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<pre><a name="line-1"></a><span class='hs-comment'>{-# OPTIONS_GHC -XNoImplicitPrelude -funbox-strict-fields -fno-warn-name-shadowing #-}</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'>-- |</span>
<a name="line-5"></a><span class='hs-comment'>-- Module : Data.HashTable</span>
<a name="line-6"></a><span class='hs-comment'>-- Copyright : (c) The University of Glasgow 2003</span>
<a name="line-7"></a><span class='hs-comment'>-- License : BSD-style (see the file libraries/base/LICENSE)</span>
<a name="line-8"></a><span class='hs-comment'>--</span>
<a name="line-9"></a><span class='hs-comment'>-- Maintainer : libraries@haskell.org</span>
<a name="line-10"></a><span class='hs-comment'>-- Stability : provisional</span>
<a name="line-11"></a><span class='hs-comment'>-- Portability : portable</span>
<a name="line-12"></a><span class='hs-comment'>--</span>
<a name="line-13"></a><span class='hs-comment'>-- An implementation of extensible hash tables, as described in</span>
<a name="line-14"></a><span class='hs-comment'>-- Per-Ake Larson, /Dynamic Hash Tables/, CACM 31(4), April 1988,</span>
<a name="line-15"></a><span class='hs-comment'>-- pp. 446--457. The implementation is also derived from the one</span>
<a name="line-16"></a><span class='hs-comment'>-- in GHC's runtime system (@ghc\/rts\/Hash.{c,h}@).</span>
<a name="line-17"></a><span class='hs-comment'>--</span>
<a name="line-18"></a><span class='hs-comment'>-----------------------------------------------------------------------------</span>
<a name="line-19"></a>
<a name="line-20"></a><span class='hs-keyword'>module</span> <span class='hs-conid'>Data</span><span class='hs-varop'>.</span><span class='hs-conid'>HashTable</span> <span class='hs-layout'>(</span>
<a name="line-21"></a> <span class='hs-comment'>-- * Basic hash table operations</span>
<a name="line-22"></a> <span class='hs-conid'>HashTable</span><span class='hs-layout'>,</span> <span class='hs-varid'>new</span><span class='hs-layout'>,</span> <span class='hs-varid'>newHint</span><span class='hs-layout'>,</span> <span class='hs-varid'>insert</span><span class='hs-layout'>,</span> <span class='hs-varid'>delete</span><span class='hs-layout'>,</span> <span class='hs-varid'>lookup</span><span class='hs-layout'>,</span> <span class='hs-varid'>update</span><span class='hs-layout'>,</span>
<a name="line-23"></a> <span class='hs-comment'>-- * Converting to and from lists</span>
<a name="line-24"></a> <span class='hs-varid'>fromList</span><span class='hs-layout'>,</span> <span class='hs-varid'>toList</span><span class='hs-layout'>,</span>
<a name="line-25"></a> <span class='hs-comment'>-- * Hash functions</span>
<a name="line-26"></a> <span class='hs-comment'>-- $hash_functions</span>
<a name="line-27"></a> <span class='hs-varid'>hashInt</span><span class='hs-layout'>,</span> <span class='hs-varid'>hashString</span><span class='hs-layout'>,</span>
<a name="line-28"></a> <span class='hs-varid'>prime</span><span class='hs-layout'>,</span>
<a name="line-29"></a> <span class='hs-comment'>-- * Diagnostics</span>
<a name="line-30"></a> <span class='hs-varid'>longestChain</span>
<a name="line-31"></a> <span class='hs-layout'>)</span> <span class='hs-keyword'>where</span>
<a name="line-32"></a>
<a name="line-33"></a><span class='hs-comment'>-- This module is imported by Data.Dynamic, which is pretty low down in the</span>
<a name="line-34"></a><span class='hs-comment'>-- module hierarchy, so don't import "high-level" modules</span>
<a name="line-35"></a>
<a name="line-36"></a><span class='hs-cpp'>#ifdef __GLASGOW_HASKELL__</span>
<a name="line-37"></a><span class='hs-keyword'>import</span> <span class='hs-conid'>GHC</span><span class='hs-varop'>.</span><span class='hs-conid'>Base</span>
<a name="line-38"></a><span class='hs-cpp'>#else</span>
<a name="line-39"></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'>lookup</span> <span class='hs-layout'>)</span>
<a name="line-40"></a><span class='hs-cpp'>#endif</span>
<a name="line-41"></a><span class='hs-keyword'>import</span> <span class='hs-conid'>Data</span><span class='hs-varop'>.</span><span class='hs-conid'>Tuple</span> <span class='hs-layout'>(</span> <span class='hs-varid'>fst</span> <span class='hs-layout'>)</span>
<a name="line-42"></a><span class='hs-keyword'>import</span> <span class='hs-conid'>Data</span><span class='hs-varop'>.</span><span class='hs-conid'>Bits</span>
<a name="line-43"></a><span class='hs-keyword'>import</span> <span class='hs-conid'>Data</span><span class='hs-varop'>.</span><span class='hs-conid'>Maybe</span>
<a name="line-44"></a><span class='hs-keyword'>import</span> <span class='hs-conid'>Data</span><span class='hs-varop'>.</span><span class='hs-conid'>List</span> <span class='hs-layout'>(</span> <span class='hs-varid'>maximumBy</span><span class='hs-layout'>,</span> <span class='hs-varid'>length</span><span class='hs-layout'>,</span> <span class='hs-varid'>concat</span><span class='hs-layout'>,</span> <span class='hs-varid'>foldl'</span><span class='hs-layout'>,</span> <span class='hs-varid'>partition</span> <span class='hs-layout'>)</span>
<a name="line-45"></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'>Int32</span> <span class='hs-layout'>)</span>
<a name="line-46"></a>
<a name="line-47"></a><span class='hs-cpp'>#if defined(__GLASGOW_HASKELL__)</span>
<a name="line-48"></a><span class='hs-keyword'>import</span> <span class='hs-conid'>GHC</span><span class='hs-varop'>.</span><span class='hs-conid'>Num</span>
<a name="line-49"></a><span class='hs-keyword'>import</span> <span class='hs-conid'>GHC</span><span class='hs-varop'>.</span><span class='hs-conid'>Real</span> <span class='hs-layout'>(</span> <span class='hs-varid'>fromIntegral</span> <span class='hs-layout'>)</span>
<a name="line-50"></a><span class='hs-keyword'>import</span> <span class='hs-conid'>GHC</span><span class='hs-varop'>.</span><span class='hs-conid'>Show</span> <span class='hs-layout'>(</span> <span class='hs-conid'>Show</span><span class='hs-layout'>(</span><span class='hs-keyglyph'>..</span><span class='hs-layout'>)</span> <span class='hs-layout'>)</span>
<a name="line-51"></a><span class='hs-keyword'>import</span> <span class='hs-conid'>GHC</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-52"></a>
<a name="line-53"></a><span class='hs-keyword'>import</span> <span class='hs-conid'>GHC</span><span class='hs-varop'>.</span><span class='hs-conid'>IO</span>
<a name="line-54"></a><span class='hs-keyword'>import</span> <span class='hs-conid'>GHC</span><span class='hs-varop'>.</span><span class='hs-conid'>IOArray</span>
<a name="line-55"></a><span class='hs-keyword'>import</span> <span class='hs-conid'>GHC</span><span class='hs-varop'>.</span><span class='hs-conid'>IORef</span>
<a name="line-56"></a><span class='hs-cpp'>#else</span>
<a name="line-57"></a><span class='hs-keyword'>import</span> <span class='hs-conid'>Data</span><span class='hs-varop'>.</span><span class='hs-conid'>Char</span> <span class='hs-layout'>(</span> <span class='hs-varid'>ord</span> <span class='hs-layout'>)</span>
<a name="line-58"></a><span class='hs-keyword'>import</span> <span class='hs-conid'>Data</span><span class='hs-varop'>.</span><span class='hs-conid'>IORef</span> <span class='hs-layout'>(</span> <span class='hs-conid'>IORef</span><span class='hs-layout'>,</span> <span class='hs-varid'>newIORef</span><span class='hs-layout'>,</span> <span class='hs-varid'>readIORef</span><span class='hs-layout'>,</span> <span class='hs-varid'>writeIORef</span> <span class='hs-layout'>)</span>
<a name="line-59"></a><span class='hs-keyword'>import</span> <span class='hs-conid'>System</span><span class='hs-varop'>.</span><span class='hs-conid'>IO</span><span class='hs-varop'>.</span><span class='hs-conid'>Unsafe</span> <span class='hs-layout'>(</span> <span class='hs-varid'>unsafePerformIO</span> <span class='hs-layout'>)</span>
<a name="line-60"></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-61"></a><span class='hs-cpp'># if defined(__HUGS__)</span>
<a name="line-62"></a><span class='hs-keyword'>import</span> <span class='hs-conid'>Hugs</span><span class='hs-varop'>.</span><span class='hs-conid'>IOArray</span> <span class='hs-layout'>(</span> <span class='hs-conid'>IOArray</span><span class='hs-layout'>,</span> <span class='hs-varid'>newIOArray</span><span class='hs-layout'>,</span>
<a name="line-63"></a> <span class='hs-varid'>unsafeReadIOArray</span><span class='hs-layout'>,</span> <span class='hs-varid'>unsafeWriteIOArray</span> <span class='hs-layout'>)</span>
<a name="line-64"></a><span class='hs-cpp'># elif defined(__NHC__)</span>
<a name="line-65"></a><span class='hs-keyword'>import</span> <span class='hs-conid'>NHC</span><span class='hs-varop'>.</span><span class='hs-conid'>IOExtras</span> <span class='hs-layout'>(</span> <span class='hs-conid'>IOArray</span><span class='hs-layout'>,</span> <span class='hs-varid'>newIOArray</span><span class='hs-layout'>,</span> <span class='hs-varid'>readIOArray</span><span class='hs-layout'>,</span> <span class='hs-varid'>writeIOArray</span> <span class='hs-layout'>)</span>
<a name="line-66"></a><span class='hs-cpp'># endif</span>
<a name="line-67"></a><span class='hs-cpp'>#endif</span>
<a name="line-68"></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-varid'>mapM</span><span class='hs-layout'>,</span> <span class='hs-varid'>mapM_</span><span class='hs-layout'>,</span> <span class='hs-varid'>sequence_</span> <span class='hs-layout'>)</span>
<a name="line-69"></a>
<a name="line-70"></a>
<a name="line-71"></a><span class='hs-comment'>-----------------------------------------------------------------------</span>
<a name="line-72"></a>
<a name="line-73"></a><a name="iNSTRUMENTED"></a><span class='hs-definition'>iNSTRUMENTED</span> <span class='hs-keyglyph'>::</span> <span class='hs-conid'>Bool</span>
<a name="line-74"></a><span class='hs-definition'>iNSTRUMENTED</span> <span class='hs-keyglyph'>=</span> <span class='hs-conid'>False</span>
<a name="line-75"></a>
<a name="line-76"></a><span class='hs-comment'>-----------------------------------------------------------------------</span>
<a name="line-77"></a>
<a name="line-78"></a><a name="readHTArray"></a><span class='hs-definition'>readHTArray</span> <span class='hs-keyglyph'>::</span> <span class='hs-conid'>HTArray</span> <span class='hs-varid'>a</span> <span class='hs-keyglyph'>-></span> <span class='hs-conid'>Int32</span> <span class='hs-keyglyph'>-></span> <span class='hs-conid'>IO</span> <span class='hs-varid'>a</span>
<a name="line-79"></a><a name="writeMutArray"></a><span class='hs-definition'>writeMutArray</span> <span class='hs-keyglyph'>::</span> <span class='hs-conid'>MutArray</span> <span class='hs-varid'>a</span> <span class='hs-keyglyph'>-></span> <span class='hs-conid'>Int32</span> <span class='hs-keyglyph'>-></span> <span class='hs-varid'>a</span> <span class='hs-keyglyph'>-></span> <span class='hs-conid'>IO</span> <span class='hs-conid'>()</span>
<a name="line-80"></a><a name="newMutArray"></a><span class='hs-definition'>newMutArray</span> <span class='hs-keyglyph'>::</span> <span class='hs-layout'>(</span><span class='hs-conid'>Int32</span><span class='hs-layout'>,</span> <span class='hs-conid'>Int32</span><span class='hs-layout'>)</span> <span class='hs-keyglyph'>-></span> <span class='hs-varid'>a</span> <span class='hs-keyglyph'>-></span> <span class='hs-conid'>IO</span> <span class='hs-layout'>(</span><span class='hs-conid'>MutArray</span> <span class='hs-varid'>a</span><span class='hs-layout'>)</span>
<a name="line-81"></a><span class='hs-definition'>newMutArray</span> <span class='hs-keyglyph'>=</span> <span class='hs-varid'>newIOArray</span>
<a name="line-82"></a><a name="MutArray"></a><span class='hs-keyword'>type</span> <span class='hs-conid'>MutArray</span> <span class='hs-varid'>a</span> <span class='hs-keyglyph'>=</span> <span class='hs-conid'>IOArray</span> <span class='hs-conid'>Int32</span> <span class='hs-varid'>a</span>
<a name="line-83"></a><a name="HTArray"></a><span class='hs-keyword'>type</span> <span class='hs-conid'>HTArray</span> <span class='hs-varid'>a</span> <span class='hs-keyglyph'>=</span> <span class='hs-conid'>MutArray</span> <span class='hs-varid'>a</span>
<a name="line-84"></a><span class='hs-cpp'>#if defined(DEBUG) || defined(__NHC__)</span>
<a name="line-85"></a><span class='hs-definition'>readHTArray</span> <span class='hs-keyglyph'>=</span> <span class='hs-varid'>readIOArray</span>
<a name="line-86"></a><span class='hs-definition'>writeMutArray</span> <span class='hs-keyglyph'>=</span> <span class='hs-varid'>writeIOArray</span>
<a name="line-87"></a><span class='hs-cpp'>#else</span>
<a name="line-88"></a><span class='hs-definition'>readHTArray</span> <span class='hs-varid'>arr</span> <span class='hs-varid'>i</span> <span class='hs-keyglyph'>=</span> <span class='hs-varid'>unsafeReadIOArray</span> <span class='hs-varid'>arr</span> <span class='hs-layout'>(</span><span class='hs-varid'>fromIntegral</span> <span class='hs-varid'>i</span><span class='hs-layout'>)</span>
<a name="line-89"></a><span class='hs-definition'>writeMutArray</span> <span class='hs-varid'>arr</span> <span class='hs-varid'>i</span> <span class='hs-varid'>x</span> <span class='hs-keyglyph'>=</span> <span class='hs-varid'>unsafeWriteIOArray</span> <span class='hs-varid'>arr</span> <span class='hs-layout'>(</span><span class='hs-varid'>fromIntegral</span> <span class='hs-varid'>i</span><span class='hs-layout'>)</span> <span class='hs-varid'>x</span>
<a name="line-90"></a><span class='hs-cpp'>#endif</span>
<a name="line-91"></a>
<a name="line-92"></a><a name="HashTable"></a><span class='hs-keyword'>data</span> <span class='hs-conid'>HashTable</span> <span class='hs-varid'>key</span> <span class='hs-varid'>val</span> <span class='hs-keyglyph'>=</span> <span class='hs-conid'>HashTable</span> <span class='hs-layout'>{</span>
<a name="line-93"></a> <span class='hs-varid'>cmp</span> <span class='hs-keyglyph'>::</span> <span class='hs-varop'>!</span><span class='hs-layout'>(</span><span class='hs-varid'>key</span> <span class='hs-keyglyph'>-></span> <span class='hs-varid'>key</span> <span class='hs-keyglyph'>-></span> <span class='hs-conid'>Bool</span><span class='hs-layout'>)</span><span class='hs-layout'>,</span>
<a name="line-94"></a> <span class='hs-varid'>hash_fn</span> <span class='hs-keyglyph'>::</span> <span class='hs-varop'>!</span><span class='hs-layout'>(</span><span class='hs-varid'>key</span> <span class='hs-keyglyph'>-></span> <span class='hs-conid'>Int32</span><span class='hs-layout'>)</span><span class='hs-layout'>,</span>
<a name="line-95"></a> <span class='hs-varid'>tab</span> <span class='hs-keyglyph'>::</span> <span class='hs-varop'>!</span><span class='hs-layout'>(</span><span class='hs-conid'>IORef</span> <span class='hs-layout'>(</span><span class='hs-conid'>HT</span> <span class='hs-varid'>key</span> <span class='hs-varid'>val</span><span class='hs-layout'>)</span><span class='hs-layout'>)</span>
<a name="line-96"></a> <span class='hs-layout'>}</span>
<a name="line-97"></a><span class='hs-comment'>-- TODO: the IORef should really be an MVar.</span>
<a name="line-98"></a>
<a name="line-99"></a><a name="HT"></a><span class='hs-keyword'>data</span> <span class='hs-conid'>HT</span> <span class='hs-varid'>key</span> <span class='hs-varid'>val</span>
<a name="line-100"></a> <span class='hs-keyglyph'>=</span> <span class='hs-conid'>HT</span> <span class='hs-layout'>{</span>
<a name="line-101"></a> <span class='hs-varid'>kcount</span> <span class='hs-keyglyph'>::</span> <span class='hs-varop'>!</span><span class='hs-conid'>Int32</span><span class='hs-layout'>,</span> <span class='hs-comment'>-- Total number of keys.</span>
<a name="line-102"></a> <span class='hs-varid'>bmask</span> <span class='hs-keyglyph'>::</span> <span class='hs-varop'>!</span><span class='hs-conid'>Int32</span><span class='hs-layout'>,</span>
<a name="line-103"></a> <span class='hs-varid'>buckets</span> <span class='hs-keyglyph'>::</span> <span class='hs-varop'>!</span><span class='hs-layout'>(</span><span class='hs-conid'>HTArray</span> <span class='hs-keyglyph'>[</span><span class='hs-layout'>(</span><span class='hs-varid'>key</span><span class='hs-layout'>,</span><span class='hs-varid'>val</span><span class='hs-layout'>)</span><span class='hs-keyglyph'>]</span><span class='hs-layout'>)</span>
<a name="line-104"></a> <span class='hs-layout'>}</span>
<a name="line-105"></a>
<a name="line-106"></a><span class='hs-comment'>-- ------------------------------------------------------------</span>
<a name="line-107"></a><span class='hs-comment'>-- Instrumentation for performance tuning</span>
<a name="line-108"></a>
<a name="line-109"></a><span class='hs-comment'>-- This ought to be roundly ignored after optimization when</span>
<a name="line-110"></a><span class='hs-comment'>-- iNSTRUMENTED=False.</span>
<a name="line-111"></a>
<a name="line-112"></a><a name="modifyIORef"></a><span class='hs-comment'>-- STRICT version of modifyIORef!</span>
<a name="line-113"></a><span class='hs-definition'>modifyIORef</span> <span class='hs-keyglyph'>::</span> <span class='hs-conid'>IORef</span> <span class='hs-varid'>a</span> <span class='hs-keyglyph'>-></span> <span class='hs-layout'>(</span><span class='hs-varid'>a</span> <span class='hs-keyglyph'>-></span> <span class='hs-varid'>a</span><span class='hs-layout'>)</span> <span class='hs-keyglyph'>-></span> <span class='hs-conid'>IO</span> <span class='hs-conid'>()</span>
<a name="line-114"></a><span class='hs-definition'>modifyIORef</span> <span class='hs-varid'>r</span> <span class='hs-varid'>f</span> <span class='hs-keyglyph'>=</span> <span class='hs-keyword'>do</span>
<a name="line-115"></a> <span class='hs-varid'>v</span> <span class='hs-keyglyph'><-</span> <span class='hs-varid'>readIORef</span> <span class='hs-varid'>r</span>
<a name="line-116"></a> <span class='hs-keyword'>let</span> <span class='hs-varid'>z</span> <span class='hs-keyglyph'>=</span> <span class='hs-varid'>f</span> <span class='hs-varid'>v</span> <span class='hs-keyword'>in</span> <span class='hs-varid'>z</span> <span class='hs-varop'>`seq`</span> <span class='hs-varid'>writeIORef</span> <span class='hs-varid'>r</span> <span class='hs-varid'>z</span>
<a name="line-117"></a>
<a name="line-118"></a><a name="HashData"></a><span class='hs-keyword'>data</span> <span class='hs-conid'>HashData</span> <span class='hs-keyglyph'>=</span> <span class='hs-conid'>HD</span> <span class='hs-layout'>{</span>
<a name="line-119"></a> <span class='hs-varid'>tables</span> <span class='hs-keyglyph'>::</span> <span class='hs-varop'>!</span><span class='hs-conid'>Integer</span><span class='hs-layout'>,</span>
<a name="line-120"></a> <span class='hs-varid'>insertions</span> <span class='hs-keyglyph'>::</span> <span class='hs-varop'>!</span><span class='hs-conid'>Integer</span><span class='hs-layout'>,</span>
<a name="line-121"></a> <span class='hs-varid'>lookups</span> <span class='hs-keyglyph'>::</span> <span class='hs-varop'>!</span><span class='hs-conid'>Integer</span><span class='hs-layout'>,</span>
<a name="line-122"></a> <span class='hs-varid'>totBuckets</span> <span class='hs-keyglyph'>::</span> <span class='hs-varop'>!</span><span class='hs-conid'>Integer</span><span class='hs-layout'>,</span>
<a name="line-123"></a> <span class='hs-varid'>maxEntries</span> <span class='hs-keyglyph'>::</span> <span class='hs-varop'>!</span><span class='hs-conid'>Int32</span><span class='hs-layout'>,</span>
<a name="line-124"></a> <span class='hs-varid'>maxChain</span> <span class='hs-keyglyph'>::</span> <span class='hs-varop'>!</span><span class='hs-conid'>Int</span><span class='hs-layout'>,</span>
<a name="line-125"></a> <span class='hs-varid'>maxBuckets</span> <span class='hs-keyglyph'>::</span> <span class='hs-varop'>!</span><span class='hs-conid'>Int32</span>
<a name="line-126"></a><span class='hs-layout'>}</span> <span class='hs-keyword'>deriving</span> <span class='hs-layout'>(</span><span class='hs-conid'>Eq</span><span class='hs-layout'>,</span> <span class='hs-conid'>Show</span><span class='hs-layout'>)</span>
<a name="line-127"></a>
<a name="line-128"></a><a name="hashData"></a><span class='hs-comment'>{-# NOINLINE hashData #-}</span>
<a name="line-129"></a><span class='hs-definition'>hashData</span> <span class='hs-keyglyph'>::</span> <span class='hs-conid'>IORef</span> <span class='hs-conid'>HashData</span>
<a name="line-130"></a><span class='hs-definition'>hashData</span> <span class='hs-keyglyph'>=</span> <span class='hs-varid'>unsafePerformIO</span> <span class='hs-layout'>(</span><span class='hs-varid'>newIORef</span> <span class='hs-layout'>(</span><span class='hs-conid'>HD</span> <span class='hs-layout'>{</span> <span class='hs-varid'>tables</span><span class='hs-keyglyph'>=</span><span class='hs-num'>0</span><span class='hs-layout'>,</span> <span class='hs-varid'>insertions</span><span class='hs-keyglyph'>=</span><span class='hs-num'>0</span><span class='hs-layout'>,</span> <span class='hs-varid'>lookups</span><span class='hs-keyglyph'>=</span><span class='hs-num'>0</span><span class='hs-layout'>,</span>
<a name="line-131"></a> <span class='hs-varid'>totBuckets</span><span class='hs-keyglyph'>=</span><span class='hs-num'>0</span><span class='hs-layout'>,</span> <span class='hs-varid'>maxEntries</span><span class='hs-keyglyph'>=</span><span class='hs-num'>0</span><span class='hs-layout'>,</span>
<a name="line-132"></a> <span class='hs-varid'>maxChain</span><span class='hs-keyglyph'>=</span><span class='hs-num'>0</span><span class='hs-layout'>,</span> <span class='hs-varid'>maxBuckets</span><span class='hs-keyglyph'>=</span><span class='hs-varid'>tABLE_MIN</span> <span class='hs-layout'>}</span> <span class='hs-layout'>)</span><span class='hs-layout'>)</span>
<a name="line-133"></a>
<a name="line-134"></a><a name="instrument"></a><span class='hs-definition'>instrument</span> <span class='hs-keyglyph'>::</span> <span class='hs-layout'>(</span><span class='hs-conid'>HashData</span> <span class='hs-keyglyph'>-></span> <span class='hs-conid'>HashData</span><span class='hs-layout'>)</span> <span class='hs-keyglyph'>-></span> <span class='hs-conid'>IO</span> <span class='hs-conid'>()</span>
<a name="line-135"></a><span class='hs-definition'>instrument</span> <span class='hs-varid'>i</span> <span class='hs-keyglyph'>|</span> <span class='hs-varid'>iNSTRUMENTED</span> <span class='hs-keyglyph'>=</span> <span class='hs-varid'>modifyIORef</span> <span class='hs-varid'>hashData</span> <span class='hs-varid'>i</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-varid'>return</span> <span class='hs-conid'>()</span>
<a name="line-137"></a>
<a name="line-138"></a><a name="recordNew"></a><span class='hs-definition'>recordNew</span> <span class='hs-keyglyph'>::</span> <span class='hs-conid'>IO</span> <span class='hs-conid'>()</span>
<a name="line-139"></a><span class='hs-definition'>recordNew</span> <span class='hs-keyglyph'>=</span> <span class='hs-varid'>instrument</span> <span class='hs-varid'>rec</span>
<a name="line-140"></a> <span class='hs-keyword'>where</span> <span class='hs-varid'>rec</span> <span class='hs-varid'>hd</span><span class='hs-keyglyph'>@</span><span class='hs-conid'>HD</span><span class='hs-layout'>{</span> <span class='hs-varid'>tables</span><span class='hs-keyglyph'>=</span><span class='hs-varid'>t</span><span class='hs-layout'>,</span> <span class='hs-varid'>totBuckets</span><span class='hs-keyglyph'>=</span><span class='hs-varid'>b</span> <span class='hs-layout'>}</span> <span class='hs-keyglyph'>=</span>
<a name="line-141"></a> <span class='hs-varid'>hd</span><span class='hs-layout'>{</span> <span class='hs-varid'>tables</span><span class='hs-keyglyph'>=</span><span class='hs-varid'>t</span><span class='hs-varop'>+</span><span class='hs-num'>1</span><span class='hs-layout'>,</span> <span class='hs-varid'>totBuckets</span><span class='hs-keyglyph'>=</span><span class='hs-varid'>b</span><span class='hs-varop'>+</span><span class='hs-varid'>fromIntegral</span> <span class='hs-varid'>tABLE_MIN</span> <span class='hs-layout'>}</span>
<a name="line-142"></a>
<a name="line-143"></a><a name="recordIns"></a><span class='hs-definition'>recordIns</span> <span class='hs-keyglyph'>::</span> <span class='hs-conid'>Int32</span> <span class='hs-keyglyph'>-></span> <span class='hs-conid'>Int32</span> <span class='hs-keyglyph'>-></span> <span class='hs-keyglyph'>[</span><span class='hs-varid'>a</span><span class='hs-keyglyph'>]</span> <span class='hs-keyglyph'>-></span> <span class='hs-conid'>IO</span> <span class='hs-conid'>()</span>
<a name="line-144"></a><span class='hs-definition'>recordIns</span> <span class='hs-varid'>i</span> <span class='hs-varid'>sz</span> <span class='hs-varid'>bkt</span> <span class='hs-keyglyph'>=</span> <span class='hs-varid'>instrument</span> <span class='hs-varid'>rec</span>
<a name="line-145"></a> <span class='hs-keyword'>where</span> <span class='hs-varid'>rec</span> <span class='hs-varid'>hd</span><span class='hs-keyglyph'>@</span><span class='hs-conid'>HD</span><span class='hs-layout'>{</span> <span class='hs-varid'>insertions</span><span class='hs-keyglyph'>=</span><span class='hs-varid'>ins</span><span class='hs-layout'>,</span> <span class='hs-varid'>maxEntries</span><span class='hs-keyglyph'>=</span><span class='hs-varid'>mx</span><span class='hs-layout'>,</span> <span class='hs-varid'>maxChain</span><span class='hs-keyglyph'>=</span><span class='hs-varid'>mc</span> <span class='hs-layout'>}</span> <span class='hs-keyglyph'>=</span>
<a name="line-146"></a> <span class='hs-varid'>hd</span><span class='hs-layout'>{</span> <span class='hs-varid'>insertions</span><span class='hs-keyglyph'>=</span><span class='hs-varid'>ins</span><span class='hs-varop'>+</span><span class='hs-varid'>fromIntegral</span> <span class='hs-varid'>i</span><span class='hs-layout'>,</span> <span class='hs-varid'>maxEntries</span><span class='hs-keyglyph'>=</span><span class='hs-varid'>mx</span> <span class='hs-varop'>`max`</span> <span class='hs-varid'>sz</span><span class='hs-layout'>,</span>
<a name="line-147"></a> <span class='hs-varid'>maxChain</span><span class='hs-keyglyph'>=</span><span class='hs-varid'>mc</span> <span class='hs-varop'>`max`</span> <span class='hs-varid'>length</span> <span class='hs-varid'>bkt</span> <span class='hs-layout'>}</span>
<a name="line-148"></a>
<a name="line-149"></a><a name="recordResize"></a><span class='hs-definition'>recordResize</span> <span class='hs-keyglyph'>::</span> <span class='hs-conid'>Int32</span> <span class='hs-keyglyph'>-></span> <span class='hs-conid'>Int32</span> <span class='hs-keyglyph'>-></span> <span class='hs-conid'>IO</span> <span class='hs-conid'>()</span>
<a name="line-150"></a><span class='hs-definition'>recordResize</span> <span class='hs-varid'>older</span> <span class='hs-varid'>newer</span> <span class='hs-keyglyph'>=</span> <span class='hs-varid'>instrument</span> <span class='hs-varid'>rec</span>
<a name="line-151"></a> <span class='hs-keyword'>where</span> <span class='hs-varid'>rec</span> <span class='hs-varid'>hd</span><span class='hs-keyglyph'>@</span><span class='hs-conid'>HD</span><span class='hs-layout'>{</span> <span class='hs-varid'>totBuckets</span><span class='hs-keyglyph'>=</span><span class='hs-varid'>b</span><span class='hs-layout'>,</span> <span class='hs-varid'>maxBuckets</span><span class='hs-keyglyph'>=</span><span class='hs-varid'>mx</span> <span class='hs-layout'>}</span> <span class='hs-keyglyph'>=</span>
<a name="line-152"></a> <span class='hs-varid'>hd</span><span class='hs-layout'>{</span> <span class='hs-varid'>totBuckets</span><span class='hs-keyglyph'>=</span><span class='hs-varid'>b</span><span class='hs-varop'>+</span><span class='hs-varid'>fromIntegral</span> <span class='hs-layout'>(</span><span class='hs-varid'>newer</span><span class='hs-comment'>-</span><span class='hs-varid'>older</span><span class='hs-layout'>)</span><span class='hs-layout'>,</span>
<a name="line-153"></a> <span class='hs-varid'>maxBuckets</span><span class='hs-keyglyph'>=</span><span class='hs-varid'>mx</span> <span class='hs-varop'>`max`</span> <span class='hs-varid'>newer</span> <span class='hs-layout'>}</span>
<a name="line-154"></a>
<a name="line-155"></a><a name="recordLookup"></a><span class='hs-definition'>recordLookup</span> <span class='hs-keyglyph'>::</span> <span class='hs-conid'>IO</span> <span class='hs-conid'>()</span>
<a name="line-156"></a><span class='hs-definition'>recordLookup</span> <span class='hs-keyglyph'>=</span> <span class='hs-varid'>instrument</span> <span class='hs-varid'>lkup</span>
<a name="line-157"></a> <span class='hs-keyword'>where</span> <span class='hs-varid'>lkup</span> <span class='hs-varid'>hd</span><span class='hs-keyglyph'>@</span><span class='hs-conid'>HD</span><span class='hs-layout'>{</span> <span class='hs-varid'>lookups</span><span class='hs-keyglyph'>=</span><span class='hs-varid'>l</span> <span class='hs-layout'>}</span> <span class='hs-keyglyph'>=</span> <span class='hs-varid'>hd</span><span class='hs-layout'>{</span> <span class='hs-varid'>lookups</span><span class='hs-keyglyph'>=</span><span class='hs-varid'>l</span><span class='hs-varop'>+</span><span class='hs-num'>1</span> <span class='hs-layout'>}</span>
<a name="line-158"></a>
<a name="line-159"></a><span class='hs-comment'>-- stats :: IO String</span>
<a name="line-160"></a><span class='hs-comment'>-- stats = fmap show $ readIORef hashData</span>
<a name="line-161"></a>
<a name="line-162"></a><span class='hs-comment'>-- ----------------------------------------------------------------------------</span>
<a name="line-163"></a><span class='hs-comment'>-- Sample hash functions</span>
<a name="line-164"></a>
<a name="line-165"></a><span class='hs-comment'>-- $hash_functions</span>
<a name="line-166"></a><span class='hs-comment'>--</span>
<a name="line-167"></a><span class='hs-comment'>-- This implementation of hash tables uses the low-order /n/ bits of the hash</span>
<a name="line-168"></a><span class='hs-comment'>-- value for a key, where /n/ varies as the hash table grows. A good hash</span>
<a name="line-169"></a><span class='hs-comment'>-- function therefore will give an even distribution regardless of /n/.</span>
<a name="line-170"></a><span class='hs-comment'>--</span>
<a name="line-171"></a><span class='hs-comment'>-- If your keyspace is integrals such that the low-order bits between</span>
<a name="line-172"></a><span class='hs-comment'>-- keys are highly variable, then you could get away with using 'fromIntegral'</span>
<a name="line-173"></a><span class='hs-comment'>-- as the hash function.</span>
<a name="line-174"></a><span class='hs-comment'>--</span>
<a name="line-175"></a><span class='hs-comment'>-- We provide some sample hash functions for 'Int' and 'String' below.</span>
<a name="line-176"></a>
<a name="line-177"></a><a name="golden"></a><span class='hs-definition'>golden</span> <span class='hs-keyglyph'>::</span> <span class='hs-conid'>Int32</span>
<a name="line-178"></a><span class='hs-definition'>golden</span> <span class='hs-keyglyph'>=</span> <span class='hs-num'>1013904242</span> <span class='hs-comment'>-- = round ((sqrt 5 - 1) * 2^32) :: Int32</span>
<a name="line-179"></a><span class='hs-comment'>-- was -1640531527 = round ((sqrt 5 - 1) * 2^31) :: Int32</span>
<a name="line-180"></a><span class='hs-comment'>-- but that has bad mulHi properties (even adding 2^32 to get its inverse)</span>
<a name="line-181"></a><span class='hs-comment'>-- Whereas the above works well and contains no hash duplications for</span>
<a name="line-182"></a><span class='hs-comment'>-- [-32767..65536]</span>
<a name="line-183"></a>
<a name="line-184"></a><a name="hashInt32"></a><span class='hs-definition'>hashInt32</span> <span class='hs-keyglyph'>::</span> <span class='hs-conid'>Int32</span> <span class='hs-keyglyph'>-></span> <span class='hs-conid'>Int32</span>
<a name="line-185"></a><span class='hs-definition'>hashInt32</span> <span class='hs-varid'>x</span> <span class='hs-keyglyph'>=</span> <span class='hs-varid'>mulHi</span> <span class='hs-varid'>x</span> <span class='hs-varid'>golden</span> <span class='hs-varop'>+</span> <span class='hs-varid'>x</span>
<a name="line-186"></a>
<a name="line-187"></a><a name="hashInt"></a><span class='hs-comment'>-- | A sample (and useful) hash function for Int and Int32,</span>
<a name="line-188"></a><span class='hs-comment'>-- implemented by extracting the uppermost 32 bits of the 64-bit</span>
<a name="line-189"></a><span class='hs-comment'>-- result of multiplying by a 33-bit constant. The constant is from</span>
<a name="line-190"></a><span class='hs-comment'>-- Knuth, derived from the golden ratio:</span>
<a name="line-191"></a><span class='hs-comment'>--</span>
<a name="line-192"></a><span class='hs-comment'>-- > golden = round ((sqrt 5 - 1) * 2^32)</span>
<a name="line-193"></a><span class='hs-comment'>--</span>
<a name="line-194"></a><span class='hs-comment'>-- We get good key uniqueness on small inputs</span>
<a name="line-195"></a><span class='hs-comment'>-- (a problem with previous versions):</span>
<a name="line-196"></a><span class='hs-comment'>-- (length $ group $ sort $ map hashInt [-32767..65536]) == 65536 + 32768</span>
<a name="line-197"></a><span class='hs-comment'>--</span>
<a name="line-198"></a><span class='hs-definition'>hashInt</span> <span class='hs-keyglyph'>::</span> <span class='hs-conid'>Int</span> <span class='hs-keyglyph'>-></span> <span class='hs-conid'>Int32</span>
<a name="line-199"></a><span class='hs-definition'>hashInt</span> <span class='hs-varid'>x</span> <span class='hs-keyglyph'>=</span> <span class='hs-varid'>hashInt32</span> <span class='hs-layout'>(</span><span class='hs-varid'>fromIntegral</span> <span class='hs-varid'>x</span><span class='hs-layout'>)</span>
<a name="line-200"></a>
<a name="line-201"></a><a name="mulHi"></a><span class='hs-comment'>-- hi 32 bits of a x-bit * 32 bit -> 64-bit multiply</span>
<a name="line-202"></a><span class='hs-definition'>mulHi</span> <span class='hs-keyglyph'>::</span> <span class='hs-conid'>Int32</span> <span class='hs-keyglyph'>-></span> <span class='hs-conid'>Int32</span> <span class='hs-keyglyph'>-></span> <span class='hs-conid'>Int32</span>
<a name="line-203"></a><span class='hs-definition'>mulHi</span> <span class='hs-varid'>a</span> <span class='hs-varid'>b</span> <span class='hs-keyglyph'>=</span> <span class='hs-varid'>fromIntegral</span> <span class='hs-layout'>(</span><span class='hs-varid'>r</span> <span class='hs-varop'>`shiftR`</span> <span class='hs-num'>32</span><span class='hs-layout'>)</span>
<a name="line-204"></a> <span class='hs-keyword'>where</span> <span class='hs-varid'>r</span> <span class='hs-keyglyph'>::</span> <span class='hs-conid'>Int64</span>
<a name="line-205"></a> <span class='hs-varid'>r</span> <span class='hs-keyglyph'>=</span> <span class='hs-varid'>fromIntegral</span> <span class='hs-varid'>a</span> <span class='hs-varop'>*</span> <span class='hs-varid'>fromIntegral</span> <span class='hs-varid'>b</span>
<a name="line-206"></a>
<a name="line-207"></a><span class='hs-comment'>-- | A sample hash function for Strings. We keep multiplying by the</span>
<a name="line-208"></a><span class='hs-comment'>-- golden ratio and adding. The implementation is:</span>
<a name="line-209"></a><span class='hs-comment'>--</span>
<a name="line-210"></a><span class='hs-comment'>-- > hashString = foldl' f golden</span>
<a name="line-211"></a><span class='hs-comment'>-- > where f m c = fromIntegral (ord c) * magic + hashInt32 m</span>
<a name="line-212"></a><span class='hs-comment'>-- > magic = 0xdeadbeef</span>
<a name="line-213"></a><span class='hs-comment'>--</span>
<a name="line-214"></a><span class='hs-comment'>-- Where hashInt32 works just as hashInt shown above.</span>
<a name="line-215"></a><span class='hs-comment'>--</span>
<a name="line-216"></a><span class='hs-comment'>-- Knuth argues that repeated multiplication by the golden ratio</span>
<a name="line-217"></a><span class='hs-comment'>-- will minimize gaps in the hash space, and thus it's a good choice</span>
<a name="line-218"></a><span class='hs-comment'>-- for combining together multiple keys to form one.</span>
<a name="line-219"></a><span class='hs-comment'>--</span>
<a name="line-220"></a><span class='hs-comment'>-- Here we know that individual characters c are often small, and this</span>
<a name="line-221"></a><span class='hs-comment'>-- produces frequent collisions if we use ord c alone. A</span>
<a name="line-222"></a><span class='hs-comment'>-- particular problem are the shorter low ASCII and ISO-8859-1</span>
<a name="line-223"></a><span class='hs-comment'>-- character strings. We pre-multiply by a magic twiddle factor to</span>
<a name="line-224"></a><span class='hs-comment'>-- obtain a good distribution. In fact, given the following test:</span>
<a name="line-225"></a><span class='hs-comment'>--</span>
<a name="line-226"></a><span class='hs-comment'>-- > testp :: Int32 -> Int</span>
<a name="line-227"></a><span class='hs-comment'>-- > testp k = (n - ) . length . group . sort . map hs . take n $ ls</span>
<a name="line-228"></a><span class='hs-comment'>-- > where ls = [] : [c : l | l <- ls, c <- ['\0'..'\xff']]</span>
<a name="line-229"></a><span class='hs-comment'>-- > hs = foldl' f golden</span>
<a name="line-230"></a><span class='hs-comment'>-- > f m c = fromIntegral (ord c) * k + hashInt32 m</span>
<a name="line-231"></a><span class='hs-comment'>-- > n = 100000</span>
<a name="line-232"></a><span class='hs-comment'>--</span>
<a name="line-233"></a><span class='hs-comment'>-- We discover that testp magic = 0.</span>
<a name="line-234"></a>
<a name="line-235"></a><a name="hashString"></a><span class='hs-definition'>hashString</span> <span class='hs-keyglyph'>::</span> <span class='hs-conid'>String</span> <span class='hs-keyglyph'>-></span> <span class='hs-conid'>Int32</span>
<a name="line-236"></a><span class='hs-definition'>hashString</span> <span class='hs-keyglyph'>=</span> <span class='hs-varid'>foldl'</span> <span class='hs-varid'>f</span> <span class='hs-varid'>golden</span>
<a name="line-237"></a> <span class='hs-keyword'>where</span> <span class='hs-varid'>f</span> <span class='hs-varid'>m</span> <span class='hs-varid'>c</span> <span class='hs-keyglyph'>=</span> <span class='hs-varid'>fromIntegral</span> <span class='hs-layout'>(</span><span class='hs-varid'>ord</span> <span class='hs-varid'>c</span><span class='hs-layout'>)</span> <span class='hs-varop'>*</span> <span class='hs-varid'>magic</span> <span class='hs-varop'>+</span> <span class='hs-varid'>hashInt32</span> <span class='hs-varid'>m</span>
<a name="line-238"></a> <span class='hs-varid'>magic</span> <span class='hs-keyglyph'>=</span> <span class='hs-num'>0xdeadbeef</span>
<a name="line-239"></a>
<a name="line-240"></a><a name="prime"></a><span class='hs-comment'>-- | A prime larger than the maximum hash table size</span>
<a name="line-241"></a><span class='hs-definition'>prime</span> <span class='hs-keyglyph'>::</span> <span class='hs-conid'>Int32</span>
<a name="line-242"></a><span class='hs-definition'>prime</span> <span class='hs-keyglyph'>=</span> <span class='hs-num'>33554467</span>
<a name="line-243"></a>
<a name="line-244"></a><span class='hs-comment'>-- -----------------------------------------------------------------------------</span>
<a name="line-245"></a><span class='hs-comment'>-- Parameters</span>
<a name="line-246"></a>
<a name="line-247"></a><a name="tABLE_MAX"></a><span class='hs-definition'>tABLE_MAX</span> <span class='hs-keyglyph'>::</span> <span class='hs-conid'>Int32</span>
<a name="line-248"></a><span class='hs-definition'>tABLE_MAX</span> <span class='hs-keyglyph'>=</span> <span class='hs-num'>32</span> <span class='hs-varop'>*</span> <span class='hs-num'>1024</span> <span class='hs-varop'>*</span> <span class='hs-num'>1024</span> <span class='hs-comment'>-- Maximum size of hash table</span>
<a name="line-249"></a><a name="tABLE_MIN"></a><span class='hs-definition'>tABLE_MIN</span> <span class='hs-keyglyph'>::</span> <span class='hs-conid'>Int32</span>
<a name="line-250"></a><span class='hs-definition'>tABLE_MIN</span> <span class='hs-keyglyph'>=</span> <span class='hs-num'>8</span>
<a name="line-251"></a>
<a name="line-252"></a><a name="hLOAD"></a><span class='hs-definition'>hLOAD</span> <span class='hs-keyglyph'>::</span> <span class='hs-conid'>Int32</span>
<a name="line-253"></a><span class='hs-definition'>hLOAD</span> <span class='hs-keyglyph'>=</span> <span class='hs-num'>7</span> <span class='hs-comment'>-- Maximum average load of a single hash bucket</span>
<a name="line-254"></a>
<a name="line-255"></a><a name="hYSTERESIS"></a><span class='hs-definition'>hYSTERESIS</span> <span class='hs-keyglyph'>::</span> <span class='hs-conid'>Int32</span>
<a name="line-256"></a><span class='hs-definition'>hYSTERESIS</span> <span class='hs-keyglyph'>=</span> <span class='hs-num'>64</span> <span class='hs-comment'>-- entries to ignore in load computation</span>
<a name="line-257"></a>
<a name="line-258"></a><span class='hs-comment'>{- Hysteresis favors long association-list-like behavior for small tables. -}</span>
<a name="line-259"></a>
<a name="line-260"></a><span class='hs-comment'>-- -----------------------------------------------------------------------------</span>
<a name="line-261"></a><span class='hs-comment'>-- Creating a new hash table</span>
<a name="line-262"></a>
<a name="line-263"></a><a name="new"></a><span class='hs-comment'>-- | Creates a new hash table. The following property should hold for the @eq@</span>
<a name="line-264"></a><span class='hs-comment'>-- and @hash@ functions passed to 'new':</span>
<a name="line-265"></a><span class='hs-comment'>--</span>
<a name="line-266"></a><span class='hs-comment'>-- > eq A B => hash A == hash B</span>
<a name="line-267"></a><span class='hs-comment'>--</span>
<a name="line-268"></a><span class='hs-definition'>new</span>
<a name="line-269"></a> <span class='hs-keyglyph'>::</span> <span class='hs-layout'>(</span><span class='hs-varid'>key</span> <span class='hs-keyglyph'>-></span> <span class='hs-varid'>key</span> <span class='hs-keyglyph'>-></span> <span class='hs-conid'>Bool</span><span class='hs-layout'>)</span> <span class='hs-comment'>-- ^ @eq@: An equality comparison on keys</span>
<a name="line-270"></a> <span class='hs-keyglyph'>-></span> <span class='hs-layout'>(</span><span class='hs-varid'>key</span> <span class='hs-keyglyph'>-></span> <span class='hs-conid'>Int32</span><span class='hs-layout'>)</span> <span class='hs-comment'>-- ^ @hash@: A hash function on keys</span>
<a name="line-271"></a> <span class='hs-keyglyph'>-></span> <span class='hs-conid'>IO</span> <span class='hs-layout'>(</span><span class='hs-conid'>HashTable</span> <span class='hs-varid'>key</span> <span class='hs-varid'>val</span><span class='hs-layout'>)</span> <span class='hs-comment'>-- ^ Returns: an empty hash table</span>
<a name="line-272"></a>
<a name="line-273"></a><span class='hs-definition'>new</span> <span class='hs-varid'>cmpr</span> <span class='hs-varid'>hash</span> <span class='hs-keyglyph'>=</span> <span class='hs-keyword'>do</span>
<a name="line-274"></a> <span class='hs-varid'>recordNew</span>
<a name="line-275"></a> <span class='hs-comment'>-- make a new hash table with a single, empty, segment</span>
<a name="line-276"></a> <span class='hs-keyword'>let</span> <span class='hs-varid'>mask</span> <span class='hs-keyglyph'>=</span> <span class='hs-varid'>tABLE_MIN</span><span class='hs-comment'>-</span><span class='hs-num'>1</span>
<a name="line-277"></a> <span class='hs-varid'>bkts</span> <span class='hs-keyglyph'><-</span> <span class='hs-varid'>newMutArray</span> <span class='hs-layout'>(</span><span class='hs-num'>0</span><span class='hs-layout'>,</span><span class='hs-varid'>mask</span><span class='hs-layout'>)</span> <span class='hs-conid'>[]</span>
<a name="line-278"></a>
<a name="line-279"></a> <span class='hs-keyword'>let</span>
<a name="line-280"></a> <span class='hs-varid'>kcnt</span> <span class='hs-keyglyph'>=</span> <span class='hs-num'>0</span>
<a name="line-281"></a> <span class='hs-varid'>ht</span> <span class='hs-keyglyph'>=</span> <span class='hs-conid'>HT</span> <span class='hs-layout'>{</span> <span class='hs-varid'>buckets</span><span class='hs-keyglyph'>=</span><span class='hs-varid'>bkts</span><span class='hs-layout'>,</span> <span class='hs-varid'>kcount</span><span class='hs-keyglyph'>=</span><span class='hs-varid'>kcnt</span><span class='hs-layout'>,</span> <span class='hs-varid'>bmask</span><span class='hs-keyglyph'>=</span><span class='hs-varid'>mask</span> <span class='hs-layout'>}</span>
<a name="line-282"></a>
<a name="line-283"></a> <span class='hs-varid'>table</span> <span class='hs-keyglyph'><-</span> <span class='hs-varid'>newIORef</span> <span class='hs-varid'>ht</span>
<a name="line-284"></a> <span class='hs-varid'>return</span> <span class='hs-layout'>(</span><span class='hs-conid'>HashTable</span> <span class='hs-layout'>{</span> <span class='hs-varid'>tab</span><span class='hs-keyglyph'>=</span><span class='hs-varid'>table</span><span class='hs-layout'>,</span> <span class='hs-varid'>hash_fn</span><span class='hs-keyglyph'>=</span><span class='hs-varid'>hash</span><span class='hs-layout'>,</span> <span class='hs-varid'>cmp</span><span class='hs-keyglyph'>=</span><span class='hs-varid'>cmpr</span> <span class='hs-layout'>}</span><span class='hs-layout'>)</span>
<a name="line-285"></a>
<a name="line-286"></a><a name="bitTwiddleSameAs"></a><span class='hs-comment'>{-
<a name="line-287"></a> bitTwiddleSameAs takes as arguments positive Int32s less than maxBound/2 and
<a name="line-288"></a> returns the smallest power of 2 that is greater than or equal to the
<a name="line-289"></a> argument.
<a name="line-290"></a> <a href="http://graphics.stanford.edu/~seander/bithacks.html#RoundUpPowerOf2">http://graphics.stanford.edu/~seander/bithacks.html#RoundUpPowerOf2</a>
<a name="line-291"></a>-}</span>
<a name="line-292"></a><span class='hs-definition'>bitTwiddleSameAs</span> <span class='hs-keyglyph'>::</span> <span class='hs-conid'>Int32</span> <span class='hs-keyglyph'>-></span> <span class='hs-conid'>Int32</span>
<a name="line-293"></a><span class='hs-definition'>bitTwiddleSameAs</span> <span class='hs-varid'>v0</span> <span class='hs-keyglyph'>=</span>
<a name="line-294"></a> <span class='hs-keyword'>let</span> <span class='hs-varid'>v1</span> <span class='hs-keyglyph'>=</span> <span class='hs-varid'>v0</span><span class='hs-comment'>-</span><span class='hs-num'>1</span>
<a name="line-295"></a> <span class='hs-varid'>v2</span> <span class='hs-keyglyph'>=</span> <span class='hs-varid'>v1</span> <span class='hs-varop'>.|.</span> <span class='hs-layout'>(</span><span class='hs-varid'>v1</span><span class='hs-varop'>`shiftR`</span><span class='hs-num'>1</span><span class='hs-layout'>)</span>
<a name="line-296"></a> <span class='hs-varid'>v3</span> <span class='hs-keyglyph'>=</span> <span class='hs-varid'>v2</span> <span class='hs-varop'>.|.</span> <span class='hs-layout'>(</span><span class='hs-varid'>v2</span><span class='hs-varop'>`shiftR`</span><span class='hs-num'>2</span><span class='hs-layout'>)</span>
<a name="line-297"></a> <span class='hs-varid'>v4</span> <span class='hs-keyglyph'>=</span> <span class='hs-varid'>v3</span> <span class='hs-varop'>.|.</span> <span class='hs-layout'>(</span><span class='hs-varid'>v3</span><span class='hs-varop'>`shiftR`</span><span class='hs-num'>4</span><span class='hs-layout'>)</span>
<a name="line-298"></a> <span class='hs-varid'>v5</span> <span class='hs-keyglyph'>=</span> <span class='hs-varid'>v4</span> <span class='hs-varop'>.|.</span> <span class='hs-layout'>(</span><span class='hs-varid'>v4</span><span class='hs-varop'>`shiftR`</span><span class='hs-num'>8</span><span class='hs-layout'>)</span>
<a name="line-299"></a> <span class='hs-varid'>v6</span> <span class='hs-keyglyph'>=</span> <span class='hs-varid'>v5</span> <span class='hs-varop'>.|.</span> <span class='hs-layout'>(</span><span class='hs-varid'>v5</span><span class='hs-varop'>`shiftR`</span><span class='hs-num'>16</span><span class='hs-layout'>)</span>
<a name="line-300"></a> <span class='hs-keyword'>in</span> <span class='hs-varid'>v6</span><span class='hs-varop'>+</span><span class='hs-num'>1</span>
<a name="line-301"></a>
<a name="line-302"></a><a name="powerOver"></a><span class='hs-comment'>{-
<a name="line-303"></a> powerOver takes as arguments Int32s and returns the smallest power of 2
<a name="line-304"></a> that is greater than or equal to the argument if that power of 2 is
<a name="line-305"></a> within [tABLE_MIN,tABLE_MAX]
<a name="line-306"></a>-}</span>
<a name="line-307"></a><span class='hs-definition'>powerOver</span> <span class='hs-keyglyph'>::</span> <span class='hs-conid'>Int32</span> <span class='hs-keyglyph'>-></span> <span class='hs-conid'>Int32</span>
<a name="line-308"></a><span class='hs-definition'>powerOver</span> <span class='hs-varid'>n</span> <span class='hs-keyglyph'>=</span>
<a name="line-309"></a> <span class='hs-keyword'>if</span> <span class='hs-varid'>n</span> <span class='hs-varop'><=</span> <span class='hs-varid'>tABLE_MIN</span>
<a name="line-310"></a> <span class='hs-keyword'>then</span> <span class='hs-varid'>tABLE_MIN</span>
<a name="line-311"></a> <span class='hs-keyword'>else</span> <span class='hs-keyword'>if</span> <span class='hs-varid'>n</span> <span class='hs-varop'>>=</span> <span class='hs-varid'>tABLE_MAX</span>
<a name="line-312"></a> <span class='hs-keyword'>then</span> <span class='hs-varid'>tABLE_MAX</span>
<a name="line-313"></a> <span class='hs-keyword'>else</span> <span class='hs-varid'>bitTwiddleSameAs</span> <span class='hs-varid'>n</span>
<a name="line-314"></a>
<a name="line-315"></a><a name="newHint"></a><span class='hs-comment'>-- | Creates a new hash table with the given minimum size.</span>
<a name="line-316"></a><span class='hs-definition'>newHint</span>
<a name="line-317"></a> <span class='hs-keyglyph'>::</span> <span class='hs-layout'>(</span><span class='hs-varid'>key</span> <span class='hs-keyglyph'>-></span> <span class='hs-varid'>key</span> <span class='hs-keyglyph'>-></span> <span class='hs-conid'>Bool</span><span class='hs-layout'>)</span> <span class='hs-comment'>-- ^ @eq@: An equality comparison on keys</span>
<a name="line-318"></a> <span class='hs-keyglyph'>-></span> <span class='hs-layout'>(</span><span class='hs-varid'>key</span> <span class='hs-keyglyph'>-></span> <span class='hs-conid'>Int32</span><span class='hs-layout'>)</span> <span class='hs-comment'>-- ^ @hash@: A hash function on keys</span>
<a name="line-319"></a> <span class='hs-keyglyph'>-></span> <span class='hs-conid'>Int</span> <span class='hs-comment'>-- ^ @minSize@: initial table size</span>
<a name="line-320"></a> <span class='hs-keyglyph'>-></span> <span class='hs-conid'>IO</span> <span class='hs-layout'>(</span><span class='hs-conid'>HashTable</span> <span class='hs-varid'>key</span> <span class='hs-varid'>val</span><span class='hs-layout'>)</span> <span class='hs-comment'>-- ^ Returns: an empty hash table</span>
<a name="line-321"></a>
<a name="line-322"></a><span class='hs-definition'>newHint</span> <span class='hs-varid'>cmpr</span> <span class='hs-varid'>hash</span> <span class='hs-varid'>minSize</span> <span class='hs-keyglyph'>=</span> <span class='hs-keyword'>do</span>
<a name="line-323"></a> <span class='hs-varid'>recordNew</span>
<a name="line-324"></a> <span class='hs-comment'>-- make a new hash table with a single, empty, segment</span>
<a name="line-325"></a> <span class='hs-keyword'>let</span> <span class='hs-varid'>mask</span> <span class='hs-keyglyph'>=</span> <span class='hs-varid'>powerOver</span> <span class='hs-varop'>$</span> <span class='hs-varid'>fromIntegral</span> <span class='hs-varid'>minSize</span>
<a name="line-326"></a> <span class='hs-varid'>bkts</span> <span class='hs-keyglyph'><-</span> <span class='hs-varid'>newMutArray</span> <span class='hs-layout'>(</span><span class='hs-num'>0</span><span class='hs-layout'>,</span><span class='hs-varid'>mask</span><span class='hs-layout'>)</span> <span class='hs-conid'>[]</span>
<a name="line-327"></a>
<a name="line-328"></a> <span class='hs-keyword'>let</span>
<a name="line-329"></a> <span class='hs-varid'>kcnt</span> <span class='hs-keyglyph'>=</span> <span class='hs-num'>0</span>
<a name="line-330"></a> <span class='hs-varid'>ht</span> <span class='hs-keyglyph'>=</span> <span class='hs-conid'>HT</span> <span class='hs-layout'>{</span> <span class='hs-varid'>buckets</span><span class='hs-keyglyph'>=</span><span class='hs-varid'>bkts</span><span class='hs-layout'>,</span> <span class='hs-varid'>kcount</span><span class='hs-keyglyph'>=</span><span class='hs-varid'>kcnt</span><span class='hs-layout'>,</span> <span class='hs-varid'>bmask</span><span class='hs-keyglyph'>=</span><span class='hs-varid'>mask</span> <span class='hs-layout'>}</span>
<a name="line-331"></a>
<a name="line-332"></a> <span class='hs-varid'>table</span> <span class='hs-keyglyph'><-</span> <span class='hs-varid'>newIORef</span> <span class='hs-varid'>ht</span>
<a name="line-333"></a> <span class='hs-varid'>return</span> <span class='hs-layout'>(</span><span class='hs-conid'>HashTable</span> <span class='hs-layout'>{</span> <span class='hs-varid'>tab</span><span class='hs-keyglyph'>=</span><span class='hs-varid'>table</span><span class='hs-layout'>,</span> <span class='hs-varid'>hash_fn</span><span class='hs-keyglyph'>=</span><span class='hs-varid'>hash</span><span class='hs-layout'>,</span> <span class='hs-varid'>cmp</span><span class='hs-keyglyph'>=</span><span class='hs-varid'>cmpr</span> <span class='hs-layout'>}</span><span class='hs-layout'>)</span>
<a name="line-334"></a>
<a name="line-335"></a><span class='hs-comment'>-- -----------------------------------------------------------------------------</span>
<a name="line-336"></a><span class='hs-comment'>-- Inserting a key\/value pair into the hash table</span>
<a name="line-337"></a>
<a name="line-338"></a><a name="insert"></a><span class='hs-comment'>-- | Inserts a key\/value mapping into the hash table.</span>
<a name="line-339"></a><span class='hs-comment'>--</span>
<a name="line-340"></a><span class='hs-comment'>-- Note that 'insert' doesn't remove the old entry from the table -</span>
<a name="line-341"></a><span class='hs-comment'>-- the behaviour is like an association list, where 'lookup' returns</span>
<a name="line-342"></a><span class='hs-comment'>-- the most-recently-inserted mapping for a key in the table. The</span>
<a name="line-343"></a><span class='hs-comment'>-- reason for this is to keep 'insert' as efficient as possible. If</span>
<a name="line-344"></a><span class='hs-comment'>-- you need to update a mapping, then we provide 'update'.</span>
<a name="line-345"></a><span class='hs-comment'>--</span>
<a name="line-346"></a><span class='hs-definition'>insert</span> <span class='hs-keyglyph'>::</span> <span class='hs-conid'>HashTable</span> <span class='hs-varid'>key</span> <span class='hs-varid'>val</span> <span class='hs-keyglyph'>-></span> <span class='hs-varid'>key</span> <span class='hs-keyglyph'>-></span> <span class='hs-varid'>val</span> <span class='hs-keyglyph'>-></span> <span class='hs-conid'>IO</span> <span class='hs-conid'>()</span>
<a name="line-347"></a>
<a name="line-348"></a><span class='hs-definition'>insert</span> <span class='hs-varid'>ht</span> <span class='hs-varid'>key</span> <span class='hs-varid'>val</span> <span class='hs-keyglyph'>=</span>
<a name="line-349"></a> <span class='hs-varid'>updatingBucket</span> <span class='hs-conid'>CanInsert</span> <span class='hs-layout'>(</span><span class='hs-keyglyph'>\</span><span class='hs-varid'>bucket</span> <span class='hs-keyglyph'>-></span> <span class='hs-layout'>(</span><span class='hs-layout'>(</span><span class='hs-varid'>key</span><span class='hs-layout'>,</span><span class='hs-varid'>val</span><span class='hs-layout'>)</span><span class='hs-conop'>:</span><span class='hs-varid'>bucket</span><span class='hs-layout'>,</span> <span class='hs-num'>1</span><span class='hs-layout'>,</span> <span class='hs-conid'>()</span><span class='hs-layout'>)</span><span class='hs-layout'>)</span> <span class='hs-varid'>ht</span> <span class='hs-varid'>key</span>
<a name="line-350"></a>
<a name="line-351"></a>
<a name="line-352"></a><span class='hs-comment'>-- ------------------------------------------------------------</span>
<a name="line-353"></a><span class='hs-comment'>-- The core of the implementation is lurking down here, in findBucket,</span>
<a name="line-354"></a><span class='hs-comment'>-- updatingBucket, and expandHashTable.</span>
<a name="line-355"></a>
<a name="line-356"></a><a name="tooBig"></a><span class='hs-definition'>tooBig</span> <span class='hs-keyglyph'>::</span> <span class='hs-conid'>Int32</span> <span class='hs-keyglyph'>-></span> <span class='hs-conid'>Int32</span> <span class='hs-keyglyph'>-></span> <span class='hs-conid'>Bool</span>
<a name="line-357"></a><span class='hs-definition'>tooBig</span> <span class='hs-varid'>k</span> <span class='hs-varid'>b</span> <span class='hs-keyglyph'>=</span> <span class='hs-varid'>k</span><span class='hs-comment'>-</span><span class='hs-varid'>hYSTERESIS</span> <span class='hs-varop'>></span> <span class='hs-varid'>hLOAD</span> <span class='hs-varop'>*</span> <span class='hs-varid'>b</span>
<a name="line-358"></a>
<a name="line-359"></a><a name="bucketIndex"></a><span class='hs-comment'>-- index of bucket within table.</span>
<a name="line-360"></a><span class='hs-definition'>bucketIndex</span> <span class='hs-keyglyph'>::</span> <span class='hs-conid'>Int32</span> <span class='hs-keyglyph'>-></span> <span class='hs-conid'>Int32</span> <span class='hs-keyglyph'>-></span> <span class='hs-conid'>Int32</span>
<a name="line-361"></a><span class='hs-definition'>bucketIndex</span> <span class='hs-varid'>mask</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'>mask</span>
<a name="line-362"></a>
<a name="line-363"></a><a name="findBucket"></a><span class='hs-comment'>-- find the bucket in which the key belongs.</span>
<a name="line-364"></a><span class='hs-comment'>-- returns (key equality, bucket index, bucket)</span>
<a name="line-365"></a><span class='hs-comment'>--</span>
<a name="line-366"></a><span class='hs-comment'>-- This rather grab-bag approach gives enough power to do pretty much</span>
<a name="line-367"></a><span class='hs-comment'>-- any bucket-finding thing you might want to do. We rely on inlining</span>
<a name="line-368"></a><span class='hs-comment'>-- to throw away the stuff we don't want. I'm proud to say that this</span>
<a name="line-369"></a><span class='hs-comment'>-- plus updatingBucket below reduce most of the other definitions to a</span>
<a name="line-370"></a><span class='hs-comment'>-- few lines of code, while actually speeding up the hashtable</span>
<a name="line-371"></a><span class='hs-comment'>-- implementation when compared with a version which does everything</span>
<a name="line-372"></a><span class='hs-comment'>-- from scratch.</span>
<a name="line-373"></a><span class='hs-comment'>{-# INLINE findBucket #-}</span>
<a name="line-374"></a><span class='hs-definition'>findBucket</span> <span class='hs-keyglyph'>::</span> <span class='hs-conid'>HashTable</span> <span class='hs-varid'>key</span> <span class='hs-varid'>val</span> <span class='hs-keyglyph'>-></span> <span class='hs-varid'>key</span> <span class='hs-keyglyph'>-></span> <span class='hs-conid'>IO</span> <span class='hs-layout'>(</span><span class='hs-conid'>HT</span> <span class='hs-varid'>key</span> <span class='hs-varid'>val</span><span class='hs-layout'>,</span> <span class='hs-conid'>Int32</span><span class='hs-layout'>,</span> <span class='hs-keyglyph'>[</span><span class='hs-layout'>(</span><span class='hs-varid'>key</span><span class='hs-layout'>,</span><span class='hs-varid'>val</span><span class='hs-layout'>)</span><span class='hs-keyglyph'>]</span><span class='hs-layout'>)</span>
<a name="line-375"></a><span class='hs-definition'>findBucket</span> <span class='hs-conid'>HashTable</span><span class='hs-layout'>{</span> <span class='hs-varid'>tab</span><span class='hs-keyglyph'>=</span><span class='hs-varid'>ref</span><span class='hs-layout'>,</span> <span class='hs-varid'>hash_fn</span><span class='hs-keyglyph'>=</span><span class='hs-varid'>hash</span><span class='hs-layout'>}</span> <span class='hs-varid'>key</span> <span class='hs-keyglyph'>=</span> <span class='hs-keyword'>do</span>
<a name="line-376"></a> <span class='hs-varid'>table</span><span class='hs-keyglyph'>@</span><span class='hs-conid'>HT</span><span class='hs-layout'>{</span> <span class='hs-varid'>buckets</span><span class='hs-keyglyph'>=</span><span class='hs-varid'>bkts</span><span class='hs-layout'>,</span> <span class='hs-varid'>bmask</span><span class='hs-keyglyph'>=</span><span class='hs-varid'>b</span> <span class='hs-layout'>}</span> <span class='hs-keyglyph'><-</span> <span class='hs-varid'>readIORef</span> <span class='hs-varid'>ref</span>
<a name="line-377"></a> <span class='hs-keyword'>let</span> <span class='hs-varid'>indx</span> <span class='hs-keyglyph'>=</span> <span class='hs-varid'>bucketIndex</span> <span class='hs-varid'>b</span> <span class='hs-layout'>(</span><span class='hs-varid'>hash</span> <span class='hs-varid'>key</span><span class='hs-layout'>)</span>
<a name="line-378"></a> <span class='hs-varid'>bucket</span> <span class='hs-keyglyph'><-</span> <span class='hs-varid'>readHTArray</span> <span class='hs-varid'>bkts</span> <span class='hs-varid'>indx</span>
<a name="line-379"></a> <span class='hs-varid'>return</span> <span class='hs-layout'>(</span><span class='hs-varid'>table</span><span class='hs-layout'>,</span> <span class='hs-varid'>indx</span><span class='hs-layout'>,</span> <span class='hs-varid'>bucket</span><span class='hs-layout'>)</span>
<a name="line-380"></a>
<a name="line-381"></a><a name="Inserts"></a><span class='hs-keyword'>data</span> <span class='hs-conid'>Inserts</span> <span class='hs-keyglyph'>=</span> <span class='hs-conid'>CanInsert</span>
<a name="line-382"></a> <span class='hs-keyglyph'>|</span> <span class='hs-conid'>Can'tInsert</span>
<a name="line-383"></a> <span class='hs-keyword'>deriving</span> <span class='hs-layout'>(</span><span class='hs-conid'>Eq</span><span class='hs-layout'>)</span>
<a name="line-384"></a>
<a name="line-385"></a><span class='hs-comment'>-- updatingBucket is the real workhorse of all single-element table</span>
<a name="line-386"></a><span class='hs-comment'>-- updates. It takes a hashtable and a key, along with a function</span>
<a name="line-387"></a><span class='hs-comment'>-- describing what to do with the bucket in which that key belongs. A</span>
<a name="line-388"></a><span class='hs-comment'>-- flag indicates whether this function may perform table insertions.</span>
<a name="line-389"></a><span class='hs-comment'>-- The function returns the new contents of the bucket, the number of</span>
<a name="line-390"></a><span class='hs-comment'>-- bucket entries inserted (negative if entries were deleted), and a</span>
<a name="line-391"></a><span class='hs-comment'>-- value which becomes the return value for the function as a whole.</span>
<a name="line-392"></a><span class='hs-comment'>-- The table sizing is enforced here, calling out to expandSubTable as</span>
<a name="line-393"></a><span class='hs-comment'>-- necessary.</span>
<a name="line-394"></a>
<a name="line-395"></a><span class='hs-comment'>-- This function is intended to be inlined and specialized for every</span>
<a name="line-396"></a><span class='hs-comment'>-- calling context (eg every provided bucketFn).</span>
<a name="line-397"></a><span class='hs-comment'>{-# INLINE updatingBucket #-}</span>
<a name="line-398"></a>
<a name="line-399"></a><a name="updatingBucket"></a><span class='hs-definition'>updatingBucket</span> <span class='hs-keyglyph'>::</span> <span class='hs-conid'>Inserts</span> <span class='hs-keyglyph'>-></span> <span class='hs-layout'>(</span><span class='hs-keyglyph'>[</span><span class='hs-layout'>(</span><span class='hs-varid'>key</span><span class='hs-layout'>,</span><span class='hs-varid'>val</span><span class='hs-layout'>)</span><span class='hs-keyglyph'>]</span> <span class='hs-keyglyph'>-></span> <span class='hs-layout'>(</span><span class='hs-keyglyph'>[</span><span class='hs-layout'>(</span><span class='hs-varid'>key</span><span class='hs-layout'>,</span><span class='hs-varid'>val</span><span class='hs-layout'>)</span><span class='hs-keyglyph'>]</span><span class='hs-layout'>,</span> <span class='hs-conid'>Int32</span><span class='hs-layout'>,</span> <span class='hs-varid'>a</span><span class='hs-layout'>)</span><span class='hs-layout'>)</span> <span class='hs-keyglyph'>-></span>
<a name="line-400"></a> <span class='hs-conid'>HashTable</span> <span class='hs-varid'>key</span> <span class='hs-varid'>val</span> <span class='hs-keyglyph'>-></span> <span class='hs-varid'>key</span> <span class='hs-keyglyph'>-></span>
<a name="line-401"></a> <span class='hs-conid'>IO</span> <span class='hs-varid'>a</span>
<a name="line-402"></a><span class='hs-definition'>updatingBucket</span> <span class='hs-varid'>canEnlarge</span> <span class='hs-varid'>bucketFn</span>
<a name="line-403"></a> <span class='hs-varid'>ht</span><span class='hs-keyglyph'>@</span><span class='hs-conid'>HashTable</span><span class='hs-layout'>{</span> <span class='hs-varid'>tab</span><span class='hs-keyglyph'>=</span><span class='hs-varid'>ref</span><span class='hs-layout'>,</span> <span class='hs-varid'>hash_fn</span><span class='hs-keyglyph'>=</span><span class='hs-varid'>hash</span> <span class='hs-layout'>}</span> <span class='hs-varid'>key</span> <span class='hs-keyglyph'>=</span> <span class='hs-keyword'>do</span>
<a name="line-404"></a> <span class='hs-layout'>(</span><span class='hs-varid'>table</span><span class='hs-keyglyph'>@</span><span class='hs-conid'>HT</span><span class='hs-layout'>{</span> <span class='hs-varid'>kcount</span><span class='hs-keyglyph'>=</span><span class='hs-varid'>k</span><span class='hs-layout'>,</span> <span class='hs-varid'>buckets</span><span class='hs-keyglyph'>=</span><span class='hs-varid'>bkts</span><span class='hs-layout'>,</span> <span class='hs-varid'>bmask</span><span class='hs-keyglyph'>=</span><span class='hs-varid'>b</span> <span class='hs-layout'>}</span><span class='hs-layout'>,</span>
<a name="line-405"></a> <span class='hs-varid'>indx</span><span class='hs-layout'>,</span> <span class='hs-varid'>bckt</span><span class='hs-layout'>)</span> <span class='hs-keyglyph'><-</span> <span class='hs-varid'>findBucket</span> <span class='hs-varid'>ht</span> <span class='hs-varid'>key</span>
<a name="line-406"></a> <span class='hs-layout'>(</span><span class='hs-varid'>bckt'</span><span class='hs-layout'>,</span> <span class='hs-varid'>inserts</span><span class='hs-layout'>,</span> <span class='hs-varid'>result</span><span class='hs-layout'>)</span> <span class='hs-keyglyph'><-</span> <span class='hs-varid'>return</span> <span class='hs-varop'>$</span> <span class='hs-varid'>bucketFn</span> <span class='hs-varid'>bckt</span>
<a name="line-407"></a> <span class='hs-keyword'>let</span> <span class='hs-varid'>k'</span> <span class='hs-keyglyph'>=</span> <span class='hs-varid'>k</span> <span class='hs-varop'>+</span> <span class='hs-varid'>inserts</span>
<a name="line-408"></a> <span class='hs-varid'>table1</span> <span class='hs-keyglyph'>=</span> <span class='hs-varid'>table</span> <span class='hs-layout'>{</span> <span class='hs-varid'>kcount</span><span class='hs-keyglyph'>=</span><span class='hs-varid'>k'</span> <span class='hs-layout'>}</span>
<a name="line-409"></a> <span class='hs-varid'>writeMutArray</span> <span class='hs-varid'>bkts</span> <span class='hs-varid'>indx</span> <span class='hs-varid'>bckt'</span>
<a name="line-410"></a> <span class='hs-varid'>table2</span> <span class='hs-keyglyph'><-</span> <span class='hs-keyword'>if</span> <span class='hs-varid'>canEnlarge</span> <span class='hs-varop'>==</span> <span class='hs-conid'>CanInsert</span> <span class='hs-varop'>&&</span> <span class='hs-varid'>inserts</span> <span class='hs-varop'>></span> <span class='hs-num'>0</span> <span class='hs-keyword'>then</span> <span class='hs-keyword'>do</span>
<a name="line-411"></a> <span class='hs-varid'>recordIns</span> <span class='hs-varid'>inserts</span> <span class='hs-varid'>k'</span> <span class='hs-varid'>bckt'</span>
<a name="line-412"></a> <span class='hs-keyword'>if</span> <span class='hs-varid'>tooBig</span> <span class='hs-varid'>k'</span> <span class='hs-varid'>b</span>
<a name="line-413"></a> <span class='hs-keyword'>then</span> <span class='hs-varid'>expandHashTable</span> <span class='hs-varid'>hash</span> <span class='hs-varid'>table1</span>
<a name="line-414"></a> <span class='hs-keyword'>else</span> <span class='hs-varid'>return</span> <span class='hs-varid'>table1</span>
<a name="line-415"></a> <span class='hs-keyword'>else</span> <span class='hs-varid'>return</span> <span class='hs-varid'>table1</span>
<a name="line-416"></a> <span class='hs-varid'>writeIORef</span> <span class='hs-varid'>ref</span> <span class='hs-varid'>table2</span>
<a name="line-417"></a> <span class='hs-varid'>return</span> <span class='hs-varid'>result</span>
<a name="line-418"></a>
<a name="line-419"></a><a name="expandHashTable"></a><span class='hs-definition'>expandHashTable</span> <span class='hs-keyglyph'>::</span> <span class='hs-layout'>(</span><span class='hs-varid'>key</span> <span class='hs-keyglyph'>-></span> <span class='hs-conid'>Int32</span><span class='hs-layout'>)</span> <span class='hs-keyglyph'>-></span> <span class='hs-conid'>HT</span> <span class='hs-varid'>key</span> <span class='hs-varid'>val</span> <span class='hs-keyglyph'>-></span> <span class='hs-conid'>IO</span> <span class='hs-layout'>(</span><span class='hs-conid'>HT</span> <span class='hs-varid'>key</span> <span class='hs-varid'>val</span><span class='hs-layout'>)</span>
<a name="line-420"></a><span class='hs-definition'>expandHashTable</span> <span class='hs-varid'>hash</span> <span class='hs-varid'>table</span><span class='hs-keyglyph'>@</span><span class='hs-conid'>HT</span><span class='hs-layout'>{</span> <span class='hs-varid'>buckets</span><span class='hs-keyglyph'>=</span><span class='hs-varid'>bkts</span><span class='hs-layout'>,</span> <span class='hs-varid'>bmask</span><span class='hs-keyglyph'>=</span><span class='hs-varid'>mask</span> <span class='hs-layout'>}</span> <span class='hs-keyglyph'>=</span> <span class='hs-keyword'>do</span>
<a name="line-421"></a> <span class='hs-keyword'>let</span>
<a name="line-422"></a> <span class='hs-varid'>oldsize</span> <span class='hs-keyglyph'>=</span> <span class='hs-varid'>mask</span> <span class='hs-varop'>+</span> <span class='hs-num'>1</span>
<a name="line-423"></a> <span class='hs-varid'>newmask</span> <span class='hs-keyglyph'>=</span> <span class='hs-varid'>mask</span> <span class='hs-varop'>+</span> <span class='hs-varid'>mask</span> <span class='hs-varop'>+</span> <span class='hs-num'>1</span>
<a name="line-424"></a> <span class='hs-varid'>recordResize</span> <span class='hs-varid'>oldsize</span> <span class='hs-layout'>(</span><span class='hs-varid'>newmask</span><span class='hs-varop'>+</span><span class='hs-num'>1</span><span class='hs-layout'>)</span>
<a name="line-425"></a> <span class='hs-comment'>--</span>
<a name="line-426"></a> <span class='hs-keyword'>if</span> <span class='hs-varid'>newmask</span> <span class='hs-varop'>></span> <span class='hs-varid'>tABLE_MAX</span><span class='hs-comment'>-</span><span class='hs-num'>1</span>
<a name="line-427"></a> <span class='hs-keyword'>then</span> <span class='hs-varid'>return</span> <span class='hs-varid'>table</span>
<a name="line-428"></a> <span class='hs-keyword'>else</span> <span class='hs-keyword'>do</span>
<a name="line-429"></a> <span class='hs-comment'>--</span>
<a name="line-430"></a> <span class='hs-varid'>newbkts</span> <span class='hs-keyglyph'><-</span> <span class='hs-varid'>newMutArray</span> <span class='hs-layout'>(</span><span class='hs-num'>0</span><span class='hs-layout'>,</span><span class='hs-varid'>newmask</span><span class='hs-layout'>)</span> <span class='hs-conid'>[]</span>
<a name="line-431"></a>
<a name="line-432"></a> <span class='hs-keyword'>let</span>
<a name="line-433"></a> <span class='hs-varid'>splitBucket</span> <span class='hs-varid'>oldindex</span> <span class='hs-keyglyph'>=</span> <span class='hs-keyword'>do</span>
<a name="line-434"></a> <span class='hs-varid'>bucket</span> <span class='hs-keyglyph'><-</span> <span class='hs-varid'>readHTArray</span> <span class='hs-varid'>bkts</span> <span class='hs-varid'>oldindex</span>
<a name="line-435"></a> <span class='hs-keyword'>let</span> <span class='hs-layout'>(</span><span class='hs-varid'>oldb</span><span class='hs-layout'>,</span><span class='hs-varid'>newb</span><span class='hs-layout'>)</span> <span class='hs-keyglyph'>=</span>
<a name="line-436"></a> <span class='hs-varid'>partition</span> <span class='hs-layout'>(</span><span class='hs-layout'>(</span><span class='hs-varid'>oldindex</span><span class='hs-varop'>==</span><span class='hs-layout'>)</span><span class='hs-varop'>.</span> <span class='hs-varid'>bucketIndex</span> <span class='hs-varid'>newmask</span> <span class='hs-varop'>.</span> <span class='hs-varid'>hash</span> <span class='hs-varop'>.</span> <span class='hs-varid'>fst</span><span class='hs-layout'>)</span> <span class='hs-varid'>bucket</span>
<a name="line-437"></a> <span class='hs-varid'>writeMutArray</span> <span class='hs-varid'>newbkts</span> <span class='hs-varid'>oldindex</span> <span class='hs-varid'>oldb</span>
<a name="line-438"></a> <span class='hs-varid'>writeMutArray</span> <span class='hs-varid'>newbkts</span> <span class='hs-layout'>(</span><span class='hs-varid'>oldindex</span> <span class='hs-varop'>+</span> <span class='hs-varid'>oldsize</span><span class='hs-layout'>)</span> <span class='hs-varid'>newb</span>
<a name="line-439"></a> <span class='hs-varid'>mapM_</span> <span class='hs-varid'>splitBucket</span> <span class='hs-keyglyph'>[</span><span class='hs-num'>0</span><span class='hs-keyglyph'>..</span><span class='hs-varid'>mask</span><span class='hs-keyglyph'>]</span>
<a name="line-440"></a>
<a name="line-441"></a> <span class='hs-varid'>return</span> <span class='hs-layout'>(</span> <span class='hs-varid'>table</span><span class='hs-layout'>{</span> <span class='hs-varid'>buckets</span><span class='hs-keyglyph'>=</span><span class='hs-varid'>newbkts</span><span class='hs-layout'>,</span> <span class='hs-varid'>bmask</span><span class='hs-keyglyph'>=</span><span class='hs-varid'>newmask</span> <span class='hs-layout'>}</span> <span class='hs-layout'>)</span>
<a name="line-442"></a>
<a name="line-443"></a><span class='hs-comment'>-- -----------------------------------------------------------------------------</span>
<a name="line-444"></a><span class='hs-comment'>-- Deleting a mapping from the hash table</span>
<a name="line-445"></a>
<a name="line-446"></a><a name="deleteBucket"></a><span class='hs-comment'>-- Remove a key from a bucket</span>
<a name="line-447"></a><span class='hs-definition'>deleteBucket</span> <span class='hs-keyglyph'>::</span> <span class='hs-layout'>(</span><span class='hs-varid'>key</span> <span class='hs-keyglyph'>-></span> <span class='hs-conid'>Bool</span><span class='hs-layout'>)</span> <span class='hs-keyglyph'>-></span> <span class='hs-keyglyph'>[</span><span class='hs-layout'>(</span><span class='hs-varid'>key</span><span class='hs-layout'>,</span><span class='hs-varid'>val</span><span class='hs-layout'>)</span><span class='hs-keyglyph'>]</span> <span class='hs-keyglyph'>-></span> <span class='hs-layout'>(</span><span class='hs-keyglyph'>[</span><span class='hs-layout'>(</span><span class='hs-varid'>key</span><span class='hs-layout'>,</span> <span class='hs-varid'>val</span><span class='hs-layout'>)</span><span class='hs-keyglyph'>]</span><span class='hs-layout'>,</span> <span class='hs-conid'>Int32</span><span class='hs-layout'>,</span> <span class='hs-conid'>()</span><span class='hs-layout'>)</span>
<a name="line-448"></a><span class='hs-definition'>deleteBucket</span> <span class='hs-keyword'>_</span> <span class='hs-conid'>[]</span> <span class='hs-keyglyph'>=</span> <span class='hs-layout'>(</span><span class='hs-conid'>[]</span><span class='hs-layout'>,</span><span class='hs-num'>0</span><span class='hs-layout'>,</span><span class='hs-conid'>()</span><span class='hs-layout'>)</span>
<a name="line-449"></a><span class='hs-definition'>deleteBucket</span> <span class='hs-varid'>del</span> <span class='hs-layout'>(</span><span class='hs-varid'>pair</span><span class='hs-keyglyph'>@</span><span class='hs-layout'>(</span><span class='hs-varid'>k</span><span class='hs-layout'>,</span><span class='hs-keyword'>_</span><span class='hs-layout'>)</span><span class='hs-conop'>:</span><span class='hs-varid'>bucket</span><span class='hs-layout'>)</span> <span class='hs-keyglyph'>=</span>
<a name="line-450"></a> <span class='hs-keyword'>case</span> <span class='hs-varid'>deleteBucket</span> <span class='hs-varid'>del</span> <span class='hs-varid'>bucket</span> <span class='hs-keyword'>of</span>
<a name="line-451"></a> <span class='hs-layout'>(</span><span class='hs-varid'>bucket'</span><span class='hs-layout'>,</span> <span class='hs-varid'>dels</span><span class='hs-layout'>,</span> <span class='hs-keyword'>_</span><span class='hs-layout'>)</span> <span class='hs-keyglyph'>|</span> <span class='hs-varid'>del</span> <span class='hs-varid'>k</span> <span class='hs-keyglyph'>-></span> <span class='hs-varid'>dels'</span> <span class='hs-varop'>`seq`</span> <span class='hs-layout'>(</span><span class='hs-varid'>bucket'</span><span class='hs-layout'>,</span> <span class='hs-varid'>dels'</span><span class='hs-layout'>,</span> <span class='hs-conid'>()</span><span class='hs-layout'>)</span>
<a name="line-452"></a> <span class='hs-keyglyph'>|</span> <span class='hs-varid'>otherwise</span> <span class='hs-keyglyph'>-></span> <span class='hs-layout'>(</span><span class='hs-varid'>pair</span><span class='hs-conop'>:</span><span class='hs-varid'>bucket'</span><span class='hs-layout'>,</span> <span class='hs-varid'>dels</span><span class='hs-layout'>,</span> <span class='hs-conid'>()</span><span class='hs-layout'>)</span>
<a name="line-453"></a> <span class='hs-keyword'>where</span> <span class='hs-varid'>dels'</span> <span class='hs-keyglyph'>=</span> <span class='hs-varid'>dels</span> <span class='hs-comment'>-</span> <span class='hs-num'>1</span>
<a name="line-454"></a>
<a name="line-455"></a><a name="delete"></a><span class='hs-comment'>-- | Remove an entry from the hash table.</span>
<a name="line-456"></a><span class='hs-definition'>delete</span> <span class='hs-keyglyph'>::</span> <span class='hs-conid'>HashTable</span> <span class='hs-varid'>key</span> <span class='hs-varid'>val</span> <span class='hs-keyglyph'>-></span> <span class='hs-varid'>key</span> <span class='hs-keyglyph'>-></span> <span class='hs-conid'>IO</span> <span class='hs-conid'>()</span>
<a name="line-457"></a>
<a name="line-458"></a><span class='hs-definition'>delete</span> <span class='hs-varid'>ht</span><span class='hs-keyglyph'>@</span><span class='hs-conid'>HashTable</span><span class='hs-layout'>{</span> <span class='hs-varid'>cmp</span><span class='hs-keyglyph'>=</span><span class='hs-varid'>eq</span> <span class='hs-layout'>}</span> <span class='hs-varid'>key</span> <span class='hs-keyglyph'>=</span>
<a name="line-459"></a> <span class='hs-varid'>updatingBucket</span> <span class='hs-conid'>Can'tInsert</span> <span class='hs-layout'>(</span><span class='hs-varid'>deleteBucket</span> <span class='hs-layout'>(</span><span class='hs-varid'>eq</span> <span class='hs-varid'>key</span><span class='hs-layout'>)</span><span class='hs-layout'>)</span> <span class='hs-varid'>ht</span> <span class='hs-varid'>key</span>
<a name="line-460"></a>
<a name="line-461"></a><span class='hs-comment'>-- -----------------------------------------------------------------------------</span>
<a name="line-462"></a><span class='hs-comment'>-- Updating a mapping in the hash table</span>
<a name="line-463"></a>
<a name="line-464"></a><a name="update"></a><span class='hs-comment'>-- | Updates an entry in the hash table, returning 'True' if there was</span>
<a name="line-465"></a><span class='hs-comment'>-- already an entry for this key, or 'False' otherwise. After 'update'</span>
<a name="line-466"></a><span class='hs-comment'>-- there will always be exactly one entry for the given key in the table.</span>
<a name="line-467"></a><span class='hs-comment'>--</span>
<a name="line-468"></a><span class='hs-comment'>-- 'insert' is more efficient than 'update' if you don't care about</span>
<a name="line-469"></a><span class='hs-comment'>-- multiple entries, or you know for sure that multiple entries can't</span>
<a name="line-470"></a><span class='hs-comment'>-- occur. However, 'update' is more efficient than 'delete' followed</span>
<a name="line-471"></a><span class='hs-comment'>-- by 'insert'.</span>
<a name="line-472"></a><span class='hs-definition'>update</span> <span class='hs-keyglyph'>::</span> <span class='hs-conid'>HashTable</span> <span class='hs-varid'>key</span> <span class='hs-varid'>val</span> <span class='hs-keyglyph'>-></span> <span class='hs-varid'>key</span> <span class='hs-keyglyph'>-></span> <span class='hs-varid'>val</span> <span class='hs-keyglyph'>-></span> <span class='hs-conid'>IO</span> <span class='hs-conid'>Bool</span>
<a name="line-473"></a>
<a name="line-474"></a><span class='hs-definition'>update</span> <span class='hs-varid'>ht</span><span class='hs-keyglyph'>@</span><span class='hs-conid'>HashTable</span><span class='hs-layout'>{</span> <span class='hs-varid'>cmp</span><span class='hs-keyglyph'>=</span><span class='hs-varid'>eq</span> <span class='hs-layout'>}</span> <span class='hs-varid'>key</span> <span class='hs-varid'>val</span> <span class='hs-keyglyph'>=</span>
<a name="line-475"></a> <span class='hs-varid'>updatingBucket</span> <span class='hs-conid'>CanInsert</span>
<a name="line-476"></a> <span class='hs-layout'>(</span><span class='hs-keyglyph'>\</span><span class='hs-varid'>bucket</span> <span class='hs-keyglyph'>-></span> <span class='hs-keyword'>let</span> <span class='hs-layout'>(</span><span class='hs-varid'>bucket'</span><span class='hs-layout'>,</span> <span class='hs-varid'>dels</span><span class='hs-layout'>,</span> <span class='hs-keyword'>_</span><span class='hs-layout'>)</span> <span class='hs-keyglyph'>=</span> <span class='hs-varid'>deleteBucket</span> <span class='hs-layout'>(</span><span class='hs-varid'>eq</span> <span class='hs-varid'>key</span><span class='hs-layout'>)</span> <span class='hs-varid'>bucket</span>
<a name="line-477"></a> <span class='hs-keyword'>in</span> <span class='hs-layout'>(</span><span class='hs-layout'>(</span><span class='hs-varid'>key</span><span class='hs-layout'>,</span><span class='hs-varid'>val</span><span class='hs-layout'>)</span><span class='hs-conop'>:</span><span class='hs-varid'>bucket'</span><span class='hs-layout'>,</span> <span class='hs-num'>1</span><span class='hs-varop'>+</span><span class='hs-varid'>dels</span><span class='hs-layout'>,</span> <span class='hs-varid'>dels</span><span class='hs-varop'>/=</span><span class='hs-num'>0</span><span class='hs-layout'>)</span><span class='hs-layout'>)</span>
<a name="line-478"></a> <span class='hs-varid'>ht</span> <span class='hs-varid'>key</span>
<a name="line-479"></a>
<a name="line-480"></a><span class='hs-comment'>-- -----------------------------------------------------------------------------</span>
<a name="line-481"></a><span class='hs-comment'>-- Looking up an entry in the hash table</span>
<a name="line-482"></a>
<a name="line-483"></a><a name="lookup"></a><span class='hs-comment'>-- | Looks up the value of a key in the hash table.</span>
<a name="line-484"></a><span class='hs-definition'>lookup</span> <span class='hs-keyglyph'>::</span> <span class='hs-conid'>HashTable</span> <span class='hs-varid'>key</span> <span class='hs-varid'>val</span> <span class='hs-keyglyph'>-></span> <span class='hs-varid'>key</span> <span class='hs-keyglyph'>-></span> <span class='hs-conid'>IO</span> <span class='hs-layout'>(</span><span class='hs-conid'>Maybe</span> <span class='hs-varid'>val</span><span class='hs-layout'>)</span>
<a name="line-485"></a>
<a name="line-486"></a><span class='hs-definition'>lookup</span> <span class='hs-varid'>ht</span><span class='hs-keyglyph'>@</span><span class='hs-conid'>HashTable</span><span class='hs-layout'>{</span> <span class='hs-varid'>cmp</span><span class='hs-keyglyph'>=</span><span class='hs-varid'>eq</span> <span class='hs-layout'>}</span> <span class='hs-varid'>key</span> <span class='hs-keyglyph'>=</span> <span class='hs-keyword'>do</span>
<a name="line-487"></a> <span class='hs-varid'>recordLookup</span>
<a name="line-488"></a> <span class='hs-layout'>(</span><span class='hs-keyword'>_</span><span class='hs-layout'>,</span> <span class='hs-keyword'>_</span><span class='hs-layout'>,</span> <span class='hs-varid'>bucket</span><span class='hs-layout'>)</span> <span class='hs-keyglyph'><-</span> <span class='hs-varid'>findBucket</span> <span class='hs-varid'>ht</span> <span class='hs-varid'>key</span>
<a name="line-489"></a> <span class='hs-keyword'>let</span> <span class='hs-varid'>firstHit</span> <span class='hs-layout'>(</span><span class='hs-varid'>k</span><span class='hs-layout'>,</span><span class='hs-varid'>v</span><span class='hs-layout'>)</span> <span class='hs-varid'>r</span> <span class='hs-keyglyph'>|</span> <span class='hs-varid'>eq</span> <span class='hs-varid'>key</span> <span class='hs-varid'>k</span> <span class='hs-keyglyph'>=</span> <span class='hs-conid'>Just</span> <span class='hs-varid'>v</span>
<a name="line-490"></a> <span class='hs-keyglyph'>|</span> <span class='hs-varid'>otherwise</span> <span class='hs-keyglyph'>=</span> <span class='hs-varid'>r</span>
<a name="line-491"></a> <span class='hs-varid'>return</span> <span class='hs-layout'>(</span><span class='hs-varid'>foldr</span> <span class='hs-varid'>firstHit</span> <span class='hs-conid'>Nothing</span> <span class='hs-varid'>bucket</span><span class='hs-layout'>)</span>
<a name="line-492"></a>
<a name="line-493"></a><span class='hs-comment'>-- -----------------------------------------------------------------------------</span>
<a name="line-494"></a><span class='hs-comment'>-- Converting to/from lists</span>
<a name="line-495"></a>
<a name="line-496"></a><a name="fromList"></a><span class='hs-comment'>-- | Convert a list of key\/value pairs into a hash table. Equality on keys</span>
<a name="line-497"></a><span class='hs-comment'>-- is taken from the Eq instance for the key type.</span>
<a name="line-498"></a><span class='hs-comment'>--</span>
<a name="line-499"></a><span class='hs-definition'>fromList</span> <span class='hs-keyglyph'>::</span> <span class='hs-layout'>(</span><span class='hs-conid'>Eq</span> <span class='hs-varid'>key</span><span class='hs-layout'>)</span> <span class='hs-keyglyph'>=></span> <span class='hs-layout'>(</span><span class='hs-varid'>key</span> <span class='hs-keyglyph'>-></span> <span class='hs-conid'>Int32</span><span class='hs-layout'>)</span> <span class='hs-keyglyph'>-></span> <span class='hs-keyglyph'>[</span><span class='hs-layout'>(</span><span class='hs-varid'>key</span><span class='hs-layout'>,</span><span class='hs-varid'>val</span><span class='hs-layout'>)</span><span class='hs-keyglyph'>]</span> <span class='hs-keyglyph'>-></span> <span class='hs-conid'>IO</span> <span class='hs-layout'>(</span><span class='hs-conid'>HashTable</span> <span class='hs-varid'>key</span> <span class='hs-varid'>val</span><span class='hs-layout'>)</span>
<a name="line-500"></a><span class='hs-definition'>fromList</span> <span class='hs-varid'>hash</span> <span class='hs-varid'>list</span> <span class='hs-keyglyph'>=</span> <span class='hs-keyword'>do</span>
<a name="line-501"></a> <span class='hs-varid'>table</span> <span class='hs-keyglyph'><-</span> <span class='hs-varid'>new</span> <span class='hs-layout'>(</span><span class='hs-varop'>==</span><span class='hs-layout'>)</span> <span class='hs-varid'>hash</span>
<a name="line-502"></a> <span class='hs-varid'>sequence_</span> <span class='hs-keyglyph'>[</span> <span class='hs-varid'>insert</span> <span class='hs-varid'>table</span> <span class='hs-varid'>k</span> <span class='hs-varid'>v</span> <span class='hs-keyglyph'>|</span> <span class='hs-layout'>(</span><span class='hs-varid'>k</span><span class='hs-layout'>,</span><span class='hs-varid'>v</span><span class='hs-layout'>)</span> <span class='hs-keyglyph'><-</span> <span class='hs-varid'>list</span> <span class='hs-keyglyph'>]</span>
<a name="line-503"></a> <span class='hs-varid'>return</span> <span class='hs-varid'>table</span>
<a name="line-504"></a>
<a name="line-505"></a><a name="toList"></a><span class='hs-comment'>-- | Converts a hash table to a list of key\/value pairs.</span>
<a name="line-506"></a><span class='hs-comment'>--</span>
<a name="line-507"></a><span class='hs-definition'>toList</span> <span class='hs-keyglyph'>::</span> <span class='hs-conid'>HashTable</span> <span class='hs-varid'>key</span> <span class='hs-varid'>val</span> <span class='hs-keyglyph'>-></span> <span class='hs-conid'>IO</span> <span class='hs-keyglyph'>[</span><span class='hs-layout'>(</span><span class='hs-varid'>key</span><span class='hs-layout'>,</span><span class='hs-varid'>val</span><span class='hs-layout'>)</span><span class='hs-keyglyph'>]</span>
<a name="line-508"></a><span class='hs-definition'>toList</span> <span class='hs-keyglyph'>=</span> <span class='hs-varid'>mapReduce</span> <span class='hs-varid'>id</span> <span class='hs-varid'>concat</span>
<a name="line-509"></a>
<a name="line-510"></a><a name="mapReduce"></a><span class='hs-comment'>{-# INLINE mapReduce #-}</span>
<a name="line-511"></a><span class='hs-definition'>mapReduce</span> <span class='hs-keyglyph'>::</span> <span class='hs-layout'>(</span><span class='hs-keyglyph'>[</span><span class='hs-layout'>(</span><span class='hs-varid'>key</span><span class='hs-layout'>,</span><span class='hs-varid'>val</span><span class='hs-layout'>)</span><span class='hs-keyglyph'>]</span> <span class='hs-keyglyph'>-></span> <span class='hs-varid'>r</span><span class='hs-layout'>)</span> <span class='hs-keyglyph'>-></span> <span class='hs-layout'>(</span><span class='hs-keyglyph'>[</span><span class='hs-varid'>r</span><span class='hs-keyglyph'>]</span> <span class='hs-keyglyph'>-></span> <span class='hs-varid'>r</span><span class='hs-layout'>)</span> <span class='hs-keyglyph'>-></span> <span class='hs-conid'>HashTable</span> <span class='hs-varid'>key</span> <span class='hs-varid'>val</span> <span class='hs-keyglyph'>-></span> <span class='hs-conid'>IO</span> <span class='hs-varid'>r</span>
<a name="line-512"></a><span class='hs-definition'>mapReduce</span> <span class='hs-varid'>m</span> <span class='hs-varid'>r</span> <span class='hs-conid'>HashTable</span><span class='hs-layout'>{</span> <span class='hs-varid'>tab</span><span class='hs-keyglyph'>=</span><span class='hs-varid'>ref</span> <span class='hs-layout'>}</span> <span class='hs-keyglyph'>=</span> <span class='hs-keyword'>do</span>
<a name="line-513"></a> <span class='hs-conid'>HT</span><span class='hs-layout'>{</span> <span class='hs-varid'>buckets</span><span class='hs-keyglyph'>=</span><span class='hs-varid'>bckts</span><span class='hs-layout'>,</span> <span class='hs-varid'>bmask</span><span class='hs-keyglyph'>=</span><span class='hs-varid'>b</span> <span class='hs-layout'>}</span> <span class='hs-keyglyph'><-</span> <span class='hs-varid'>readIORef</span> <span class='hs-varid'>ref</span>
<a name="line-514"></a> <span class='hs-varid'>fmap</span> <span class='hs-varid'>r</span> <span class='hs-layout'>(</span><span class='hs-varid'>mapM</span> <span class='hs-layout'>(</span><span class='hs-varid'>fmap</span> <span class='hs-varid'>m</span> <span class='hs-varop'>.</span> <span class='hs-varid'>readHTArray</span> <span class='hs-varid'>bckts</span><span class='hs-layout'>)</span> <span class='hs-keyglyph'>[</span><span class='hs-num'>0</span><span class='hs-keyglyph'>..</span><span class='hs-varid'>b</span><span class='hs-keyglyph'>]</span><span class='hs-layout'>)</span>
<a name="line-515"></a>
<a name="line-516"></a><span class='hs-comment'>-- -----------------------------------------------------------------------------</span>
<a name="line-517"></a><span class='hs-comment'>-- Diagnostics</span>
<a name="line-518"></a>
<a name="line-519"></a><a name="longestChain"></a><span class='hs-comment'>-- | This function is useful for determining whether your hash</span>
<a name="line-520"></a><span class='hs-comment'>-- function is working well for your data set. It returns the longest</span>
<a name="line-521"></a><span class='hs-comment'>-- chain of key\/value pairs in the hash table for which all the keys</span>
<a name="line-522"></a><span class='hs-comment'>-- hash to the same bucket. If this chain is particularly long (say,</span>
<a name="line-523"></a><span class='hs-comment'>-- longer than 14 elements or so), then it might be a good idea to try</span>
<a name="line-524"></a><span class='hs-comment'>-- a different hash function.</span>
<a name="line-525"></a><span class='hs-comment'>--</span>
<a name="line-526"></a><span class='hs-definition'>longestChain</span> <span class='hs-keyglyph'>::</span> <span class='hs-conid'>HashTable</span> <span class='hs-varid'>key</span> <span class='hs-varid'>val</span> <span class='hs-keyglyph'>-></span> <span class='hs-conid'>IO</span> <span class='hs-keyglyph'>[</span><span class='hs-layout'>(</span><span class='hs-varid'>key</span><span class='hs-layout'>,</span><span class='hs-varid'>val</span><span class='hs-layout'>)</span><span class='hs-keyglyph'>]</span>
<a name="line-527"></a><span class='hs-definition'>longestChain</span> <span class='hs-keyglyph'>=</span> <span class='hs-varid'>mapReduce</span> <span class='hs-varid'>id</span> <span class='hs-layout'>(</span><span class='hs-varid'>maximumBy</span> <span class='hs-varid'>lengthCmp</span><span class='hs-layout'>)</span>
<a name="line-528"></a> <span class='hs-keyword'>where</span> <span class='hs-varid'>lengthCmp</span> <span class='hs-layout'>(</span><span class='hs-keyword'>_</span><span class='hs-conop'>:</span><span class='hs-varid'>x</span><span class='hs-layout'>)</span><span class='hs-layout'>(</span><span class='hs-keyword'>_</span><span class='hs-conop'>:</span><span class='hs-varid'>y</span><span class='hs-layout'>)</span> <span class='hs-keyglyph'>=</span> <span class='hs-varid'>lengthCmp</span> <span class='hs-varid'>x</span> <span class='hs-varid'>y</span>
<a name="line-529"></a> <span class='hs-varid'>lengthCmp</span> <span class='hs-conid'>[]</span> <span class='hs-conid'>[]</span> <span class='hs-keyglyph'>=</span> <span class='hs-conid'>EQ</span>
<a name="line-530"></a> <span class='hs-varid'>lengthCmp</span> <span class='hs-conid'>[]</span> <span class='hs-keyword'>_</span> <span class='hs-keyglyph'>=</span> <span class='hs-conid'>LT</span>
<a name="line-531"></a> <span class='hs-varid'>lengthCmp</span> <span class='hs-keyword'>_</span> <span class='hs-conid'>[]</span> <span class='hs-keyglyph'>=</span> <span class='hs-conid'>GT</span>
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