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<pre><a name="line-1"></a><span class='hs-comment'>{-# LANGUAGE BangPatterns, ScopedTypeVariables #-}</span>
<a name="line-2"></a>
<a name="line-3"></a><span class='hs-comment'>-- |</span>
<a name="line-4"></a><span class='hs-comment'>-- Module : Data.Text.Lazy.Search</span>
<a name="line-5"></a><span class='hs-comment'>-- Copyright : (c) 2009, 2010 Bryan O'Sullivan</span>
<a name="line-6"></a><span class='hs-comment'>--</span>
<a name="line-7"></a><span class='hs-comment'>-- License : BSD-style</span>
<a name="line-8"></a><span class='hs-comment'>-- Maintainer : bos@serpentine.com, rtomharper@googlemail.com,</span>
<a name="line-9"></a><span class='hs-comment'>-- duncan@haskell.org</span>
<a name="line-10"></a><span class='hs-comment'>-- Stability : experimental</span>
<a name="line-11"></a><span class='hs-comment'>-- Portability : GHC</span>
<a name="line-12"></a><span class='hs-comment'>--</span>
<a name="line-13"></a><span class='hs-comment'>-- Fast substring search for lazy 'Text', based on work by Boyer,</span>
<a name="line-14"></a><span class='hs-comment'>-- Moore, Horspool, Sunday, and Lundh. Adapted from the strict</span>
<a name="line-15"></a><span class='hs-comment'>-- implementation.</span>
<a name="line-16"></a>
<a name="line-17"></a><span class='hs-keyword'>module</span> <span class='hs-conid'>Data</span><span class='hs-varop'>.</span><span class='hs-conid'>Text</span><span class='hs-varop'>.</span><span class='hs-conid'>Lazy</span><span class='hs-varop'>.</span><span class='hs-conid'>Search</span>
<a name="line-18"></a> <span class='hs-layout'>(</span>
<a name="line-19"></a> <span class='hs-varid'>indices</span>
<a name="line-20"></a> <span class='hs-layout'>)</span> <span class='hs-keyword'>where</span>
<a name="line-21"></a>
<a name="line-22"></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'>Text</span><span class='hs-varop'>.</span><span class='hs-conid'>Array</span> <span class='hs-keyword'>as</span> <span class='hs-conid'>A</span>
<a name="line-23"></a><span class='hs-keyword'>import</span> <span class='hs-conid'>Data</span><span class='hs-varop'>.</span><span class='hs-conid'>Int</span> <span class='hs-layout'>(</span><span class='hs-conid'>Int64</span><span class='hs-layout'>)</span>
<a name="line-24"></a><span class='hs-keyword'>import</span> <span class='hs-conid'>Data</span><span class='hs-varop'>.</span><span class='hs-conid'>Word</span> <span class='hs-layout'>(</span><span class='hs-conid'>Word16</span><span class='hs-layout'>,</span> <span class='hs-conid'>Word64</span><span class='hs-layout'>)</span>
<a name="line-25"></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'>Text</span><span class='hs-varop'>.</span><span class='hs-conid'>Internal</span> <span class='hs-keyword'>as</span> <span class='hs-conid'>T</span>
<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'>Text</span><span class='hs-varop'>.</span><span class='hs-conid'>Fusion</span><span class='hs-varop'>.</span><span class='hs-conid'>Internal</span> <span class='hs-layout'>(</span><span class='hs-conid'>PairS</span><span class='hs-layout'>(</span><span class='hs-keyglyph'>..</span><span class='hs-layout'>)</span><span class='hs-layout'>)</span>
<a name="line-27"></a><span class='hs-keyword'>import</span> <span class='hs-conid'>Data</span><span class='hs-varop'>.</span><span class='hs-conid'>Text</span><span class='hs-varop'>.</span><span class='hs-conid'>Lazy</span><span class='hs-varop'>.</span><span class='hs-conid'>Internal</span> <span class='hs-layout'>(</span><span class='hs-conid'>Text</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'>foldlChunks</span><span class='hs-layout'>)</span>
<a name="line-28"></a><span class='hs-keyword'>import</span> <span class='hs-conid'>Data</span><span class='hs-varop'>.</span><span class='hs-conid'>Bits</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-varop'>.&.</span><span class='hs-layout'>)</span><span class='hs-layout'>)</span>
<a name="line-29"></a><span class='hs-keyword'>import</span> <span class='hs-conid'>Data</span><span class='hs-varop'>.</span><span class='hs-conid'>Text</span><span class='hs-varop'>.</span><span class='hs-conid'>UnsafeShift</span> <span class='hs-layout'>(</span><span class='hs-varid'>shiftL</span><span class='hs-layout'>)</span>
<a name="line-30"></a>
<a name="line-31"></a><a name="indices"></a><span class='hs-comment'>-- | /O(n+m)/ Find the offsets of all non-overlapping indices of</span>
<a name="line-32"></a><span class='hs-comment'>-- @needle@ within @haystack@.</span>
<a name="line-33"></a><span class='hs-comment'>--</span>
<a name="line-34"></a><span class='hs-comment'>-- This function is strict in @needle@, and lazy (as far as possible)</span>
<a name="line-35"></a><span class='hs-comment'>-- in the chunks of @haystack@.</span>
<a name="line-36"></a><span class='hs-comment'>--</span>
<a name="line-37"></a><span class='hs-comment'>-- In (unlikely) bad cases, this algorithm's complexity degrades</span>
<a name="line-38"></a><span class='hs-comment'>-- towards /O(n*m)/.</span>
<a name="line-39"></a><span class='hs-definition'>indices</span> <span class='hs-keyglyph'>::</span> <span class='hs-conid'>Text</span> <span class='hs-comment'>-- ^ Substring to search for (@needle@)</span>
<a name="line-40"></a> <span class='hs-keyglyph'>-></span> <span class='hs-conid'>Text</span> <span class='hs-comment'>-- ^ Text to search in (@haystack@)</span>
<a name="line-41"></a> <span class='hs-keyglyph'>-></span> <span class='hs-keyglyph'>[</span><span class='hs-conid'>Int64</span><span class='hs-keyglyph'>]</span>
<a name="line-42"></a><span class='hs-definition'>indices</span> <span class='hs-varid'>needle</span><span class='hs-keyglyph'>@</span><span class='hs-layout'>(</span><span class='hs-conid'>Chunk</span> <span class='hs-varid'>n</span> <span class='hs-varid'>ns</span><span class='hs-layout'>)</span> <span class='hs-sel'>_haystack</span><span class='hs-keyglyph'>@</span><span class='hs-layout'>(</span><span class='hs-conid'>Chunk</span> <span class='hs-varid'>k</span> <span class='hs-varid'>ks</span><span class='hs-layout'>)</span>
<a name="line-43"></a> <span class='hs-keyglyph'>|</span> <span class='hs-varid'>nlen</span> <span class='hs-varop'><=</span> <span class='hs-num'>0</span> <span class='hs-keyglyph'>=</span> <span class='hs-conid'>[]</span>
<a name="line-44"></a> <span class='hs-keyglyph'>|</span> <span class='hs-varid'>nlen</span> <span class='hs-varop'>==</span> <span class='hs-num'>1</span> <span class='hs-keyglyph'>=</span> <span class='hs-varid'>indicesOne</span> <span class='hs-layout'>(</span><span class='hs-varid'>nindex</span> <span class='hs-num'>0</span><span class='hs-layout'>)</span> <span class='hs-num'>0</span> <span class='hs-varid'>k</span> <span class='hs-varid'>ks</span>
<a name="line-45"></a> <span class='hs-keyglyph'>|</span> <span class='hs-varid'>otherwise</span> <span class='hs-keyglyph'>=</span> <span class='hs-varid'>advance</span> <span class='hs-varid'>k</span> <span class='hs-varid'>ks</span> <span class='hs-num'>0</span> <span class='hs-num'>0</span>
<a name="line-46"></a> <span class='hs-keyword'>where</span>
<a name="line-47"></a> <span class='hs-varid'>advance</span> <span class='hs-varid'>x</span><span class='hs-keyglyph'>@</span><span class='hs-layout'>(</span><span class='hs-conid'>T</span><span class='hs-varop'>.</span><span class='hs-conid'>Text</span> <span class='hs-keyword'>_</span> <span class='hs-keyword'>_</span> <span class='hs-varid'>l</span><span class='hs-layout'>)</span> <span class='hs-varid'>xs</span> <span class='hs-keyglyph'>=</span> <span class='hs-varid'>scan</span>
<a name="line-48"></a> <span class='hs-keyword'>where</span>
<a name="line-49"></a> <span class='hs-varid'>scan</span> <span class='hs-varop'>!</span><span class='hs-varid'>g</span> <span class='hs-varop'>!</span><span class='hs-varid'>i</span>
<a name="line-50"></a> <span class='hs-keyglyph'>|</span> <span class='hs-varid'>i</span> <span class='hs-varop'>>=</span> <span class='hs-varid'>m</span> <span class='hs-keyglyph'>=</span> <span class='hs-keyword'>case</span> <span class='hs-varid'>xs</span> <span class='hs-keyword'>of</span>
<a name="line-51"></a> <span class='hs-conid'>Empty</span> <span class='hs-keyglyph'>-></span> <span class='hs-conid'>[]</span>
<a name="line-52"></a> <span class='hs-conid'>Chunk</span> <span class='hs-varid'>y</span> <span class='hs-varid'>ys</span> <span class='hs-keyglyph'>-></span> <span class='hs-varid'>advance</span> <span class='hs-varid'>y</span> <span class='hs-varid'>ys</span> <span class='hs-varid'>g</span> <span class='hs-layout'>(</span><span class='hs-varid'>i</span><span class='hs-comment'>-</span><span class='hs-varid'>m</span><span class='hs-layout'>)</span>
<a name="line-53"></a> <span class='hs-keyglyph'>|</span> <span class='hs-varid'>lackingHay</span> <span class='hs-layout'>(</span><span class='hs-varid'>i</span> <span class='hs-varop'>+</span> <span class='hs-varid'>nlen</span><span class='hs-layout'>)</span> <span class='hs-varid'>x</span> <span class='hs-varid'>xs</span> <span class='hs-keyglyph'>=</span> <span class='hs-conid'>[]</span>
<a name="line-54"></a> <span class='hs-keyglyph'>|</span> <span class='hs-varid'>c</span> <span class='hs-varop'>==</span> <span class='hs-varid'>z</span> <span class='hs-varop'>&&</span> <span class='hs-varid'>candidateMatch</span> <span class='hs-num'>0</span> <span class='hs-keyglyph'>=</span> <span class='hs-varid'>g</span> <span class='hs-conop'>:</span> <span class='hs-varid'>scan</span> <span class='hs-layout'>(</span><span class='hs-varid'>g</span><span class='hs-varop'>+</span><span class='hs-varid'>nlen</span><span class='hs-layout'>)</span> <span class='hs-layout'>(</span><span class='hs-varid'>i</span><span class='hs-varop'>+</span><span class='hs-varid'>nlen</span><span class='hs-layout'>)</span>
<a name="line-55"></a> <span class='hs-keyglyph'>|</span> <span class='hs-varid'>otherwise</span> <span class='hs-keyglyph'>=</span> <span class='hs-varid'>scan</span> <span class='hs-layout'>(</span><span class='hs-varid'>g</span><span class='hs-varop'>+</span><span class='hs-varid'>delta</span><span class='hs-layout'>)</span> <span class='hs-layout'>(</span><span class='hs-varid'>i</span><span class='hs-varop'>+</span><span class='hs-varid'>delta</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'>m</span> <span class='hs-keyglyph'>=</span> <span class='hs-varid'>fromIntegral</span> <span class='hs-varid'>l</span>
<a name="line-58"></a> <span class='hs-varid'>c</span> <span class='hs-keyglyph'>=</span> <span class='hs-varid'>hindex</span> <span class='hs-layout'>(</span><span class='hs-varid'>i</span> <span class='hs-varop'>+</span> <span class='hs-varid'>nlast</span><span class='hs-layout'>)</span>
<a name="line-59"></a> <span class='hs-varid'>delta</span> <span class='hs-keyglyph'>|</span> <span class='hs-varid'>nextInPattern</span> <span class='hs-keyglyph'>=</span> <span class='hs-varid'>nlen</span> <span class='hs-varop'>+</span> <span class='hs-num'>1</span>
<a name="line-60"></a> <span class='hs-keyglyph'>|</span> <span class='hs-varid'>c</span> <span class='hs-varop'>==</span> <span class='hs-varid'>z</span> <span class='hs-keyglyph'>=</span> <span class='hs-varid'>skip</span> <span class='hs-varop'>+</span> <span class='hs-num'>1</span>
<a name="line-61"></a> <span class='hs-keyglyph'>|</span> <span class='hs-varid'>otherwise</span> <span class='hs-keyglyph'>=</span> <span class='hs-num'>1</span>
<a name="line-62"></a> <span class='hs-varid'>nextInPattern</span> <span class='hs-keyglyph'>=</span> <span class='hs-varid'>mask</span> <span class='hs-varop'>.&.</span> <span class='hs-varid'>swizzle</span> <span class='hs-layout'>(</span><span class='hs-varid'>hindex</span> <span class='hs-layout'>(</span><span class='hs-varid'>i</span><span class='hs-varop'>+</span><span class='hs-varid'>nlen</span><span class='hs-layout'>)</span><span class='hs-layout'>)</span> <span class='hs-varop'>==</span> <span class='hs-num'>0</span>
<a name="line-63"></a> <span class='hs-varid'>candidateMatch</span> <span class='hs-varop'>!</span><span class='hs-varid'>j</span>
<a name="line-64"></a> <span class='hs-keyglyph'>|</span> <span class='hs-varid'>j</span> <span class='hs-varop'>>=</span> <span class='hs-varid'>nlast</span> <span class='hs-keyglyph'>=</span> <span class='hs-conid'>True</span>
<a name="line-65"></a> <span class='hs-keyglyph'>|</span> <span class='hs-varid'>hindex</span> <span class='hs-layout'>(</span><span class='hs-varid'>i</span><span class='hs-varop'>+</span><span class='hs-varid'>j</span><span class='hs-layout'>)</span> <span class='hs-varop'>/=</span> <span class='hs-varid'>nindex</span> <span class='hs-varid'>j</span> <span class='hs-keyglyph'>=</span> <span class='hs-conid'>False</span>
<a name="line-66"></a> <span class='hs-keyglyph'>|</span> <span class='hs-varid'>otherwise</span> <span class='hs-keyglyph'>=</span> <span class='hs-varid'>candidateMatch</span> <span class='hs-layout'>(</span><span class='hs-varid'>j</span><span class='hs-varop'>+</span><span class='hs-num'>1</span><span class='hs-layout'>)</span>
<a name="line-67"></a> <span class='hs-varid'>hindex</span> <span class='hs-keyglyph'>=</span> <span class='hs-varid'>index</span> <span class='hs-varid'>x</span> <span class='hs-varid'>xs</span>
<a name="line-68"></a> <span class='hs-varid'>nlen</span> <span class='hs-keyglyph'>=</span> <span class='hs-varid'>wordLength</span> <span class='hs-varid'>needle</span>
<a name="line-69"></a> <span class='hs-varid'>nlast</span> <span class='hs-keyglyph'>=</span> <span class='hs-varid'>nlen</span> <span class='hs-comment'>-</span> <span class='hs-num'>1</span>
<a name="line-70"></a> <span class='hs-varid'>nindex</span> <span class='hs-keyglyph'>=</span> <span class='hs-varid'>index</span> <span class='hs-varid'>n</span> <span class='hs-varid'>ns</span>
<a name="line-71"></a> <span class='hs-varid'>z</span> <span class='hs-keyglyph'>=</span> <span class='hs-varid'>foldlChunks</span> <span class='hs-varid'>fin</span> <span class='hs-num'>0</span> <span class='hs-varid'>needle</span>
<a name="line-72"></a> <span class='hs-keyword'>where</span> <span class='hs-varid'>fin</span> <span class='hs-keyword'>_</span> <span class='hs-layout'>(</span><span class='hs-conid'>T</span><span class='hs-varop'>.</span><span class='hs-conid'>Text</span> <span class='hs-varid'>farr</span> <span class='hs-varid'>foff</span> <span class='hs-varid'>flen</span><span class='hs-layout'>)</span> <span class='hs-keyglyph'>=</span> <span class='hs-conid'>A</span><span class='hs-varop'>.</span><span class='hs-varid'>unsafeIndex</span> <span class='hs-varid'>farr</span> <span class='hs-layout'>(</span><span class='hs-varid'>foff</span><span class='hs-varop'>+</span><span class='hs-varid'>flen</span><span class='hs-comment'>-</span><span class='hs-num'>1</span><span class='hs-layout'>)</span>
<a name="line-73"></a> <span class='hs-layout'>(</span><span class='hs-varid'>mask</span> <span class='hs-keyglyph'>::</span> <span class='hs-conid'>Word64</span><span class='hs-layout'>)</span> <span class='hs-conop'>:*:</span> <span class='hs-varid'>skip</span> <span class='hs-keyglyph'>=</span> <span class='hs-varid'>buildTable</span> <span class='hs-varid'>n</span> <span class='hs-varid'>ns</span> <span class='hs-num'>0</span> <span class='hs-num'>0</span> <span class='hs-num'>0</span> <span class='hs-layout'>(</span><span class='hs-varid'>nlen</span><span class='hs-comment'>-</span><span class='hs-num'>2</span><span class='hs-layout'>)</span>
<a name="line-74"></a> <span class='hs-varid'>swizzle</span> <span class='hs-varid'>w</span> <span class='hs-keyglyph'>=</span> <span class='hs-num'>1</span> <span class='hs-varop'>`shiftL`</span> <span class='hs-layout'>(</span><span class='hs-varid'>fromIntegral</span> <span class='hs-varid'>w</span> <span class='hs-varop'>.&.</span> <span class='hs-num'>0x3f</span><span class='hs-layout'>)</span>
<a name="line-75"></a> <span class='hs-varid'>buildTable</span> <span class='hs-layout'>(</span><span class='hs-conid'>T</span><span class='hs-varop'>.</span><span class='hs-conid'>Text</span> <span class='hs-varid'>xarr</span> <span class='hs-varid'>xoff</span> <span class='hs-varid'>xlen</span><span class='hs-layout'>)</span> <span class='hs-varid'>xs</span> <span class='hs-keyglyph'>=</span> <span class='hs-varid'>go</span>
<a name="line-76"></a> <span class='hs-keyword'>where</span>
<a name="line-77"></a> <span class='hs-varid'>go</span> <span class='hs-varop'>!</span><span class='hs-layout'>(</span><span class='hs-varid'>g</span><span class='hs-keyglyph'>::</span><span class='hs-conid'>Int64</span><span class='hs-layout'>)</span> <span class='hs-varop'>!</span><span class='hs-varid'>i</span> <span class='hs-varop'>!</span><span class='hs-varid'>msk</span> <span class='hs-varop'>!</span><span class='hs-varid'>skp</span>
<a name="line-78"></a> <span class='hs-keyglyph'>|</span> <span class='hs-varid'>i</span> <span class='hs-varop'>>=</span> <span class='hs-varid'>xlast</span> <span class='hs-keyglyph'>=</span> <span class='hs-keyword'>case</span> <span class='hs-varid'>xs</span> <span class='hs-keyword'>of</span>
<a name="line-79"></a> <span class='hs-conid'>Empty</span> <span class='hs-keyglyph'>-></span> <span class='hs-layout'>(</span><span class='hs-varid'>msk</span> <span class='hs-varop'>.|.</span> <span class='hs-varid'>swizzle</span> <span class='hs-varid'>z</span><span class='hs-layout'>)</span> <span class='hs-conop'>:*:</span> <span class='hs-varid'>skp</span>
<a name="line-80"></a> <span class='hs-conid'>Chunk</span> <span class='hs-varid'>y</span> <span class='hs-varid'>ys</span> <span class='hs-keyglyph'>-></span> <span class='hs-varid'>buildTable</span> <span class='hs-varid'>y</span> <span class='hs-varid'>ys</span> <span class='hs-varid'>g</span> <span class='hs-num'>0</span> <span class='hs-varid'>msk</span> <span class='hs-varid'>skp</span>
<a name="line-81"></a> <span class='hs-keyglyph'>|</span> <span class='hs-varid'>otherwise</span> <span class='hs-keyglyph'>=</span> <span class='hs-varid'>go</span> <span class='hs-layout'>(</span><span class='hs-varid'>g</span><span class='hs-varop'>+</span><span class='hs-num'>1</span><span class='hs-layout'>)</span> <span class='hs-layout'>(</span><span class='hs-varid'>i</span><span class='hs-varop'>+</span><span class='hs-num'>1</span><span class='hs-layout'>)</span> <span class='hs-layout'>(</span><span class='hs-varid'>msk</span> <span class='hs-varop'>.|.</span> <span class='hs-varid'>swizzle</span> <span class='hs-varid'>c</span><span class='hs-layout'>)</span> <span class='hs-varid'>skp'</span>
<a name="line-82"></a> <span class='hs-keyword'>where</span> <span class='hs-varid'>c</span> <span class='hs-keyglyph'>=</span> <span class='hs-conid'>A</span><span class='hs-varop'>.</span><span class='hs-varid'>unsafeIndex</span> <span class='hs-varid'>xarr</span> <span class='hs-layout'>(</span><span class='hs-varid'>xoff</span><span class='hs-varop'>+</span><span class='hs-varid'>i</span><span class='hs-layout'>)</span>
<a name="line-83"></a> <span class='hs-varid'>skp'</span> <span class='hs-keyglyph'>|</span> <span class='hs-varid'>c</span> <span class='hs-varop'>==</span> <span class='hs-varid'>z</span> <span class='hs-keyglyph'>=</span> <span class='hs-varid'>nlen</span> <span class='hs-comment'>-</span> <span class='hs-varid'>fromIntegral</span> <span class='hs-varid'>g</span> <span class='hs-comment'>-</span> <span class='hs-num'>2</span>
<a name="line-84"></a> <span class='hs-keyglyph'>|</span> <span class='hs-varid'>otherwise</span> <span class='hs-keyglyph'>=</span> <span class='hs-varid'>skp</span>
<a name="line-85"></a> <span class='hs-varid'>xlast</span> <span class='hs-keyglyph'>=</span> <span class='hs-varid'>xlen</span> <span class='hs-comment'>-</span> <span class='hs-num'>1</span>
<a name="line-86"></a> <span class='hs-comment'>-- | Check whether an attempt to index into the haystack at the</span>
<a name="line-87"></a> <span class='hs-comment'>-- given offset would fail.</span>
<a name="line-88"></a> <span class='hs-varid'>lackingHay</span> <span class='hs-varid'>q</span> <span class='hs-keyglyph'>=</span> <span class='hs-varid'>go</span> <span class='hs-num'>0</span>
<a name="line-89"></a> <span class='hs-keyword'>where</span>
<a name="line-90"></a> <span class='hs-varid'>go</span> <span class='hs-varid'>p</span> <span class='hs-layout'>(</span><span class='hs-conid'>T</span><span class='hs-varop'>.</span><span class='hs-conid'>Text</span> <span class='hs-keyword'>_</span> <span class='hs-keyword'>_</span> <span class='hs-varid'>l</span><span class='hs-layout'>)</span> <span class='hs-varid'>ps</span> <span class='hs-keyglyph'>=</span> <span class='hs-varid'>p'</span> <span class='hs-varop'><</span> <span class='hs-varid'>q</span> <span class='hs-varop'>&&</span> <span class='hs-keyword'>case</span> <span class='hs-varid'>ps</span> <span class='hs-keyword'>of</span>
<a name="line-91"></a> <span class='hs-conid'>Empty</span> <span class='hs-keyglyph'>-></span> <span class='hs-conid'>True</span>
<a name="line-92"></a> <span class='hs-conid'>Chunk</span> <span class='hs-varid'>r</span> <span class='hs-varid'>rs</span> <span class='hs-keyglyph'>-></span> <span class='hs-varid'>go</span> <span class='hs-varid'>p'</span> <span class='hs-varid'>r</span> <span class='hs-varid'>rs</span>
<a name="line-93"></a> <span class='hs-keyword'>where</span> <span class='hs-varid'>p'</span> <span class='hs-keyglyph'>=</span> <span class='hs-varid'>p</span> <span class='hs-varop'>+</span> <span class='hs-varid'>fromIntegral</span> <span class='hs-varid'>l</span>
<a name="line-94"></a><span class='hs-definition'>indices</span> <span class='hs-keyword'>_</span> <span class='hs-keyword'>_</span> <span class='hs-keyglyph'>=</span> <span class='hs-conid'>[]</span>
<a name="line-95"></a>
<a name="line-96"></a><a name="index"></a><span class='hs-comment'>-- | Fast index into a partly unpacked 'Text'. We take into account</span>
<a name="line-97"></a><span class='hs-comment'>-- the possibility that the caller might try to access one element</span>
<a name="line-98"></a><span class='hs-comment'>-- past the end.</span>
<a name="line-99"></a><span class='hs-definition'>index</span> <span class='hs-keyglyph'>::</span> <span class='hs-conid'>T</span><span class='hs-varop'>.</span><span class='hs-conid'>Text</span> <span class='hs-keyglyph'>-></span> <span class='hs-conid'>Text</span> <span class='hs-keyglyph'>-></span> <span class='hs-conid'>Int64</span> <span class='hs-keyglyph'>-></span> <span class='hs-conid'>Word16</span>
<a name="line-100"></a><span class='hs-definition'>index</span> <span class='hs-layout'>(</span><span class='hs-conid'>T</span><span class='hs-varop'>.</span><span class='hs-conid'>Text</span> <span class='hs-varid'>arr</span> <span class='hs-varid'>off</span> <span class='hs-varid'>len</span><span class='hs-layout'>)</span> <span class='hs-varid'>xs</span> <span class='hs-varop'>!</span><span class='hs-varid'>i</span>
<a name="line-101"></a> <span class='hs-keyglyph'>|</span> <span class='hs-varid'>j</span> <span class='hs-varop'><</span> <span class='hs-varid'>len</span> <span class='hs-keyglyph'>=</span> <span class='hs-conid'>A</span><span class='hs-varop'>.</span><span class='hs-varid'>unsafeIndex</span> <span class='hs-varid'>arr</span> <span class='hs-layout'>(</span><span class='hs-varid'>off</span><span class='hs-varop'>+</span><span class='hs-varid'>j</span><span class='hs-layout'>)</span>
<a name="line-102"></a> <span class='hs-keyglyph'>|</span> <span class='hs-varid'>otherwise</span> <span class='hs-keyglyph'>=</span> <span class='hs-keyword'>case</span> <span class='hs-varid'>xs</span> <span class='hs-keyword'>of</span>
<a name="line-103"></a> <span class='hs-conid'>Empty</span>
<a name="line-104"></a> <span class='hs-comment'>-- out of bounds, but legal</span>
<a name="line-105"></a> <span class='hs-keyglyph'>|</span> <span class='hs-varid'>j</span> <span class='hs-varop'>==</span> <span class='hs-varid'>len</span> <span class='hs-keyglyph'>-></span> <span class='hs-num'>0</span>
<a name="line-106"></a> <span class='hs-comment'>-- should never happen, due to lackingHay above</span>
<a name="line-107"></a> <span class='hs-keyglyph'>|</span> <span class='hs-varid'>otherwise</span> <span class='hs-keyglyph'>-></span> <span class='hs-varid'>emptyError</span> <span class='hs-str'>"index"</span>
<a name="line-108"></a> <span class='hs-conid'>Chunk</span> <span class='hs-varid'>c</span> <span class='hs-varid'>cs</span> <span class='hs-keyglyph'>-></span> <span class='hs-varid'>index</span> <span class='hs-varid'>c</span> <span class='hs-varid'>cs</span> <span class='hs-layout'>(</span><span class='hs-varid'>i</span><span class='hs-comment'>-</span><span class='hs-varid'>fromIntegral</span> <span class='hs-varid'>len</span><span class='hs-layout'>)</span>
<a name="line-109"></a> <span class='hs-keyword'>where</span> <span class='hs-varid'>j</span> <span class='hs-keyglyph'>=</span> <span class='hs-varid'>fromIntegral</span> <span class='hs-varid'>i</span>
<a name="line-110"></a>
<a name="line-111"></a><a name="indicesOne"></a><span class='hs-comment'>-- | A variant of 'indices' that scans linearly for a single 'Word16'.</span>
<a name="line-112"></a><span class='hs-definition'>indicesOne</span> <span class='hs-keyglyph'>::</span> <span class='hs-conid'>Word16</span> <span class='hs-keyglyph'>-></span> <span class='hs-conid'>Int64</span> <span class='hs-keyglyph'>-></span> <span class='hs-conid'>T</span><span class='hs-varop'>.</span><span class='hs-conid'>Text</span> <span class='hs-keyglyph'>-></span> <span class='hs-conid'>Text</span> <span class='hs-keyglyph'>-></span> <span class='hs-keyglyph'>[</span><span class='hs-conid'>Int64</span><span class='hs-keyglyph'>]</span>
<a name="line-113"></a><span class='hs-definition'>indicesOne</span> <span class='hs-varid'>c</span> <span class='hs-keyglyph'>=</span> <span class='hs-varid'>chunk</span>
<a name="line-114"></a> <span class='hs-keyword'>where</span>
<a name="line-115"></a> <span class='hs-varid'>chunk</span> <span class='hs-varop'>!</span><span class='hs-varid'>i</span> <span class='hs-layout'>(</span><span class='hs-conid'>T</span><span class='hs-varop'>.</span><span class='hs-conid'>Text</span> <span class='hs-varid'>oarr</span> <span class='hs-varid'>ooff</span> <span class='hs-varid'>olen</span><span class='hs-layout'>)</span> <span class='hs-varid'>os</span> <span class='hs-keyglyph'>=</span> <span class='hs-varid'>go</span> <span class='hs-num'>0</span>
<a name="line-116"></a> <span class='hs-keyword'>where</span>
<a name="line-117"></a> <span class='hs-varid'>go</span> <span class='hs-varid'>h</span> <span class='hs-keyglyph'>|</span> <span class='hs-varid'>h</span> <span class='hs-varop'>>=</span> <span class='hs-varid'>olen</span> <span class='hs-keyglyph'>=</span> <span class='hs-keyword'>case</span> <span class='hs-varid'>os</span> <span class='hs-keyword'>of</span>
<a name="line-118"></a> <span class='hs-conid'>Empty</span> <span class='hs-keyglyph'>-></span> <span class='hs-conid'>[]</span>
<a name="line-119"></a> <span class='hs-conid'>Chunk</span> <span class='hs-varid'>y</span> <span class='hs-varid'>ys</span> <span class='hs-keyglyph'>-></span> <span class='hs-varid'>chunk</span> <span class='hs-layout'>(</span><span class='hs-varid'>i</span><span class='hs-varop'>+</span><span class='hs-varid'>fromIntegral</span> <span class='hs-varid'>olen</span><span class='hs-layout'>)</span> <span class='hs-varid'>y</span> <span class='hs-varid'>ys</span>
<a name="line-120"></a> <span class='hs-keyglyph'>|</span> <span class='hs-varid'>on</span> <span class='hs-varop'>==</span> <span class='hs-varid'>c</span> <span class='hs-keyglyph'>=</span> <span class='hs-varid'>i</span> <span class='hs-varop'>+</span> <span class='hs-varid'>fromIntegral</span> <span class='hs-varid'>h</span> <span class='hs-conop'>:</span> <span class='hs-varid'>go</span> <span class='hs-layout'>(</span><span class='hs-varid'>h</span><span class='hs-varop'>+</span><span class='hs-num'>1</span><span class='hs-layout'>)</span>
<a name="line-121"></a> <span class='hs-keyglyph'>|</span> <span class='hs-varid'>otherwise</span> <span class='hs-keyglyph'>=</span> <span class='hs-varid'>go</span> <span class='hs-layout'>(</span><span class='hs-varid'>h</span><span class='hs-varop'>+</span><span class='hs-num'>1</span><span class='hs-layout'>)</span>
<a name="line-122"></a> <span class='hs-keyword'>where</span> <span class='hs-varid'>on</span> <span class='hs-keyglyph'>=</span> <span class='hs-conid'>A</span><span class='hs-varop'>.</span><span class='hs-varid'>unsafeIndex</span> <span class='hs-varid'>oarr</span> <span class='hs-layout'>(</span><span class='hs-varid'>ooff</span><span class='hs-varop'>+</span><span class='hs-varid'>h</span><span class='hs-layout'>)</span>
<a name="line-123"></a>
<a name="line-124"></a><a name="wordLength"></a><span class='hs-comment'>-- | The number of 'Word16' values in a 'Text'.</span>
<a name="line-125"></a><span class='hs-definition'>wordLength</span> <span class='hs-keyglyph'>::</span> <span class='hs-conid'>Text</span> <span class='hs-keyglyph'>-></span> <span class='hs-conid'>Int64</span>
<a name="line-126"></a><span class='hs-definition'>wordLength</span> <span class='hs-keyglyph'>=</span> <span class='hs-varid'>foldlChunks</span> <span class='hs-varid'>sumLength</span> <span class='hs-num'>0</span>
<a name="line-127"></a> <span class='hs-keyword'>where</span> <span class='hs-varid'>sumLength</span> <span class='hs-varid'>i</span> <span class='hs-layout'>(</span><span class='hs-conid'>T</span><span class='hs-varop'>.</span><span class='hs-conid'>Text</span> <span class='hs-keyword'>_</span> <span class='hs-keyword'>_</span> <span class='hs-varid'>l</span><span class='hs-layout'>)</span> <span class='hs-keyglyph'>=</span> <span class='hs-varid'>i</span> <span class='hs-varop'>+</span> <span class='hs-varid'>fromIntegral</span> <span class='hs-varid'>l</span>
<a name="line-128"></a>
<a name="line-129"></a><a name="emptyError"></a><span class='hs-definition'>emptyError</span> <span class='hs-keyglyph'>::</span> <span class='hs-conid'>String</span> <span class='hs-keyglyph'>-></span> <span class='hs-varid'>a</span>
<a name="line-130"></a><span class='hs-definition'>emptyError</span> <span class='hs-varid'>fun</span> <span class='hs-keyglyph'>=</span> <span class='hs-varid'>error</span> <span class='hs-layout'>(</span><span class='hs-str'>"Data.Text.Lazy.Search."</span> <span class='hs-varop'>++</span> <span class='hs-varid'>fun</span> <span class='hs-varop'>++</span> <span class='hs-str'>": empty input"</span><span class='hs-layout'>)</span>
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