph'>=</span> <span class='hs-varid'>return</span> <span class='hs-conid'>[]</span>
<a name="line-230"></a>
<a name="line-231"></a><a name="concatMapAccumM"></a><span class='hs-comment'>-- | 'concatMapM' with an accumulator.</span>
<a name="line-232"></a><span class='hs-comment'>--</span>
<a name="line-233"></a><span class='hs-comment'>-- Since 0.2.0</span>
<a name="line-234"></a><span class='hs-definition'>concatMapAccumM</span> <span class='hs-keyglyph'>::</span> <span class='hs-conid'>Resource</span> <span class='hs-varid'>m</span> <span class='hs-keyglyph'>=></span> <span class='hs-layout'>(</span><span class='hs-varid'>a</span> <span class='hs-keyglyph'>-></span> <span class='hs-varid'>accum</span> <span class='hs-keyglyph'>-></span> <span class='hs-varid'>m</span> <span class='hs-layout'>(</span><span class='hs-varid'>accum</span><span class='hs-layout'>,</span> <span class='hs-keyglyph'>[</span><span class='hs-varid'>b</span><span class='hs-keyglyph'>]</span><span class='hs-layout'>)</span><span class='hs-layout'>)</span> <span class='hs-keyglyph'>-></span> <span class='hs-varid'>accum</span> <span class='hs-keyglyph'>-></span> <span class='hs-conid'>Conduit</span> <span class='hs-varid'>a</span> <span class='hs-varid'>m</span> <span class='hs-varid'>b</span>
<a name="line-235"></a><span class='hs-definition'>concatMapAccumM</span> <span class='hs-varid'>f</span> <span class='hs-varid'>accum</span> <span class='hs-keyglyph'>=</span> <span class='hs-varid'>conduitState</span> <span class='hs-varid'>accum</span> <span class='hs-varid'>push</span> <span class='hs-varid'>close</span>
<a name="line-236"></a> <span class='hs-keyword'>where</span>
<a name="line-237"></a> <span class='hs-varid'>push</span> <span class='hs-varid'>state</span> <span class='hs-varid'>input</span> <span class='hs-keyglyph'>=</span> <span class='hs-keyword'>do</span> <span class='hs-layout'>(</span><span class='hs-varid'>state'</span><span class='hs-layout'>,</span> <span class='hs-varid'>result</span><span class='hs-layout'>)</span> <span class='hs-keyglyph'><-</span> <span class='hs-varid'>lift</span> <span class='hs-layout'>(</span><span class='hs-varid'>f</span> <span class='hs-varid'>input</span> <span class='hs-varid'>state</span><span class='hs-layout'>)</span>
<a name="line-238"></a> <span class='hs-varid'>return</span> <span class='hs-varop'>$</span> <span class='hs-conid'>StateProducing</span> <span class='hs-varid'>state'</span> <span class='hs-varid'>result</span>
<a name="line-239"></a> <span class='hs-varid'>close</span> <span class='hs-keyword'>_</span> <span class='hs-keyglyph'>=</span> <span class='hs-varid'>return</span> <span class='hs-conid'>[]</span>
<a name="line-240"></a>
<a name="line-241"></a><a name="consume"></a><span class='hs-comment'>-- | Consume all values from the stream and return as a list. Note that this</span>
<a name="line-242"></a><span class='hs-comment'>-- will pull all values into memory. For a lazy variant, see</span>
<a name="line-243"></a><span class='hs-comment'>-- "Data.Conduit.Lazy".</span>
<a name="line-244"></a><span class='hs-comment'>--</span>
<a name="line-245"></a><span class='hs-comment'>-- Since 0.2.0</span>
<a name="line-246"></a><span class='hs-definition'>consume</span> <span class='hs-keyglyph'>::</span> <span class='hs-conid'>Resource</span> <span class='hs-varid'>m</span> <span class='hs-keyglyph'>=></span> <span class='hs-conid'>Sink</span> <span class='hs-varid'>a</span> <span class='hs-varid'>m</span> <span class='hs-keyglyph'>[</span><span class='hs-varid'>a</span><span class='hs-keyglyph'>]</span>
<a name="line-247"></a><span class='hs-definition'>consume</span> <span class='hs-keyglyph'>=</span> <span class='hs-varid'>sinkState</span>
<a name="line-248"></a> <span class='hs-varid'>id</span>
<a name="line-249"></a> <span class='hs-layout'>(</span><span class='hs-keyglyph'>\</span><span class='hs-varid'>front</span> <span class='hs-varid'>input</span> <span class='hs-keyglyph'>-></span> <span class='hs-varid'>return</span> <span class='hs-layout'>(</span><span class='hs-conid'>StateProcessing</span> <span class='hs-varop'>$</span> <span class='hs-varid'>front</span> <span class='hs-varop'>.</span> <span class='hs-layout'>(</span><span class='hs-varid'>input</span> <span class='hs-conop'>:</span><span class='hs-layout'>)</span><span class='hs-layout'>)</span><span class='hs-layout'>)</span>
<a name="line-250"></a> <span class='hs-layout'>(</span><span class='hs-keyglyph'>\</span><span class='hs-varid'>front</span> <span class='hs-keyglyph'>-></span> <span class='hs-varid'>return</span> <span class='hs-varop'>$</span> <span class='hs-varid'>front</span> <span class='hs-conid'>[]</span><span class='hs-layout'>)</span>
<a name="line-251"></a>
<a name="line-252"></a><a name="groupBy"></a><span class='hs-comment'>-- | Grouping input according to an equality function.</span>
<a name="line-253"></a><span class='hs-comment'>--</span>
<a name="line-254"></a><span class='hs-comment'>-- Since 0.2.0</span>
<a name="line-255"></a><span class='hs-definition'>groupBy</span> <span class='hs-keyglyph'>::</span> <span class='hs-conid'>Resource</span> <span class='hs-varid'>m</span> <span class='hs-keyglyph'>=></span> <span class='hs-layout'>(</span><span class='hs-varid'>a</span> <span class='hs-keyglyph'>-></span> <span class='hs-varid'>a</span> <span class='hs-keyglyph'>-></span> <span class='hs-conid'>Bool</span><span class='hs-layout'>)</span> <span class='hs-keyglyph'>-></span> <span class='hs-conid'>Conduit</span> <span class='hs-varid'>a</span> <span class='hs-varid'>m</span> <span class='hs-keyglyph'>[</span><span class='hs-varid'>a</span><span class='hs-keyglyph'>]</span>
<a name="line-256"></a><span class='hs-definition'>groupBy</span> <span class='hs-varid'>f</span> <span class='hs-keyglyph'>=</span> <span class='hs-varid'>conduitState</span>
<a name="line-257"></a> <span class='hs-conid'>[]</span>
<a name="line-258"></a> <span class='hs-varid'>push</span>
<a name="line-259"></a> <span class='hs-varid'>close</span>
<a name="line-260"></a> <span class='hs-keyword'>where</span>
<a name="line-261"></a> <span class='hs-varid'>push</span> <span class='hs-conid'>[]</span> <span class='hs-varid'>v</span> <span class='hs-keyglyph'>=</span> <span class='hs-varid'>return</span> <span class='hs-varop'>$</span> <span class='hs-conid'>StateProducing</span> <span class='hs-keyglyph'>[</span><span class='hs-varid'>v</span><span class='hs-keyglyph'>]</span> <span class='hs-conid'>[]</span>
<a name="line-262"></a> <span class='hs-varid'>push</span> <span class='hs-varid'>s</span><span class='hs-keyglyph'>@</span><span class='hs-layout'>(</span><span class='hs-varid'>x</span><span class='hs-conop'>:</span><span class='hs-keyword'>_</span><span class='hs-layout'>)</span> <span class='hs-varid'>v</span> <span class='hs-keyglyph'>=</span>
<a name="line-263"></a> <span class='hs-keyword'>if</span> <span class='hs-varid'>f</span> <span class='hs-varid'>x</span> <span class='hs-varid'>v</span> <span class='hs-keyword'>then</span>
<a name="line-264"></a> <span class='hs-varid'>return</span> <span class='hs-varop'>$</span> <span class='hs-conid'>StateProducing</span> <span class='hs-layout'>(</span><span class='hs-varid'>v</span><span class='hs-conop'>:</span><span class='hs-varid'>s</span><span class='hs-layout'>)</span> <span class='hs-conid'>[]</span>
<a name="line-265"></a> <span class='hs-keyword'>else</span>
<a name="line-266"></a> <span class='hs-varid'>return</span> <span class='hs-varop'>$</span> <span class='hs-conid'>StateProducing</span> <span class='hs-keyglyph'>[</span><span class='hs-varid'>v</span><span class='hs-keyglyph'>]</span> <span class='hs-keyglyph'>[</span><span class='hs-varid'>s</span><span class='hs-keyglyph'>]</span>
<a name="line-267"></a> <span class='hs-varid'>close</span> <span class='hs-varid'>s</span> <span class='hs-keyglyph'>=</span> <span class='hs-varid'>return</span> <span class='hs-keyglyph'>[</span><span class='hs-varid'>s</span><span class='hs-keyglyph'>]</span>
<a name="line-268"></a>
<a name="line-269"></a><a name="isolate"></a><span class='hs-comment'>-- | Ensure that the inner sink consumes no more than the given number of</span>
<a name="line-270"></a><span class='hs-comment'>-- values. Note this this does /not/ ensure that the sink consumes all of those</span>
<a name="line-271"></a><span class='hs-comment'>-- values. To get the latter behavior, combine with 'sinkNull', e.g.:</span>
<a name="line-272"></a><span class='hs-comment'>--</span>
<a name="line-273"></a><span class='hs-comment'>-- > src $$ do</span>
<a name="line-274"></a><span class='hs-comment'>-- > x <- isolate count =$ do</span>
<a name="line-275"></a><span class='hs-comment'>-- > x <- someSink</span>
<a name="line-276"></a><span class='hs-comment'>-- > sinkNull</span>
<a name="line-277"></a><span class='hs-comment'>-- > return x</span>
<a name="line-278"></a><span class='hs-comment'>-- > someOtherSink</span>
<a name="line-279"></a><span class='hs-comment'>-- > ...</span>
<a name="line-280"></a><span class='hs-comment'>--</span>
<a name="line-281"></a><span class='hs-comment'>-- Since 0.2.0</span>
<a name="line-282"></a><span class='hs-definition'>isolate</span> <span class='hs-keyglyph'>::</span> <span class='hs-conid'>Resource</span> <span class='hs-varid'>m</span> <span class='hs-keyglyph'>=></span> <span class='hs-conid'>Int</span> <span class='hs-keyglyph'>-></span> <span class='hs-conid'>Conduit</span> <span class='hs-varid'>a</span> <span class='hs-varid'>m</span> <span class='hs-varid'>a</span>
<a name="line-283"></a><span class='hs-definition'>isolate</span> <span class='hs-varid'>count0</span> <span class='hs-keyglyph'>=</span> <span class='hs-varid'>conduitState</span>
<a name="line-284"></a> <span class='hs-varid'>count0</span>
<a name="line-285"></a> <span class='hs-varid'>push</span>
<a name="line-286"></a> <span class='hs-varid'>close</span>
<a name="line-287"></a> <span class='hs-keyword'>where</span>
<a name="line-288"></a> <span class='hs-varid'>close</span> <span class='hs-keyword'>_</span> <span class='hs-keyglyph'>=</span> <span class='hs-varid'>return</span> <span class='hs-conid'>[]</span>
<a name="line-289"></a> <span class='hs-varid'>push</span> <span class='hs-varid'>count</span> <span class='hs-varid'>x</span> <span class='hs-keyglyph'>=</span> <span class='hs-keyword'>do</span>
<a name="line-290"></a> <span class='hs-keyword'>if</span> <span class='hs-varid'>count</span> <span class='hs-varop'>==</span> <span class='hs-num'>0</span>
<a name="line-291"></a> <span class='hs-keyword'>then</span> <span class='hs-varid'>return</span> <span class='hs-varop'>$</span> <span class='hs-conid'>StateFinished</span> <span class='hs-layout'>(</span><span class='hs-conid'>Just</span> <span class='hs-varid'>x</span><span class='hs-layout'>)</span> <span class='hs-conid'>[]</span>
<a name="line-292"></a> <span class='hs-keyword'>else</span> <span class='hs-keyword'>do</span>
<a name="line-293"></a> <span class='hs-keyword'>let</span> <span class='hs-varid'>count'</span> <span class='hs-keyglyph'>=</span> <span class='hs-varid'>count</span> <span class='hs-comment'>-</span> <span class='hs-num'>1</span>
<a name="line-294"></a> <span class='hs-varid'>return</span> <span class='hs-varop'>$</span> <span class='hs-keyword'>if</span> <span class='hs-varid'>count'</span> <span class='hs-varop'>==</span> <span class='hs-num'>0</span>
<a name="line-295"></a> <span class='hs-keyword'>then</span> <span class='hs-conid'>StateFinished</span> <span class='hs-conid'>Nothing</span> <span class='hs-keyglyph'>[</span><span class='hs-varid'>x</span><span class='hs-keyglyph'>]</span>
<a name="line-296"></a> <span class='hs-keyword'>else</span> <span class='hs-conid'>StateProducing</span> <span class='hs-varid'>count'</span> <span class='hs-keyglyph'>[</span><span class='hs-varid'>x</span><span class='hs-keyglyph'>]</span>
<a name="line-297"></a>
<a name="line-298"></a><a name="filter"></a><span class='hs-comment'>-- | Keep only values in the stream passing a given predicate.</span>
<a name="line-299"></a><span class='hs-comment'>--</span>
<a name="line-300"></a><span class='hs-comment'>-- Since 0.2.0</span>
<a name="line-301"></a><span class='hs-definition'>filter</span> <span class='hs-keyglyph'>::</span> <span class='hs-conid'>Resource</span> <span class='hs-varid'>m</span> <span class='hs-keyglyph'>=></span> <span class='hs-layout'>(</span><span class='hs-varid'>a</span> <span class='hs-keyglyph'>-></span> <span class='hs-conid'>Bool</span><span class='hs-layout'>)</span> <span class='hs-keyglyph'>-></span> <span class='hs-conid'>Conduit</span> <span class='hs-varid'>a</span> <span class='hs-varid'>m</span> <span class='hs-varid'>a</span>
<a name="line-302"></a><span class='hs-definition'>filter</span> <span class='hs-varid'>f</span> <span class='hs-keyglyph'>=</span>
<a name="line-303"></a> <span class='hs-varid'>conduit</span>
<a name="line-304"></a> <span class='hs-keyword'>where</span>
<a name="line-305"></a> <span class='hs-varid'>conduit</span> <span class='hs-keyglyph'>=</span> <span class='hs-conid'>Conduit</span> <span class='hs-varid'>push</span> <span class='hs-varid'>close</span>
<a name="line-306"></a> <span class='hs-varid'>push</span> <span class='hs-keyglyph'>=</span> <span class='hs-varid'>return</span> <span class='hs-varop'>.</span> <span class='hs-conid'>Producing</span> <span class='hs-varid'>conduit</span> <span class='hs-varop'>.</span> <span class='hs-conid'>Prelude</span><span class='hs-varop'>.</span><span class='hs-varid'>filter</span> <span class='hs-varid'>f</span> <span class='hs-varop'>.</span> <span class='hs-varid'>return</span>
<a name="line-307"></a> <span class='hs-varid'>close</span> <span class='hs-keyglyph'>=</span> <span class='hs-varid'>return</span> <span class='hs-conid'>[]</span>
<a name="line-308"></a>
<a name="line-309"></a><a name="sinkNull"></a><span class='hs-comment'>-- | Ignore the remainder of values in the source. Particularly useful when</span>
<a name="line-310"></a><span class='hs-comment'>-- combined with 'isolate'.</span>
<a name="line-311"></a><span class='hs-comment'>--</span>
<a name="line-312"></a><span class='hs-comment'>-- Since 0.2.0</span>
<a name="line-313"></a><span class='hs-definition'>sinkNull</span> <span class='hs-keyglyph'>::</span> <span class='hs-conid'>Resource</span> <span class='hs-varid'>m</span> <span class='hs-keyglyph'>=></span> <span class='hs-conid'>Sink</span> <span class='hs-varid'>a</span> <span class='hs-varid'>m</span> <span class='hs-conid'>()</span>
<a name="line-314"></a><span class='hs-definition'>sinkNull</span> <span class='hs-keyglyph'>=</span>
<a name="line-315"></a> <span class='hs-conid'>SinkData</span> <span class='hs-varid'>push</span> <span class='hs-varid'>close</span>
<a name="line-316"></a> <span class='hs-keyword'>where</span>
<a name="line-317"></a> <span class='hs-varid'>push</span> <span class='hs-keyword'>_</span> <span class='hs-keyglyph'>=</span> <span class='hs-varid'>return</span> <span class='hs-varop'>$</span> <span class='hs-conid'>Processing</span> <span class='hs-varid'>push</span> <span class='hs-varid'>close</span>
<a name="line-318"></a> <span class='hs-varid'>close</span> <span class='hs-keyglyph'>=</span> <span class='hs-varid'>return</span> <span class='hs-conid'>()</span>
<a name="line-319"></a>
<a name="line-320"></a><a name="sourceNull"></a><span class='hs-comment'>-- | A source that returns nothing. Note that this is just a type-restricted</span>
<a name="line-321"></a><span class='hs-comment'>-- synonym for 'mempty'.</span>
<a name="line-322"></a><span class='hs-comment'>--</span>
<a name="line-323"></a><span class='hs-comment'>-- Since 0.2.0</span>
<a name="line-324"></a><span class='hs-definition'>sourceNull</span> <span class='hs-keyglyph'>::</span> <span class='hs-conid'>Resource</span> <span class='hs-varid'>m</span> <span class='hs-keyglyph'>=></span> <span class='hs-conid'>Source</span> <span class='hs-varid'>m</span> <span class='hs-varid'>a</span>
<a name="line-325"></a><span class='hs-definition'>sourceNull</span> <span class='hs-keyglyph'>=</span> <span class='hs-varid'>mempty</span>
<a name="line-326"></a>
<a name="line-327"></a><a name="zip"></a><span class='hs-comment'>-- | Combines two sources. The new source will stop producing once either</span>
<a name="line-328"></a><span class='hs-comment'>-- source has been exhausted.</span>
<a name="line-329"></a><span class='hs-comment'>--</span>
<a name="line-330"></a><span class='hs-comment'>-- Since 0.2.2</span>
<a name="line-331"></a><span class='hs-definition'>zip</span> <span class='hs-keyglyph'>::</span> <span class='hs-conid'>Resource</span> <span class='hs-varid'>m</span> <span class='hs-keyglyph'>=></span> <span class='hs-conid'>Source</span> <span class='hs-varid'>m</span> <span class='hs-varid'>a</span> <span class='hs-keyglyph'>-></span> <span class='hs-conid'>Source</span> <span class='hs-varid'>m</span> <span class='hs-varid'>b</span> <span class='hs-keyglyph'>-></span> <span class='hs-conid'>Source</span> <span class='hs-varid'>m</span> <span class='hs-layout'>(</span><span class='hs-varid'>a</span><span class='hs-layout'>,</span> <span class='hs-varid'>b</span><span class='hs-layout'>)</span>
<a name="line-332"></a><span class='hs-definition'>zip</span> <span class='hs-varid'>sa</span> <span class='hs-varid'>sb</span> <span class='hs-keyglyph'>=</span> <span class='hs-conid'>Source</span> <span class='hs-varid'>pull</span> <span class='hs-varid'>close</span>
<a name="line-333"></a> <span class='hs-keyword'>where</span>
<a name="line-334"></a> <span class='hs-varid'>pull</span> <span class='hs-keyglyph'>=</span> <span class='hs-keyword'>do</span> <span class='hs-varid'>ra</span> <span class='hs-keyglyph'><-</span> <span class='hs-varid'>sourcePull</span> <span class='hs-varid'>sa</span>
<a name="line-335"></a> <span class='hs-keyword'>case</span> <span class='hs-varid'>ra</span> <span class='hs-keyword'>of</span>
<a name="line-336"></a> <span class='hs-conid'>Closed</span> <span class='hs-keyglyph'>-></span> <span class='hs-varid'>return</span> <span class='hs-conid'>Closed</span>
<a name="line-337"></a> <span class='hs-conid'>Open</span> <span class='hs-varid'>ra'</span> <span class='hs-varid'>a</span> <span class='hs-keyglyph'>-></span> <span class='hs-keyword'>do</span> <span class='hs-varid'>rb</span> <span class='hs-keyglyph'><-</span> <span class='hs-varid'>sourcePull</span> <span class='hs-varid'>sb</span>
<a name="line-338"></a> <span class='hs-keyword'>case</span> <span class='hs-varid'>rb</span> <span class='hs-keyword'>of</span>
<a name="line-339"></a> <span class='hs-conid'>Closed</span> <span class='hs-keyglyph'>-></span> <span class='hs-varid'>return</span> <span class='hs-conid'>Closed</span>
<a name="line-340"></a> <span class='hs-conid'>Open</span> <span class='hs-varid'>rb'</span> <span class='hs-varid'>b</span> <span class='hs-keyglyph'>-></span> <span class='hs-varid'>return</span> <span class='hs-varop'>$</span> <span class='hs-conid'>Open</span> <span class='hs-layout'>(</span><span class='hs-varid'>zip</span> <span class='hs-varid'>ra'</span> <span class='hs-varid'>rb'</span><span class='hs-layout'>)</span> <span class='hs-layout'>(</span><span class='hs-varid'>a</span><span class='hs-layout'>,</span> <span class='hs-varid'>b</span><span class='hs-layout'>)</span>
<a name="line-341"></a> <span class='hs-varid'>close</span> <span class='hs-keyglyph'>=</span> <span class='hs-varid'>sourceClose</span> <span class='hs-varid'>sa</span> <span class='hs-varop'>>></span> <span class='hs-varid'>sourceClose</span> <span class='hs-varid'>sb</span>
<a name="line-342"></a>
</pre></body>
</html>
