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<pre><a name="line-1"></a><span class='hs-comment'>{-# OPTIONS_GHC -Wall -fwarn-tabs #-}</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'>-- ~ 2011.02.12</span>
<a name="line-5"></a><span class='hs-comment'>-- |</span>
<a name="line-6"></a><span class='hs-comment'>-- Module : Data.Trie.Convenience</span>
<a name="line-7"></a><span class='hs-comment'>-- Copyright : Copyright (c) 2008--2011 wren ng thornton</span>
<a name="line-8"></a><span class='hs-comment'>-- License : BSD3</span>
<a name="line-9"></a><span class='hs-comment'>-- Maintainer : wren@community.haskell.org</span>
<a name="line-10"></a><span class='hs-comment'>-- Stability : experimental</span>
<a name="line-11"></a><span class='hs-comment'>-- Portability : portable</span>
<a name="line-12"></a><span class='hs-comment'>--</span>
<a name="line-13"></a><span class='hs-comment'>-- Additional convenience functions. In order to keep "Data.Trie"</span>
<a name="line-14"></a><span class='hs-comment'>-- concise, non-essential and uncommonly used functions have been</span>
<a name="line-15"></a><span class='hs-comment'>-- moved here. Most of these functions simplify the generic functions</span>
<a name="line-16"></a><span class='hs-comment'>-- from "Data.Trie", following after the interface for "Data.Map"</span>
<a name="line-17"></a><span class='hs-comment'>-- and "Data.IntMap".</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'>Trie</span><span class='hs-varop'>.</span><span class='hs-conid'>Convenience</span>
<a name="line-21"></a> <span class='hs-layout'>(</span>
<a name="line-22"></a> <span class='hs-comment'>-- * Conversion functions ('fromList' variants)</span>
<a name="line-23"></a> <span class='hs-comment'>-- $fromList</span>
<a name="line-24"></a> <span class='hs-varid'>fromListL</span><span class='hs-layout'>,</span> <span class='hs-varid'>fromListR</span><span class='hs-layout'>,</span> <span class='hs-varid'>fromListS</span>
<a name="line-25"></a> <span class='hs-layout'>,</span> <span class='hs-varid'>fromListWith</span><span class='hs-layout'>,</span> <span class='hs-varid'>fromListWith'</span>
<a name="line-26"></a> <span class='hs-layout'>,</span> <span class='hs-varid'>fromListWithL</span><span class='hs-layout'>,</span> <span class='hs-varid'>fromListWithL'</span>
<a name="line-27"></a>
<a name="line-28"></a> <span class='hs-comment'>-- * Query functions ('lookupBy' variants)</span>
<a name="line-29"></a> <span class='hs-layout'>,</span> <span class='hs-varid'>lookupWithDefault</span>
<a name="line-30"></a>
<a name="line-31"></a> <span class='hs-comment'>-- * Inserting values ('alterBy' variants)</span>
<a name="line-32"></a> <span class='hs-layout'>,</span> <span class='hs-varid'>insertIfAbsent</span>
<a name="line-33"></a> <span class='hs-layout'>,</span> <span class='hs-varid'>insertWith</span><span class='hs-layout'>,</span> <span class='hs-varid'>insertWith'</span>
<a name="line-34"></a> <span class='hs-layout'>,</span> <span class='hs-varid'>insertWithKey</span><span class='hs-layout'>,</span> <span class='hs-varid'>insertWithKey'</span>
<a name="line-35"></a>
<a name="line-36"></a> <span class='hs-comment'>-- * Updating and adjusting values ('alterBy' and 'adjustBy' variants)</span>
<a name="line-37"></a> <span class='hs-layout'>,</span> <span class='hs-varid'>adjustWithKey</span>
<a name="line-38"></a> <span class='hs-layout'>,</span> <span class='hs-varid'>update</span><span class='hs-layout'>,</span> <span class='hs-varid'>updateWithKey</span>
<a name="line-39"></a>
<a name="line-40"></a> <span class='hs-comment'>-- * Combining tries ('mergeBy' variants)</span>
<a name="line-41"></a> <span class='hs-layout'>,</span> <span class='hs-varid'>disunion</span>
<a name="line-42"></a> <span class='hs-layout'>,</span> <span class='hs-varid'>unionWith</span><span class='hs-layout'>,</span> <span class='hs-varid'>unionWith'</span>
<a name="line-43"></a> <span class='hs-layout'>)</span> <span class='hs-keyword'>where</span>
<a name="line-44"></a>
<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'>Trie</span>
<a name="line-46"></a><span class='hs-keyword'>import</span> <span class='hs-conid'>Data</span><span class='hs-varop'>.</span><span class='hs-conid'>Trie</span><span class='hs-varop'>.</span><span class='hs-conid'>Internal</span> <span class='hs-layout'>(</span><span class='hs-varid'>lookupBy_</span><span class='hs-layout'>,</span> <span class='hs-varid'>adjustBy</span><span class='hs-layout'>)</span>
<a name="line-47"></a><span class='hs-keyword'>import</span> <span class='hs-conid'>Data</span><span class='hs-varop'>.</span><span class='hs-conid'>Trie</span><span class='hs-varop'>.</span><span class='hs-conid'>Errors</span> <span class='hs-layout'>(</span><span class='hs-varid'>impossible</span><span class='hs-layout'>)</span>
<a name="line-48"></a><span class='hs-keyword'>import</span> <span class='hs-conid'>Data</span><span class='hs-varop'>.</span><span class='hs-conid'>ByteString</span> <span class='hs-layout'>(</span><span class='hs-conid'>ByteString</span><span class='hs-layout'>)</span>
<a name="line-49"></a><span class='hs-keyword'>import</span> <span class='hs-conid'>Data</span><span class='hs-varop'>.</span><span class='hs-conid'>List</span> <span class='hs-layout'>(</span><span class='hs-varid'>foldl'</span><span class='hs-layout'>,</span> <span class='hs-varid'>sortBy</span><span class='hs-layout'>)</span>
<a name="line-50"></a><span class='hs-keyword'>import</span> <span class='hs-conid'>Data</span><span class='hs-varop'>.</span><span class='hs-conid'>Ord</span> <span class='hs-layout'>(</span><span class='hs-varid'>comparing</span><span class='hs-layout'>)</span>
<a name="line-51"></a>
<a name="line-52"></a><span class='hs-comment'>----------------------------------------------------------------</span>
<a name="line-53"></a><span class='hs-comment'>----------------------------------------------------------------</span>
<a name="line-54"></a><span class='hs-comment'>-- $fromList</span>
<a name="line-55"></a><span class='hs-comment'>-- Just like 'fromList' all of these functions convert an association</span>
<a name="line-56"></a><span class='hs-comment'>-- list into a trie, with earlier values shadowing later ones when</span>
<a name="line-57"></a><span class='hs-comment'>-- keys conflict. Depending on the order of keys in the list, there</span>
<a name="line-58"></a><span class='hs-comment'>-- can be as much as 5x speed difference between the left and right</span>
<a name="line-59"></a><span class='hs-comment'>-- variants. Yet, performance is about the same when matching</span>
<a name="line-60"></a><span class='hs-comment'>-- best-case to best-case and worst-case to worst-case (which is</span>
<a name="line-61"></a><span class='hs-comment'>-- which is swapped when reversing the list or changing which</span>
<a name="line-62"></a><span class='hs-comment'>-- function is used).</span>
<a name="line-63"></a>
<a name="line-64"></a>
<a name="line-65"></a><a name="fromListL"></a><span class='hs-comment'>-- | A left-fold version of 'fromList'. If you run into issues with</span>
<a name="line-66"></a><span class='hs-comment'>-- stack overflows when using 'fromList' or 'fromListR', then you</span>
<a name="line-67"></a><span class='hs-comment'>-- should use this function instead.</span>
<a name="line-68"></a><span class='hs-definition'>fromListL</span> <span class='hs-keyglyph'>::</span> <span class='hs-keyglyph'>[</span><span class='hs-layout'>(</span><span class='hs-conid'>ByteString</span><span class='hs-layout'>,</span><span class='hs-varid'>a</span><span class='hs-layout'>)</span><span class='hs-keyglyph'>]</span> <span class='hs-keyglyph'>-></span> <span class='hs-conid'>Trie</span> <span class='hs-varid'>a</span>
<a name="line-69"></a><span class='hs-comment'>{-# INLINE fromListL #-}</span>
<a name="line-70"></a><span class='hs-definition'>fromListL</span> <span class='hs-keyglyph'>=</span> <span class='hs-varid'>foldl'</span> <span class='hs-layout'>(</span><span class='hs-varid'>flip</span> <span class='hs-varop'>.</span> <span class='hs-varid'>uncurry</span> <span class='hs-varop'>$</span> <span class='hs-varid'>insertIfAbsent</span><span class='hs-layout'>)</span> <span class='hs-varid'>empty</span>
<a name="line-71"></a>
<a name="line-72"></a>
<a name="line-73"></a><a name="fromListR"></a><span class='hs-comment'>-- | An explicitly right-fold variant of 'fromList'. It is a good</span>
<a name="line-74"></a><span class='hs-comment'>-- consumer for list fusion. Worst-case behavior is somewhat worse</span>
<a name="line-75"></a><span class='hs-comment'>-- than worst-case for 'fromListL'. The 'fromList' function is</span>
<a name="line-76"></a><span class='hs-comment'>-- currently just an alias for 'fromListR'.</span>
<a name="line-77"></a><span class='hs-definition'>fromListR</span> <span class='hs-keyglyph'>::</span> <span class='hs-keyglyph'>[</span><span class='hs-layout'>(</span><span class='hs-conid'>ByteString</span><span class='hs-layout'>,</span><span class='hs-varid'>a</span><span class='hs-layout'>)</span><span class='hs-keyglyph'>]</span> <span class='hs-keyglyph'>-></span> <span class='hs-conid'>Trie</span> <span class='hs-varid'>a</span>
<a name="line-78"></a><span class='hs-comment'>{-# INLINE fromListR #-}</span>
<a name="line-79"></a><span class='hs-definition'>fromListR</span> <span class='hs-keyglyph'>=</span> <span class='hs-varid'>fromList</span> <span class='hs-comment'>-- == foldr (uncurry insert) empty</span>
<a name="line-80"></a>
<a name="line-81"></a>
<a name="line-82"></a><a name="fromListS"></a><span class='hs-comment'>-- TODO: compare performance against a fromListL variant, adjusting the sort appropriately</span>
<a name="line-83"></a><span class='hs-comment'>--</span>
<a name="line-84"></a><span class='hs-comment'>-- | This variant sorts the list before folding over it. This adds</span>
<a name="line-85"></a><span class='hs-comment'>-- /O(n log n)/ overhead and requires the whole list be in memory</span>
<a name="line-86"></a><span class='hs-comment'>-- at once, but it ensures that the list is in best-case order. The</span>
<a name="line-87"></a><span class='hs-comment'>-- benefits generally outweigh the costs.</span>
<a name="line-88"></a><span class='hs-definition'>fromListS</span> <span class='hs-keyglyph'>::</span> <span class='hs-keyglyph'>[</span><span class='hs-layout'>(</span><span class='hs-conid'>ByteString</span><span class='hs-layout'>,</span><span class='hs-varid'>a</span><span class='hs-layout'>)</span><span class='hs-keyglyph'>]</span> <span class='hs-keyglyph'>-></span> <span class='hs-conid'>Trie</span> <span class='hs-varid'>a</span>
<a name="line-89"></a><span class='hs-comment'>{-# INLINE fromListS #-}</span>
<a name="line-90"></a><span class='hs-definition'>fromListS</span> <span class='hs-keyglyph'>=</span> <span class='hs-varid'>fromListR</span> <span class='hs-varop'>.</span> <span class='hs-varid'>sortBy</span> <span class='hs-layout'>(</span><span class='hs-varid'>comparing</span> <span class='hs-varid'>fst</span><span class='hs-layout'>)</span>
<a name="line-91"></a>
<a name="line-92"></a>
<a name="line-93"></a><a name="fromListWith"></a><span class='hs-comment'>-- | A variant of 'fromListR' that takes a function for combining</span>
<a name="line-94"></a><span class='hs-comment'>-- values on conflict. The first argument to the combining function</span>
<a name="line-95"></a><span class='hs-comment'>-- is the ``new'' value from the initial portion of the list; the</span>
<a name="line-96"></a><span class='hs-comment'>-- second argument is the value that has been accumulated into the</span>
<a name="line-97"></a><span class='hs-comment'>-- trie from the tail of the list (just like the first argument to</span>
<a name="line-98"></a><span class='hs-comment'>-- 'foldr'). Thus, @fromList = fromListWith const@.</span>
<a name="line-99"></a><span class='hs-definition'>fromListWith</span> <span class='hs-keyglyph'>::</span> <span class='hs-layout'>(</span><span class='hs-varid'>a</span> <span class='hs-keyglyph'>-></span> <span class='hs-varid'>a</span> <span class='hs-keyglyph'>-></span> <span class='hs-varid'>a</span><span class='hs-layout'>)</span> <span class='hs-keyglyph'>-></span> <span class='hs-keyglyph'>[</span><span class='hs-layout'>(</span><span class='hs-conid'>ByteString</span><span class='hs-layout'>,</span><span class='hs-varid'>a</span><span class='hs-layout'>)</span><span class='hs-keyglyph'>]</span> <span class='hs-keyglyph'>-></span> <span class='hs-conid'>Trie</span> <span class='hs-varid'>a</span>
<a name="line-100"></a><span class='hs-comment'>{-# INLINE fromListWith #-}</span>
<a name="line-101"></a><span class='hs-definition'>fromListWith</span> <span class='hs-varid'>f</span> <span class='hs-keyglyph'>=</span> <span class='hs-varid'>foldr</span> <span class='hs-layout'>(</span><span class='hs-varid'>uncurry</span> <span class='hs-varop'>$</span> <span class='hs-varid'>alterBy</span> <span class='hs-varid'>g</span><span class='hs-layout'>)</span> <span class='hs-varid'>empty</span>
<a name="line-102"></a> <span class='hs-keyword'>where</span>
<a name="line-103"></a> <span class='hs-varid'>g</span> <span class='hs-keyword'>_</span> <span class='hs-varid'>v</span> <span class='hs-conid'>Nothing</span> <span class='hs-keyglyph'>=</span> <span class='hs-conid'>Just</span> <span class='hs-varid'>v</span>
<a name="line-104"></a> <span class='hs-varid'>g</span> <span class='hs-keyword'>_</span> <span class='hs-varid'>v</span> <span class='hs-layout'>(</span><span class='hs-conid'>Just</span> <span class='hs-varid'>w</span><span class='hs-layout'>)</span> <span class='hs-keyglyph'>=</span> <span class='hs-conid'>Just</span> <span class='hs-layout'>(</span><span class='hs-varid'>f</span> <span class='hs-varid'>v</span> <span class='hs-varid'>w</span><span class='hs-layout'>)</span>
<a name="line-105"></a>
<a name="line-106"></a>
<a name="line-107"></a><a name="fromListWith'"></a><span class='hs-comment'>-- | A variant of 'fromListWith' which applies the combining</span>
<a name="line-108"></a><span class='hs-comment'>-- function strictly. This function is a good consumer for list</span>
<a name="line-109"></a><span class='hs-comment'>-- fusion. If you need list fusion and are running into stack</span>
<a name="line-110"></a><span class='hs-comment'>-- overflow problems with 'fromListWith', then this function may</span>
<a name="line-111"></a><span class='hs-comment'>-- solve the problem.</span>
<a name="line-112"></a><span class='hs-definition'>fromListWith'</span> <span class='hs-keyglyph'>::</span> <span class='hs-layout'>(</span><span class='hs-varid'>a</span> <span class='hs-keyglyph'>-></span> <span class='hs-varid'>a</span> <span class='hs-keyglyph'>-></span> <span class='hs-varid'>a</span><span class='hs-layout'>)</span> <span class='hs-keyglyph'>-></span> <span class='hs-keyglyph'>[</span><span class='hs-layout'>(</span><span class='hs-conid'>ByteString</span><span class='hs-layout'>,</span><span class='hs-varid'>a</span><span class='hs-layout'>)</span><span class='hs-keyglyph'>]</span> <span class='hs-keyglyph'>-></span> <span class='hs-conid'>Trie</span> <span class='hs-varid'>a</span>
<a name="line-113"></a><span class='hs-comment'>{-# INLINE fromListWith' #-}</span>
<a name="line-114"></a><span class='hs-definition'>fromListWith'</span> <span class='hs-varid'>f</span> <span class='hs-keyglyph'>=</span> <span class='hs-varid'>foldr</span> <span class='hs-layout'>(</span><span class='hs-varid'>uncurry</span> <span class='hs-varop'>$</span> <span class='hs-varid'>alterBy</span> <span class='hs-varid'>g'</span><span class='hs-layout'>)</span> <span class='hs-varid'>empty</span>
<a name="line-115"></a> <span class='hs-keyword'>where</span>
<a name="line-116"></a> <span class='hs-varid'>g'</span> <span class='hs-keyword'>_</span> <span class='hs-varid'>v</span> <span class='hs-conid'>Nothing</span> <span class='hs-keyglyph'>=</span> <span class='hs-conid'>Just</span> <span class='hs-varid'>v</span>
<a name="line-117"></a> <span class='hs-varid'>g'</span> <span class='hs-keyword'>_</span> <span class='hs-varid'>v</span> <span class='hs-layout'>(</span><span class='hs-conid'>Just</span> <span class='hs-varid'>w</span><span class='hs-layout'>)</span> <span class='hs-keyglyph'>=</span> <span class='hs-conid'>Just</span> <span class='hs-varop'>$!</span> <span class='hs-varid'>f</span> <span class='hs-varid'>v</span> <span class='hs-varid'>w</span>
<a name="line-118"></a>
<a name="line-119"></a>
<a name="line-120"></a><a name="fromListWithL"></a><span class='hs-comment'>-- | A left-fold variant of 'fromListWith'. Note that the arguments</span>
<a name="line-121"></a><span class='hs-comment'>-- to the combining function are swapped: the first is the value</span>
<a name="line-122"></a><span class='hs-comment'>-- in the trie which has been accumulated from the initial part of</span>
<a name="line-123"></a><span class='hs-comment'>-- the list; the second argument is the ``new'' value from the</span>
<a name="line-124"></a><span class='hs-comment'>-- remaining tail of the list (just like the first argument to</span>
<a name="line-125"></a><span class='hs-comment'>-- 'foldl'). Thus, @fromListL = fromListWithL const@.</span>
<a name="line-126"></a><span class='hs-definition'>fromListWithL</span> <span class='hs-keyglyph'>::</span> <span class='hs-layout'>(</span><span class='hs-varid'>a</span> <span class='hs-keyglyph'>-></span> <span class='hs-varid'>a</span> <span class='hs-keyglyph'>-></span> <span class='hs-varid'>a</span><span class='hs-layout'>)</span> <span class='hs-keyglyph'>-></span> <span class='hs-keyglyph'>[</span><span class='hs-layout'>(</span><span class='hs-conid'>ByteString</span><span class='hs-layout'>,</span><span class='hs-varid'>a</span><span class='hs-layout'>)</span><span class='hs-keyglyph'>]</span> <span class='hs-keyglyph'>-></span> <span class='hs-conid'>Trie</span> <span class='hs-varid'>a</span>
<a name="line-127"></a><span class='hs-comment'>{-# INLINE fromListWithL #-}</span>
<a name="line-128"></a><span class='hs-definition'>fromListWithL</span> <span class='hs-varid'>f</span> <span class='hs-keyglyph'>=</span> <span class='hs-varid'>foldl'</span> <span class='hs-layout'>(</span><span class='hs-varid'>flip</span> <span class='hs-varop'>.</span> <span class='hs-varid'>uncurry</span> <span class='hs-varop'>$</span> <span class='hs-varid'>alterBy</span> <span class='hs-varid'>flipG</span><span class='hs-layout'>)</span> <span class='hs-varid'>empty</span>
<a name="line-129"></a> <span class='hs-keyword'>where</span>
<a name="line-130"></a> <span class='hs-varid'>flipG</span> <span class='hs-keyword'>_</span> <span class='hs-varid'>v</span> <span class='hs-conid'>Nothing</span> <span class='hs-keyglyph'>=</span> <span class='hs-conid'>Just</span> <span class='hs-varid'>v</span>
<a name="line-131"></a> <span class='hs-varid'>flipG</span> <span class='hs-keyword'>_</span> <span class='hs-varid'>v</span> <span class='hs-layout'>(</span><span class='hs-conid'>Just</span> <span class='hs-varid'>w</span><span class='hs-layout'>)</span> <span class='hs-keyglyph'>=</span> <span class='hs-conid'>Just</span> <span class='hs-layout'>(</span><span class='hs-varid'>f</span> <span class='hs-varid'>w</span> <span class='hs-varid'>v</span><span class='hs-layout'>)</span>
<a name="line-132"></a>
<a name="line-133"></a>
<a name="line-134"></a><a name="fromListWithL'"></a><span class='hs-comment'>-- | A variant of 'fromListWithL' which applies the combining</span>
<a name="line-135"></a><span class='hs-comment'>-- function strictly.</span>
<a name="line-136"></a><span class='hs-definition'>fromListWithL'</span> <span class='hs-keyglyph'>::</span> <span class='hs-layout'>(</span><span class='hs-varid'>a</span> <span class='hs-keyglyph'>-></span> <span class='hs-varid'>a</span> <span class='hs-keyglyph'>-></span> <span class='hs-varid'>a</span><span class='hs-layout'>)</span> <span class='hs-keyglyph'>-></span> <span class='hs-keyglyph'>[</span><span class='hs-layout'>(</span><span class='hs-conid'>ByteString</span><span class='hs-layout'>,</span><span class='hs-varid'>a</span><span class='hs-layout'>)</span><span class='hs-keyglyph'>]</span> <span class='hs-keyglyph'>-></span> <span class='hs-conid'>Trie</span> <span class='hs-varid'>a</span>
<a name="line-137"></a><span class='hs-comment'>{-# INLINE fromListWithL' #-}</span>
<a name="line-138"></a><span class='hs-definition'>fromListWithL'</span> <span class='hs-varid'>f</span> <span class='hs-keyglyph'>=</span> <span class='hs-varid'>foldl'</span> <span class='hs-layout'>(</span><span class='hs-varid'>flip</span> <span class='hs-varop'>.</span> <span class='hs-varid'>uncurry</span> <span class='hs-varop'>$</span> <span class='hs-varid'>alterBy</span> <span class='hs-varid'>flipG'</span><span class='hs-layout'>)</span> <span class='hs-varid'>empty</span>
<a name="line-139"></a> <span class='hs-keyword'>where</span>
<a name="line-140"></a> <span class='hs-varid'>flipG'</span> <span class='hs-keyword'>_</span> <span class='hs-varid'>v</span> <span class='hs-conid'>Nothing</span> <span class='hs-keyglyph'>=</span> <span class='hs-conid'>Just</span> <span class='hs-varid'>v</span>
<a name="line-141"></a> <span class='hs-varid'>flipG'</span> <span class='hs-keyword'>_</span> <span class='hs-varid'>v</span> <span class='hs-layout'>(</span><span class='hs-conid'>Just</span> <span class='hs-varid'>w</span><span class='hs-layout'>)</span> <span class='hs-keyglyph'>=</span> <span class='hs-conid'>Just</span> <span class='hs-varop'>$!</span> <span class='hs-varid'>f</span> <span class='hs-varid'>w</span> <span class='hs-varid'>v</span>
<a name="line-142"></a>
<a name="line-143"></a><a name="lookupWithDefault"></a><span class='hs-comment'>----------------------------------------------------------------</span>
<a name="line-144"></a><span class='hs-comment'>-- | Lookup a key, returning a default value if it's not found.</span>
<a name="line-145"></a><span class='hs-definition'>lookupWithDefault</span> <span class='hs-keyglyph'>::</span> <span class='hs-varid'>a</span> <span class='hs-keyglyph'>-></span> <span class='hs-conid'>ByteString</span> <span class='hs-keyglyph'>-></span> <span class='hs-conid'>Trie</span> <span class='hs-varid'>a</span> <span class='hs-keyglyph'>-></span> <span class='hs-varid'>a</span>
<a name="line-146"></a><span class='hs-definition'>lookupWithDefault</span> <span class='hs-varid'>def</span> <span class='hs-keyglyph'>=</span> <span class='hs-varid'>lookupBy_</span> <span class='hs-varid'>f</span> <span class='hs-varid'>def</span> <span class='hs-layout'>(</span><span class='hs-varid'>const</span> <span class='hs-varid'>def</span><span class='hs-layout'>)</span>
<a name="line-147"></a> <span class='hs-keyword'>where</span>
<a name="line-148"></a> <span class='hs-varid'>f</span> <span class='hs-conid'>Nothing</span> <span class='hs-keyword'>_</span> <span class='hs-keyglyph'>=</span> <span class='hs-varid'>def</span>
<a name="line-149"></a> <span class='hs-varid'>f</span> <span class='hs-layout'>(</span><span class='hs-conid'>Just</span> <span class='hs-varid'>v</span><span class='hs-layout'>)</span> <span class='hs-keyword'>_</span> <span class='hs-keyglyph'>=</span> <span class='hs-varid'>v</span>
<a name="line-150"></a>
<a name="line-151"></a><span class='hs-comment'>----------------------------------------------------------------</span>
<a name="line-152"></a>
<a name="line-153"></a><a name="insertIfAbsent"></a><span class='hs-comment'>-- | Insert a new key, retaining old value on conflict.</span>
<a name="line-154"></a><span class='hs-definition'>insertIfAbsent</span> <span class='hs-keyglyph'>::</span> <span class='hs-conid'>ByteString</span> <span class='hs-keyglyph'>-></span> <span class='hs-varid'>a</span> <span class='hs-keyglyph'>-></span> <span class='hs-conid'>Trie</span> <span class='hs-varid'>a</span> <span class='hs-keyglyph'>-></span> <span class='hs-conid'>Trie</span> <span class='hs-varid'>a</span>
<a name="line-155"></a><span class='hs-definition'>insertIfAbsent</span> <span class='hs-keyglyph'>=</span>
<a name="line-156"></a> <span class='hs-varid'>alterBy</span> <span class='hs-varop'>$</span> <span class='hs-keyglyph'>\</span><span class='hs-keyword'>_</span> <span class='hs-varid'>x</span> <span class='hs-varid'>mv</span> <span class='hs-keyglyph'>-></span>
<a name="line-157"></a> <span class='hs-keyword'>case</span> <span class='hs-varid'>mv</span> <span class='hs-keyword'>of</span>
<a name="line-158"></a> <span class='hs-conid'>Nothing</span> <span class='hs-keyglyph'>-></span> <span class='hs-conid'>Just</span> <span class='hs-varid'>x</span>
<a name="line-159"></a> <span class='hs-conid'>Just</span> <span class='hs-keyword'>_</span> <span class='hs-keyglyph'>-></span> <span class='hs-varid'>mv</span>
<a name="line-160"></a>
<a name="line-161"></a><a name="insertWith"></a><span class='hs-comment'>-- | Insert a new key, with a function to resolve conflicts.</span>
<a name="line-162"></a><span class='hs-definition'>insertWith</span> <span class='hs-keyglyph'>::</span> <span class='hs-layout'>(</span><span class='hs-varid'>a</span> <span class='hs-keyglyph'>-></span> <span class='hs-varid'>a</span> <span class='hs-keyglyph'>-></span> <span class='hs-varid'>a</span><span class='hs-layout'>)</span> <span class='hs-keyglyph'>-></span> <span class='hs-conid'>ByteString</span> <span class='hs-keyglyph'>-></span> <span class='hs-varid'>a</span> <span class='hs-keyglyph'>-></span> <span class='hs-conid'>Trie</span> <span class='hs-varid'>a</span> <span class='hs-keyglyph'>-></span> <span class='hs-conid'>Trie</span> <span class='hs-varid'>a</span>
<a name="line-163"></a><span class='hs-definition'>insertWith</span> <span class='hs-varid'>f</span> <span class='hs-keyglyph'>=</span>
<a name="line-164"></a> <span class='hs-varid'>alterBy</span> <span class='hs-varop'>$</span> <span class='hs-keyglyph'>\</span><span class='hs-keyword'>_</span> <span class='hs-varid'>x</span> <span class='hs-varid'>mv</span> <span class='hs-keyglyph'>-></span>
<a name="line-165"></a> <span class='hs-keyword'>case</span> <span class='hs-varid'>mv</span> <span class='hs-keyword'>of</span>
<a name="line-166"></a> <span class='hs-conid'>Nothing</span> <span class='hs-keyglyph'>-></span> <span class='hs-conid'>Just</span> <span class='hs-varid'>x</span>
<a name="line-167"></a> <span class='hs-conid'>Just</span> <span class='hs-varid'>v</span> <span class='hs-keyglyph'>-></span> <span class='hs-conid'>Just</span> <span class='hs-layout'>(</span><span class='hs-varid'>f</span> <span class='hs-varid'>x</span> <span class='hs-varid'>v</span><span class='hs-layout'>)</span>
<a name="line-168"></a>
<a name="line-169"></a><a name="insertWith'"></a><span class='hs-comment'>-- | A variant of 'insertWith' which applies the combining function</span>
<a name="line-170"></a><span class='hs-comment'>-- strictly.</span>
<a name="line-171"></a><span class='hs-definition'>insertWith'</span> <span class='hs-keyglyph'>::</span> <span class='hs-layout'>(</span><span class='hs-varid'>a</span> <span class='hs-keyglyph'>-></span> <span class='hs-varid'>a</span> <span class='hs-keyglyph'>-></span> <span class='hs-varid'>a</span><span class='hs-layout'>)</span> <span class='hs-keyglyph'>-></span> <span class='hs-conid'>ByteString</span> <span class='hs-keyglyph'>-></span> <span class='hs-varid'>a</span> <span class='hs-keyglyph'>-></span> <span class='hs-conid'>Trie</span> <span class='hs-varid'>a</span> <span class='hs-keyglyph'>-></span> <span class='hs-conid'>Trie</span> <span class='hs-varid'>a</span>
<a name="line-172"></a><span class='hs-definition'>insertWith'</span> <span class='hs-varid'>f</span> <span class='hs-keyglyph'>=</span>
<a name="line-173"></a> <span class='hs-varid'>alterBy</span> <span class='hs-varop'>$</span> <span class='hs-keyglyph'>\</span><span class='hs-keyword'>_</span> <span class='hs-varid'>x</span> <span class='hs-varid'>mv</span> <span class='hs-keyglyph'>-></span>
<a name="line-174"></a> <span class='hs-keyword'>case</span> <span class='hs-varid'>mv</span> <span class='hs-keyword'>of</span>
<a name="line-175"></a> <span class='hs-conid'>Nothing</span> <span class='hs-keyglyph'>-></span> <span class='hs-conid'>Just</span> <span class='hs-varid'>x</span>
<a name="line-176"></a> <span class='hs-conid'>Just</span> <span class='hs-varid'>v</span> <span class='hs-keyglyph'>-></span> <span class='hs-conid'>Just</span> <span class='hs-varop'>$!</span> <span class='hs-varid'>f</span> <span class='hs-varid'>x</span> <span class='hs-varid'>v</span>
<a name="line-177"></a>
<a name="line-178"></a><a name="insertWithKey"></a><span class='hs-comment'>-- | A variant of 'insertWith' which also provides the key to the</span>
<a name="line-179"></a><span class='hs-comment'>-- combining function.</span>
<a name="line-180"></a><span class='hs-definition'>insertWithKey</span> <span class='hs-keyglyph'>::</span> <span class='hs-layout'>(</span><span class='hs-conid'>ByteString</span> <span class='hs-keyglyph'>-></span> <span class='hs-varid'>a</span> <span class='hs-keyglyph'>-></span> <span class='hs-varid'>a</span> <span class='hs-keyglyph'>-></span> <span class='hs-varid'>a</span><span class='hs-layout'>)</span> <span class='hs-keyglyph'>-></span> <span class='hs-conid'>ByteString</span> <span class='hs-keyglyph'>-></span> <span class='hs-varid'>a</span> <span class='hs-keyglyph'>-></span> <span class='hs-conid'>Trie</span> <span class='hs-varid'>a</span> <span class='hs-keyglyph'>-></span> <span class='hs-conid'>Trie</span> <span class='hs-varid'>a</span>
<a name="line-181"></a><span class='hs-definition'>insertWithKey</span> <span class='hs-varid'>f</span> <span class='hs-keyglyph'>=</span>
<a name="line-182"></a> <span class='hs-varid'>alterBy</span> <span class='hs-varop'>$</span> <span class='hs-keyglyph'>\</span><span class='hs-varid'>k</span> <span class='hs-varid'>x</span> <span class='hs-varid'>mv</span> <span class='hs-keyglyph'>-></span>
<a name="line-183"></a> <span class='hs-keyword'>case</span> <span class='hs-varid'>mv</span> <span class='hs-keyword'>of</span>
<a name="line-184"></a> <span class='hs-conid'>Nothing</span> <span class='hs-keyglyph'>-></span> <span class='hs-conid'>Just</span> <span class='hs-varid'>x</span>
<a name="line-185"></a> <span class='hs-conid'>Just</span> <span class='hs-varid'>v</span> <span class='hs-keyglyph'>-></span> <span class='hs-conid'>Just</span> <span class='hs-layout'>(</span><span class='hs-varid'>f</span> <span class='hs-varid'>k</span> <span class='hs-varid'>x</span> <span class='hs-varid'>v</span><span class='hs-layout'>)</span>
<a name="line-186"></a>
<a name="line-187"></a><a name="insertWithKey'"></a><span class='hs-comment'>-- | A variant of 'insertWithKey' which applies the combining</span>
<a name="line-188"></a><span class='hs-comment'>-- function strictly.</span>
<a name="line-189"></a><span class='hs-definition'>insertWithKey'</span> <span class='hs-keyglyph'>::</span> <span class='hs-layout'>(</span><span class='hs-conid'>ByteString</span> <span class='hs-keyglyph'>-></span> <span class='hs-varid'>a</span> <span class='hs-keyglyph'>-></span> <span class='hs-varid'>a</span> <span class='hs-keyglyph'>-></span> <span class='hs-varid'>a</span><span class='hs-layout'>)</span> <span class='hs-keyglyph'>-></span> <span class='hs-conid'>ByteString</span> <span class='hs-keyglyph'>-></span> <span class='hs-varid'>a</span> <span class='hs-keyglyph'>-></span> <span class='hs-conid'>Trie</span> <span class='hs-varid'>a</span> <span class='hs-keyglyph'>-></span> <span class='hs-conid'>Trie</span> <span class='hs-varid'>a</span>
<a name="line-190"></a><span class='hs-definition'>insertWithKey'</span> <span class='hs-varid'>f</span> <span class='hs-keyglyph'>=</span>
<a name="line-191"></a> <span class='hs-varid'>alterBy</span> <span class='hs-varop'>$</span> <span class='hs-keyglyph'>\</span><span class='hs-varid'>k</span> <span class='hs-varid'>x</span> <span class='hs-varid'>mv</span> <span class='hs-keyglyph'>-></span>
<a name="line-192"></a> <span class='hs-keyword'>case</span> <span class='hs-varid'>mv</span> <span class='hs-keyword'>of</span>
<a name="line-193"></a> <span class='hs-conid'>Nothing</span> <span class='hs-keyglyph'>-></span> <span class='hs-conid'>Just</span> <span class='hs-varid'>x</span>
<a name="line-194"></a> <span class='hs-conid'>Just</span> <span class='hs-varid'>v</span> <span class='hs-keyglyph'>-></span> <span class='hs-conid'>Just</span> <span class='hs-varop'>$!</span> <span class='hs-varid'>f</span> <span class='hs-varid'>k</span> <span class='hs-varid'>x</span> <span class='hs-varid'>v</span>
<a name="line-195"></a>
<a name="line-196"></a><span class='hs-comment'>{- This is a tricky one...
<a name="line-197"></a>insertLookupWithKey :: (ByteString -> a -> a -> a) -> ByteString -> a -> Trie a -> (Maybe a, Trie a)
<a name="line-198"></a>-}</span>
<a name="line-199"></a>
<a name="line-200"></a><a name="adjustWithKey"></a><span class='hs-comment'>----------------------------------------------------------------</span>
<a name="line-201"></a><span class='hs-comment'>-- | Apply a function to change the value at a key.</span>
<a name="line-202"></a><span class='hs-definition'>adjustWithKey</span> <span class='hs-keyglyph'>::</span> <span class='hs-layout'>(</span><span class='hs-conid'>ByteString</span> <span class='hs-keyglyph'>-></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'>ByteString</span> <span class='hs-keyglyph'>-></span> <span class='hs-conid'>Trie</span> <span class='hs-varid'>a</span> <span class='hs-keyglyph'>-></span> <span class='hs-conid'>Trie</span> <span class='hs-varid'>a</span>
<a name="line-203"></a><span class='hs-definition'>adjustWithKey</span> <span class='hs-varid'>f</span> <span class='hs-varid'>q</span> <span class='hs-keyglyph'>=</span>
<a name="line-204"></a> <span class='hs-varid'>adjustBy</span> <span class='hs-layout'>(</span><span class='hs-keyglyph'>\</span><span class='hs-varid'>k</span> <span class='hs-keyword'>_</span> <span class='hs-keyglyph'>-></span> <span class='hs-varid'>f</span> <span class='hs-varid'>k</span><span class='hs-layout'>)</span> <span class='hs-varid'>q</span> <span class='hs-layout'>(</span><span class='hs-varid'>impossible</span> <span class='hs-str'>"Convenience.adjustWithKey"</span><span class='hs-layout'>)</span>
<a name="line-205"></a><span class='hs-comment'>-- TODO: benchmark vs the definition with alterBy/liftM</span>
<a name="line-206"></a>
<a name="line-207"></a><a name="update"></a><span class='hs-comment'>-- | Apply a function to the value at a key, possibly removing it.</span>
<a name="line-208"></a><span class='hs-definition'>update</span> <span class='hs-keyglyph'>::</span> <span class='hs-layout'>(</span><span class='hs-varid'>a</span> <span class='hs-keyglyph'>-></span> <span class='hs-conid'>Maybe</span> <span class='hs-varid'>a</span><span class='hs-layout'>)</span> <span class='hs-keyglyph'>-></span> <span class='hs-conid'>ByteString</span> <span class='hs-keyglyph'>-></span> <span class='hs-conid'>Trie</span> <span class='hs-varid'>a</span> <span class='hs-keyglyph'>-></span> <span class='hs-conid'>Trie</span> <span class='hs-varid'>a</span>
<a name="line-209"></a><span class='hs-definition'>update</span> <span class='hs-varid'>f</span> <span class='hs-varid'>q</span> <span class='hs-keyglyph'>=</span>
<a name="line-210"></a> <span class='hs-varid'>alterBy</span> <span class='hs-layout'>(</span><span class='hs-keyglyph'>\</span><span class='hs-keyword'>_</span> <span class='hs-keyword'>_</span> <span class='hs-varid'>mx</span> <span class='hs-keyglyph'>-></span> <span class='hs-varid'>mx</span> <span class='hs-varop'>>>=</span> <span class='hs-varid'>f</span><span class='hs-layout'>)</span> <span class='hs-varid'>q</span> <span class='hs-layout'>(</span><span class='hs-varid'>impossible</span> <span class='hs-str'>"Convenience.update"</span><span class='hs-layout'>)</span>
<a name="line-211"></a>
<a name="line-212"></a><a name="updateWithKey"></a><span class='hs-comment'>-- | A variant of 'update' which also provides the key to the function.</span>
<a name="line-213"></a><span class='hs-definition'>updateWithKey</span> <span class='hs-keyglyph'>::</span> <span class='hs-layout'>(</span><span class='hs-conid'>ByteString</span> <span class='hs-keyglyph'>-></span> <span class='hs-varid'>a</span> <span class='hs-keyglyph'>-></span> <span class='hs-conid'>Maybe</span> <span class='hs-varid'>a</span><span class='hs-layout'>)</span> <span class='hs-keyglyph'>-></span> <span class='hs-conid'>ByteString</span> <span class='hs-keyglyph'>-></span> <span class='hs-conid'>Trie</span> <span class='hs-varid'>a</span> <span class='hs-keyglyph'>-></span> <span class='hs-conid'>Trie</span> <span class='hs-varid'>a</span>
<a name="line-214"></a><span class='hs-definition'>updateWithKey</span> <span class='hs-varid'>f</span> <span class='hs-varid'>q</span> <span class='hs-keyglyph'>=</span>
<a name="line-215"></a> <span class='hs-varid'>alterBy</span> <span class='hs-layout'>(</span><span class='hs-keyglyph'>\</span><span class='hs-varid'>k</span> <span class='hs-keyword'>_</span> <span class='hs-varid'>mx</span> <span class='hs-keyglyph'>-></span> <span class='hs-varid'>mx</span> <span class='hs-varop'>>>=</span> <span class='hs-varid'>f</span> <span class='hs-varid'>k</span><span class='hs-layout'>)</span> <span class='hs-varid'>q</span> <span class='hs-layout'>(</span><span class='hs-varid'>impossible</span> <span class='hs-str'>"Convenience.updateWithKey"</span><span class='hs-layout'>)</span>
<a name="line-216"></a>
<a name="line-217"></a><span class='hs-comment'>{-
<a name="line-218"></a>updateLookupWithKey :: (ByteString -> a -> Maybe a) -> ByteString -> Trie a -> (Maybe a, Trie a)
<a name="line-219"></a>-- Also tricky
<a name="line-220"></a>-}</span>
<a name="line-221"></a>
<a name="line-222"></a><span class='hs-comment'>----------------------------------------------------------------</span>
<a name="line-223"></a>
<a name="line-224"></a><a name="disunion"></a><span class='hs-comment'>-- | Combine two tries, a la symmetric difference. If they define</span>
<a name="line-225"></a><span class='hs-comment'>-- the same key, it is removed; otherwise it is retained with the</span>
<a name="line-226"></a><span class='hs-comment'>-- value it has in whichever trie.</span>
<a name="line-227"></a><span class='hs-definition'>disunion</span> <span class='hs-keyglyph'>::</span> <span class='hs-conid'>Trie</span> <span class='hs-varid'>a</span> <span class='hs-keyglyph'>-></span> <span class='hs-conid'>Trie</span> <span class='hs-varid'>a</span> <span class='hs-keyglyph'>-></span> <span class='hs-conid'>Trie</span> <span class='hs-varid'>a</span>
<a name="line-228"></a><span class='hs-definition'>disunion</span> <span class='hs-keyglyph'>=</span> <span class='hs-varid'>mergeBy</span> <span class='hs-layout'>(</span><span class='hs-keyglyph'>\</span><span class='hs-keyword'>_</span> <span class='hs-keyword'>_</span> <span class='hs-keyglyph'>-></span> <span class='hs-conid'>Nothing</span><span class='hs-layout'>)</span>
<a name="line-229"></a>
<a name="line-230"></a><a name="unionWith"></a><span class='hs-comment'>-- | Combine two tries, using a function to resolve conflicts.</span>
<a name="line-231"></a><span class='hs-definition'>unionWith</span> <span class='hs-keyglyph'>::</span> <span class='hs-layout'>(</span><span class='hs-varid'>a</span> <span class='hs-keyglyph'>-></span> <span class='hs-varid'>a</span> <span class='hs-keyglyph'>-></span> <span class='hs-varid'>a</span><span class='hs-layout'>)</span> <span class='hs-keyglyph'>-></span> <span class='hs-conid'>Trie</span> <span class='hs-varid'>a</span> <span class='hs-keyglyph'>-></span> <span class='hs-conid'>Trie</span> <span class='hs-varid'>a</span> <span class='hs-keyglyph'>-></span> <span class='hs-conid'>Trie</span> <span class='hs-varid'>a</span>
<a name="line-232"></a><span class='hs-definition'>unionWith</span> <span class='hs-varid'>f</span> <span class='hs-keyglyph'>=</span> <span class='hs-varid'>mergeBy</span> <span class='hs-layout'>(</span><span class='hs-keyglyph'>\</span><span class='hs-varid'>x</span> <span class='hs-varid'>y</span> <span class='hs-keyglyph'>-></span> <span class='hs-conid'>Just</span> <span class='hs-layout'>(</span><span class='hs-varid'>f</span> <span class='hs-varid'>x</span> <span class='hs-varid'>y</span><span class='hs-layout'>)</span><span class='hs-layout'>)</span>
<a name="line-233"></a>
<a name="line-234"></a><a name="unionWith'"></a><span class='hs-comment'>-- | A variant of 'unionWith' which applies the combining function</span>
<a name="line-235"></a><span class='hs-comment'>-- strictly.</span>
<a name="line-236"></a><span class='hs-definition'>unionWith'</span> <span class='hs-keyglyph'>::</span> <span class='hs-layout'>(</span><span class='hs-varid'>a</span> <span class='hs-keyglyph'>-></span> <span class='hs-varid'>a</span> <span class='hs-keyglyph'>-></span> <span class='hs-varid'>a</span><span class='hs-layout'>)</span> <span class='hs-keyglyph'>-></span> <span class='hs-conid'>Trie</span> <span class='hs-varid'>a</span> <span class='hs-keyglyph'>-></span> <span class='hs-conid'>Trie</span> <span class='hs-varid'>a</span> <span class='hs-keyglyph'>-></span> <span class='hs-conid'>Trie</span> <span class='hs-varid'>a</span>
<a name="line-237"></a><span class='hs-definition'>unionWith'</span> <span class='hs-varid'>f</span> <span class='hs-keyglyph'>=</span> <span class='hs-varid'>mergeBy</span> <span class='hs-layout'>(</span><span class='hs-keyglyph'>\</span><span class='hs-varid'>x</span> <span class='hs-varid'>y</span> <span class='hs-keyglyph'>-></span> <span class='hs-conid'>Just</span> <span class='hs-varop'>$!</span> <span class='hs-varid'>f</span> <span class='hs-varid'>x</span> <span class='hs-varid'>y</span><span class='hs-layout'>)</span>
<a name="line-238"></a>
<a name="line-239"></a><span class='hs-comment'>{- TODO: (efficiently)
<a name="line-240"></a>difference, intersection
<a name="line-241"></a>-}</span>
<a name="line-242"></a>
<a name="line-243"></a><span class='hs-comment'>----------------------------------------------------------------</span>
<a name="line-244"></a><span class='hs-comment'>----------------------------------------------------------- fin.</span>
</pre></body>
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