<?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>src/Codec/Binary/Yenc.hs</title>
<link type='text/css' rel='stylesheet' href='hscolour.css' />
</head>
<body>
<pre><a name="line-1"></a><span class='hs-comment'>-- |</span>
<a name="line-2"></a><span class='hs-comment'>-- Module : Codec.Binary.Yenc</span>
<a name="line-3"></a><span class='hs-comment'>-- Copyright : (c) 2007 Magnus Therning</span>
<a name="line-4"></a><span class='hs-comment'>-- License : BSD3</span>
<a name="line-5"></a><span class='hs-comment'>--</span>
<a name="line-6"></a><span class='hs-comment'>-- Implementation based on the specification found at</span>
<a name="line-7"></a><span class='hs-comment'>-- <<a href="http://yence.sourceforge.net/docs/protocol/version1_3_draft.html">http://yence.sourceforge.net/docs/protocol/version1_3_draft.html</a>>.</span>
<a name="line-8"></a><span class='hs-comment'>--</span>
<a name="line-9"></a><span class='hs-comment'>-- Further documentation and information can be found at</span>
<a name="line-10"></a><span class='hs-comment'>-- <<a href="http://www.haskell.org/haskellwiki/Library/Data_encoding">http://www.haskell.org/haskellwiki/Library/Data_encoding</a>>.</span>
<a name="line-11"></a><span class='hs-keyword'>module</span> <span class='hs-conid'>Codec</span><span class='hs-varop'>.</span><span class='hs-conid'>Binary</span><span class='hs-varop'>.</span><span class='hs-conid'>Yenc</span>
<a name="line-12"></a> <span class='hs-layout'>(</span> <span class='hs-conid'>EncIncData</span><span class='hs-layout'>(</span><span class='hs-keyglyph'>..</span><span class='hs-layout'>)</span>
<a name="line-13"></a> <span class='hs-layout'>,</span> <span class='hs-conid'>EncIncRes</span><span class='hs-layout'>(</span><span class='hs-keyglyph'>..</span><span class='hs-layout'>)</span>
<a name="line-14"></a> <span class='hs-layout'>,</span> <span class='hs-varid'>encodeInc</span>
<a name="line-15"></a> <span class='hs-layout'>,</span> <span class='hs-varid'>encode</span>
<a name="line-16"></a> <span class='hs-layout'>,</span> <span class='hs-conid'>DecIncData</span><span class='hs-layout'>(</span><span class='hs-keyglyph'>..</span><span class='hs-layout'>)</span>
<a name="line-17"></a> <span class='hs-layout'>,</span> <span class='hs-conid'>DecIncRes</span><span class='hs-layout'>(</span><span class='hs-keyglyph'>..</span><span class='hs-layout'>)</span>
<a name="line-18"></a> <span class='hs-layout'>,</span> <span class='hs-varid'>decodeInc</span>
<a name="line-19"></a> <span class='hs-layout'>,</span> <span class='hs-varid'>decode</span>
<a name="line-20"></a> <span class='hs-layout'>,</span> <span class='hs-varid'>chop</span>
<a name="line-21"></a> <span class='hs-layout'>,</span> <span class='hs-varid'>unchop</span>
<a name="line-22"></a> <span class='hs-layout'>)</span> <span class='hs-keyword'>where</span>
<a name="line-23"></a>
<a name="line-24"></a><span class='hs-keyword'>import</span> <span class='hs-conid'>Codec</span><span class='hs-varop'>.</span><span class='hs-conid'>Binary</span><span class='hs-varop'>.</span><span class='hs-conid'>Util</span>
<a name="line-25"></a>
<a name="line-26"></a><span class='hs-keyword'>import</span> <span class='hs-conid'>Data</span><span class='hs-varop'>.</span><span class='hs-conid'>Word</span>
<a name="line-27"></a>
<a name="line-28"></a><span class='hs-sel'>_criticalsIn</span> <span class='hs-keyglyph'>=</span> <span class='hs-keyglyph'>[</span><span class='hs-num'>0xd6</span><span class='hs-layout'>,</span> <span class='hs-num'>0xe0</span><span class='hs-layout'>,</span> <span class='hs-num'>0xe3</span><span class='hs-layout'>,</span> <span class='hs-num'>0x13</span><span class='hs-keyglyph'>]</span>
<a name="line-29"></a><span class='hs-sel'>_equal</span> <span class='hs-keyglyph'>=</span> <span class='hs-num'>0x3d</span>
<a name="line-30"></a>
<a name="line-31"></a><a name="encodeInc"></a><span class='hs-comment'>-- {{{1 encode</span>
<a name="line-32"></a><span class='hs-comment'>-- | Incremental encoder function.</span>
<a name="line-33"></a><span class='hs-definition'>encodeInc</span> <span class='hs-keyglyph'>::</span> <span class='hs-conid'>EncIncData</span> <span class='hs-keyglyph'>-></span> <span class='hs-conid'>EncIncRes</span> <span class='hs-keyglyph'>[</span><span class='hs-conid'>Word8</span><span class='hs-keyglyph'>]</span>
<a name="line-34"></a><span class='hs-definition'>encodeInc</span> <span class='hs-varid'>e</span> <span class='hs-keyglyph'>=</span> <span class='hs-varid'>eI</span> <span class='hs-varid'>e</span>
<a name="line-35"></a> <span class='hs-keyword'>where</span>
<a name="line-36"></a> <span class='hs-varid'>enc</span> <span class='hs-conid'>[]</span> <span class='hs-keyglyph'>=</span> <span class='hs-conid'>[]</span>
<a name="line-37"></a> <span class='hs-varid'>enc</span> <span class='hs-layout'>(</span><span class='hs-varid'>o</span><span class='hs-conop'>:</span><span class='hs-varid'>os</span><span class='hs-layout'>)</span>
<a name="line-38"></a> <span class='hs-keyglyph'>|</span> <span class='hs-varid'>o</span> <span class='hs-varop'>`elem`</span> <span class='hs-sel'>_criticalsIn</span> <span class='hs-keyglyph'>=</span> <span class='hs-sel'>_equal</span> <span class='hs-conop'>:</span> <span class='hs-varid'>o</span> <span class='hs-varop'>+</span> <span class='hs-num'>106</span> <span class='hs-conop'>:</span> <span class='hs-varid'>enc</span> <span class='hs-varid'>os</span>
<a name="line-39"></a> <span class='hs-keyglyph'>|</span> <span class='hs-varid'>otherwise</span> <span class='hs-keyglyph'>=</span> <span class='hs-varid'>o</span> <span class='hs-varop'>+</span> <span class='hs-num'>42</span> <span class='hs-conop'>:</span> <span class='hs-varid'>enc</span> <span class='hs-varid'>os</span>
<a name="line-40"></a>
<a name="line-41"></a> <span class='hs-varid'>eI</span> <span class='hs-conid'>EDone</span> <span class='hs-keyglyph'>=</span> <span class='hs-conid'>EFinal</span> <span class='hs-conid'>[]</span>
<a name="line-42"></a> <span class='hs-varid'>eI</span> <span class='hs-layout'>(</span><span class='hs-conid'>EChunk</span> <span class='hs-varid'>bs</span><span class='hs-layout'>)</span> <span class='hs-keyglyph'>=</span> <span class='hs-conid'>EPart</span> <span class='hs-layout'>(</span><span class='hs-varid'>enc</span> <span class='hs-varid'>bs</span><span class='hs-layout'>)</span> <span class='hs-varid'>encodeInc</span>
<a name="line-43"></a>
<a name="line-44"></a><a name="encode"></a><span class='hs-comment'>-- | Encode data.</span>
<a name="line-45"></a><span class='hs-definition'>encode</span> <span class='hs-keyglyph'>::</span> <span class='hs-keyglyph'>[</span><span class='hs-conid'>Word8</span><span class='hs-keyglyph'>]</span> <span class='hs-keyglyph'>-></span> <span class='hs-keyglyph'>[</span><span class='hs-conid'>Word8</span><span class='hs-keyglyph'>]</span>
<a name="line-46"></a><span class='hs-definition'>encode</span> <span class='hs-keyglyph'>=</span> <span class='hs-varid'>encoder</span> <span class='hs-varid'>encodeInc</span>
<a name="line-47"></a>
<a name="line-48"></a><a name="decodeInc"></a><span class='hs-comment'>-- {{{1 decode</span>
<a name="line-49"></a><span class='hs-comment'>-- | Incremental decoder function.</span>
<a name="line-50"></a><span class='hs-definition'>decodeInc</span> <span class='hs-keyglyph'>::</span> <span class='hs-conid'>DecIncData</span> <span class='hs-keyglyph'>[</span><span class='hs-conid'>Word8</span><span class='hs-keyglyph'>]</span> <span class='hs-keyglyph'>-></span> <span class='hs-conid'>DecIncRes</span> <span class='hs-keyglyph'>[</span><span class='hs-conid'>Word8</span><span class='hs-keyglyph'>]</span>
<a name="line-51"></a><span class='hs-definition'>decodeInc</span> <span class='hs-varid'>d</span> <span class='hs-keyglyph'>=</span> <span class='hs-varid'>dI</span> <span class='hs-conid'>[]</span> <span class='hs-varid'>d</span>
<a name="line-52"></a> <span class='hs-keyword'>where</span>
<a name="line-53"></a> <span class='hs-varid'>dI</span> <span class='hs-conid'>[]</span> <span class='hs-conid'>DDone</span> <span class='hs-keyglyph'>=</span> <span class='hs-conid'>DFinal</span> <span class='hs-conid'>[]</span> <span class='hs-conid'>[]</span>
<a name="line-54"></a> <span class='hs-varid'>dI</span> <span class='hs-varid'>lo</span> <span class='hs-conid'>DDone</span> <span class='hs-keyglyph'>=</span> <span class='hs-conid'>DFail</span> <span class='hs-conid'>[]</span> <span class='hs-varid'>lo</span>
<a name="line-55"></a> <span class='hs-varid'>dI</span> <span class='hs-varid'>lo</span> <span class='hs-layout'>(</span><span class='hs-conid'>DChunk</span> <span class='hs-varid'>s</span><span class='hs-layout'>)</span> <span class='hs-keyglyph'>=</span> <span class='hs-varid'>doDec</span> <span class='hs-conid'>[]</span> <span class='hs-layout'>(</span><span class='hs-varid'>lo</span> <span class='hs-varop'>++</span> <span class='hs-varid'>s</span><span class='hs-layout'>)</span>
<a name="line-56"></a> <span class='hs-keyword'>where</span>
<a name="line-57"></a> <span class='hs-varid'>doDec</span> <span class='hs-varid'>acc</span> <span class='hs-layout'>(</span><span class='hs-num'>0x3d</span><span class='hs-conop'>:</span><span class='hs-varid'>d</span><span class='hs-conop'>:</span><span class='hs-varid'>ds</span><span class='hs-layout'>)</span> <span class='hs-keyglyph'>=</span> <span class='hs-varid'>doDec</span> <span class='hs-layout'>(</span><span class='hs-varid'>acc</span> <span class='hs-varop'>++</span> <span class='hs-keyglyph'>[</span><span class='hs-varid'>d</span> <span class='hs-varop'>+</span> <span class='hs-num'>150</span><span class='hs-keyglyph'>]</span><span class='hs-layout'>)</span> <span class='hs-varid'>ds</span>
<a name="line-58"></a> <span class='hs-varid'>doDec</span> <span class='hs-varid'>acc</span> <span class='hs-layout'>(</span><span class='hs-varid'>d</span><span class='hs-conop'>:</span><span class='hs-varid'>ds</span><span class='hs-layout'>)</span> <span class='hs-keyglyph'>=</span> <span class='hs-varid'>doDec</span> <span class='hs-layout'>(</span><span class='hs-varid'>acc</span> <span class='hs-varop'>++</span> <span class='hs-keyglyph'>[</span><span class='hs-varid'>d</span> <span class='hs-varop'>+</span> <span class='hs-num'>214</span><span class='hs-keyglyph'>]</span><span class='hs-layout'>)</span> <span class='hs-varid'>ds</span>
<a name="line-59"></a> <span class='hs-varid'>doDec</span> <span class='hs-varid'>acc</span> <span class='hs-varid'>s'</span> <span class='hs-keyglyph'>=</span> <span class='hs-conid'>DPart</span> <span class='hs-varid'>acc</span> <span class='hs-layout'>(</span><span class='hs-varid'>dI</span> <span class='hs-varid'>s'</span><span class='hs-layout'>)</span>
<a name="line-60"></a>
<a name="line-61"></a><a name="decode"></a><span class='hs-comment'>-- | Decode data.</span>
<a name="line-62"></a><span class='hs-definition'>decode</span> <span class='hs-keyglyph'>::</span> <span class='hs-keyglyph'>[</span><span class='hs-conid'>Word8</span><span class='hs-keyglyph'>]</span> <span class='hs-keyglyph'>-></span> <span class='hs-conid'>Maybe</span> <span class='hs-keyglyph'>[</span><span class='hs-conid'>Word8</span><span class='hs-keyglyph'>]</span>
<a name="line-63"></a><span class='hs-definition'>decode</span> <span class='hs-keyglyph'>=</span> <span class='hs-varid'>decoder</span> <span class='hs-varid'>decodeInc</span>
<a name="line-64"></a>
<a name="line-65"></a><a name="chop"></a><span class='hs-comment'>-- {{{1 chop</span>
<a name="line-66"></a><span class='hs-comment'>-- | Chop up a string in parts.</span>
<a name="line-67"></a><span class='hs-definition'>chop</span> <span class='hs-keyglyph'>::</span> <span class='hs-conid'>Int</span> <span class='hs-comment'>-- ^ length of individual lines</span>
<a name="line-68"></a> <span class='hs-keyglyph'>-></span> <span class='hs-keyglyph'>[</span><span class='hs-conid'>Word8</span><span class='hs-keyglyph'>]</span>
<a name="line-69"></a> <span class='hs-keyglyph'>-></span> <span class='hs-keyglyph'>[</span><span class='hs-keyglyph'>[</span><span class='hs-conid'>Word8</span><span class='hs-keyglyph'>]</span><span class='hs-keyglyph'>]</span>
<a name="line-70"></a><span class='hs-definition'>chop</span> <span class='hs-keyword'>_</span> <span class='hs-conid'>[]</span> <span class='hs-keyglyph'>=</span> <span class='hs-conid'>[]</span>
<a name="line-71"></a><span class='hs-definition'>chop</span> <span class='hs-varid'>n</span> <span class='hs-varid'>ws</span> <span class='hs-keyglyph'>=</span> <span class='hs-keyword'>let</span>
<a name="line-72"></a> <span class='hs-sel'>_n</span> <span class='hs-keyglyph'>=</span> <span class='hs-varid'>max</span> <span class='hs-varid'>n</span> <span class='hs-num'>1</span>
<a name="line-73"></a> <span class='hs-layout'>(</span><span class='hs-varid'>p1</span><span class='hs-layout'>,</span> <span class='hs-varid'>p2</span><span class='hs-layout'>)</span> <span class='hs-keyglyph'>=</span> <span class='hs-varid'>splitAt</span> <span class='hs-sel'>_n</span> <span class='hs-varid'>ws</span>
<a name="line-74"></a> <span class='hs-keyword'>in</span>
<a name="line-75"></a> <span class='hs-keyword'>if</span> <span class='hs-varid'>last</span> <span class='hs-varid'>p1</span> <span class='hs-varop'>==</span> <span class='hs-sel'>_equal</span>
<a name="line-76"></a> <span class='hs-keyword'>then</span> <span class='hs-layout'>(</span><span class='hs-varid'>p1</span> <span class='hs-varop'>++</span> <span class='hs-varid'>take</span> <span class='hs-num'>1</span> <span class='hs-varid'>p2</span><span class='hs-layout'>)</span> <span class='hs-conop'>:</span> <span class='hs-varid'>chop</span> <span class='hs-sel'>_n</span> <span class='hs-layout'>(</span><span class='hs-varid'>drop</span> <span class='hs-num'>1</span> <span class='hs-varid'>p2</span><span class='hs-layout'>)</span>
<a name="line-77"></a> <span class='hs-keyword'>else</span> <span class='hs-varid'>p1</span> <span class='hs-conop'>:</span> <span class='hs-varid'>chop</span> <span class='hs-sel'>_n</span> <span class='hs-varid'>p2</span>
<a name="line-78"></a>
<a name="line-79"></a><a name="unchop"></a><span class='hs-comment'>-- {{{1 unchop</span>
<a name="line-80"></a><span class='hs-comment'>-- | Concatenate the strings into one long string.</span>
<a name="line-81"></a><span class='hs-definition'>unchop</span> <span class='hs-keyglyph'>::</span> <span class='hs-keyglyph'>[</span><span class='hs-keyglyph'>[</span><span class='hs-conid'>Word8</span><span class='hs-keyglyph'>]</span><span class='hs-keyglyph'>]</span>
<a name="line-82"></a> <span class='hs-keyglyph'>-></span> <span class='hs-keyglyph'>[</span><span class='hs-conid'>Word8</span><span class='hs-keyglyph'>]</span>
<a name="line-83"></a><span class='hs-definition'>unchop</span> <span class='hs-keyglyph'>=</span> <span class='hs-varid'>concat</span>
</pre></body>
</html>
