<?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://code.haskell.org/~malcolm/hscolour/ -->
<title>src/Darcs/Patch/Prim/V1/Commute.hs</title>
<link type='text/css' rel='stylesheet' href='hscolour.css' />
</head>
<body>
<pre><a name="line-1"></a><span class='hs-comment'>{-# OPTIONS_GHC -fno-warn-orphans #-}</span>
<a name="line-2"></a><span class='hs-keyword'>module</span> <span class='hs-conid'>Darcs</span><span class='hs-varop'>.</span><span class='hs-conid'>Patch</span><span class='hs-varop'>.</span><span class='hs-conid'>Prim</span><span class='hs-varop'>.</span><span class='hs-conid'>V1</span><span class='hs-varop'>.</span><span class='hs-conid'>Commute</span>
<a name="line-3"></a> <span class='hs-layout'>(</span> <span class='hs-conid'>Perhaps</span><span class='hs-layout'>(</span><span class='hs-keyglyph'>..</span><span class='hs-layout'>)</span>
<a name="line-4"></a> <span class='hs-layout'>,</span> <span class='hs-varid'>subcommutes</span><span class='hs-layout'>,</span> <span class='hs-conid'>WrappedCommuteFunction</span><span class='hs-layout'>(</span><span class='hs-keyglyph'>..</span><span class='hs-layout'>)</span>
<a name="line-5"></a> <span class='hs-layout'>)</span>
<a name="line-6"></a> <span class='hs-keyword'>where</span>
<a name="line-7"></a>
<a name="line-8"></a><span class='hs-keyword'>import</span> <span class='hs-conid'>Prelude</span> <span class='hs-varid'>hiding</span> <span class='hs-layout'>(</span> <span class='hs-varid'>pi</span> <span class='hs-layout'>)</span>
<a name="line-9"></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-layout'>(</span> <span class='hs-conid'>MonadPlus</span><span class='hs-layout'>,</span> <span class='hs-varid'>msum</span><span class='hs-layout'>,</span> <span class='hs-varid'>mzero</span><span class='hs-layout'>,</span> <span class='hs-varid'>mplus</span> <span class='hs-layout'>)</span>
<a name="line-10"></a>
<a name="line-11"></a><span class='hs-keyword'>import</span> <span class='hs-keyword'>qualified</span> <span class='hs-conid'>Data</span><span class='hs-varop'>.</span><span class='hs-conid'>ByteString</span> <span class='hs-keyword'>as</span> <span class='hs-conid'>B</span> <span class='hs-layout'>(</span><span class='hs-conid'>ByteString</span><span class='hs-layout'>,</span> <span class='hs-varid'>concat</span><span class='hs-layout'>)</span>
<a name="line-12"></a><span class='hs-keyword'>import</span> <span class='hs-keyword'>qualified</span> <span class='hs-conid'>Data</span><span class='hs-varop'>.</span><span class='hs-conid'>ByteString</span><span class='hs-varop'>.</span><span class='hs-conid'>Char8</span> <span class='hs-keyword'>as</span> <span class='hs-conid'>BC</span> <span class='hs-layout'>(</span><span class='hs-varid'>pack</span><span class='hs-layout'>)</span>
<a name="line-13"></a>
<a name="line-14"></a><span class='hs-keyword'>import</span> <span class='hs-conid'>Darcs</span><span class='hs-varop'>.</span><span class='hs-conid'>Patch</span><span class='hs-varop'>.</span><span class='hs-conid'>FileName</span> <span class='hs-layout'>(</span> <span class='hs-conid'>FileName</span><span class='hs-layout'>,</span> <span class='hs-varid'>fn2fp</span><span class='hs-layout'>,</span> <span class='hs-varid'>movedirfilename</span> <span class='hs-layout'>)</span>
<a name="line-15"></a><span class='hs-keyword'>import</span> <span class='hs-conid'>Darcs</span><span class='hs-varop'>.</span><span class='hs-conid'>Witnesses</span><span class='hs-varop'>.</span><span class='hs-conid'>Ordered</span> <span class='hs-layout'>(</span> <span class='hs-layout'>(</span><span class='hs-conop'>:<</span><span class='hs-layout'>)</span><span class='hs-layout'>(</span><span class='hs-keyglyph'>..</span><span class='hs-layout'>)</span> <span class='hs-layout'>)</span>
<a name="line-16"></a><span class='hs-keyword'>import</span> <span class='hs-conid'>Darcs</span><span class='hs-varop'>.</span><span class='hs-conid'>Witnesses</span><span class='hs-varop'>.</span><span class='hs-conid'>Unsafe</span> <span class='hs-layout'>(</span> <span class='hs-varid'>unsafeCoerceP</span> <span class='hs-layout'>)</span>
<a name="line-17"></a><span class='hs-keyword'>import</span> <span class='hs-conid'>Darcs</span><span class='hs-varop'>.</span><span class='hs-conid'>Patch</span><span class='hs-varop'>.</span><span class='hs-conid'>Prim</span><span class='hs-varop'>.</span><span class='hs-conid'>V1</span><span class='hs-varop'>.</span><span class='hs-conid'>Core</span>
<a name="line-18"></a> <span class='hs-layout'>(</span> <span class='hs-conid'>Prim</span><span class='hs-layout'>(</span><span class='hs-keyglyph'>..</span><span class='hs-layout'>)</span><span class='hs-layout'>,</span> <span class='hs-conid'>FilePatchType</span><span class='hs-layout'>(</span><span class='hs-keyglyph'>..</span><span class='hs-layout'>)</span> <span class='hs-layout'>)</span>
<a name="line-19"></a><span class='hs-keyword'>import</span> <span class='hs-conid'>Darcs</span><span class='hs-varop'>.</span><span class='hs-conid'>Patch</span><span class='hs-varop'>.</span><span class='hs-conid'>Invert</span> <span class='hs-layout'>(</span> <span class='hs-conid'>Invert</span><span class='hs-layout'>(</span><span class='hs-keyglyph'>..</span><span class='hs-layout'>)</span> <span class='hs-layout'>)</span>
<a name="line-20"></a><span class='hs-keyword'>import</span> <span class='hs-conid'>Darcs</span><span class='hs-varop'>.</span><span class='hs-conid'>Patch</span><span class='hs-varop'>.</span><span class='hs-conid'>Commute</span> <span class='hs-layout'>(</span> <span class='hs-conid'>Commute</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'>toFwdCommute</span><span class='hs-layout'>,</span> <span class='hs-varid'>toRevCommute</span> <span class='hs-layout'>)</span>
<a name="line-21"></a><span class='hs-keyword'>import</span> <span class='hs-conid'>Darcs</span><span class='hs-varop'>.</span><span class='hs-conid'>Patch</span><span class='hs-varop'>.</span><span class='hs-conid'>Permutations</span> <span class='hs-conid'>()</span> <span class='hs-comment'>-- for Invert instance of FL</span>
<a name="line-22"></a><span class='hs-keyword'>import</span> <span class='hs-conid'>Darcs</span><span class='hs-varop'>.</span><span class='hs-conid'>Patch</span><span class='hs-varop'>.</span><span class='hs-conid'>TokenReplace</span> <span class='hs-layout'>(</span> <span class='hs-varid'>tryTokInternal</span> <span class='hs-layout'>)</span>
<a name="line-23"></a>
<a name="line-24"></a><span class='hs-cpp'>#include "impossible.h"</span>
<a name="line-25"></a><span class='hs-cpp'>#include "gadts.h"</span>
<a name="line-26"></a>
<a name="line-27"></a><a name="isInDirectory"></a><span class='hs-definition'>isInDirectory</span> <span class='hs-keyglyph'>::</span> <span class='hs-conid'>FileName</span> <span class='hs-keyglyph'>-></span> <span class='hs-conid'>FileName</span> <span class='hs-keyglyph'>-></span> <span class='hs-conid'>Bool</span>
<a name="line-28"></a><span class='hs-definition'>isInDirectory</span> <span class='hs-varid'>d</span> <span class='hs-varid'>f</span> <span class='hs-keyglyph'>=</span> <span class='hs-varid'>iid</span> <span class='hs-layout'>(</span><span class='hs-varid'>fn2fp</span> <span class='hs-varid'>d</span><span class='hs-layout'>)</span> <span class='hs-layout'>(</span><span class='hs-varid'>fn2fp</span> <span class='hs-varid'>f</span><span class='hs-layout'>)</span>
<a name="line-29"></a> <span class='hs-keyword'>where</span> <span class='hs-varid'>iid</span> <span class='hs-layout'>(</span><span class='hs-varid'>cd</span><span class='hs-conop'>:</span><span class='hs-varid'>cds</span><span class='hs-layout'>)</span> <span class='hs-layout'>(</span><span class='hs-varid'>cf</span><span class='hs-conop'>:</span><span class='hs-varid'>cfs</span><span class='hs-layout'>)</span>
<a name="line-30"></a> <span class='hs-keyglyph'>|</span> <span class='hs-varid'>cd</span> <span class='hs-varop'>/=</span> <span class='hs-varid'>cf</span> <span class='hs-keyglyph'>=</span> <span class='hs-conid'>False</span>
<a name="line-31"></a> <span class='hs-keyglyph'>|</span> <span class='hs-varid'>otherwise</span> <span class='hs-keyglyph'>=</span> <span class='hs-varid'>iid</span> <span class='hs-varid'>cds</span> <span class='hs-varid'>cfs</span>
<a name="line-32"></a> <span class='hs-varid'>iid</span> <span class='hs-conid'>[]</span> <span class='hs-layout'>(</span><span class='hs-chr'>'/'</span><span class='hs-conop'>:</span><span class='hs-keyword'>_</span><span class='hs-layout'>)</span> <span class='hs-keyglyph'>=</span> <span class='hs-conid'>True</span>
<a name="line-33"></a> <span class='hs-varid'>iid</span> <span class='hs-conid'>[]</span> <span class='hs-conid'>[]</span> <span class='hs-keyglyph'>=</span> <span class='hs-conid'>True</span> <span class='hs-comment'>-- Count directory itself as being in directory...</span>
<a name="line-34"></a> <span class='hs-varid'>iid</span> <span class='hs-keyword'>_</span> <span class='hs-keyword'>_</span> <span class='hs-keyglyph'>=</span> <span class='hs-conid'>False</span>
<a name="line-35"></a>
<a name="line-36"></a><a name="Perhaps"></a><span class='hs-keyword'>data</span> <span class='hs-conid'>Perhaps</span> <span class='hs-varid'>a</span> <span class='hs-keyglyph'>=</span> <span class='hs-conid'>Unknown</span> <span class='hs-keyglyph'>|</span> <span class='hs-conid'>Failed</span> <span class='hs-keyglyph'>|</span> <span class='hs-conid'>Succeeded</span> <span class='hs-varid'>a</span>
<a name="line-37"></a>
<a name="line-38"></a><a name="instance%20Monad%20Perhaps"></a><span class='hs-keyword'>instance</span> <span class='hs-conid'>Monad</span> <span class='hs-conid'>Perhaps</span> <span class='hs-keyword'>where</span>
<a name="line-39"></a> <span class='hs-layout'>(</span><span class='hs-conid'>Succeeded</span> <span class='hs-varid'>x</span><span class='hs-layout'>)</span> <span class='hs-varop'>>>=</span> <span class='hs-varid'>k</span> <span class='hs-keyglyph'>=</span> <span class='hs-varid'>k</span> <span class='hs-varid'>x</span>
<a name="line-40"></a> <span class='hs-conid'>Failed</span> <span class='hs-varop'>>>=</span> <span class='hs-keyword'>_</span> <span class='hs-keyglyph'>=</span> <span class='hs-conid'>Failed</span>
<a name="line-41"></a> <span class='hs-conid'>Unknown</span> <span class='hs-varop'>>>=</span> <span class='hs-keyword'>_</span> <span class='hs-keyglyph'>=</span> <span class='hs-conid'>Unknown</span>
<a name="line-42"></a> <span class='hs-conid'>Failed</span> <span class='hs-varop'>>></span> <span class='hs-keyword'>_</span> <span class='hs-keyglyph'>=</span> <span class='hs-conid'>Failed</span>
<a name="line-43"></a> <span class='hs-layout'>(</span><span class='hs-conid'>Succeeded</span> <span class='hs-keyword'>_</span><span class='hs-layout'>)</span> <span class='hs-varop'>>></span> <span class='hs-varid'>k</span> <span class='hs-keyglyph'>=</span> <span class='hs-varid'>k</span>
<a name="line-44"></a> <span class='hs-conid'>Unknown</span> <span class='hs-varop'>>></span> <span class='hs-varid'>k</span> <span class='hs-keyglyph'>=</span> <span class='hs-varid'>k</span>
<a name="line-45"></a> <span class='hs-varid'>return</span> <span class='hs-keyglyph'>=</span> <span class='hs-conid'>Succeeded</span>
<a name="line-46"></a> <span class='hs-varid'>fail</span> <span class='hs-keyword'>_</span> <span class='hs-keyglyph'>=</span> <span class='hs-conid'>Unknown</span>
<a name="line-47"></a>
<a name="line-48"></a><a name="instance%20MonadPlus%20Perhaps"></a><span class='hs-keyword'>instance</span> <span class='hs-conid'>MonadPlus</span> <span class='hs-conid'>Perhaps</span> <span class='hs-keyword'>where</span>
<a name="line-49"></a> <span class='hs-varid'>mzero</span> <span class='hs-keyglyph'>=</span> <span class='hs-conid'>Unknown</span>
<a name="line-50"></a> <span class='hs-conid'>Unknown</span> <span class='hs-varop'>`mplus`</span> <span class='hs-varid'>ys</span> <span class='hs-keyglyph'>=</span> <span class='hs-varid'>ys</span>
<a name="line-51"></a> <span class='hs-conid'>Failed</span> <span class='hs-varop'>`mplus`</span> <span class='hs-keyword'>_</span> <span class='hs-keyglyph'>=</span> <span class='hs-conid'>Failed</span>
<a name="line-52"></a> <span class='hs-layout'>(</span><span class='hs-conid'>Succeeded</span> <span class='hs-varid'>x</span><span class='hs-layout'>)</span> <span class='hs-varop'>`mplus`</span> <span class='hs-keyword'>_</span> <span class='hs-keyglyph'>=</span> <span class='hs-conid'>Succeeded</span> <span class='hs-varid'>x</span>
<a name="line-53"></a>
<a name="line-54"></a><a name="toMaybe"></a><span class='hs-definition'>toMaybe</span> <span class='hs-keyglyph'>::</span> <span class='hs-conid'>Perhaps</span> <span class='hs-varid'>a</span> <span class='hs-keyglyph'>-></span> <span class='hs-conid'>Maybe</span> <span class='hs-varid'>a</span>
<a name="line-55"></a><span class='hs-definition'>toMaybe</span> <span class='hs-layout'>(</span><span class='hs-conid'>Succeeded</span> <span class='hs-varid'>x</span><span class='hs-layout'>)</span> <span class='hs-keyglyph'>=</span> <span class='hs-conid'>Just</span> <span class='hs-varid'>x</span>
<a name="line-56"></a><span class='hs-definition'>toMaybe</span> <span class='hs-keyword'>_</span> <span class='hs-keyglyph'>=</span> <span class='hs-conid'>Nothing</span>
<a name="line-57"></a>
<a name="line-58"></a><a name="toPerhaps"></a><span class='hs-definition'>toPerhaps</span> <span class='hs-keyglyph'>::</span> <span class='hs-conid'>Maybe</span> <span class='hs-varid'>a</span> <span class='hs-keyglyph'>-></span> <span class='hs-conid'>Perhaps</span> <span class='hs-varid'>a</span>
<a name="line-59"></a><span class='hs-definition'>toPerhaps</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-keyglyph'>=</span> <span class='hs-conid'>Succeeded</span> <span class='hs-varid'>x</span>
<a name="line-60"></a><span class='hs-definition'>toPerhaps</span> <span class='hs-conid'>Nothing</span> <span class='hs-keyglyph'>=</span> <span class='hs-conid'>Failed</span>
<a name="line-61"></a>
<a name="line-62"></a><a name="cleverCommute"></a><span class='hs-definition'>cleverCommute</span> <span class='hs-keyglyph'>::</span> <span class='hs-conid'>CommuteFunction</span> <span class='hs-keyglyph'>-></span> <span class='hs-conid'>CommuteFunction</span>
<a name="line-63"></a><span class='hs-definition'>cleverCommute</span> <span class='hs-varid'>c</span> <span class='hs-layout'>(</span><span class='hs-varid'>p1</span><span class='hs-conop'>:<</span><span class='hs-varid'>p2</span><span class='hs-layout'>)</span> <span class='hs-keyglyph'>=</span>
<a name="line-64"></a> <span class='hs-keyword'>case</span> <span class='hs-varid'>c</span> <span class='hs-layout'>(</span><span class='hs-varid'>p1</span> <span class='hs-conop'>:<</span> <span class='hs-varid'>p2</span><span class='hs-layout'>)</span> <span class='hs-keyword'>of</span>
<a name="line-65"></a> <span class='hs-conid'>Succeeded</span> <span class='hs-varid'>x</span> <span class='hs-keyglyph'>-></span> <span class='hs-conid'>Succeeded</span> <span class='hs-varid'>x</span>
<a name="line-66"></a> <span class='hs-conid'>Failed</span> <span class='hs-keyglyph'>-></span> <span class='hs-conid'>Failed</span>
<a name="line-67"></a> <span class='hs-conid'>Unknown</span> <span class='hs-keyglyph'>-></span> <span class='hs-keyword'>case</span> <span class='hs-varid'>c</span> <span class='hs-layout'>(</span><span class='hs-varid'>invert</span> <span class='hs-varid'>p2</span> <span class='hs-conop'>:<</span> <span class='hs-varid'>invert</span> <span class='hs-varid'>p1</span><span class='hs-layout'>)</span> <span class='hs-keyword'>of</span>
<a name="line-68"></a> <span class='hs-conid'>Succeeded</span> <span class='hs-layout'>(</span><span class='hs-varid'>p1'</span> <span class='hs-conop'>:<</span> <span class='hs-varid'>p2'</span><span class='hs-layout'>)</span> <span class='hs-keyglyph'>-></span> <span class='hs-conid'>Succeeded</span> <span class='hs-layout'>(</span><span class='hs-varid'>invert</span> <span class='hs-varid'>p2'</span> <span class='hs-conop'>:<</span> <span class='hs-varid'>invert</span> <span class='hs-varid'>p1'</span><span class='hs-layout'>)</span>
<a name="line-69"></a> <span class='hs-conid'>Failed</span> <span class='hs-keyglyph'>-></span> <span class='hs-conid'>Failed</span>
<a name="line-70"></a> <span class='hs-conid'>Unknown</span> <span class='hs-keyglyph'>-></span> <span class='hs-conid'>Unknown</span>
<a name="line-71"></a><span class='hs-comment'>--cleverCommute c (p1,p2) = c (p1,p2) `mplus`</span>
<a name="line-72"></a><span class='hs-comment'>-- (case c (invert p2,invert p1) of</span>
<a name="line-73"></a><span class='hs-comment'>-- Succeeded (p1', p2') -> Succeeded (invert p2', invert p1')</span>
<a name="line-74"></a><span class='hs-comment'>-- Failed -> Failed</span>
<a name="line-75"></a><span class='hs-comment'>-- Unknown -> Unknown)</span>
<a name="line-76"></a>
<a name="line-77"></a><a name="speedyCommute"></a><span class='hs-definition'>speedyCommute</span> <span class='hs-keyglyph'>::</span> <span class='hs-conid'>CommuteFunction</span> <span class='hs-comment'>-- Deal with common cases quickly!</span>
<a name="line-78"></a> <span class='hs-comment'>-- Two file-patches modifying different files trivially commute.</span>
<a name="line-79"></a><span class='hs-definition'>speedyCommute</span> <span class='hs-layout'>(</span><span class='hs-varid'>p2</span><span class='hs-keyglyph'>@</span><span class='hs-layout'>(</span><span class='hs-conid'>FP</span> <span class='hs-varid'>f'</span> <span class='hs-keyword'>_</span><span class='hs-layout'>)</span> <span class='hs-conop'>:<</span> <span class='hs-varid'>p1</span><span class='hs-keyglyph'>@</span><span class='hs-layout'>(</span><span class='hs-conid'>FP</span> <span class='hs-varid'>f</span> <span class='hs-keyword'>_</span><span class='hs-layout'>)</span><span class='hs-layout'>)</span>
<a name="line-80"></a> <span class='hs-keyglyph'>|</span> <span class='hs-varid'>f</span> <span class='hs-varop'>/=</span> <span class='hs-varid'>f'</span> <span class='hs-keyglyph'>=</span> <span class='hs-conid'>Succeeded</span> <span class='hs-layout'>(</span><span class='hs-varid'>unsafeCoerceP</span> <span class='hs-varid'>p1</span> <span class='hs-conop'>:<</span> <span class='hs-varid'>unsafeCoerceP</span> <span class='hs-varid'>p2</span><span class='hs-layout'>)</span>
<a name="line-81"></a><span class='hs-definition'>speedyCommute</span> <span class='hs-sel'>_other</span> <span class='hs-keyglyph'>=</span> <span class='hs-conid'>Unknown</span>
<a name="line-82"></a>
<a name="line-83"></a><a name="everythingElseCommute"></a><span class='hs-definition'>everythingElseCommute</span> <span class='hs-keyglyph'>::</span> <span class='hs-conid'>CommuteFunction</span>
<a name="line-84"></a><span class='hs-definition'>everythingElseCommute</span> <span class='hs-varid'>x</span> <span class='hs-keyglyph'>=</span> <span class='hs-varid'>eec</span> <span class='hs-varid'>x</span>
<a name="line-85"></a> <span class='hs-keyword'>where</span>
<a name="line-86"></a> <span class='hs-varid'>eec</span> <span class='hs-keyglyph'>::</span> <span class='hs-conid'>CommuteFunction</span>
<a name="line-87"></a> <span class='hs-varid'>eec</span> <span class='hs-layout'>(</span><span class='hs-conid'>ChangePref</span> <span class='hs-varid'>p</span> <span class='hs-varid'>f</span> <span class='hs-varid'>t</span> <span class='hs-conop'>:<</span><span class='hs-varid'>p1</span><span class='hs-layout'>)</span> <span class='hs-keyglyph'>=</span> <span class='hs-conid'>Succeeded</span> <span class='hs-layout'>(</span><span class='hs-varid'>unsafeCoerceP</span> <span class='hs-varid'>p1</span> <span class='hs-conop'>:<</span> <span class='hs-conid'>ChangePref</span> <span class='hs-varid'>p</span> <span class='hs-varid'>f</span> <span class='hs-varid'>t</span><span class='hs-layout'>)</span>
<a name="line-88"></a> <span class='hs-varid'>eec</span> <span class='hs-layout'>(</span><span class='hs-varid'>p2</span> <span class='hs-conop'>:<</span><span class='hs-conid'>ChangePref</span> <span class='hs-varid'>p</span> <span class='hs-varid'>f</span> <span class='hs-varid'>t</span><span class='hs-layout'>)</span> <span class='hs-keyglyph'>=</span> <span class='hs-conid'>Succeeded</span> <span class='hs-layout'>(</span><span class='hs-conid'>ChangePref</span> <span class='hs-varid'>p</span> <span class='hs-varid'>f</span> <span class='hs-varid'>t</span> <span class='hs-conop'>:<</span> <span class='hs-varid'>unsafeCoerceP</span> <span class='hs-varid'>p2</span><span class='hs-layout'>)</span>
<a name="line-89"></a> <span class='hs-varid'>eec</span> <span class='hs-varid'>xx</span> <span class='hs-keyglyph'>=</span> <span class='hs-varid'>cleverCommute</span> <span class='hs-varid'>commuteFiledir</span> <span class='hs-varid'>xx</span>
<a name="line-90"></a>
<a name="line-91"></a><span class='hs-comment'>{-
<a name="line-92"></a>Note that it must be true that
<a name="line-93"></a>
<a name="line-94"></a>commutex (A^-1 A, P) = Just (P, A'^-1 A')
<a name="line-95"></a>
<a name="line-96"></a>and
<a name="line-97"></a>
<a name="line-98"></a>if commutex (A, B) == Just (B', A')
<a name="line-99"></a>then commutex (B^-1, A^-1) == Just (A'^-1, B'^-1)
<a name="line-100"></a>-}</span>
<a name="line-101"></a>
<a name="line-102"></a><a name="instance%20Commute%20Prim"></a><span class='hs-keyword'>instance</span> <span class='hs-conid'>Commute</span> <span class='hs-conid'>Prim</span> <span class='hs-keyword'>where</span>
<a name="line-103"></a> <span class='hs-varid'>commute</span> <span class='hs-varid'>x</span> <span class='hs-keyglyph'>=</span> <span class='hs-varid'>toMaybe</span> <span class='hs-varop'>$</span> <span class='hs-varid'>msum</span> <span class='hs-keyglyph'>[</span><span class='hs-varid'>toFwdCommute</span> <span class='hs-varid'>speedyCommute</span> <span class='hs-varid'>x</span><span class='hs-layout'>,</span>
<a name="line-104"></a> <span class='hs-varid'>toFwdCommute</span> <span class='hs-varid'>everythingElseCommute</span> <span class='hs-varid'>x</span>
<a name="line-105"></a> <span class='hs-keyglyph'>]</span>
<a name="line-106"></a>
<a name="line-107"></a><a name="isSuperdir"></a><span class='hs-definition'>isSuperdir</span> <span class='hs-keyglyph'>::</span> <span class='hs-conid'>FileName</span> <span class='hs-keyglyph'>-></span> <span class='hs-conid'>FileName</span> <span class='hs-keyglyph'>-></span> <span class='hs-conid'>Bool</span>
<a name="line-108"></a><span class='hs-definition'>isSuperdir</span> <span class='hs-varid'>d1</span> <span class='hs-varid'>d2</span> <span class='hs-keyglyph'>=</span> <span class='hs-varid'>isd</span> <span class='hs-layout'>(</span><span class='hs-varid'>fn2fp</span> <span class='hs-varid'>d1</span><span class='hs-layout'>)</span> <span class='hs-layout'>(</span><span class='hs-varid'>fn2fp</span> <span class='hs-varid'>d2</span><span class='hs-layout'>)</span>
<a name="line-109"></a> <span class='hs-keyword'>where</span> <span class='hs-varid'>isd</span> <span class='hs-varid'>s1</span> <span class='hs-varid'>s2</span> <span class='hs-keyglyph'>=</span>
<a name="line-110"></a> <span class='hs-varid'>length</span> <span class='hs-varid'>s2</span> <span class='hs-varop'>>=</span> <span class='hs-varid'>length</span> <span class='hs-varid'>s1</span> <span class='hs-varop'>+</span> <span class='hs-num'>1</span> <span class='hs-varop'>&&</span> <span class='hs-varid'>take</span> <span class='hs-layout'>(</span><span class='hs-varid'>length</span> <span class='hs-varid'>s1</span> <span class='hs-varop'>+</span> <span class='hs-num'>1</span><span class='hs-layout'>)</span> <span class='hs-varid'>s2</span> <span class='hs-varop'>==</span> <span class='hs-varid'>s1</span> <span class='hs-varop'>++</span> <span class='hs-str'>"/"</span>
<a name="line-111"></a>
<a name="line-112"></a><a name="commuteFiledir"></a><span class='hs-definition'>commuteFiledir</span> <span class='hs-keyglyph'>::</span> <span class='hs-conid'>CommuteFunction</span>
<a name="line-113"></a><span class='hs-definition'>commuteFiledir</span> <span class='hs-layout'>(</span><span class='hs-conid'>FP</span> <span class='hs-varid'>f1</span> <span class='hs-varid'>p1</span> <span class='hs-conop'>:<</span> <span class='hs-conid'>FP</span> <span class='hs-varid'>f2</span> <span class='hs-varid'>p2</span><span class='hs-layout'>)</span> <span class='hs-keyglyph'>=</span>
<a name="line-114"></a> <span class='hs-keyword'>if</span> <span class='hs-varid'>f1</span> <span class='hs-varop'>/=</span> <span class='hs-varid'>f2</span> <span class='hs-keyword'>then</span> <span class='hs-conid'>Succeeded</span> <span class='hs-layout'>(</span> <span class='hs-conid'>FP</span> <span class='hs-varid'>f2</span> <span class='hs-layout'>(</span><span class='hs-varid'>unsafeCoerceP</span> <span class='hs-varid'>p2</span><span class='hs-layout'>)</span> <span class='hs-conop'>:<</span> <span class='hs-conid'>FP</span> <span class='hs-varid'>f1</span> <span class='hs-layout'>(</span><span class='hs-varid'>unsafeCoerceP</span> <span class='hs-varid'>p1</span><span class='hs-layout'>)</span> <span class='hs-layout'>)</span>
<a name="line-115"></a> <span class='hs-keyword'>else</span> <span class='hs-varid'>commuteFP</span> <span class='hs-varid'>f1</span> <span class='hs-layout'>(</span><span class='hs-varid'>p1</span> <span class='hs-conop'>:<</span> <span class='hs-varid'>p2</span><span class='hs-layout'>)</span>
<a name="line-116"></a><span class='hs-definition'>commuteFiledir</span> <span class='hs-layout'>(</span><span class='hs-conid'>DP</span> <span class='hs-varid'>d1</span> <span class='hs-varid'>p1</span> <span class='hs-conop'>:<</span> <span class='hs-conid'>DP</span> <span class='hs-varid'>d2</span> <span class='hs-varid'>p2</span><span class='hs-layout'>)</span> <span class='hs-keyglyph'>=</span>
<a name="line-117"></a> <span class='hs-keyword'>if</span> <span class='hs-layout'>(</span><span class='hs-varid'>not</span> <span class='hs-varop'>$</span> <span class='hs-varid'>isInDirectory</span> <span class='hs-varid'>d1</span> <span class='hs-varid'>d2</span><span class='hs-layout'>)</span> <span class='hs-varop'>&&</span> <span class='hs-layout'>(</span><span class='hs-varid'>not</span> <span class='hs-varop'>$</span> <span class='hs-varid'>isInDirectory</span> <span class='hs-varid'>d2</span> <span class='hs-varid'>d1</span><span class='hs-layout'>)</span> <span class='hs-varop'>&&</span>
<a name="line-118"></a> <span class='hs-varid'>d1</span> <span class='hs-varop'>/=</span> <span class='hs-varid'>d2</span>
<a name="line-119"></a> <span class='hs-keyword'>then</span> <span class='hs-conid'>Succeeded</span> <span class='hs-layout'>(</span> <span class='hs-conid'>DP</span> <span class='hs-varid'>d2</span> <span class='hs-layout'>(</span><span class='hs-varid'>unsafeCoerceP</span> <span class='hs-varid'>p2</span><span class='hs-layout'>)</span> <span class='hs-conop'>:<</span> <span class='hs-conid'>DP</span> <span class='hs-varid'>d1</span> <span class='hs-layout'>(</span><span class='hs-varid'>unsafeCoerceP</span> <span class='hs-varid'>p1</span><span class='hs-layout'>)</span> <span class='hs-layout'>)</span>
<a name="line-120"></a> <span class='hs-keyword'>else</span> <span class='hs-conid'>Failed</span>
<a name="line-121"></a><span class='hs-definition'>commuteFiledir</span> <span class='hs-layout'>(</span><span class='hs-conid'>DP</span> <span class='hs-varid'>d</span> <span class='hs-varid'>dp</span> <span class='hs-conop'>:<</span> <span class='hs-conid'>FP</span> <span class='hs-varid'>f</span> <span class='hs-varid'>fp</span><span class='hs-layout'>)</span> <span class='hs-keyglyph'>=</span>
<a name="line-122"></a> <span class='hs-keyword'>if</span> <span class='hs-varid'>not</span> <span class='hs-varop'>$</span> <span class='hs-varid'>isInDirectory</span> <span class='hs-varid'>d</span> <span class='hs-varid'>f</span>
<a name="line-123"></a> <span class='hs-keyword'>then</span> <span class='hs-conid'>Succeeded</span> <span class='hs-layout'>(</span><span class='hs-conid'>FP</span> <span class='hs-varid'>f</span> <span class='hs-layout'>(</span><span class='hs-varid'>unsafeCoerceP</span> <span class='hs-varid'>fp</span><span class='hs-layout'>)</span> <span class='hs-conop'>:<</span> <span class='hs-conid'>DP</span> <span class='hs-varid'>d</span> <span class='hs-layout'>(</span><span class='hs-varid'>unsafeCoerceP</span> <span class='hs-varid'>dp</span><span class='hs-layout'>)</span><span class='hs-layout'>)</span>
<a name="line-124"></a> <span class='hs-keyword'>else</span> <span class='hs-conid'>Failed</span>
<a name="line-125"></a>
<a name="line-126"></a><span class='hs-definition'>commuteFiledir</span> <span class='hs-layout'>(</span><span class='hs-conid'>Move</span> <span class='hs-varid'>d</span> <span class='hs-varid'>d'</span> <span class='hs-conop'>:<</span> <span class='hs-conid'>FP</span> <span class='hs-varid'>f2</span> <span class='hs-varid'>p2</span><span class='hs-layout'>)</span>
<a name="line-127"></a> <span class='hs-keyglyph'>|</span> <span class='hs-varid'>f2</span> <span class='hs-varop'>==</span> <span class='hs-varid'>d'</span> <span class='hs-keyglyph'>=</span> <span class='hs-conid'>Failed</span>
<a name="line-128"></a> <span class='hs-keyglyph'>|</span> <span class='hs-layout'>(</span><span class='hs-varid'>p2</span> <span class='hs-varop'>==</span> <span class='hs-conid'>AddFile</span> <span class='hs-varop'>||</span> <span class='hs-varid'>p2</span> <span class='hs-varop'>==</span> <span class='hs-conid'>RmFile</span><span class='hs-layout'>)</span> <span class='hs-varop'>&&</span> <span class='hs-varid'>d</span> <span class='hs-varop'>==</span> <span class='hs-varid'>f2</span> <span class='hs-keyglyph'>=</span> <span class='hs-conid'>Failed</span>
<a name="line-129"></a> <span class='hs-keyglyph'>|</span> <span class='hs-varid'>otherwise</span> <span class='hs-keyglyph'>=</span> <span class='hs-conid'>Succeeded</span> <span class='hs-layout'>(</span><span class='hs-conid'>FP</span> <span class='hs-layout'>(</span><span class='hs-varid'>movedirfilename</span> <span class='hs-varid'>d</span> <span class='hs-varid'>d'</span> <span class='hs-varid'>f2</span><span class='hs-layout'>)</span> <span class='hs-layout'>(</span><span class='hs-varid'>unsafeCoerceP</span> <span class='hs-varid'>p2</span><span class='hs-layout'>)</span> <span class='hs-conop'>:<</span> <span class='hs-conid'>Move</span> <span class='hs-varid'>d</span> <span class='hs-varid'>d'</span><span class='hs-layout'>)</span>
<a name="line-130"></a><span class='hs-definition'>commuteFiledir</span> <span class='hs-layout'>(</span><span class='hs-conid'>Move</span> <span class='hs-varid'>d</span> <span class='hs-varid'>d'</span> <span class='hs-conop'>:<</span> <span class='hs-conid'>DP</span> <span class='hs-varid'>d2</span> <span class='hs-varid'>p2</span><span class='hs-layout'>)</span>
<a name="line-131"></a> <span class='hs-keyglyph'>|</span> <span class='hs-varid'>isSuperdir</span> <span class='hs-varid'>d2</span> <span class='hs-varid'>d'</span> <span class='hs-varop'>||</span> <span class='hs-varid'>isSuperdir</span> <span class='hs-varid'>d2</span> <span class='hs-varid'>d</span> <span class='hs-keyglyph'>=</span> <span class='hs-conid'>Failed</span>
<a name="line-132"></a> <span class='hs-keyglyph'>|</span> <span class='hs-varid'>d</span> <span class='hs-varop'>==</span> <span class='hs-varid'>d2</span> <span class='hs-keyglyph'>=</span> <span class='hs-conid'>Failed</span> <span class='hs-comment'>-- The exact guard is p2 == AddDir && d == d2</span>
<a name="line-133"></a> <span class='hs-comment'>-- but note d == d2 suffices because we know p2 != RmDir</span>
<a name="line-134"></a> <span class='hs-comment'>-- (and hence p2 == AddDir) since patches must be sequential.</span>
<a name="line-135"></a> <span class='hs-keyglyph'>|</span> <span class='hs-varid'>d2</span> <span class='hs-varop'>==</span> <span class='hs-varid'>d'</span> <span class='hs-keyglyph'>=</span> <span class='hs-conid'>Failed</span>
<a name="line-136"></a> <span class='hs-keyglyph'>|</span> <span class='hs-varid'>otherwise</span> <span class='hs-keyglyph'>=</span> <span class='hs-conid'>Succeeded</span> <span class='hs-layout'>(</span><span class='hs-conid'>DP</span> <span class='hs-layout'>(</span><span class='hs-varid'>movedirfilename</span> <span class='hs-varid'>d</span> <span class='hs-varid'>d'</span> <span class='hs-varid'>d2</span><span class='hs-layout'>)</span> <span class='hs-layout'>(</span><span class='hs-varid'>unsafeCoerceP</span> <span class='hs-varid'>p2</span><span class='hs-layout'>)</span> <span class='hs-conop'>:<</span> <span class='hs-conid'>Move</span> <span class='hs-varid'>d</span> <span class='hs-varid'>d'</span><span class='hs-layout'>)</span>
<a name="line-137"></a><span class='hs-definition'>commuteFiledir</span> <span class='hs-layout'>(</span><span class='hs-conid'>Move</span> <span class='hs-varid'>d</span> <span class='hs-varid'>d'</span> <span class='hs-conop'>:<</span> <span class='hs-conid'>Move</span> <span class='hs-varid'>f</span> <span class='hs-varid'>f'</span><span class='hs-layout'>)</span>
<a name="line-138"></a> <span class='hs-keyglyph'>|</span> <span class='hs-varid'>f</span> <span class='hs-varop'>==</span> <span class='hs-varid'>d'</span> <span class='hs-varop'>||</span> <span class='hs-varid'>f'</span> <span class='hs-varop'>==</span> <span class='hs-varid'>d</span> <span class='hs-keyglyph'>=</span> <span class='hs-conid'>Failed</span>
<a name="line-139"></a> <span class='hs-keyglyph'>|</span> <span class='hs-varid'>f</span> <span class='hs-varop'>==</span> <span class='hs-varid'>d</span> <span class='hs-varop'>||</span> <span class='hs-varid'>f'</span> <span class='hs-varop'>==</span> <span class='hs-varid'>d'</span> <span class='hs-keyglyph'>=</span> <span class='hs-conid'>Failed</span>
<a name="line-140"></a> <span class='hs-keyglyph'>|</span> <span class='hs-varid'>d</span> <span class='hs-varop'>`isSuperdir`</span> <span class='hs-varid'>f</span> <span class='hs-varop'>&&</span> <span class='hs-varid'>f'</span> <span class='hs-varop'>`isSuperdir`</span> <span class='hs-varid'>d'</span> <span class='hs-keyglyph'>=</span> <span class='hs-conid'>Failed</span>
<a name="line-141"></a> <span class='hs-keyglyph'>|</span> <span class='hs-varid'>otherwise</span> <span class='hs-keyglyph'>=</span>
<a name="line-142"></a> <span class='hs-conid'>Succeeded</span> <span class='hs-layout'>(</span><span class='hs-conid'>Move</span> <span class='hs-layout'>(</span><span class='hs-varid'>movedirfilename</span> <span class='hs-varid'>d</span> <span class='hs-varid'>d'</span> <span class='hs-varid'>f</span><span class='hs-layout'>)</span> <span class='hs-layout'>(</span><span class='hs-varid'>movedirfilename</span> <span class='hs-varid'>d</span> <span class='hs-varid'>d'</span> <span class='hs-varid'>f'</span><span class='hs-layout'>)</span> <span class='hs-conop'>:<</span>
<a name="line-143"></a> <span class='hs-conid'>Move</span> <span class='hs-layout'>(</span><span class='hs-varid'>movedirfilename</span> <span class='hs-varid'>f'</span> <span class='hs-varid'>f</span> <span class='hs-varid'>d</span><span class='hs-layout'>)</span> <span class='hs-layout'>(</span><span class='hs-varid'>movedirfilename</span> <span class='hs-varid'>f'</span> <span class='hs-varid'>f</span> <span class='hs-varid'>d'</span><span class='hs-layout'>)</span><span class='hs-layout'>)</span>
<a name="line-144"></a>
<a name="line-145"></a><span class='hs-definition'>commuteFiledir</span> <span class='hs-keyword'>_</span> <span class='hs-keyglyph'>=</span> <span class='hs-conid'>Unknown</span>
<a name="line-146"></a>
<a name="line-147"></a><a name="CommuteFunction"></a><span class='hs-keyword'>type</span> <span class='hs-conid'>CommuteFunction</span> <span class='hs-keyglyph'>=</span> <span class='hs-conid'>FORALL</span><span class='hs-layout'>(</span><span class='hs-varid'>x</span> <span class='hs-varid'>y</span><span class='hs-layout'>)</span> <span class='hs-layout'>(</span><span class='hs-conid'>Prim</span> <span class='hs-conop'>:<</span> <span class='hs-conid'>Prim</span><span class='hs-layout'>)</span> <span class='hs-conid'>C</span><span class='hs-layout'>(</span><span class='hs-varid'>x</span> <span class='hs-varid'>y</span><span class='hs-layout'>)</span> <span class='hs-keyglyph'>-></span> <span class='hs-conid'>Perhaps</span> <span class='hs-layout'>(</span><span class='hs-layout'>(</span><span class='hs-conid'>Prim</span> <span class='hs-conop'>:<</span> <span class='hs-conid'>Prim</span><span class='hs-layout'>)</span> <span class='hs-conid'>C</span><span class='hs-layout'>(</span><span class='hs-varid'>x</span> <span class='hs-varid'>y</span><span class='hs-layout'>)</span><span class='hs-layout'>)</span>
<a name="line-148"></a><a name="WrappedCommuteFunction"></a><span class='hs-keyword'>newtype</span> <span class='hs-conid'>WrappedCommuteFunction</span> <span class='hs-keyglyph'>=</span> <span class='hs-conid'>WrappedCommuteFunction</span> <span class='hs-layout'>{</span> <span class='hs-varid'>runWrappedCommuteFunction</span> <span class='hs-keyglyph'>::</span> <span class='hs-conid'>CommuteFunction</span> <span class='hs-layout'>}</span>
<a name="line-149"></a>
<a name="line-150"></a><a name="subcommutes"></a><span class='hs-definition'>subcommutes</span> <span class='hs-keyglyph'>::</span> <span class='hs-keyglyph'>[</span><span class='hs-layout'>(</span><span class='hs-conid'>String</span><span class='hs-layout'>,</span> <span class='hs-conid'>WrappedCommuteFunction</span><span class='hs-layout'>)</span><span class='hs-keyglyph'>]</span>
<a name="line-151"></a><span class='hs-definition'>subcommutes</span> <span class='hs-keyglyph'>=</span>
<a name="line-152"></a> <span class='hs-keyglyph'>[</span><span class='hs-layout'>(</span><span class='hs-str'>"speedyCommute"</span><span class='hs-layout'>,</span> <span class='hs-conid'>WrappedCommuteFunction</span> <span class='hs-varid'>speedyCommute</span><span class='hs-layout'>)</span><span class='hs-layout'>,</span>
<a name="line-153"></a> <span class='hs-layout'>(</span><span class='hs-str'>"commuteFiledir"</span><span class='hs-layout'>,</span> <span class='hs-conid'>WrappedCommuteFunction</span> <span class='hs-layout'>(</span><span class='hs-varid'>cleverCommute</span> <span class='hs-varid'>commuteFiledir</span><span class='hs-layout'>)</span><span class='hs-layout'>)</span><span class='hs-layout'>,</span>
<a name="line-154"></a> <span class='hs-layout'>(</span><span class='hs-str'>"commuteFilepatches"</span><span class='hs-layout'>,</span> <span class='hs-conid'>WrappedCommuteFunction</span> <span class='hs-layout'>(</span><span class='hs-varid'>cleverCommute</span> <span class='hs-varid'>commuteFilepatches</span><span class='hs-layout'>)</span><span class='hs-layout'>)</span><span class='hs-layout'>,</span>
<a name="line-155"></a> <span class='hs-layout'>(</span><span class='hs-str'>"commutex"</span><span class='hs-layout'>,</span> <span class='hs-conid'>WrappedCommuteFunction</span> <span class='hs-layout'>(</span><span class='hs-varid'>toPerhaps</span> <span class='hs-varop'>.</span> <span class='hs-varid'>toRevCommute</span> <span class='hs-varid'>commute</span><span class='hs-layout'>)</span><span class='hs-layout'>)</span>
<a name="line-156"></a> <span class='hs-keyglyph'>]</span>
<a name="line-157"></a>
<a name="line-158"></a><a name="commuteFilepatches"></a><span class='hs-definition'>commuteFilepatches</span> <span class='hs-keyglyph'>::</span> <span class='hs-conid'>CommuteFunction</span>
<a name="line-159"></a><span class='hs-definition'>commuteFilepatches</span> <span class='hs-layout'>(</span><span class='hs-conid'>FP</span> <span class='hs-varid'>f1</span> <span class='hs-varid'>p1</span> <span class='hs-conop'>:<</span> <span class='hs-conid'>FP</span> <span class='hs-varid'>f2</span> <span class='hs-varid'>p2</span><span class='hs-layout'>)</span> <span class='hs-keyglyph'>|</span> <span class='hs-varid'>f1</span> <span class='hs-varop'>==</span> <span class='hs-varid'>f2</span> <span class='hs-keyglyph'>=</span> <span class='hs-varid'>commuteFP</span> <span class='hs-varid'>f1</span> <span class='hs-layout'>(</span><span class='hs-varid'>p1</span> <span class='hs-conop'>:<</span> <span class='hs-varid'>p2</span><span class='hs-layout'>)</span>
<a name="line-160"></a><span class='hs-definition'>commuteFilepatches</span> <span class='hs-keyword'>_</span> <span class='hs-keyglyph'>=</span> <span class='hs-conid'>Unknown</span>
<a name="line-161"></a>
<a name="line-162"></a><a name="commuteFP"></a><span class='hs-definition'>commuteFP</span> <span class='hs-keyglyph'>::</span> <span class='hs-conid'>FileName</span> <span class='hs-keyglyph'>-></span> <span class='hs-layout'>(</span><span class='hs-conid'>FilePatchType</span> <span class='hs-conop'>:<</span> <span class='hs-conid'>FilePatchType</span><span class='hs-layout'>)</span> <span class='hs-conid'>C</span><span class='hs-layout'>(</span><span class='hs-varid'>x</span> <span class='hs-varid'>y</span><span class='hs-layout'>)</span>
<a name="line-163"></a> <span class='hs-keyglyph'>-></span> <span class='hs-conid'>Perhaps</span> <span class='hs-layout'>(</span><span class='hs-layout'>(</span><span class='hs-conid'>Prim</span> <span class='hs-conop'>:<</span> <span class='hs-conid'>Prim</span><span class='hs-layout'>)</span> <span class='hs-conid'>C</span><span class='hs-layout'>(</span><span class='hs-varid'>x</span> <span class='hs-varid'>y</span><span class='hs-layout'>)</span><span class='hs-layout'>)</span>
<a name="line-164"></a><span class='hs-definition'>commuteFP</span> <span class='hs-varid'>f</span> <span class='hs-layout'>(</span><span class='hs-conid'>Hunk</span> <span class='hs-varid'>line1</span> <span class='hs-conid'>[]</span> <span class='hs-conid'>[]</span> <span class='hs-conop'>:<</span> <span class='hs-varid'>p2</span><span class='hs-layout'>)</span> <span class='hs-keyglyph'>=</span>
<a name="line-165"></a> <span class='hs-varid'>seq</span> <span class='hs-varid'>f</span> <span class='hs-varop'>$</span> <span class='hs-conid'>Succeeded</span> <span class='hs-layout'>(</span><span class='hs-conid'>FP</span> <span class='hs-varid'>f</span> <span class='hs-layout'>(</span><span class='hs-varid'>unsafeCoerceP</span> <span class='hs-varid'>p2</span><span class='hs-layout'>)</span> <span class='hs-conop'>:<</span> <span class='hs-conid'>FP</span> <span class='hs-varid'>f</span> <span class='hs-layout'>(</span><span class='hs-conid'>Hunk</span> <span class='hs-varid'>line1</span> <span class='hs-conid'>[]</span> <span class='hs-conid'>[]</span><span class='hs-layout'>)</span><span class='hs-layout'>)</span>
<a name="line-166"></a><span class='hs-definition'>commuteFP</span> <span class='hs-varid'>f</span> <span class='hs-layout'>(</span><span class='hs-varid'>p2</span> <span class='hs-conop'>:<</span> <span class='hs-conid'>Hunk</span> <span class='hs-varid'>line1</span> <span class='hs-conid'>[]</span> <span class='hs-conid'>[]</span><span class='hs-layout'>)</span> <span class='hs-keyglyph'>=</span>
<a name="line-167"></a> <span class='hs-varid'>seq</span> <span class='hs-varid'>f</span> <span class='hs-varop'>$</span> <span class='hs-conid'>Succeeded</span> <span class='hs-layout'>(</span><span class='hs-conid'>FP</span> <span class='hs-varid'>f</span> <span class='hs-layout'>(</span><span class='hs-conid'>Hunk</span> <span class='hs-varid'>line1</span> <span class='hs-conid'>[]</span> <span class='hs-conid'>[]</span><span class='hs-layout'>)</span> <span class='hs-conop'>:<</span> <span class='hs-conid'>FP</span> <span class='hs-varid'>f</span> <span class='hs-layout'>(</span><span class='hs-varid'>unsafeCoerceP</span> <span class='hs-varid'>p2</span><span class='hs-layout'>)</span><span class='hs-layout'>)</span>
<a name="line-168"></a><span class='hs-definition'>commuteFP</span> <span class='hs-varid'>f</span> <span class='hs-layout'>(</span><span class='hs-conid'>Hunk</span> <span class='hs-varid'>line1</span> <span class='hs-varid'>old1</span> <span class='hs-varid'>new1</span> <span class='hs-conop'>:<</span> <span class='hs-conid'>Hunk</span> <span class='hs-varid'>line2</span> <span class='hs-varid'>old2</span> <span class='hs-varid'>new2</span><span class='hs-layout'>)</span> <span class='hs-keyglyph'>=</span> <span class='hs-varid'>seq</span> <span class='hs-varid'>f</span> <span class='hs-varop'>$</span>
<a name="line-169"></a> <span class='hs-varid'>toPerhaps</span> <span class='hs-varop'>$</span> <span class='hs-varid'>commuteHunk</span> <span class='hs-varid'>f</span> <span class='hs-layout'>(</span><span class='hs-conid'>Hunk</span> <span class='hs-varid'>line1</span> <span class='hs-varid'>old1</span> <span class='hs-varid'>new1</span> <span class='hs-conop'>:<</span> <span class='hs-conid'>Hunk</span> <span class='hs-varid'>line2</span> <span class='hs-varid'>old2</span> <span class='hs-varid'>new2</span><span class='hs-layout'>)</span>
<a name="line-170"></a><span class='hs-definition'>commuteFP</span> <span class='hs-varid'>f</span> <span class='hs-layout'>(</span><span class='hs-conid'>TokReplace</span> <span class='hs-varid'>t</span> <span class='hs-varid'>o</span> <span class='hs-varid'>n</span> <span class='hs-conop'>:<</span> <span class='hs-conid'>Hunk</span> <span class='hs-varid'>line2</span> <span class='hs-varid'>old2</span> <span class='hs-varid'>new2</span><span class='hs-layout'>)</span> <span class='hs-keyglyph'>=</span> <span class='hs-varid'>seq</span> <span class='hs-varid'>f</span> <span class='hs-varop'>$</span>
<a name="line-171"></a> <span class='hs-keyword'>case</span> <span class='hs-varid'>tryTokReplace</span> <span class='hs-varid'>t</span> <span class='hs-varid'>o</span> <span class='hs-varid'>n</span> <span class='hs-varid'>old2</span> <span class='hs-keyword'>of</span>
<a name="line-172"></a> <span class='hs-conid'>Nothing</span> <span class='hs-keyglyph'>-></span> <span class='hs-conid'>Failed</span>
<a name="line-173"></a> <span class='hs-conid'>Just</span> <span class='hs-varid'>old2'</span> <span class='hs-keyglyph'>-></span>
<a name="line-174"></a> <span class='hs-keyword'>case</span> <span class='hs-varid'>tryTokReplace</span> <span class='hs-varid'>t</span> <span class='hs-varid'>o</span> <span class='hs-varid'>n</span> <span class='hs-varid'>new2</span> <span class='hs-keyword'>of</span>
<a name="line-175"></a> <span class='hs-conid'>Nothing</span> <span class='hs-keyglyph'>-></span> <span class='hs-conid'>Failed</span>
<a name="line-176"></a> <span class='hs-conid'>Just</span> <span class='hs-varid'>new2'</span> <span class='hs-keyglyph'>-></span> <span class='hs-conid'>Succeeded</span> <span class='hs-layout'>(</span><span class='hs-conid'>FP</span> <span class='hs-varid'>f</span> <span class='hs-layout'>(</span><span class='hs-conid'>Hunk</span> <span class='hs-varid'>line2</span> <span class='hs-varid'>old2'</span> <span class='hs-varid'>new2'</span><span class='hs-layout'>)</span> <span class='hs-conop'>:<</span>
<a name="line-177"></a> <span class='hs-conid'>FP</span> <span class='hs-varid'>f</span> <span class='hs-layout'>(</span><span class='hs-conid'>TokReplace</span> <span class='hs-varid'>t</span> <span class='hs-varid'>o</span> <span class='hs-varid'>n</span><span class='hs-layout'>)</span><span class='hs-layout'>)</span>
<a name="line-178"></a><span class='hs-definition'>commuteFP</span> <span class='hs-varid'>f</span> <span class='hs-layout'>(</span><span class='hs-conid'>TokReplace</span> <span class='hs-varid'>t</span> <span class='hs-varid'>o</span> <span class='hs-varid'>n</span> <span class='hs-conop'>:<</span> <span class='hs-conid'>TokReplace</span> <span class='hs-varid'>t2</span> <span class='hs-varid'>o2</span> <span class='hs-varid'>n2</span><span class='hs-layout'>)</span>
<a name="line-179"></a> <span class='hs-keyglyph'>|</span> <span class='hs-varid'>seq</span> <span class='hs-varid'>f</span> <span class='hs-varop'>$</span> <span class='hs-varid'>t</span> <span class='hs-varop'>/=</span> <span class='hs-varid'>t2</span> <span class='hs-keyglyph'>=</span> <span class='hs-conid'>Failed</span>
<a name="line-180"></a> <span class='hs-keyglyph'>|</span> <span class='hs-varid'>o</span> <span class='hs-varop'>==</span> <span class='hs-varid'>o2</span> <span class='hs-keyglyph'>=</span> <span class='hs-conid'>Failed</span>
<a name="line-181"></a> <span class='hs-keyglyph'>|</span> <span class='hs-varid'>n</span> <span class='hs-varop'>==</span> <span class='hs-varid'>o2</span> <span class='hs-keyglyph'>=</span> <span class='hs-conid'>Failed</span>
<a name="line-182"></a> <span class='hs-keyglyph'>|</span> <span class='hs-varid'>o</span> <span class='hs-varop'>==</span> <span class='hs-varid'>n2</span> <span class='hs-keyglyph'>=</span> <span class='hs-conid'>Failed</span>
<a name="line-183"></a> <span class='hs-keyglyph'>|</span> <span class='hs-varid'>n</span> <span class='hs-varop'>==</span> <span class='hs-varid'>n2</span> <span class='hs-keyglyph'>=</span> <span class='hs-conid'>Failed</span>
<a name="line-184"></a> <span class='hs-keyglyph'>|</span> <span class='hs-varid'>otherwise</span> <span class='hs-keyglyph'>=</span> <span class='hs-conid'>Succeeded</span> <span class='hs-layout'>(</span><span class='hs-conid'>FP</span> <span class='hs-varid'>f</span> <span class='hs-layout'>(</span><span class='hs-conid'>TokReplace</span> <span class='hs-varid'>t2</span> <span class='hs-varid'>o2</span> <span class='hs-varid'>n2</span><span class='hs-layout'>)</span> <span class='hs-conop'>:<</span>
<a name="line-185"></a> <span class='hs-conid'>FP</span> <span class='hs-varid'>f</span> <span class='hs-layout'>(</span><span class='hs-conid'>TokReplace</span> <span class='hs-varid'>t</span> <span class='hs-varid'>o</span> <span class='hs-varid'>n</span><span class='hs-layout'>)</span><span class='hs-layout'>)</span>
<a name="line-186"></a><span class='hs-definition'>commuteFP</span> <span class='hs-keyword'>_</span> <span class='hs-keyword'>_</span> <span class='hs-keyglyph'>=</span> <span class='hs-conid'>Unknown</span>
<a name="line-187"></a>
<a name="line-188"></a><a name="commuteHunk"></a><span class='hs-definition'>commuteHunk</span> <span class='hs-keyglyph'>::</span> <span class='hs-conid'>FileName</span> <span class='hs-keyglyph'>-></span> <span class='hs-layout'>(</span><span class='hs-conid'>FilePatchType</span> <span class='hs-conop'>:<</span> <span class='hs-conid'>FilePatchType</span><span class='hs-layout'>)</span> <span class='hs-conid'>C</span><span class='hs-layout'>(</span><span class='hs-varid'>x</span> <span class='hs-varid'>y</span><span class='hs-layout'>)</span>
<a name="line-189"></a> <span class='hs-keyglyph'>-></span> <span class='hs-conid'>Maybe</span> <span class='hs-layout'>(</span><span class='hs-layout'>(</span><span class='hs-conid'>Prim</span> <span class='hs-conop'>:<</span> <span class='hs-conid'>Prim</span><span class='hs-layout'>)</span> <span class='hs-conid'>C</span><span class='hs-layout'>(</span><span class='hs-varid'>x</span> <span class='hs-varid'>y</span><span class='hs-layout'>)</span><span class='hs-layout'>)</span>
<a name="line-190"></a><span class='hs-definition'>commuteHunk</span> <span class='hs-varid'>f</span> <span class='hs-layout'>(</span><span class='hs-conid'>Hunk</span> <span class='hs-varid'>line2</span> <span class='hs-varid'>old2</span> <span class='hs-varid'>new2</span> <span class='hs-conop'>:<</span> <span class='hs-conid'>Hunk</span> <span class='hs-varid'>line1</span> <span class='hs-varid'>old1</span> <span class='hs-varid'>new1</span><span class='hs-layout'>)</span>
<a name="line-191"></a> <span class='hs-keyglyph'>|</span> <span class='hs-varid'>seq</span> <span class='hs-varid'>f</span> <span class='hs-varop'>$</span> <span class='hs-varid'>line1</span> <span class='hs-varop'>+</span> <span class='hs-varid'>lengthnew1</span> <span class='hs-varop'><</span> <span class='hs-varid'>line2</span> <span class='hs-keyglyph'>=</span>
<a name="line-192"></a> <span class='hs-conid'>Just</span> <span class='hs-layout'>(</span><span class='hs-conid'>FP</span> <span class='hs-varid'>f</span> <span class='hs-layout'>(</span><span class='hs-conid'>Hunk</span> <span class='hs-varid'>line1</span> <span class='hs-varid'>old1</span> <span class='hs-varid'>new1</span><span class='hs-layout'>)</span> <span class='hs-conop'>:<</span>
<a name="line-193"></a> <span class='hs-conid'>FP</span> <span class='hs-varid'>f</span> <span class='hs-layout'>(</span><span class='hs-conid'>Hunk</span> <span class='hs-layout'>(</span><span class='hs-varid'>line2</span> <span class='hs-comment'>-</span> <span class='hs-varid'>lengthnew1</span> <span class='hs-varop'>+</span> <span class='hs-varid'>lengthold1</span><span class='hs-layout'>)</span> <span class='hs-varid'>old2</span> <span class='hs-varid'>new2</span><span class='hs-layout'>)</span><span class='hs-layout'>)</span>
<a name="line-194"></a> <span class='hs-keyglyph'>|</span> <span class='hs-varid'>line2</span> <span class='hs-varop'>+</span> <span class='hs-varid'>lengthold2</span> <span class='hs-varop'><</span> <span class='hs-varid'>line1</span> <span class='hs-keyglyph'>=</span>
<a name="line-195"></a> <span class='hs-conid'>Just</span> <span class='hs-layout'>(</span><span class='hs-conid'>FP</span> <span class='hs-varid'>f</span> <span class='hs-layout'>(</span><span class='hs-conid'>Hunk</span> <span class='hs-layout'>(</span><span class='hs-varid'>line1</span><span class='hs-varop'>+</span> <span class='hs-varid'>lengthnew2</span> <span class='hs-comment'>-</span> <span class='hs-varid'>lengthold2</span><span class='hs-layout'>)</span> <span class='hs-varid'>old1</span> <span class='hs-varid'>new1</span><span class='hs-layout'>)</span> <span class='hs-conop'>:<</span>
<a name="line-196"></a> <span class='hs-conid'>FP</span> <span class='hs-varid'>f</span> <span class='hs-layout'>(</span><span class='hs-conid'>Hunk</span> <span class='hs-varid'>line2</span> <span class='hs-varid'>old2</span> <span class='hs-varid'>new2</span><span class='hs-layout'>)</span><span class='hs-layout'>)</span>
<a name="line-197"></a> <span class='hs-keyglyph'>|</span> <span class='hs-varid'>line1</span> <span class='hs-varop'>+</span> <span class='hs-varid'>lengthnew1</span> <span class='hs-varop'>==</span> <span class='hs-varid'>line2</span> <span class='hs-varop'>&&</span>
<a name="line-198"></a> <span class='hs-varid'>lengthold2</span> <span class='hs-varop'>/=</span> <span class='hs-num'>0</span> <span class='hs-varop'>&&</span> <span class='hs-varid'>lengthold1</span> <span class='hs-varop'>/=</span> <span class='hs-num'>0</span> <span class='hs-varop'>&&</span> <span class='hs-varid'>lengthnew2</span> <span class='hs-varop'>/=</span> <span class='hs-num'>0</span> <span class='hs-varop'>&&</span> <span class='hs-varid'>lengthnew1</span> <span class='hs-varop'>/=</span> <span class='hs-num'>0</span> <span class='hs-keyglyph'>=</span>
<a name="line-199"></a> <span class='hs-conid'>Just</span> <span class='hs-layout'>(</span><span class='hs-conid'>FP</span> <span class='hs-varid'>f</span> <span class='hs-layout'>(</span><span class='hs-conid'>Hunk</span> <span class='hs-varid'>line1</span> <span class='hs-varid'>old1</span> <span class='hs-varid'>new1</span><span class='hs-layout'>)</span> <span class='hs-conop'>:<</span>
<a name="line-200"></a> <span class='hs-conid'>FP</span> <span class='hs-varid'>f</span> <span class='hs-layout'>(</span><span class='hs-conid'>Hunk</span> <span class='hs-layout'>(</span><span class='hs-varid'>line2</span> <span class='hs-comment'>-</span> <span class='hs-varid'>lengthnew1</span> <span class='hs-varop'>+</span> <span class='hs-varid'>lengthold1</span><span class='hs-layout'>)</span> <span class='hs-varid'>old2</span> <span class='hs-varid'>new2</span><span class='hs-layout'>)</span><span class='hs-layout'>)</span>
<a name="line-201"></a> <span class='hs-keyglyph'>|</span> <span class='hs-varid'>line2</span> <span class='hs-varop'>+</span> <span class='hs-varid'>lengthold2</span> <span class='hs-varop'>==</span> <span class='hs-varid'>line1</span> <span class='hs-varop'>&&</span>
<a name="line-202"></a> <span class='hs-varid'>lengthold2</span> <span class='hs-varop'>/=</span> <span class='hs-num'>0</span> <span class='hs-varop'>&&</span> <span class='hs-varid'>lengthold1</span> <span class='hs-varop'>/=</span> <span class='hs-num'>0</span> <span class='hs-varop'>&&</span> <span class='hs-varid'>lengthnew2</span> <span class='hs-varop'>/=</span> <span class='hs-num'>0</span> <span class='hs-varop'>&&</span> <span class='hs-varid'>lengthnew1</span> <span class='hs-varop'>/=</span> <span class='hs-num'>0</span> <span class='hs-keyglyph'>=</span>
<a name="line-203"></a> <span class='hs-conid'>Just</span> <span class='hs-layout'>(</span><span class='hs-conid'>FP</span> <span class='hs-varid'>f</span> <span class='hs-layout'>(</span><span class='hs-conid'>Hunk</span> <span class='hs-layout'>(</span><span class='hs-varid'>line1</span> <span class='hs-varop'>+</span> <span class='hs-varid'>lengthnew2</span> <span class='hs-comment'>-</span> <span class='hs-varid'>lengthold2</span><span class='hs-layout'>)</span> <span class='hs-varid'>old1</span> <span class='hs-varid'>new1</span><span class='hs-layout'>)</span> <span class='hs-conop'>:<</span>
<a name="line-204"></a> <span class='hs-conid'>FP</span> <span class='hs-varid'>f</span> <span class='hs-layout'>(</span><span class='hs-conid'>Hunk</span> <span class='hs-varid'>line2</span> <span class='hs-varid'>old2</span> <span class='hs-varid'>new2</span><span class='hs-layout'>)</span><span class='hs-layout'>)</span>
<a name="line-205"></a> <span class='hs-keyglyph'>|</span> <span class='hs-varid'>otherwise</span> <span class='hs-keyglyph'>=</span> <span class='hs-varid'>seq</span> <span class='hs-varid'>f</span> <span class='hs-conid'>Nothing</span>
<a name="line-206"></a> <span class='hs-keyword'>where</span> <span class='hs-varid'>lengthnew1</span> <span class='hs-keyglyph'>=</span> <span class='hs-varid'>length</span> <span class='hs-varid'>new1</span>
<a name="line-207"></a> <span class='hs-varid'>lengthnew2</span> <span class='hs-keyglyph'>=</span> <span class='hs-varid'>length</span> <span class='hs-varid'>new2</span>
<a name="line-208"></a> <span class='hs-varid'>lengthold1</span> <span class='hs-keyglyph'>=</span> <span class='hs-varid'>length</span> <span class='hs-varid'>old1</span>
<a name="line-209"></a> <span class='hs-varid'>lengthold2</span> <span class='hs-keyglyph'>=</span> <span class='hs-varid'>length</span> <span class='hs-varid'>old2</span>
<a name="line-210"></a><span class='hs-definition'>commuteHunk</span> <span class='hs-keyword'>_</span> <span class='hs-keyword'>_</span> <span class='hs-keyglyph'>=</span> <span class='hs-varid'>impossible</span>
<a name="line-211"></a>
<a name="line-212"></a><a name="tryTokReplace"></a><span class='hs-definition'>tryTokReplace</span> <span class='hs-keyglyph'>::</span> <span class='hs-conid'>String</span> <span class='hs-keyglyph'>-></span> <span class='hs-conid'>String</span> <span class='hs-keyglyph'>-></span> <span class='hs-conid'>String</span>
<a name="line-213"></a> <span class='hs-keyglyph'>-></span> <span class='hs-keyglyph'>[</span><span class='hs-conid'>B</span><span class='hs-varop'>.</span><span class='hs-conid'>ByteString</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'>B</span><span class='hs-varop'>.</span><span class='hs-conid'>ByteString</span><span class='hs-keyglyph'>]</span>
<a name="line-214"></a><span class='hs-definition'>tryTokReplace</span> <span class='hs-varid'>t</span> <span class='hs-varid'>o</span> <span class='hs-varid'>n</span> <span class='hs-varid'>mss</span> <span class='hs-keyglyph'>=</span>
<a name="line-215"></a> <span class='hs-varid'>mapM</span> <span class='hs-layout'>(</span><span class='hs-varid'>fmap</span> <span class='hs-conid'>B</span><span class='hs-varop'>.</span><span class='hs-varid'>concat</span> <span class='hs-varop'>.</span> <span class='hs-varid'>tryTokInternal</span> <span class='hs-varid'>t</span> <span class='hs-layout'>(</span><span class='hs-conid'>BC</span><span class='hs-varop'>.</span><span class='hs-varid'>pack</span> <span class='hs-varid'>o</span><span class='hs-layout'>)</span> <span class='hs-layout'>(</span><span class='hs-conid'>BC</span><span class='hs-varop'>.</span><span class='hs-varid'>pack</span> <span class='hs-varid'>n</span><span class='hs-layout'>)</span><span class='hs-layout'>)</span> <span class='hs-varid'>mss</span>
</pre></body>
</html>
