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<pre><a name="line-1"></a><span class='hs-comment'>{-# LANGUAGE PatternGuards #-}</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 : XMonad.Util.Stack</span>
<a name="line-6"></a><span class='hs-comment'>-- Copyright : Quentin Moser <moserq@gmail.com></span>
<a name="line-7"></a><span class='hs-comment'>-- License : BSD-style (see LICENSE)</span>
<a name="line-8"></a><span class='hs-comment'>--</span>
<a name="line-9"></a><span class='hs-comment'>-- Maintainer : orphaned</span>
<a name="line-10"></a><span class='hs-comment'>-- Stability : unstable</span>
<a name="line-11"></a><span class='hs-comment'>-- Portability : unportable</span>
<a name="line-12"></a><span class='hs-comment'>--</span>
<a name="line-13"></a><span class='hs-comment'>-- Utility functions for manipulating @Maybe Stack@s.</span>
<a name="line-14"></a><span class='hs-comment'>--</span>
<a name="line-15"></a><span class='hs-comment'>-----------------------------------------------------------------------------</span>
<a name="line-16"></a>
<a name="line-17"></a><span class='hs-keyword'>module</span> <span class='hs-conid'>XMonad</span><span class='hs-varop'>.</span><span class='hs-conid'>Util</span><span class='hs-varop'>.</span><span class='hs-conid'>Stack</span> <span class='hs-layout'>(</span> <span class='hs-comment'>-- * Usage</span>
<a name="line-18"></a> <span class='hs-comment'>-- | This is a developer-oriented module, intended to be used</span>
<a name="line-19"></a> <span class='hs-comment'>-- for writing new extentions.</span>
<a name="line-20"></a> <span class='hs-conid'>Zipper</span>
<a name="line-21"></a> <span class='hs-layout'>,</span> <span class='hs-varid'>emptyZ</span>
<a name="line-22"></a> <span class='hs-layout'>,</span> <span class='hs-varid'>singletonZ</span>
<a name="line-23"></a>
<a name="line-24"></a> <span class='hs-comment'>-- * Conversions</span>
<a name="line-25"></a> <span class='hs-layout'>,</span> <span class='hs-varid'>fromIndex</span>
<a name="line-26"></a> <span class='hs-layout'>,</span> <span class='hs-varid'>toIndex</span>
<a name="line-27"></a> <span class='hs-layout'>,</span> <span class='hs-varid'>fromTags</span>
<a name="line-28"></a> <span class='hs-layout'>,</span> <span class='hs-varid'>toTags</span>
<a name="line-29"></a>
<a name="line-30"></a> <span class='hs-comment'>-- * 'Zipper' manipulation functions</span>
<a name="line-31"></a> <span class='hs-comment'>-- ** Insertion, movement</span>
<a name="line-32"></a> <span class='hs-layout'>,</span> <span class='hs-varid'>insertUpZ</span>
<a name="line-33"></a> <span class='hs-layout'>,</span> <span class='hs-varid'>insertDownZ</span>
<a name="line-34"></a> <span class='hs-layout'>,</span> <span class='hs-varid'>swapUpZ</span>
<a name="line-35"></a> <span class='hs-layout'>,</span> <span class='hs-varid'>swapDownZ</span>
<a name="line-36"></a> <span class='hs-layout'>,</span> <span class='hs-varid'>swapMasterZ</span>
<a name="line-37"></a> <span class='hs-comment'>-- ** Focus movement</span>
<a name="line-38"></a> <span class='hs-layout'>,</span> <span class='hs-varid'>focusUpZ</span>
<a name="line-39"></a> <span class='hs-layout'>,</span> <span class='hs-varid'>focusDownZ</span>
<a name="line-40"></a> <span class='hs-layout'>,</span> <span class='hs-varid'>focusMasterZ</span>
<a name="line-41"></a> <span class='hs-comment'>-- ** Extraction</span>
<a name="line-42"></a> <span class='hs-layout'>,</span> <span class='hs-varid'>getFocusZ</span>
<a name="line-43"></a> <span class='hs-layout'>,</span> <span class='hs-varid'>getIZ</span>
<a name="line-44"></a> <span class='hs-comment'>-- ** Sorting</span>
<a name="line-45"></a> <span class='hs-layout'>,</span> <span class='hs-varid'>sortZ</span>
<a name="line-46"></a> <span class='hs-layout'>,</span> <span class='hs-varid'>sortByZ</span>
<a name="line-47"></a> <span class='hs-comment'>-- ** Maps</span>
<a name="line-48"></a> <span class='hs-layout'>,</span> <span class='hs-varid'>mapZ</span>
<a name="line-49"></a> <span class='hs-layout'>,</span> <span class='hs-varid'>mapZ_</span>
<a name="line-50"></a> <span class='hs-layout'>,</span> <span class='hs-varid'>mapZM</span>
<a name="line-51"></a> <span class='hs-layout'>,</span> <span class='hs-varid'>mapZM_</span>
<a name="line-52"></a> <span class='hs-layout'>,</span> <span class='hs-varid'>onFocusedZ</span>
<a name="line-53"></a> <span class='hs-layout'>,</span> <span class='hs-varid'>onFocusedZM</span>
<a name="line-54"></a> <span class='hs-layout'>,</span> <span class='hs-varid'>onIndexZ</span>
<a name="line-55"></a> <span class='hs-layout'>,</span> <span class='hs-varid'>onIndexZM</span>
<a name="line-56"></a> <span class='hs-comment'>-- ** Filters</span>
<a name="line-57"></a> <span class='hs-layout'>,</span> <span class='hs-varid'>filterZ</span>
<a name="line-58"></a> <span class='hs-layout'>,</span> <span class='hs-varid'>filterZ_</span>
<a name="line-59"></a> <span class='hs-layout'>,</span> <span class='hs-varid'>deleteFocusedZ</span>
<a name="line-60"></a> <span class='hs-layout'>,</span> <span class='hs-varid'>deleteIndexZ</span>
<a name="line-61"></a> <span class='hs-comment'>-- ** Folds</span>
<a name="line-62"></a> <span class='hs-layout'>,</span> <span class='hs-varid'>foldrZ</span>
<a name="line-63"></a> <span class='hs-layout'>,</span> <span class='hs-varid'>foldlZ</span>
<a name="line-64"></a> <span class='hs-layout'>,</span> <span class='hs-varid'>foldrZ_</span>
<a name="line-65"></a> <span class='hs-layout'>,</span> <span class='hs-varid'>foldlZ_</span>
<a name="line-66"></a> <span class='hs-layout'>,</span> <span class='hs-varid'>elemZ</span>
<a name="line-67"></a>
<a name="line-68"></a> <span class='hs-comment'>-- * Other utility functions</span>
<a name="line-69"></a> <span class='hs-layout'>,</span> <span class='hs-varid'>getI</span>
<a name="line-70"></a> <span class='hs-layout'>,</span> <span class='hs-varid'>tagBy</span>
<a name="line-71"></a> <span class='hs-layout'>,</span> <span class='hs-varid'>fromE</span>
<a name="line-72"></a> <span class='hs-layout'>,</span> <span class='hs-varid'>mapE</span>
<a name="line-73"></a> <span class='hs-layout'>,</span> <span class='hs-varid'>mapE_</span>
<a name="line-74"></a> <span class='hs-layout'>,</span> <span class='hs-varid'>mapEM</span>
<a name="line-75"></a> <span class='hs-layout'>,</span> <span class='hs-varid'>mapEM_</span>
<a name="line-76"></a> <span class='hs-layout'>)</span> <span class='hs-keyword'>where</span>
<a name="line-77"></a>
<a name="line-78"></a><span class='hs-keyword'>import</span> <span class='hs-keyword'>qualified</span> <span class='hs-conid'>XMonad</span><span class='hs-varop'>.</span><span class='hs-conid'>StackSet</span> <span class='hs-keyword'>as</span> <span class='hs-conid'>W</span>
<a name="line-79"></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'>liftM</span><span class='hs-layout'>)</span>
<a name="line-80"></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'>sortBy</span><span class='hs-layout'>)</span>
<a name="line-81"></a>
<a name="line-82"></a>
<a name="line-83"></a>
<a name="line-84"></a><a name="Zipper"></a><span class='hs-keyword'>type</span> <span class='hs-conid'>Zipper</span> <span class='hs-varid'>a</span> <span class='hs-keyglyph'>=</span> <span class='hs-conid'>Maybe</span> <span class='hs-layout'>(</span><span class='hs-conid'>W</span><span class='hs-varop'>.</span><span class='hs-conid'>Stack</span> <span class='hs-varid'>a</span><span class='hs-layout'>)</span>
<a name="line-85"></a>
<a name="line-86"></a><a name="emptyZ"></a><span class='hs-definition'>emptyZ</span> <span class='hs-keyglyph'>::</span> <span class='hs-conid'>Zipper</span> <span class='hs-varid'>a</span>
<a name="line-87"></a><span class='hs-definition'>emptyZ</span> <span class='hs-keyglyph'>=</span> <span class='hs-conid'>Nothing</span>
<a name="line-88"></a>
<a name="line-89"></a><a name="singletonZ"></a><span class='hs-definition'>singletonZ</span> <span class='hs-keyglyph'>::</span> <span class='hs-varid'>a</span> <span class='hs-keyglyph'>-></span> <span class='hs-conid'>Zipper</span> <span class='hs-varid'>a</span>
<a name="line-90"></a><span class='hs-definition'>singletonZ</span> <span class='hs-varid'>a</span> <span class='hs-keyglyph'>=</span> <span class='hs-conid'>Just</span> <span class='hs-varop'>$</span> <span class='hs-conid'>W</span><span class='hs-varop'>.</span><span class='hs-conid'>Stack</span> <span class='hs-varid'>a</span> <span class='hs-conid'>[]</span> <span class='hs-conid'>[]</span>
<a name="line-91"></a>
<a name="line-92"></a><span class='hs-comment'>-- * Conversions</span>
<a name="line-93"></a>
<a name="line-94"></a><a name="fromIndex"></a><span class='hs-comment'>-- | Create a stack from a list, and the 0-based index of the focused element.</span>
<a name="line-95"></a><span class='hs-comment'>-- If the index is out of bounds, focus will go to the first element.</span>
<a name="line-96"></a><span class='hs-definition'>fromIndex</span> <span class='hs-keyglyph'>::</span> <span class='hs-keyglyph'>[</span><span class='hs-varid'>a</span><span class='hs-keyglyph'>]</span> <span class='hs-keyglyph'>-></span> <span class='hs-conid'>Int</span> <span class='hs-keyglyph'>-></span> <span class='hs-conid'>Zipper</span> <span class='hs-varid'>a</span>
<a name="line-97"></a><span class='hs-definition'>fromIndex</span> <span class='hs-keyword'>as</span> <span class='hs-varid'>i</span> <span class='hs-keyglyph'>=</span> <span class='hs-varid'>fromTags</span> <span class='hs-varop'>$</span> <span class='hs-varid'>zipWith</span> <span class='hs-layout'>(</span><span class='hs-varop'>$</span><span class='hs-layout'>)</span> <span class='hs-layout'>(</span><span class='hs-varid'>replicate</span> <span class='hs-varid'>i</span> <span class='hs-conid'>Left</span> <span class='hs-varop'>++</span> <span class='hs-keyglyph'>[</span><span class='hs-conid'>Right</span><span class='hs-keyglyph'>]</span> <span class='hs-varop'>++</span> <span class='hs-varid'>repeat</span> <span class='hs-conid'>Left</span><span class='hs-layout'>)</span> <span class='hs-keyword'>as</span>
<a name="line-98"></a>
<a name="line-99"></a><a name="toIndex"></a><span class='hs-comment'>-- | Turn a stack into a list and the index of its focused element.</span>
<a name="line-100"></a><span class='hs-definition'>toIndex</span> <span class='hs-keyglyph'>::</span> <span class='hs-conid'>Zipper</span> <span class='hs-varid'>a</span> <span class='hs-keyglyph'>-></span> <span class='hs-layout'>(</span><span class='hs-keyglyph'>[</span><span class='hs-varid'>a</span><span class='hs-keyglyph'>]</span><span class='hs-layout'>,</span> <span class='hs-conid'>Maybe</span> <span class='hs-conid'>Int</span><span class='hs-layout'>)</span>
<a name="line-101"></a><span class='hs-definition'>toIndex</span> <span class='hs-conid'>Nothing</span> <span class='hs-keyglyph'>=</span> <span class='hs-layout'>(</span><span class='hs-conid'>[]</span><span class='hs-layout'>,</span> <span class='hs-conid'>Nothing</span><span class='hs-layout'>)</span>
<a name="line-102"></a><span class='hs-definition'>toIndex</span> <span class='hs-layout'>(</span><span class='hs-conid'>Just</span> <span class='hs-varid'>s</span><span class='hs-layout'>)</span> <span class='hs-keyglyph'>=</span> <span class='hs-layout'>(</span><span class='hs-conid'>W</span><span class='hs-varop'>.</span><span class='hs-varid'>integrate</span> <span class='hs-varid'>s</span><span class='hs-layout'>,</span> <span class='hs-conid'>Just</span> <span class='hs-varop'>$</span> <span class='hs-varid'>length</span> <span class='hs-varop'>$</span> <span class='hs-conid'>W</span><span class='hs-varop'>.</span><span class='hs-varid'>up</span> <span class='hs-varid'>s</span><span class='hs-layout'>)</span>
<a name="line-103"></a>
<a name="line-104"></a><a name="fromTags"></a><span class='hs-comment'>-- | Create a stack from a list of 'Either'-tagged values. Focus will go to</span>
<a name="line-105"></a><span class='hs-comment'>-- the first 'Right' value, or if there is none, to the first 'Left' one.</span>
<a name="line-106"></a><span class='hs-definition'>fromTags</span> <span class='hs-keyglyph'>::</span> <span class='hs-keyglyph'>[</span><span class='hs-conid'>Either</span> <span class='hs-varid'>a</span> <span class='hs-varid'>a</span><span class='hs-keyglyph'>]</span> <span class='hs-keyglyph'>-></span> <span class='hs-conid'>Zipper</span> <span class='hs-varid'>a</span>
<a name="line-107"></a><span class='hs-definition'>fromTags</span> <span class='hs-keyglyph'>=</span> <span class='hs-varid'>finalize</span> <span class='hs-varop'>.</span> <span class='hs-varid'>foldr</span> <span class='hs-varid'>step</span> <span class='hs-layout'>(</span><span class='hs-conid'>[]</span><span class='hs-layout'>,</span> <span class='hs-conid'>Nothing</span><span class='hs-layout'>,</span> <span class='hs-conid'>[]</span><span class='hs-layout'>)</span>
<a name="line-108"></a> <span class='hs-keyword'>where</span> <span class='hs-varid'>step</span> <span class='hs-layout'>(</span><span class='hs-conid'>Right</span> <span class='hs-varid'>a</span><span class='hs-layout'>)</span> <span class='hs-layout'>(</span><span class='hs-varid'>u</span><span class='hs-layout'>,</span> <span class='hs-conid'>Just</span> <span class='hs-varid'>f</span><span class='hs-layout'>,</span> <span class='hs-varid'>d</span><span class='hs-layout'>)</span> <span class='hs-keyglyph'>=</span> <span class='hs-layout'>(</span><span class='hs-conid'>[]</span><span class='hs-layout'>,</span> <span class='hs-conid'>Just</span> <span class='hs-varid'>a</span><span class='hs-layout'>,</span> <span class='hs-varid'>u</span><span class='hs-varop'>++</span><span class='hs-varid'>f</span><span class='hs-conop'>:</span><span class='hs-varid'>d</span><span class='hs-layout'>)</span>
<a name="line-109"></a> <span class='hs-varid'>step</span> <span class='hs-layout'>(</span><span class='hs-conid'>Right</span> <span class='hs-varid'>a</span><span class='hs-layout'>)</span> <span class='hs-layout'>(</span><span class='hs-varid'>u</span><span class='hs-layout'>,</span> <span class='hs-conid'>Nothing</span><span class='hs-layout'>,</span> <span class='hs-varid'>d</span><span class='hs-layout'>)</span> <span class='hs-keyglyph'>=</span> <span class='hs-layout'>(</span><span class='hs-varid'>u</span><span class='hs-layout'>,</span> <span class='hs-conid'>Just</span> <span class='hs-varid'>a</span><span class='hs-layout'>,</span> <span class='hs-varid'>d</span><span class='hs-layout'>)</span>
<a name="line-110"></a> <span class='hs-varid'>step</span> <span class='hs-layout'>(</span><span class='hs-conid'>Left</span> <span class='hs-varid'>a</span><span class='hs-layout'>)</span> <span class='hs-layout'>(</span><span class='hs-varid'>u</span><span class='hs-layout'>,</span> <span class='hs-conid'>Just</span> <span class='hs-varid'>f</span><span class='hs-layout'>,</span> <span class='hs-varid'>d</span><span class='hs-layout'>)</span> <span class='hs-keyglyph'>=</span> <span class='hs-layout'>(</span><span class='hs-varid'>a</span><span class='hs-conop'>:</span><span class='hs-varid'>u</span><span class='hs-layout'>,</span> <span class='hs-conid'>Just</span> <span class='hs-varid'>f</span><span class='hs-layout'>,</span> <span class='hs-varid'>d</span><span class='hs-layout'>)</span>
<a name="line-111"></a> <span class='hs-varid'>step</span> <span class='hs-layout'>(</span><span class='hs-conid'>Left</span> <span class='hs-varid'>a</span><span class='hs-layout'>)</span> <span class='hs-layout'>(</span><span class='hs-varid'>u</span><span class='hs-layout'>,</span> <span class='hs-conid'>Nothing</span><span class='hs-layout'>,</span> <span class='hs-varid'>d</span><span class='hs-layout'>)</span> <span class='hs-keyglyph'>=</span> <span class='hs-layout'>(</span><span class='hs-varid'>u</span><span class='hs-layout'>,</span> <span class='hs-conid'>Nothing</span><span class='hs-layout'>,</span> <span class='hs-varid'>a</span><span class='hs-conop'>:</span><span class='hs-varid'>d</span><span class='hs-layout'>)</span>
<a name="line-112"></a> <span class='hs-varid'>finalize</span> <span class='hs-layout'>(</span><span class='hs-varid'>u</span><span class='hs-layout'>,</span> <span class='hs-conid'>Just</span> <span class='hs-varid'>f</span><span class='hs-layout'>,</span> <span class='hs-varid'>d</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-conid'>W</span><span class='hs-varop'>.</span><span class='hs-conid'>Stack</span> <span class='hs-varid'>f</span> <span class='hs-layout'>(</span><span class='hs-varid'>reverse</span> <span class='hs-varid'>u</span><span class='hs-layout'>)</span> <span class='hs-varid'>d</span>
<a name="line-113"></a> <span class='hs-varid'>finalize</span> <span class='hs-layout'>(</span><span class='hs-varid'>u</span><span class='hs-layout'>,</span> <span class='hs-conid'>Nothing</span><span class='hs-layout'>,</span> <span class='hs-varid'>a</span><span class='hs-conop'>:</span><span class='hs-varid'>d</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-conid'>W</span><span class='hs-varop'>.</span><span class='hs-conid'>Stack</span> <span class='hs-varid'>a</span> <span class='hs-layout'>(</span><span class='hs-varid'>reverse</span> <span class='hs-varid'>u</span><span class='hs-layout'>)</span> <span class='hs-varid'>d</span>
<a name="line-114"></a> <span class='hs-varid'>finalize</span> <span class='hs-layout'>(</span><span class='hs-keyword'>_</span><span class='hs-layout'>,</span> <span class='hs-conid'>Nothing</span><span class='hs-layout'>,</span> <span class='hs-conid'>[]</span><span class='hs-layout'>)</span> <span class='hs-keyglyph'>=</span> <span class='hs-conid'>Nothing</span>
<a name="line-115"></a>
<a name="line-116"></a><a name="toTags"></a><span class='hs-comment'>-- | Turn a stack into an 'Either'-tagged list. The focused element</span>
<a name="line-117"></a><span class='hs-comment'>-- will be tagged with 'Right', the others with 'Left'.</span>
<a name="line-118"></a><span class='hs-definition'>toTags</span> <span class='hs-keyglyph'>::</span> <span class='hs-conid'>Zipper</span> <span class='hs-varid'>a</span> <span class='hs-keyglyph'>-></span> <span class='hs-keyglyph'>[</span><span class='hs-conid'>Either</span> <span class='hs-varid'>a</span> <span class='hs-varid'>a</span><span class='hs-keyglyph'>]</span>
<a name="line-119"></a><span class='hs-definition'>toTags</span> <span class='hs-conid'>Nothing</span> <span class='hs-keyglyph'>=</span> <span class='hs-conid'>[]</span>
<a name="line-120"></a><span class='hs-definition'>toTags</span> <span class='hs-layout'>(</span><span class='hs-conid'>Just</span> <span class='hs-varid'>s</span><span class='hs-layout'>)</span> <span class='hs-keyglyph'>=</span> <span class='hs-varid'>map</span> <span class='hs-conid'>Left</span> <span class='hs-layout'>(</span><span class='hs-varid'>reverse</span> <span class='hs-varop'>.</span> <span class='hs-conid'>W</span><span class='hs-varop'>.</span><span class='hs-varid'>up</span> <span class='hs-varop'>$</span> <span class='hs-varid'>s</span><span class='hs-layout'>)</span> <span class='hs-varop'>++</span> <span class='hs-keyglyph'>[</span><span class='hs-conid'>Right</span> <span class='hs-varop'>.</span> <span class='hs-conid'>W</span><span class='hs-varop'>.</span><span class='hs-varid'>focus</span> <span class='hs-varop'>$</span> <span class='hs-varid'>s</span><span class='hs-keyglyph'>]</span>
<a name="line-121"></a> <span class='hs-varop'>++</span> <span class='hs-varid'>map</span> <span class='hs-conid'>Left</span> <span class='hs-layout'>(</span><span class='hs-conid'>W</span><span class='hs-varop'>.</span><span class='hs-varid'>down</span> <span class='hs-varid'>s</span><span class='hs-layout'>)</span>
<a name="line-122"></a>
<a name="line-123"></a>
<a name="line-124"></a><span class='hs-comment'>-- * Zipper functions</span>
<a name="line-125"></a>
<a name="line-126"></a><span class='hs-comment'>-- ** Insertion, movement</span>
<a name="line-127"></a>
<a name="line-128"></a><a name="insertUpZ"></a><span class='hs-comment'>-- | Insert an element before the focused one, and focus it</span>
<a name="line-129"></a><span class='hs-definition'>insertUpZ</span> <span class='hs-keyglyph'>::</span> <span class='hs-varid'>a</span> <span class='hs-keyglyph'>-></span> <span class='hs-conid'>Zipper</span> <span class='hs-varid'>a</span> <span class='hs-keyglyph'>-></span> <span class='hs-conid'>Zipper</span> <span class='hs-varid'>a</span>
<a name="line-130"></a><span class='hs-definition'>insertUpZ</span> <span class='hs-varid'>a</span> <span class='hs-conid'>Nothing</span> <span class='hs-keyglyph'>=</span> <span class='hs-conid'>W</span><span class='hs-varop'>.</span><span class='hs-varid'>differentiate</span> <span class='hs-keyglyph'>[</span><span class='hs-varid'>a</span><span class='hs-keyglyph'>]</span>
<a name="line-131"></a><span class='hs-definition'>insertUpZ</span> <span class='hs-varid'>a</span> <span class='hs-layout'>(</span><span class='hs-conid'>Just</span> <span class='hs-varid'>s</span><span class='hs-layout'>)</span> <span class='hs-keyglyph'>=</span> <span class='hs-conid'>Just</span> <span class='hs-varid'>s</span> <span class='hs-layout'>{</span> <span class='hs-conid'>W</span><span class='hs-varop'>.</span><span class='hs-varid'>focus</span> <span class='hs-keyglyph'>=</span> <span class='hs-varid'>a</span> <span class='hs-layout'>,</span> <span class='hs-conid'>W</span><span class='hs-varop'>.</span><span class='hs-varid'>down</span> <span class='hs-keyglyph'>=</span> <span class='hs-conid'>W</span><span class='hs-varop'>.</span><span class='hs-varid'>focus</span> <span class='hs-varid'>s</span> <span class='hs-conop'>:</span> <span class='hs-conid'>W</span><span class='hs-varop'>.</span><span class='hs-varid'>down</span> <span class='hs-varid'>s</span> <span class='hs-layout'>}</span>
<a name="line-132"></a>
<a name="line-133"></a><a name="insertDownZ"></a><span class='hs-comment'>-- | Insert an element after the focused one, and focus it</span>
<a name="line-134"></a><span class='hs-definition'>insertDownZ</span> <span class='hs-keyglyph'>::</span> <span class='hs-varid'>a</span> <span class='hs-keyglyph'>-></span> <span class='hs-conid'>Zipper</span> <span class='hs-varid'>a</span> <span class='hs-keyglyph'>-></span> <span class='hs-conid'>Zipper</span> <span class='hs-varid'>a</span>
<a name="line-135"></a><span class='hs-definition'>insertDownZ</span> <span class='hs-varid'>a</span> <span class='hs-conid'>Nothing</span> <span class='hs-keyglyph'>=</span> <span class='hs-conid'>W</span><span class='hs-varop'>.</span><span class='hs-varid'>differentiate</span> <span class='hs-keyglyph'>[</span><span class='hs-varid'>a</span><span class='hs-keyglyph'>]</span>
<a name="line-136"></a><span class='hs-definition'>insertDownZ</span> <span class='hs-varid'>a</span> <span class='hs-layout'>(</span><span class='hs-conid'>Just</span> <span class='hs-varid'>s</span><span class='hs-layout'>)</span> <span class='hs-keyglyph'>=</span> <span class='hs-conid'>Just</span> <span class='hs-varid'>s</span> <span class='hs-layout'>{</span> <span class='hs-conid'>W</span><span class='hs-varop'>.</span><span class='hs-varid'>focus</span> <span class='hs-keyglyph'>=</span> <span class='hs-varid'>a</span><span class='hs-layout'>,</span> <span class='hs-conid'>W</span><span class='hs-varop'>.</span><span class='hs-varid'>up</span> <span class='hs-keyglyph'>=</span> <span class='hs-conid'>W</span><span class='hs-varop'>.</span><span class='hs-varid'>focus</span> <span class='hs-varid'>s</span> <span class='hs-conop'>:</span> <span class='hs-conid'>W</span><span class='hs-varop'>.</span><span class='hs-varid'>up</span> <span class='hs-varid'>s</span> <span class='hs-layout'>}</span>
<a name="line-137"></a>
<a name="line-138"></a><a name="swapUpZ"></a><span class='hs-comment'>-- | Swap the focused element with the previous one</span>
<a name="line-139"></a><span class='hs-definition'>swapUpZ</span> <span class='hs-keyglyph'>::</span> <span class='hs-conid'>Zipper</span> <span class='hs-varid'>a</span> <span class='hs-keyglyph'>-></span> <span class='hs-conid'>Zipper</span> <span class='hs-varid'>a</span>
<a name="line-140"></a><span class='hs-definition'>swapUpZ</span> <span class='hs-conid'>Nothing</span> <span class='hs-keyglyph'>=</span> <span class='hs-conid'>Nothing</span>
<a name="line-141"></a><span class='hs-definition'>swapUpZ</span> <span class='hs-layout'>(</span><span class='hs-conid'>Just</span> <span class='hs-varid'>s</span><span class='hs-layout'>)</span> <span class='hs-keyglyph'>|</span> <span class='hs-varid'>u</span><span class='hs-conop'>:</span><span class='hs-varid'>up</span> <span class='hs-keyglyph'><-</span> <span class='hs-conid'>W</span><span class='hs-varop'>.</span><span class='hs-varid'>up</span> <span class='hs-varid'>s</span> <span class='hs-keyglyph'>=</span> <span class='hs-conid'>Just</span> <span class='hs-varid'>s</span> <span class='hs-layout'>{</span> <span class='hs-conid'>W</span><span class='hs-varop'>.</span><span class='hs-varid'>up</span> <span class='hs-keyglyph'>=</span> <span class='hs-varid'>up</span><span class='hs-layout'>,</span> <span class='hs-conid'>W</span><span class='hs-varop'>.</span><span class='hs-varid'>down</span> <span class='hs-keyglyph'>=</span> <span class='hs-varid'>u</span><span class='hs-conop'>:</span><span class='hs-conid'>W</span><span class='hs-varop'>.</span><span class='hs-varid'>down</span> <span class='hs-varid'>s</span><span class='hs-layout'>}</span>
<a name="line-142"></a><span class='hs-definition'>swapUpZ</span> <span class='hs-layout'>(</span><span class='hs-conid'>Just</span> <span class='hs-varid'>s</span><span class='hs-layout'>)</span> <span class='hs-keyglyph'>=</span> <span class='hs-conid'>Just</span> <span class='hs-varid'>s</span> <span class='hs-layout'>{</span> <span class='hs-conid'>W</span><span class='hs-varop'>.</span><span class='hs-varid'>up</span> <span class='hs-keyglyph'>=</span> <span class='hs-varid'>reverse</span> <span class='hs-layout'>(</span><span class='hs-conid'>W</span><span class='hs-varop'>.</span><span class='hs-varid'>down</span> <span class='hs-varid'>s</span><span class='hs-layout'>)</span><span class='hs-layout'>,</span> <span class='hs-conid'>W</span><span class='hs-varop'>.</span><span class='hs-varid'>down</span> <span class='hs-keyglyph'>=</span> <span class='hs-conid'>[]</span> <span class='hs-layout'>}</span>
<a name="line-143"></a>
<a name="line-144"></a><a name="swapDownZ"></a><span class='hs-comment'>-- | Swap the focused element with the next one</span>
<a name="line-145"></a><span class='hs-definition'>swapDownZ</span> <span class='hs-keyglyph'>::</span> <span class='hs-conid'>Zipper</span> <span class='hs-varid'>a</span> <span class='hs-keyglyph'>-></span> <span class='hs-conid'>Zipper</span> <span class='hs-varid'>a</span>
<a name="line-146"></a><span class='hs-definition'>swapDownZ</span> <span class='hs-conid'>Nothing</span> <span class='hs-keyglyph'>=</span> <span class='hs-conid'>Nothing</span>
<a name="line-147"></a><span class='hs-definition'>swapDownZ</span> <span class='hs-layout'>(</span><span class='hs-conid'>Just</span> <span class='hs-varid'>s</span><span class='hs-layout'>)</span> <span class='hs-keyglyph'>|</span> <span class='hs-varid'>d</span><span class='hs-conop'>:</span><span class='hs-varid'>down</span> <span class='hs-keyglyph'><-</span> <span class='hs-conid'>W</span><span class='hs-varop'>.</span><span class='hs-varid'>down</span> <span class='hs-varid'>s</span> <span class='hs-keyglyph'>=</span> <span class='hs-conid'>Just</span> <span class='hs-varid'>s</span> <span class='hs-layout'>{</span> <span class='hs-conid'>W</span><span class='hs-varop'>.</span><span class='hs-varid'>down</span> <span class='hs-keyglyph'>=</span> <span class='hs-varid'>down</span><span class='hs-layout'>,</span> <span class='hs-conid'>W</span><span class='hs-varop'>.</span><span class='hs-varid'>up</span> <span class='hs-keyglyph'>=</span> <span class='hs-varid'>d</span><span class='hs-conop'>:</span><span class='hs-conid'>W</span><span class='hs-varop'>.</span><span class='hs-varid'>up</span> <span class='hs-varid'>s</span> <span class='hs-layout'>}</span>
<a name="line-148"></a><span class='hs-definition'>swapDownZ</span> <span class='hs-layout'>(</span><span class='hs-conid'>Just</span> <span class='hs-varid'>s</span><span class='hs-layout'>)</span> <span class='hs-keyglyph'>=</span> <span class='hs-conid'>Just</span> <span class='hs-varid'>s</span> <span class='hs-layout'>{</span> <span class='hs-conid'>W</span><span class='hs-varop'>.</span><span class='hs-varid'>up</span> <span class='hs-keyglyph'>=</span> <span class='hs-conid'>[]</span><span class='hs-layout'>,</span> <span class='hs-conid'>W</span><span class='hs-varop'>.</span><span class='hs-varid'>down</span> <span class='hs-keyglyph'>=</span> <span class='hs-varid'>reverse</span> <span class='hs-layout'>(</span><span class='hs-conid'>W</span><span class='hs-varop'>.</span><span class='hs-varid'>up</span> <span class='hs-varid'>s</span><span class='hs-layout'>)</span> <span class='hs-layout'>}</span>
<a name="line-149"></a>
<a name="line-150"></a><a name="swapMasterZ"></a><span class='hs-comment'>-- | Swap the focused element with the first one</span>
<a name="line-151"></a><span class='hs-definition'>swapMasterZ</span> <span class='hs-keyglyph'>::</span> <span class='hs-conid'>Zipper</span> <span class='hs-varid'>a</span> <span class='hs-keyglyph'>-></span> <span class='hs-conid'>Zipper</span> <span class='hs-varid'>a</span>
<a name="line-152"></a><span class='hs-definition'>swapMasterZ</span> <span class='hs-conid'>Nothing</span> <span class='hs-keyglyph'>=</span> <span class='hs-conid'>Nothing</span>
<a name="line-153"></a><span class='hs-definition'>swapMasterZ</span> <span class='hs-layout'>(</span><span class='hs-conid'>Just</span> <span class='hs-layout'>(</span><span class='hs-conid'>W</span><span class='hs-varop'>.</span><span class='hs-conid'>Stack</span> <span class='hs-varid'>f</span> <span class='hs-varid'>up</span> <span class='hs-varid'>down</span><span class='hs-layout'>)</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-conid'>W</span><span class='hs-varop'>.</span><span class='hs-conid'>Stack</span> <span class='hs-varid'>f</span> <span class='hs-conid'>[]</span> <span class='hs-layout'>(</span><span class='hs-varid'>reverse</span> <span class='hs-varid'>up</span> <span class='hs-varop'>++</span> <span class='hs-varid'>down</span><span class='hs-layout'>)</span>
<a name="line-154"></a>
<a name="line-155"></a><span class='hs-comment'>-- ** Focus movement</span>
<a name="line-156"></a>
<a name="line-157"></a><a name="focusUpZ"></a><span class='hs-comment'>-- | Move the focus to the previous element</span>
<a name="line-158"></a><span class='hs-definition'>focusUpZ</span> <span class='hs-keyglyph'>::</span> <span class='hs-conid'>Zipper</span> <span class='hs-varid'>a</span> <span class='hs-keyglyph'>-></span> <span class='hs-conid'>Zipper</span> <span class='hs-varid'>a</span>
<a name="line-159"></a><span class='hs-definition'>focusUpZ</span> <span class='hs-conid'>Nothing</span> <span class='hs-keyglyph'>=</span> <span class='hs-conid'>Nothing</span>
<a name="line-160"></a><span class='hs-definition'>focusUpZ</span> <span class='hs-layout'>(</span><span class='hs-conid'>Just</span> <span class='hs-varid'>s</span><span class='hs-layout'>)</span> <span class='hs-keyglyph'>|</span> <span class='hs-varid'>u</span><span class='hs-conop'>:</span><span class='hs-varid'>up</span> <span class='hs-keyglyph'><-</span> <span class='hs-conid'>W</span><span class='hs-varop'>.</span><span class='hs-varid'>up</span> <span class='hs-varid'>s</span> <span class='hs-keyglyph'>=</span> <span class='hs-conid'>Just</span> <span class='hs-varop'>$</span> <span class='hs-conid'>W</span><span class='hs-varop'>.</span><span class='hs-conid'>Stack</span> <span class='hs-varid'>u</span> <span class='hs-varid'>up</span> <span class='hs-layout'>(</span><span class='hs-conid'>W</span><span class='hs-varop'>.</span><span class='hs-varid'>focus</span> <span class='hs-varid'>s</span><span class='hs-conop'>:</span><span class='hs-conid'>W</span><span class='hs-varop'>.</span><span class='hs-varid'>down</span> <span class='hs-varid'>s</span><span class='hs-layout'>)</span>
<a name="line-161"></a><span class='hs-definition'>focusUpZ</span> <span class='hs-layout'>(</span><span class='hs-conid'>Just</span> <span class='hs-varid'>s</span><span class='hs-layout'>)</span> <span class='hs-keyglyph'>|</span> <span class='hs-varid'>null</span> <span class='hs-varop'>$</span> <span class='hs-conid'>W</span><span class='hs-varop'>.</span><span class='hs-varid'>down</span> <span class='hs-varid'>s</span> <span class='hs-keyglyph'>=</span> <span class='hs-conid'>Just</span> <span class='hs-varid'>s</span>
<a name="line-162"></a><span class='hs-definition'>focusUpZ</span> <span class='hs-layout'>(</span><span class='hs-conid'>Just</span> <span class='hs-layout'>(</span><span class='hs-conid'>W</span><span class='hs-varop'>.</span><span class='hs-conid'>Stack</span> <span class='hs-varid'>f</span> <span class='hs-keyword'>_</span> <span class='hs-varid'>down</span><span class='hs-layout'>)</span><span class='hs-layout'>)</span> <span class='hs-keyglyph'>=</span> <span class='hs-conid'>Just</span> <span class='hs-varop'>$</span> <span class='hs-conid'>W</span><span class='hs-varop'>.</span><span class='hs-conid'>Stack</span> <span class='hs-layout'>(</span><span class='hs-varid'>last</span> <span class='hs-varid'>down</span><span class='hs-layout'>)</span> <span class='hs-layout'>(</span><span class='hs-varid'>reverse</span> <span class='hs-layout'>(</span><span class='hs-varid'>init</span> <span class='hs-varid'>down</span><span class='hs-layout'>)</span> <span class='hs-varop'>++</span> <span class='hs-keyglyph'>[</span><span class='hs-varid'>f</span><span class='hs-keyglyph'>]</span><span class='hs-layout'>)</span> <span class='hs-conid'>[]</span>
<a name="line-163"></a>
<a name="line-164"></a><a name="focusDownZ"></a><span class='hs-comment'>-- | Move the focus to the next element</span>
<a name="line-165"></a><span class='hs-definition'>focusDownZ</span> <span class='hs-keyglyph'>::</span> <span class='hs-conid'>Zipper</span> <span class='hs-varid'>a</span> <span class='hs-keyglyph'>-></span> <span class='hs-conid'>Zipper</span> <span class='hs-varid'>a</span>
<a name="line-166"></a><span class='hs-definition'>focusDownZ</span> <span class='hs-conid'>Nothing</span> <span class='hs-keyglyph'>=</span> <span class='hs-conid'>Nothing</span>
<a name="line-167"></a><span class='hs-definition'>focusDownZ</span> <span class='hs-layout'>(</span><span class='hs-conid'>Just</span> <span class='hs-varid'>s</span><span class='hs-layout'>)</span> <span class='hs-keyglyph'>|</span> <span class='hs-varid'>d</span><span class='hs-conop'>:</span><span class='hs-varid'>down</span> <span class='hs-keyglyph'><-</span> <span class='hs-conid'>W</span><span class='hs-varop'>.</span><span class='hs-varid'>down</span> <span class='hs-varid'>s</span> <span class='hs-keyglyph'>=</span> <span class='hs-conid'>Just</span> <span class='hs-varop'>$</span> <span class='hs-conid'>W</span><span class='hs-varop'>.</span><span class='hs-conid'>Stack</span> <span class='hs-varid'>d</span> <span class='hs-layout'>(</span><span class='hs-conid'>W</span><span class='hs-varop'>.</span><span class='hs-varid'>focus</span> <span class='hs-varid'>s</span><span class='hs-conop'>:</span><span class='hs-conid'>W</span><span class='hs-varop'>.</span><span class='hs-varid'>up</span> <span class='hs-varid'>s</span><span class='hs-layout'>)</span> <span class='hs-varid'>down</span>
<a name="line-168"></a><span class='hs-definition'>focusDownZ</span> <span class='hs-layout'>(</span><span class='hs-conid'>Just</span> <span class='hs-varid'>s</span><span class='hs-layout'>)</span> <span class='hs-keyglyph'>|</span> <span class='hs-varid'>null</span> <span class='hs-varop'>$</span> <span class='hs-conid'>W</span><span class='hs-varop'>.</span><span class='hs-varid'>up</span> <span class='hs-varid'>s</span> <span class='hs-keyglyph'>=</span> <span class='hs-conid'>Just</span> <span class='hs-varid'>s</span>
<a name="line-169"></a><span class='hs-definition'>focusDownZ</span> <span class='hs-layout'>(</span><span class='hs-conid'>Just</span> <span class='hs-layout'>(</span><span class='hs-conid'>W</span><span class='hs-varop'>.</span><span class='hs-conid'>Stack</span> <span class='hs-varid'>f</span> <span class='hs-varid'>up</span> <span class='hs-keyword'>_</span><span class='hs-layout'>)</span><span class='hs-layout'>)</span> <span class='hs-keyglyph'>=</span> <span class='hs-conid'>Just</span> <span class='hs-varop'>$</span> <span class='hs-conid'>W</span><span class='hs-varop'>.</span><span class='hs-conid'>Stack</span> <span class='hs-layout'>(</span><span class='hs-varid'>last</span> <span class='hs-varid'>up</span><span class='hs-layout'>)</span> <span class='hs-conid'>[]</span> <span class='hs-layout'>(</span><span class='hs-varid'>reverse</span> <span class='hs-layout'>(</span><span class='hs-varid'>init</span> <span class='hs-varid'>up</span><span class='hs-layout'>)</span> <span class='hs-varop'>++</span> <span class='hs-keyglyph'>[</span><span class='hs-varid'>f</span><span class='hs-keyglyph'>]</span><span class='hs-layout'>)</span>
<a name="line-170"></a>
<a name="line-171"></a><a name="focusMasterZ"></a><span class='hs-comment'>-- | Move the focus to the first element</span>
<a name="line-172"></a><span class='hs-definition'>focusMasterZ</span> <span class='hs-keyglyph'>::</span> <span class='hs-conid'>Zipper</span> <span class='hs-varid'>a</span> <span class='hs-keyglyph'>-></span> <span class='hs-conid'>Zipper</span> <span class='hs-varid'>a</span>
<a name="line-173"></a><span class='hs-definition'>focusMasterZ</span> <span class='hs-conid'>Nothing</span> <span class='hs-keyglyph'>=</span> <span class='hs-conid'>Nothing</span>
<a name="line-174"></a><span class='hs-definition'>focusMasterZ</span> <span class='hs-layout'>(</span><span class='hs-conid'>Just</span> <span class='hs-layout'>(</span><span class='hs-conid'>W</span><span class='hs-varop'>.</span><span class='hs-conid'>Stack</span> <span class='hs-varid'>f</span> <span class='hs-varid'>up</span> <span class='hs-varid'>down</span><span class='hs-layout'>)</span><span class='hs-layout'>)</span> <span class='hs-keyglyph'>|</span> <span class='hs-varid'>not</span> <span class='hs-varop'>$</span> <span class='hs-varid'>null</span> <span class='hs-varid'>up</span>
<a name="line-175"></a> <span class='hs-keyglyph'>=</span> <span class='hs-conid'>Just</span> <span class='hs-varop'>$</span> <span class='hs-conid'>W</span><span class='hs-varop'>.</span><span class='hs-conid'>Stack</span> <span class='hs-layout'>(</span><span class='hs-varid'>last</span> <span class='hs-varid'>up</span><span class='hs-layout'>)</span> <span class='hs-conid'>[]</span> <span class='hs-layout'>(</span><span class='hs-varid'>reverse</span> <span class='hs-layout'>(</span><span class='hs-varid'>init</span> <span class='hs-varid'>up</span><span class='hs-layout'>)</span> <span class='hs-varop'>++</span> <span class='hs-keyglyph'>[</span><span class='hs-varid'>f</span><span class='hs-keyglyph'>]</span> <span class='hs-varop'>++</span> <span class='hs-varid'>down</span><span class='hs-layout'>)</span>
<a name="line-176"></a><span class='hs-definition'>focusMasterZ</span> <span class='hs-layout'>(</span><span class='hs-conid'>Just</span> <span class='hs-varid'>s</span><span class='hs-layout'>)</span> <span class='hs-keyglyph'>=</span> <span class='hs-conid'>Just</span> <span class='hs-varid'>s</span>
<a name="line-177"></a>
<a name="line-178"></a><span class='hs-comment'>-- ** Extraction</span>
<a name="line-179"></a>
<a name="line-180"></a><a name="getFocusZ"></a><span class='hs-comment'>-- | Get the focused element</span>
<a name="line-181"></a><span class='hs-definition'>getFocusZ</span> <span class='hs-keyglyph'>::</span> <span class='hs-conid'>Zipper</span> <span class='hs-varid'>a</span> <span class='hs-keyglyph'>-></span> <span class='hs-conid'>Maybe</span> <span class='hs-varid'>a</span>
<a name="line-182"></a><span class='hs-definition'>getFocusZ</span> <span class='hs-keyglyph'>=</span> <span class='hs-varid'>fmap</span> <span class='hs-conid'>W</span><span class='hs-varop'>.</span><span class='hs-varid'>focus</span>
<a name="line-183"></a>
<a name="line-184"></a><a name="getIZ"></a><span class='hs-comment'>-- | Get the element at a given index</span>
<a name="line-185"></a><span class='hs-definition'>getIZ</span> <span class='hs-keyglyph'>::</span> <span class='hs-conid'>Int</span> <span class='hs-keyglyph'>-></span> <span class='hs-conid'>Zipper</span> <span class='hs-varid'>a</span> <span class='hs-keyglyph'>-></span> <span class='hs-conid'>Maybe</span> <span class='hs-varid'>a</span>
<a name="line-186"></a><span class='hs-definition'>getIZ</span> <span class='hs-varid'>i</span> <span class='hs-keyglyph'>=</span> <span class='hs-varid'>getI</span> <span class='hs-varid'>i</span> <span class='hs-varop'>.</span> <span class='hs-conid'>W</span><span class='hs-varop'>.</span><span class='hs-varid'>integrate'</span>
<a name="line-187"></a>
<a name="line-188"></a><span class='hs-comment'>-- ** Sorting</span>
<a name="line-189"></a>
<a name="line-190"></a><a name="sortZ"></a><span class='hs-comment'>-- | Sort a stack of elements supporting 'Ord'</span>
<a name="line-191"></a><span class='hs-definition'>sortZ</span> <span class='hs-keyglyph'>::</span> <span class='hs-conid'>Ord</span> <span class='hs-varid'>a</span> <span class='hs-keyglyph'>=></span> <span class='hs-conid'>Zipper</span> <span class='hs-varid'>a</span> <span class='hs-keyglyph'>-></span> <span class='hs-conid'>Zipper</span> <span class='hs-varid'>a</span>
<a name="line-192"></a><span class='hs-definition'>sortZ</span> <span class='hs-keyglyph'>=</span> <span class='hs-varid'>sortByZ</span> <span class='hs-varid'>compare</span>
<a name="line-193"></a>
<a name="line-194"></a><a name="sortByZ"></a><span class='hs-comment'>-- | Sort a stack with an arbitrary sorting function</span>
<a name="line-195"></a><span class='hs-definition'>sortByZ</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-conid'>Ordering</span><span class='hs-layout'>)</span> <span class='hs-keyglyph'>-></span> <span class='hs-conid'>Zipper</span> <span class='hs-varid'>a</span> <span class='hs-keyglyph'>-></span> <span class='hs-conid'>Zipper</span> <span class='hs-varid'>a</span>
<a name="line-196"></a><span class='hs-definition'>sortByZ</span> <span class='hs-varid'>f</span> <span class='hs-keyglyph'>=</span> <span class='hs-varid'>fromTags</span> <span class='hs-varop'>.</span> <span class='hs-varid'>sortBy</span> <span class='hs-layout'>(</span><span class='hs-varid'>adapt</span> <span class='hs-varid'>f</span><span class='hs-layout'>)</span> <span class='hs-varop'>.</span> <span class='hs-varid'>toTags</span>
<a name="line-197"></a> <span class='hs-keyword'>where</span> <span class='hs-varid'>adapt</span> <span class='hs-varid'>g</span> <span class='hs-varid'>e1</span> <span class='hs-varid'>e2</span> <span class='hs-keyglyph'>=</span> <span class='hs-varid'>g</span> <span class='hs-layout'>(</span><span class='hs-varid'>fromE</span> <span class='hs-varid'>e1</span><span class='hs-layout'>)</span> <span class='hs-layout'>(</span><span class='hs-varid'>fromE</span> <span class='hs-varid'>e2</span><span class='hs-layout'>)</span>
<a name="line-198"></a>
<a name="line-199"></a><span class='hs-comment'>-- ** Maps</span>
<a name="line-200"></a>
<a name="line-201"></a><a name="mapZ"></a><span class='hs-comment'>-- | Map a function over a stack. The boolean argument indcates whether</span>
<a name="line-202"></a><span class='hs-comment'>-- the current element is the focused one</span>
<a name="line-203"></a><span class='hs-definition'>mapZ</span> <span class='hs-keyglyph'>::</span> <span class='hs-layout'>(</span><span class='hs-conid'>Bool</span> <span class='hs-keyglyph'>-></span> <span class='hs-varid'>a</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-conid'>Zipper</span> <span class='hs-varid'>a</span> <span class='hs-keyglyph'>-></span> <span class='hs-conid'>Zipper</span> <span class='hs-varid'>b</span>
<a name="line-204"></a><span class='hs-definition'>mapZ</span> <span class='hs-varid'>f</span> <span class='hs-keyword'>as</span> <span class='hs-keyglyph'>=</span> <span class='hs-varid'>fromTags</span> <span class='hs-varop'>.</span> <span class='hs-varid'>map</span> <span class='hs-layout'>(</span><span class='hs-varid'>mapE</span> <span class='hs-varid'>f</span><span class='hs-layout'>)</span> <span class='hs-varop'>.</span> <span class='hs-varid'>toTags</span> <span class='hs-varop'>$</span> <span class='hs-keyword'>as</span>
<a name="line-205"></a>
<a name="line-206"></a><a name="mapZ_"></a><span class='hs-comment'>-- | 'mapZ' without the 'Bool' argument</span>
<a name="line-207"></a><span class='hs-definition'>mapZ_</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'>b</span><span class='hs-layout'>)</span> <span class='hs-keyglyph'>-></span> <span class='hs-conid'>Zipper</span> <span class='hs-varid'>a</span> <span class='hs-keyglyph'>-></span> <span class='hs-conid'>Zipper</span> <span class='hs-varid'>b</span>
<a name="line-208"></a><span class='hs-definition'>mapZ_</span> <span class='hs-keyglyph'>=</span> <span class='hs-varid'>mapZ</span> <span class='hs-varop'>.</span> <span class='hs-varid'>const</span>
<a name="line-209"></a>
<a name="line-210"></a><a name="mapZM"></a><span class='hs-comment'>-- | Monadic version of 'mapZ'</span>
<a name="line-211"></a><span class='hs-definition'>mapZM</span> <span class='hs-keyglyph'>::</span> <span class='hs-conid'>Monad</span> <span class='hs-varid'>m</span> <span class='hs-keyglyph'>=></span> <span class='hs-layout'>(</span><span class='hs-conid'>Bool</span> <span class='hs-keyglyph'>-></span> <span class='hs-varid'>a</span> <span class='hs-keyglyph'>-></span> <span class='hs-varid'>m</span> <span class='hs-varid'>b</span><span class='hs-layout'>)</span> <span class='hs-keyglyph'>-></span> <span class='hs-conid'>Zipper</span> <span class='hs-varid'>a</span> <span class='hs-keyglyph'>-></span> <span class='hs-varid'>m</span> <span class='hs-layout'>(</span><span class='hs-conid'>Zipper</span> <span class='hs-varid'>b</span><span class='hs-layout'>)</span>
<a name="line-212"></a><span class='hs-definition'>mapZM</span> <span class='hs-varid'>f</span> <span class='hs-keyword'>as</span> <span class='hs-keyglyph'>=</span> <span class='hs-varid'>fromTags</span> <span class='hs-varop'>`liftM`</span> <span class='hs-layout'>(</span><span class='hs-varid'>mapM</span> <span class='hs-layout'>(</span><span class='hs-varid'>mapEM</span> <span class='hs-varid'>f</span><span class='hs-layout'>)</span> <span class='hs-varop'>.</span> <span class='hs-varid'>toTags</span><span class='hs-layout'>)</span> <span class='hs-keyword'>as</span>
<a name="line-213"></a>
<a name="line-214"></a>
<a name="line-215"></a><a name="mapZM_"></a><span class='hs-comment'>-- | Monadic version of 'mapZ_'</span>
<a name="line-216"></a><span class='hs-definition'>mapZM_</span> <span class='hs-keyglyph'>::</span> <span class='hs-conid'>Monad</span> <span class='hs-varid'>m</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'>m</span> <span class='hs-varid'>b</span><span class='hs-layout'>)</span> <span class='hs-keyglyph'>-></span> <span class='hs-conid'>Zipper</span> <span class='hs-varid'>a</span> <span class='hs-keyglyph'>-></span> <span class='hs-varid'>m</span> <span class='hs-layout'>(</span><span class='hs-conid'>Zipper</span> <span class='hs-varid'>b</span><span class='hs-layout'>)</span>
<a name="line-217"></a><span class='hs-definition'>mapZM_</span> <span class='hs-keyglyph'>=</span> <span class='hs-varid'>mapZM</span> <span class='hs-varop'>.</span> <span class='hs-varid'>const</span>
<a name="line-218"></a>
<a name="line-219"></a><a name="onFocusedZ"></a><span class='hs-comment'>-- | Apply a function to the focused element</span>
<a name="line-220"></a><span class='hs-definition'>onFocusedZ</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'>Zipper</span> <span class='hs-varid'>a</span> <span class='hs-keyglyph'>-></span> <span class='hs-conid'>Zipper</span> <span class='hs-varid'>a</span>
<a name="line-221"></a><span class='hs-definition'>onFocusedZ</span> <span class='hs-varid'>f</span> <span class='hs-keyglyph'>=</span> <span class='hs-varid'>mapZ</span> <span class='hs-varop'>$</span> <span class='hs-keyglyph'>\</span><span class='hs-varid'>b</span> <span class='hs-varid'>a</span> <span class='hs-keyglyph'>-></span> <span class='hs-keyword'>if</span> <span class='hs-varid'>b</span> <span class='hs-keyword'>then</span> <span class='hs-varid'>f</span> <span class='hs-varid'>a</span> <span class='hs-keyword'>else</span> <span class='hs-varid'>a</span>
<a name="line-222"></a>
<a name="line-223"></a><a name="onFocusedZM"></a><span class='hs-comment'>-- | Monadic version of 'onFocusedZ'</span>
<a name="line-224"></a><span class='hs-definition'>onFocusedZM</span> <span class='hs-keyglyph'>::</span> <span class='hs-conid'>Monad</span> <span class='hs-varid'>m</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'>m</span> <span class='hs-varid'>a</span><span class='hs-layout'>)</span> <span class='hs-keyglyph'>-></span> <span class='hs-conid'>Zipper</span> <span class='hs-varid'>a</span> <span class='hs-keyglyph'>-></span> <span class='hs-varid'>m</span> <span class='hs-layout'>(</span><span class='hs-conid'>Zipper</span> <span class='hs-varid'>a</span><span class='hs-layout'>)</span>
<a name="line-225"></a><span class='hs-definition'>onFocusedZM</span> <span class='hs-varid'>f</span> <span class='hs-keyglyph'>=</span> <span class='hs-varid'>mapZM</span> <span class='hs-varop'>$</span> <span class='hs-keyglyph'>\</span><span class='hs-varid'>b</span> <span class='hs-varid'>a</span> <span class='hs-keyglyph'>-></span> <span class='hs-keyword'>if</span> <span class='hs-varid'>b</span> <span class='hs-keyword'>then</span> <span class='hs-varid'>f</span> <span class='hs-varid'>a</span> <span class='hs-keyword'>else</span> <span class='hs-varid'>return</span> <span class='hs-varid'>a</span>
<a name="line-226"></a>
<a name="line-227"></a><a name="onIndexZ"></a><span class='hs-comment'>-- | Apply a function to the element at the given index</span>
<a name="line-228"></a><span class='hs-definition'>onIndexZ</span> <span class='hs-keyglyph'>::</span> <span class='hs-conid'>Int</span> <span class='hs-keyglyph'>-></span> <span class='hs-layout'>(</span><span class='hs-varid'>a</span> <span class='hs-keyglyph'>-></span> <span class='hs-varid'>a</span><span class='hs-layout'>)</span> <span class='hs-keyglyph'>-></span> <span class='hs-conid'>Zipper</span> <span class='hs-varid'>a</span> <span class='hs-keyglyph'>-></span> <span class='hs-conid'>Zipper</span> <span class='hs-varid'>a</span>
<a name="line-229"></a><span class='hs-definition'>onIndexZ</span> <span class='hs-varid'>i</span> <span class='hs-keyword'>_</span> <span class='hs-keyword'>as</span> <span class='hs-keyglyph'>|</span> <span class='hs-varid'>i</span> <span class='hs-varop'><</span> <span class='hs-num'>0</span> <span class='hs-keyglyph'>=</span> <span class='hs-keyword'>as</span>
<a name="line-230"></a><span class='hs-definition'>onIndexZ</span> <span class='hs-varid'>i</span> <span class='hs-varid'>f</span> <span class='hs-keyword'>as</span> <span class='hs-keyglyph'>=</span> <span class='hs-keyword'>case</span> <span class='hs-varid'>splitAt</span> <span class='hs-varid'>i</span> <span class='hs-varop'>$</span> <span class='hs-varid'>toTags</span> <span class='hs-keyword'>as</span> <span class='hs-keyword'>of</span>
<a name="line-231"></a> <span class='hs-layout'>(</span><span class='hs-varid'>before</span><span class='hs-layout'>,</span> <span class='hs-conid'>[]</span><span class='hs-layout'>)</span> <span class='hs-keyglyph'>-></span> <span class='hs-varid'>fromTags</span> <span class='hs-varid'>before</span>
<a name="line-232"></a> <span class='hs-layout'>(</span><span class='hs-varid'>before</span><span class='hs-layout'>,</span> <span class='hs-varid'>a</span><span class='hs-conop'>:</span><span class='hs-varid'>after</span><span class='hs-layout'>)</span> <span class='hs-keyglyph'>-></span> <span class='hs-varid'>fromTags</span> <span class='hs-varop'>$</span> <span class='hs-varid'>before</span> <span class='hs-varop'>++</span> <span class='hs-varid'>mapE</span> <span class='hs-layout'>(</span><span class='hs-varid'>const</span> <span class='hs-varid'>f</span><span class='hs-layout'>)</span> <span class='hs-varid'>a</span> <span class='hs-conop'>:</span> <span class='hs-varid'>after</span>
<a name="line-233"></a>
<a name="line-234"></a><a name="onIndexZM"></a><span class='hs-comment'>-- | Monadic version of 'onIndexZ'</span>
<a name="line-235"></a><span class='hs-definition'>onIndexZM</span> <span class='hs-keyglyph'>::</span> <span class='hs-conid'>Monad</span> <span class='hs-varid'>m</span> <span class='hs-keyglyph'>=></span> <span class='hs-conid'>Int</span> <span class='hs-keyglyph'>-></span> <span class='hs-layout'>(</span><span class='hs-varid'>a</span> <span class='hs-keyglyph'>-></span> <span class='hs-varid'>m</span> <span class='hs-varid'>a</span><span class='hs-layout'>)</span> <span class='hs-keyglyph'>-></span> <span class='hs-conid'>Zipper</span> <span class='hs-varid'>a</span> <span class='hs-keyglyph'>-></span> <span class='hs-varid'>m</span> <span class='hs-layout'>(</span><span class='hs-conid'>Zipper</span> <span class='hs-varid'>a</span><span class='hs-layout'>)</span>
<a name="line-236"></a><span class='hs-definition'>onIndexZM</span> <span class='hs-varid'>i</span> <span class='hs-varid'>f</span> <span class='hs-keyword'>as</span> <span class='hs-keyglyph'>=</span> <span class='hs-keyword'>case</span> <span class='hs-varid'>splitAt</span> <span class='hs-varid'>i</span> <span class='hs-varop'>$</span> <span class='hs-varid'>toTags</span> <span class='hs-keyword'>as</span> <span class='hs-keyword'>of</span>
<a name="line-237"></a> <span class='hs-layout'>(</span><span class='hs-varid'>before</span><span class='hs-layout'>,</span> <span class='hs-conid'>[]</span><span class='hs-layout'>)</span> <span class='hs-keyglyph'>-></span> <span class='hs-varid'>return</span> <span class='hs-varop'>$</span> <span class='hs-varid'>fromTags</span> <span class='hs-varid'>before</span>
<a name="line-238"></a> <span class='hs-layout'>(</span><span class='hs-varid'>before</span><span class='hs-layout'>,</span> <span class='hs-varid'>a</span><span class='hs-conop'>:</span><span class='hs-varid'>after</span><span class='hs-layout'>)</span> <span class='hs-keyglyph'>-></span> <span class='hs-keyword'>do</span> <span class='hs-varid'>a'</span> <span class='hs-keyglyph'><-</span> <span class='hs-varid'>mapEM</span> <span class='hs-layout'>(</span><span class='hs-varid'>const</span> <span class='hs-varid'>f</span><span class='hs-layout'>)</span> <span class='hs-varid'>a</span>
<a name="line-239"></a> <span class='hs-varid'>return</span> <span class='hs-varop'>$</span> <span class='hs-varid'>fromTags</span> <span class='hs-varop'>$</span> <span class='hs-varid'>before</span> <span class='hs-varop'>++</span> <span class='hs-varid'>a'</span> <span class='hs-conop'>:</span> <span class='hs-varid'>after</span>
<a name="line-240"></a>
<a name="line-241"></a><span class='hs-comment'>-- ** Filters</span>
<a name="line-242"></a>
<a name="line-243"></a><a name="filterZ"></a><span class='hs-comment'>-- | Fiter a stack according to a predicate. The refocusing behavior</span>
<a name="line-244"></a><span class='hs-comment'>-- mimics XMonad's usual one. The boolean argument indicates whether the current</span>
<a name="line-245"></a><span class='hs-comment'>-- element is the focused one.</span>
<a name="line-246"></a><span class='hs-definition'>filterZ</span> <span class='hs-keyglyph'>::</span> <span class='hs-layout'>(</span><span class='hs-conid'>Bool</span> <span class='hs-keyglyph'>-></span> <span class='hs-varid'>a</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-conid'>Zipper</span> <span class='hs-varid'>a</span> <span class='hs-keyglyph'>-></span> <span class='hs-conid'>Zipper</span> <span class='hs-varid'>a</span>
<a name="line-247"></a><span class='hs-definition'>filterZ</span> <span class='hs-keyword'>_</span> <span class='hs-conid'>Nothing</span> <span class='hs-keyglyph'>=</span> <span class='hs-conid'>Nothing</span>
<a name="line-248"></a><span class='hs-definition'>filterZ</span> <span class='hs-varid'>p</span> <span class='hs-layout'>(</span><span class='hs-conid'>Just</span> <span class='hs-varid'>s</span><span class='hs-layout'>)</span> <span class='hs-keyglyph'>=</span> <span class='hs-keyword'>case</span> <span class='hs-layout'>(</span> <span class='hs-varid'>p</span> <span class='hs-conid'>True</span> <span class='hs-layout'>(</span><span class='hs-conid'>W</span><span class='hs-varop'>.</span><span class='hs-varid'>focus</span> <span class='hs-varid'>s</span><span class='hs-layout'>)</span>
<a name="line-249"></a> <span class='hs-layout'>,</span> <span class='hs-varid'>filter</span> <span class='hs-layout'>(</span><span class='hs-varid'>p</span> <span class='hs-conid'>False</span><span class='hs-layout'>)</span> <span class='hs-layout'>(</span><span class='hs-conid'>W</span><span class='hs-varop'>.</span><span class='hs-varid'>up</span> <span class='hs-varid'>s</span><span class='hs-layout'>)</span>
<a name="line-250"></a> <span class='hs-layout'>,</span> <span class='hs-varid'>filter</span> <span class='hs-layout'>(</span><span class='hs-varid'>p</span> <span class='hs-conid'>False</span><span class='hs-layout'>)</span> <span class='hs-layout'>(</span><span class='hs-conid'>W</span><span class='hs-varop'>.</span><span class='hs-varid'>down</span> <span class='hs-varid'>s</span><span class='hs-layout'>)</span> <span class='hs-layout'>)</span> <span class='hs-keyword'>of</span>
<a name="line-251"></a> <span class='hs-layout'>(</span><span class='hs-conid'>True</span><span class='hs-layout'>,</span> <span class='hs-varid'>up'</span><span class='hs-layout'>,</span> <span class='hs-varid'>down'</span><span class='hs-layout'>)</span> <span class='hs-keyglyph'>-></span> <span class='hs-conid'>Just</span> <span class='hs-varid'>s</span> <span class='hs-layout'>{</span> <span class='hs-conid'>W</span><span class='hs-varop'>.</span><span class='hs-varid'>up</span> <span class='hs-keyglyph'>=</span> <span class='hs-varid'>up'</span><span class='hs-layout'>,</span> <span class='hs-conid'>W</span><span class='hs-varop'>.</span><span class='hs-varid'>down</span> <span class='hs-keyglyph'>=</span> <span class='hs-varid'>down'</span> <span class='hs-layout'>}</span>
<a name="line-252"></a> <span class='hs-layout'>(</span><span class='hs-conid'>False</span><span class='hs-layout'>,</span> <span class='hs-conid'>[]</span><span class='hs-layout'>,</span> <span class='hs-conid'>[]</span><span class='hs-layout'>)</span> <span class='hs-keyglyph'>-></span> <span class='hs-conid'>Nothing</span>
<a name="line-253"></a> <span class='hs-layout'>(</span><span class='hs-conid'>False</span><span class='hs-layout'>,</span> <span class='hs-varid'>f</span><span class='hs-conop'>:</span><span class='hs-varid'>up'</span><span class='hs-layout'>,</span> <span class='hs-conid'>[]</span><span class='hs-layout'>)</span> <span class='hs-keyglyph'>-></span> <span class='hs-conid'>Just</span> <span class='hs-varid'>s</span> <span class='hs-layout'>{</span> <span class='hs-conid'>W</span><span class='hs-varop'>.</span><span class='hs-varid'>focus</span> <span class='hs-keyglyph'>=</span> <span class='hs-varid'>f</span><span class='hs-layout'>,</span> <span class='hs-conid'>W</span><span class='hs-varop'>.</span><span class='hs-varid'>up</span> <span class='hs-keyglyph'>=</span> <span class='hs-varid'>up'</span><span class='hs-layout'>,</span> <span class='hs-conid'>W</span><span class='hs-varop'>.</span><span class='hs-varid'>down</span> <span class='hs-keyglyph'>=</span> <span class='hs-conid'>[]</span> <span class='hs-layout'>}</span>
<a name="line-254"></a> <span class='hs-layout'>(</span><span class='hs-conid'>False</span><span class='hs-layout'>,</span> <span class='hs-varid'>up'</span><span class='hs-layout'>,</span> <span class='hs-varid'>f</span><span class='hs-conop'>:</span><span class='hs-varid'>down'</span><span class='hs-layout'>)</span> <span class='hs-keyglyph'>-></span> <span class='hs-conid'>Just</span> <span class='hs-varid'>s</span> <span class='hs-layout'>{</span> <span class='hs-conid'>W</span><span class='hs-varop'>.</span><span class='hs-varid'>focus</span> <span class='hs-keyglyph'>=</span> <span class='hs-varid'>f</span>
<a name="line-255"></a> <span class='hs-layout'>,</span> <span class='hs-conid'>W</span><span class='hs-varop'>.</span><span class='hs-varid'>up</span> <span class='hs-keyglyph'>=</span> <span class='hs-varid'>up'</span>
<a name="line-256"></a> <span class='hs-layout'>,</span> <span class='hs-conid'>W</span><span class='hs-varop'>.</span><span class='hs-varid'>down</span> <span class='hs-keyglyph'>=</span> <span class='hs-varid'>down'</span> <span class='hs-layout'>}</span>
<a name="line-257"></a>
<a name="line-258"></a><a name="filterZ_"></a><span class='hs-comment'>-- | 'filterZ' without the 'Bool' argument</span>
<a name="line-259"></a><span class='hs-definition'>filterZ_</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'>Bool</span><span class='hs-layout'>)</span> <span class='hs-keyglyph'>-></span> <span class='hs-conid'>Zipper</span> <span class='hs-varid'>a</span> <span class='hs-keyglyph'>-></span> <span class='hs-conid'>Zipper</span> <span class='hs-varid'>a</span>
<a name="line-260"></a><span class='hs-definition'>filterZ_</span> <span class='hs-keyglyph'>=</span> <span class='hs-varid'>filterZ</span> <span class='hs-varop'>.</span> <span class='hs-varid'>const</span>
<a name="line-261"></a>
<a name="line-262"></a><a name="deleteFocusedZ"></a><span class='hs-comment'>-- | Delete the focused element</span>
<a name="line-263"></a><span class='hs-definition'>deleteFocusedZ</span> <span class='hs-keyglyph'>::</span> <span class='hs-conid'>Zipper</span> <span class='hs-varid'>a</span> <span class='hs-keyglyph'>-></span> <span class='hs-conid'>Zipper</span> <span class='hs-varid'>a</span>
<a name="line-264"></a><span class='hs-definition'>deleteFocusedZ</span> <span class='hs-keyglyph'>=</span> <span class='hs-varid'>filterZ</span> <span class='hs-layout'>(</span><span class='hs-keyglyph'>\</span><span class='hs-varid'>b</span> <span class='hs-keyword'>_</span> <span class='hs-keyglyph'>-></span> <span class='hs-varid'>not</span> <span class='hs-varid'>b</span><span class='hs-layout'>)</span>
<a name="line-265"></a>
<a name="line-266"></a><a name="deleteIndexZ"></a><span class='hs-comment'>-- | Delete the ith element</span>
<a name="line-267"></a><span class='hs-definition'>deleteIndexZ</span> <span class='hs-keyglyph'>::</span> <span class='hs-conid'>Int</span> <span class='hs-keyglyph'>-></span> <span class='hs-conid'>Zipper</span> <span class='hs-varid'>a</span> <span class='hs-keyglyph'>-></span> <span class='hs-conid'>Zipper</span> <span class='hs-varid'>a</span>
<a name="line-268"></a><span class='hs-definition'>deleteIndexZ</span> <span class='hs-varid'>i</span> <span class='hs-varid'>z</span> <span class='hs-keyglyph'>=</span> <span class='hs-keyword'>let</span> <span class='hs-varid'>numbered</span> <span class='hs-keyglyph'>=</span> <span class='hs-layout'>(</span><span class='hs-varid'>fromTags</span> <span class='hs-varop'>.</span> <span class='hs-varid'>zipWith</span> <span class='hs-varid'>number</span> <span class='hs-keyglyph'>[</span><span class='hs-num'>0</span><span class='hs-keyglyph'>..</span><span class='hs-keyglyph'>]</span> <span class='hs-varop'>.</span> <span class='hs-varid'>toTags</span><span class='hs-layout'>)</span> <span class='hs-varid'>z</span>
<a name="line-269"></a> <span class='hs-varid'>number</span> <span class='hs-varid'>j</span> <span class='hs-varid'>ea</span> <span class='hs-keyglyph'>=</span> <span class='hs-varid'>mapE</span> <span class='hs-layout'>(</span><span class='hs-keyglyph'>\</span><span class='hs-keyword'>_</span> <span class='hs-varid'>a</span> <span class='hs-keyglyph'>-></span> <span class='hs-layout'>(</span><span class='hs-varid'>j</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-varid'>ea</span>
<a name="line-270"></a> <span class='hs-keyword'>in</span> <span class='hs-varid'>mapZ_</span> <span class='hs-varid'>snd</span> <span class='hs-varop'>$</span> <span class='hs-varid'>filterZ_</span> <span class='hs-layout'>(</span><span class='hs-layout'>(</span><span class='hs-varop'>/=</span><span class='hs-varid'>i</span><span class='hs-layout'>)</span> <span class='hs-varop'>.</span> <span class='hs-varid'>fst</span><span class='hs-layout'>)</span> <span class='hs-varid'>numbered</span>
<a name="line-271"></a>
<a name="line-272"></a><span class='hs-comment'>-- ** Folds</span>
<a name="line-273"></a>
<a name="line-274"></a><a name="foldrZ"></a><span class='hs-comment'>-- | Analogous to 'foldr'. The 'Bool' argument to the step functions indicates</span>
<a name="line-275"></a><span class='hs-comment'>-- whether the current element is the focused one</span>
<a name="line-276"></a><span class='hs-definition'>foldrZ</span> <span class='hs-keyglyph'>::</span> <span class='hs-layout'>(</span><span class='hs-conid'>Bool</span> <span class='hs-keyglyph'>-></span> <span class='hs-varid'>a</span> <span class='hs-keyglyph'>-></span> <span class='hs-varid'>b</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'>b</span> <span class='hs-keyglyph'>-></span> <span class='hs-conid'>Zipper</span> <span class='hs-varid'>a</span> <span class='hs-keyglyph'>-></span> <span class='hs-varid'>b</span>
<a name="line-277"></a><span class='hs-definition'>foldrZ</span> <span class='hs-keyword'>_</span> <span class='hs-varid'>b</span> <span class='hs-conid'>Nothing</span> <span class='hs-keyglyph'>=</span> <span class='hs-varid'>b</span>
<a name="line-278"></a><span class='hs-definition'>foldrZ</span> <span class='hs-varid'>f</span> <span class='hs-varid'>b</span> <span class='hs-layout'>(</span><span class='hs-conid'>Just</span> <span class='hs-varid'>s</span><span class='hs-layout'>)</span> <span class='hs-keyglyph'>=</span> <span class='hs-keyword'>let</span> <span class='hs-varid'>b1</span> <span class='hs-keyglyph'>=</span> <span class='hs-varid'>foldr</span> <span class='hs-layout'>(</span><span class='hs-varid'>f</span> <span class='hs-conid'>False</span><span class='hs-layout'>)</span> <span class='hs-varid'>b</span> <span class='hs-layout'>(</span><span class='hs-conid'>W</span><span class='hs-varop'>.</span><span class='hs-varid'>down</span> <span class='hs-varid'>s</span><span class='hs-layout'>)</span>
<a name="line-279"></a> <span class='hs-varid'>b2</span> <span class='hs-keyglyph'>=</span> <span class='hs-varid'>f</span> <span class='hs-conid'>True</span> <span class='hs-layout'>(</span><span class='hs-conid'>W</span><span class='hs-varop'>.</span><span class='hs-varid'>focus</span> <span class='hs-varid'>s</span><span class='hs-layout'>)</span> <span class='hs-varid'>b1</span>
<a name="line-280"></a> <span class='hs-varid'>b3</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'>f</span> <span class='hs-conid'>False</span><span class='hs-layout'>)</span> <span class='hs-varid'>b2</span> <span class='hs-layout'>(</span><span class='hs-conid'>W</span><span class='hs-varop'>.</span><span class='hs-varid'>up</span> <span class='hs-varid'>s</span><span class='hs-layout'>)</span>
<a name="line-281"></a> <span class='hs-keyword'>in</span> <span class='hs-varid'>b3</span>
<a name="line-282"></a>
<a name="line-283"></a><a name="foldlZ"></a><span class='hs-comment'>-- | Analogous to 'foldl'. The 'Bool' argument to the step functions indicates</span>
<a name="line-284"></a><span class='hs-comment'>-- whether the current element is the focused one</span>
<a name="line-285"></a><span class='hs-definition'>foldlZ</span> <span class='hs-keyglyph'>::</span> <span class='hs-layout'>(</span><span class='hs-conid'>Bool</span> <span class='hs-keyglyph'>-></span> <span class='hs-varid'>b</span> <span class='hs-keyglyph'>-></span> <span class='hs-varid'>a</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'>b</span> <span class='hs-keyglyph'>-></span> <span class='hs-conid'>Zipper</span> <span class='hs-varid'>a</span> <span class='hs-keyglyph'>-></span> <span class='hs-varid'>b</span>
<a name="line-286"></a><span class='hs-definition'>foldlZ</span> <span class='hs-keyword'>_</span> <span class='hs-varid'>b</span> <span class='hs-conid'>Nothing</span> <span class='hs-keyglyph'>=</span> <span class='hs-varid'>b</span>
<a name="line-287"></a><span class='hs-definition'>foldlZ</span> <span class='hs-varid'>f</span> <span class='hs-varid'>b</span> <span class='hs-layout'>(</span><span class='hs-conid'>Just</span> <span class='hs-varid'>s</span><span class='hs-layout'>)</span> <span class='hs-keyglyph'>=</span> <span class='hs-keyword'>let</span> <span class='hs-varid'>b1</span> <span class='hs-keyglyph'>=</span> <span class='hs-varid'>foldr</span> <span class='hs-layout'>(</span><span class='hs-varid'>flip</span> <span class='hs-varop'>$</span> <span class='hs-varid'>f</span> <span class='hs-conid'>False</span><span class='hs-layout'>)</span> <span class='hs-varid'>b</span> <span class='hs-layout'>(</span><span class='hs-conid'>W</span><span class='hs-varop'>.</span><span class='hs-varid'>up</span> <span class='hs-varid'>s</span><span class='hs-layout'>)</span>
<a name="line-288"></a> <span class='hs-varid'>b2</span> <span class='hs-keyglyph'>=</span> <span class='hs-varid'>f</span> <span class='hs-conid'>True</span> <span class='hs-varid'>b1</span> <span class='hs-layout'>(</span><span class='hs-conid'>W</span><span class='hs-varop'>.</span><span class='hs-varid'>focus</span> <span class='hs-varid'>s</span><span class='hs-layout'>)</span>
<a name="line-289"></a> <span class='hs-varid'>b3</span> <span class='hs-keyglyph'>=</span> <span class='hs-varid'>foldl</span> <span class='hs-layout'>(</span><span class='hs-varid'>f</span> <span class='hs-conid'>False</span><span class='hs-layout'>)</span> <span class='hs-varid'>b2</span> <span class='hs-layout'>(</span><span class='hs-conid'>W</span><span class='hs-varop'>.</span><span class='hs-varid'>down</span> <span class='hs-varid'>s</span><span class='hs-layout'>)</span>
<a name="line-290"></a> <span class='hs-keyword'>in</span> <span class='hs-varid'>b3</span>
<a name="line-291"></a>
<a name="line-292"></a><a name="foldrZ_"></a><span class='hs-comment'>-- | 'foldrZ' without the 'Bool' argument.</span>
<a name="line-293"></a><span class='hs-definition'>foldrZ_</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'>b</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'>b</span> <span class='hs-keyglyph'>-></span> <span class='hs-conid'>Zipper</span> <span class='hs-varid'>a</span> <span class='hs-keyglyph'>-></span> <span class='hs-varid'>b</span>
<a name="line-294"></a><span class='hs-definition'>foldrZ_</span> <span class='hs-keyglyph'>=</span> <span class='hs-varid'>foldrZ</span> <span class='hs-varop'>.</span> <span class='hs-varid'>const</span>
<a name="line-295"></a>
<a name="line-296"></a><a name="foldlZ_"></a><span class='hs-comment'>-- | 'foldlZ' without the 'Bool' argument.</span>
<a name="line-297"></a><span class='hs-definition'>foldlZ_</span> <span class='hs-keyglyph'>::</span> <span class='hs-layout'>(</span><span class='hs-varid'>b</span> <span class='hs-keyglyph'>-></span> <span class='hs-varid'>a</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'>b</span> <span class='hs-keyglyph'>-></span> <span class='hs-conid'>Zipper</span> <span class='hs-varid'>a</span> <span class='hs-keyglyph'>-></span> <span class='hs-varid'>b</span>
<a name="line-298"></a><span class='hs-definition'>foldlZ_</span> <span class='hs-keyglyph'>=</span> <span class='hs-varid'>foldlZ</span> <span class='hs-varop'>.</span> <span class='hs-varid'>const</span>
<a name="line-299"></a>
<a name="line-300"></a><a name="elemZ"></a><span class='hs-comment'>-- | Find whether an element is present in a stack.</span>
<a name="line-301"></a><span class='hs-definition'>elemZ</span> <span class='hs-keyglyph'>::</span> <span class='hs-conid'>Eq</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-conid'>Zipper</span> <span class='hs-varid'>a</span> <span class='hs-keyglyph'>-></span> <span class='hs-conid'>Bool</span>
<a name="line-302"></a><span class='hs-definition'>elemZ</span> <span class='hs-varid'>a</span> <span class='hs-keyword'>as</span> <span class='hs-keyglyph'>=</span> <span class='hs-varid'>foldlZ_</span> <span class='hs-varid'>step</span> <span class='hs-conid'>False</span> <span class='hs-keyword'>as</span>
<a name="line-303"></a> <span class='hs-keyword'>where</span> <span class='hs-varid'>step</span> <span class='hs-conid'>True</span> <span class='hs-keyword'>_</span> <span class='hs-keyglyph'>=</span> <span class='hs-conid'>True</span>
<a name="line-304"></a> <span class='hs-varid'>step</span> <span class='hs-conid'>False</span> <span class='hs-varid'>a'</span> <span class='hs-keyglyph'>=</span> <span class='hs-varid'>a'</span> <span class='hs-varop'>==</span> <span class='hs-varid'>a</span>
<a name="line-305"></a>
<a name="line-306"></a>
<a name="line-307"></a><span class='hs-comment'>-- * Other utility functions</span>
<a name="line-308"></a>
<a name="line-309"></a><a name="getI"></a><span class='hs-comment'>-- | Safe version of '!!'</span>
<a name="line-310"></a><span class='hs-definition'>getI</span> <span class='hs-keyglyph'>::</span> <span class='hs-conid'>Int</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'>Maybe</span> <span class='hs-varid'>a</span>
<a name="line-311"></a><span class='hs-definition'>getI</span> <span class='hs-keyword'>_</span> <span class='hs-conid'>[]</span> <span class='hs-keyglyph'>=</span> <span class='hs-conid'>Nothing</span>
<a name="line-312"></a><span class='hs-definition'>getI</span> <span class='hs-num'>0</span> <span class='hs-layout'>(</span><span class='hs-varid'>a</span><span class='hs-conop'>:</span><span class='hs-keyword'>_</span><span class='hs-layout'>)</span> <span class='hs-keyglyph'>=</span> <span class='hs-conid'>Just</span> <span class='hs-varid'>a</span>
<a name="line-313"></a><span class='hs-definition'>getI</span> <span class='hs-varid'>i</span> <span class='hs-layout'>(</span><span class='hs-keyword'>_</span><span class='hs-conop'>:</span><span class='hs-keyword'>as</span><span class='hs-layout'>)</span> <span class='hs-keyglyph'>=</span> <span class='hs-varid'>getI</span> <span class='hs-layout'>(</span><span class='hs-varid'>i</span><span class='hs-comment'>-</span><span class='hs-num'>1</span><span class='hs-layout'>)</span> <span class='hs-keyword'>as</span>
<a name="line-314"></a>
<a name="line-315"></a><a name="mapE"></a><span class='hs-comment'>-- | Map a function across both 'Left's and 'Right's.</span>
<a name="line-316"></a><span class='hs-comment'>-- The 'Bool' argument is 'True' in a 'Right', 'False'</span>
<a name="line-317"></a><span class='hs-comment'>-- in a 'Left'.</span>
<a name="line-318"></a><span class='hs-definition'>mapE</span> <span class='hs-keyglyph'>::</span> <span class='hs-layout'>(</span><span class='hs-conid'>Bool</span> <span class='hs-keyglyph'>-></span> <span class='hs-varid'>a</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-conid'>Either</span> <span class='hs-varid'>a</span> <span class='hs-varid'>a</span> <span class='hs-keyglyph'>-></span> <span class='hs-conid'>Either</span> <span class='hs-varid'>b</span> <span class='hs-varid'>b</span>
<a name="line-319"></a><span class='hs-definition'>mapE</span> <span class='hs-varid'>f</span> <span class='hs-layout'>(</span><span class='hs-conid'>Left</span> <span class='hs-varid'>a</span><span class='hs-layout'>)</span> <span class='hs-keyglyph'>=</span> <span class='hs-conid'>Left</span> <span class='hs-varop'>$</span> <span class='hs-varid'>f</span> <span class='hs-conid'>False</span> <span class='hs-varid'>a</span>
<a name="line-320"></a><span class='hs-definition'>mapE</span> <span class='hs-varid'>f</span> <span class='hs-layout'>(</span><span class='hs-conid'>Right</span> <span class='hs-varid'>a</span><span class='hs-layout'>)</span> <span class='hs-keyglyph'>=</span> <span class='hs-conid'>Right</span> <span class='hs-varop'>$</span> <span class='hs-varid'>f</span> <span class='hs-conid'>True</span> <span class='hs-varid'>a</span>
<a name="line-321"></a>
<a name="line-322"></a><a name="mapE_"></a><span class='hs-definition'>mapE_</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'>b</span><span class='hs-layout'>)</span> <span class='hs-keyglyph'>-></span> <span class='hs-conid'>Either</span> <span class='hs-varid'>a</span> <span class='hs-varid'>a</span> <span class='hs-keyglyph'>-></span> <span class='hs-conid'>Either</span> <span class='hs-varid'>b</span> <span class='hs-varid'>b</span>
<a name="line-323"></a><span class='hs-definition'>mapE_</span> <span class='hs-keyglyph'>=</span> <span class='hs-varid'>mapE</span> <span class='hs-varop'>.</span> <span class='hs-varid'>const</span>
<a name="line-324"></a>
<a name="line-325"></a><a name="mapEM"></a><span class='hs-comment'>-- | Monadic version of 'mapE'</span>
<a name="line-326"></a><span class='hs-definition'>mapEM</span> <span class='hs-keyglyph'>::</span> <span class='hs-conid'>Monad</span> <span class='hs-varid'>m</span> <span class='hs-keyglyph'>=></span> <span class='hs-layout'>(</span><span class='hs-conid'>Bool</span> <span class='hs-keyglyph'>-></span> <span class='hs-varid'>a</span> <span class='hs-keyglyph'>-></span> <span class='hs-varid'>m</span> <span class='hs-varid'>b</span><span class='hs-layout'>)</span> <span class='hs-keyglyph'>-></span> <span class='hs-conid'>Either</span> <span class='hs-varid'>a</span> <span class='hs-varid'>a</span> <span class='hs-keyglyph'>-></span> <span class='hs-varid'>m</span> <span class='hs-layout'>(</span><span class='hs-conid'>Either</span> <span class='hs-varid'>b</span> <span class='hs-varid'>b</span><span class='hs-layout'>)</span>
<a name="line-327"></a><span class='hs-definition'>mapEM</span> <span class='hs-varid'>f</span> <span class='hs-layout'>(</span><span class='hs-conid'>Left</span> <span class='hs-varid'>a</span><span class='hs-layout'>)</span> <span class='hs-keyglyph'>=</span> <span class='hs-conid'>Left</span> <span class='hs-varop'>`liftM`</span> <span class='hs-varid'>f</span> <span class='hs-conid'>False</span> <span class='hs-varid'>a</span>
<a name="line-328"></a><span class='hs-definition'>mapEM</span> <span class='hs-varid'>f</span> <span class='hs-layout'>(</span><span class='hs-conid'>Right</span> <span class='hs-varid'>a</span><span class='hs-layout'>)</span> <span class='hs-keyglyph'>=</span> <span class='hs-conid'>Right</span> <span class='hs-varop'>`liftM`</span> <span class='hs-varid'>f</span> <span class='hs-conid'>True</span> <span class='hs-varid'>a</span>
<a name="line-329"></a>
<a name="line-330"></a><a name="mapEM_"></a><span class='hs-definition'>mapEM_</span> <span class='hs-keyglyph'>::</span> <span class='hs-conid'>Monad</span> <span class='hs-varid'>m</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'>m</span> <span class='hs-varid'>b</span><span class='hs-layout'>)</span> <span class='hs-keyglyph'>-></span> <span class='hs-conid'>Either</span> <span class='hs-varid'>a</span> <span class='hs-varid'>a</span> <span class='hs-keyglyph'>-></span> <span class='hs-varid'>m</span> <span class='hs-layout'>(</span><span class='hs-conid'>Either</span> <span class='hs-varid'>b</span> <span class='hs-varid'>b</span><span class='hs-layout'>)</span>
<a name="line-331"></a><span class='hs-definition'>mapEM_</span> <span class='hs-keyglyph'>=</span> <span class='hs-varid'>mapEM</span> <span class='hs-varop'>.</span> <span class='hs-varid'>const</span>
<a name="line-332"></a>
<a name="line-333"></a><a name="fromE"></a><span class='hs-comment'>-- | Get the @a@ from an @Either a a@</span>
<a name="line-334"></a><span class='hs-definition'>fromE</span> <span class='hs-keyglyph'>::</span> <span class='hs-conid'>Either</span> <span class='hs-varid'>a</span> <span class='hs-varid'>a</span> <span class='hs-keyglyph'>-></span> <span class='hs-varid'>a</span>
<a name="line-335"></a><span class='hs-definition'>fromE</span> <span class='hs-layout'>(</span><span class='hs-conid'>Right</span> <span class='hs-varid'>a</span><span class='hs-layout'>)</span> <span class='hs-keyglyph'>=</span> <span class='hs-varid'>a</span>
<a name="line-336"></a><span class='hs-definition'>fromE</span> <span class='hs-layout'>(</span><span class='hs-conid'>Left</span> <span class='hs-varid'>a</span><span class='hs-layout'>)</span> <span class='hs-keyglyph'>=</span> <span class='hs-varid'>a</span>
<a name="line-337"></a>
<a name="line-338"></a><a name="tagBy"></a><span class='hs-comment'>-- | Tag the element with 'Right' if the property is true, 'Left' otherwise</span>
<a name="line-339"></a><span class='hs-definition'>tagBy</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'>Bool</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'>Either</span> <span class='hs-varid'>a</span> <span class='hs-varid'>a</span>
<a name="line-340"></a><span class='hs-definition'>tagBy</span> <span class='hs-varid'>p</span> <span class='hs-varid'>a</span> <span class='hs-keyglyph'>=</span> <span class='hs-keyword'>if</span> <span class='hs-varid'>p</span> <span class='hs-varid'>a</span> <span class='hs-keyword'>then</span> <span class='hs-conid'>Right</span> <span class='hs-varid'>a</span> <span class='hs-keyword'>else</span> <span class='hs-conid'>Left</span> <span class='hs-varid'>a</span>
</pre></body>
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