<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Strict//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-strict.dtd">
<html>
<head>
<!-- Generated by HsColour, http://code.haskell.org/~malcolm/hscolour/ -->
<title>XMonad/Layout/ComboP.hs</title>
<link type='text/css' rel='stylesheet' href='hscolour.css' />
</head>
<body>
<pre><a name="line-1"></a><span class='hs-comment'>{-# LANGUAGE TypeSynonymInstances, DeriveDataTypeable, MultiParamTypeClasses, FlexibleContexts, FlexibleInstances, PatternGuards #-}</span>
<a name="line-2"></a><span class='hs-comment'>-----------------------------------------------------------------------------</span>
<a name="line-3"></a><span class='hs-comment'>-- |</span>
<a name="line-4"></a><span class='hs-comment'>-- Module : XMonad.Layout.ComboP</span>
<a name="line-5"></a><span class='hs-comment'>-- Copyright : (c) Konstantin Sobolev <konstantin.sobolev@gmail.com></span>
<a name="line-6"></a><span class='hs-comment'>-- License : BSD-style (see LICENSE)</span>
<a name="line-7"></a><span class='hs-comment'>--</span>
<a name="line-8"></a><span class='hs-comment'>-- Maintainer : Konstantin Sobolev <konstantin.sobolev@gmail.com></span>
<a name="line-9"></a><span class='hs-comment'>-- Stability : unstable</span>
<a name="line-10"></a><span class='hs-comment'>-- Portability : unportable</span>
<a name="line-11"></a><span class='hs-comment'>--</span>
<a name="line-12"></a><span class='hs-comment'>-- A layout that combines multiple layouts and allows to specify where to put</span>
<a name="line-13"></a><span class='hs-comment'>-- new windows.</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'>Layout</span><span class='hs-varop'>.</span><span class='hs-conid'>ComboP</span> <span class='hs-layout'>(</span>
<a name="line-18"></a> <span class='hs-comment'>-- * Usage</span>
<a name="line-19"></a> <span class='hs-comment'>-- $usage</span>
<a name="line-20"></a> <span class='hs-varid'>combineTwoP</span><span class='hs-layout'>,</span>
<a name="line-21"></a> <span class='hs-conid'>CombineTwoP</span><span class='hs-layout'>,</span>
<a name="line-22"></a> <span class='hs-conid'>SwapWindow</span><span class='hs-layout'>(</span><span class='hs-keyglyph'>..</span><span class='hs-layout'>)</span><span class='hs-layout'>,</span>
<a name="line-23"></a> <span class='hs-conid'>Property</span><span class='hs-layout'>(</span><span class='hs-keyglyph'>..</span><span class='hs-layout'>)</span>
<a name="line-24"></a> <span class='hs-layout'>)</span> <span class='hs-keyword'>where</span>
<a name="line-25"></a>
<a name="line-26"></a><span class='hs-keyword'>import</span> <span class='hs-conid'>Data</span><span class='hs-varop'>.</span><span class='hs-conid'>List</span> <span class='hs-layout'>(</span> <span class='hs-varid'>delete</span><span class='hs-layout'>,</span> <span class='hs-varid'>intersect</span><span class='hs-layout'>,</span> <span class='hs-layout'>(</span><span class='hs-varop'>\\</span><span class='hs-layout'>)</span> <span class='hs-layout'>)</span>
<a name="line-27"></a><span class='hs-keyword'>import</span> <span class='hs-conid'>Data</span><span class='hs-varop'>.</span><span class='hs-conid'>Maybe</span> <span class='hs-layout'>(</span> <span class='hs-varid'>isJust</span> <span class='hs-layout'>)</span>
<a name="line-28"></a><span class='hs-keyword'>import</span> <span class='hs-conid'>Control</span><span class='hs-varop'>.</span><span class='hs-conid'>Monad</span>
<a name="line-29"></a><span class='hs-keyword'>import</span> <span class='hs-conid'>XMonad</span> <span class='hs-varid'>hiding</span> <span class='hs-layout'>(</span><span class='hs-varid'>focus</span><span class='hs-layout'>)</span>
<a name="line-30"></a><span class='hs-keyword'>import</span> <span class='hs-conid'>XMonad</span><span class='hs-varop'>.</span><span class='hs-conid'>StackSet</span> <span class='hs-layout'>(</span> <span class='hs-varid'>integrate</span><span class='hs-layout'>,</span> <span class='hs-conid'>Workspace</span> <span class='hs-layout'>(</span><span class='hs-keyglyph'>..</span><span class='hs-layout'>)</span><span class='hs-layout'>,</span> <span class='hs-conid'>Stack</span><span class='hs-layout'>(</span><span class='hs-keyglyph'>..</span><span class='hs-layout'>)</span> <span class='hs-layout'>)</span>
<a name="line-31"></a><span class='hs-keyword'>import</span> <span class='hs-conid'>XMonad</span><span class='hs-varop'>.</span><span class='hs-conid'>Layout</span><span class='hs-varop'>.</span><span class='hs-conid'>WindowNavigation</span>
<a name="line-32"></a><span class='hs-keyword'>import</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'>WindowProperties</span>
<a name="line-33"></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-34"></a>
<a name="line-35"></a><span class='hs-comment'>-- $usage</span>
<a name="line-36"></a><span class='hs-comment'>-- You can use this module with the following in your @~\/.xmonad\/xmonad.hs@:</span>
<a name="line-37"></a><span class='hs-comment'>--</span>
<a name="line-38"></a><span class='hs-comment'>-- > import XMonad.Layout.ComboP</span>
<a name="line-39"></a><span class='hs-comment'>--</span>
<a name="line-40"></a><span class='hs-comment'>-- and add something like</span>
<a name="line-41"></a><span class='hs-comment'>--</span>
<a name="line-42"></a><span class='hs-comment'>-- > combineTwoP (TwoPane 0.03 0.5) (tabbed shrinkText defaultTConf) (tabbed shrinkText defaultTConf) (ClassName "Firefox")</span>
<a name="line-43"></a><span class='hs-comment'>--</span>
<a name="line-44"></a><span class='hs-comment'>-- to your layouts. This way all windows with class = \"Firefox\" will always go</span>
<a name="line-45"></a><span class='hs-comment'>-- to the left pane, all others - to the right.</span>
<a name="line-46"></a><span class='hs-comment'>--</span>
<a name="line-47"></a><span class='hs-comment'>-- For more detailed instructions on editing the layoutHook see:</span>
<a name="line-48"></a><span class='hs-comment'>--</span>
<a name="line-49"></a><span class='hs-comment'>-- "XMonad.Doc.Extending#Editing_the_layout_hook"</span>
<a name="line-50"></a><span class='hs-comment'>--</span>
<a name="line-51"></a><span class='hs-comment'>-- 'combineTwoP' is a simple layout combinator based on 'combineTwo' from Combo, with</span>
<a name="line-52"></a><span class='hs-comment'>-- addition of a 'Property' which tells where to put new windows. Windows mathing</span>
<a name="line-53"></a><span class='hs-comment'>-- the property will go into the first part, all others will go into the second</span>
<a name="line-54"></a><span class='hs-comment'>-- part. It supports @Move@ messages as 'combineTwo' does, but it also introduces</span>
<a name="line-55"></a><span class='hs-comment'>-- 'SwapWindow' message which sends focused window to the other part. It is</span>
<a name="line-56"></a><span class='hs-comment'>-- required because @Move@ commands don't work when one of the parts is empty.</span>
<a name="line-57"></a><span class='hs-comment'>-- To use it, import \"XMonad.Layout.WindowNavigation\", and add the following key</span>
<a name="line-58"></a><span class='hs-comment'>-- bindings (or something similar):</span>
<a name="line-59"></a><span class='hs-comment'>--</span>
<a name="line-60"></a><span class='hs-comment'>-- > , ((modm .|. controlMask .|. shiftMask, xK_Right), sendMessage $ Move R)</span>
<a name="line-61"></a><span class='hs-comment'>-- > , ((modm .|. controlMask .|. shiftMask, xK_Left ), sendMessage $ Move L)</span>
<a name="line-62"></a><span class='hs-comment'>-- > , ((modm .|. controlMask .|. shiftMask, xK_Up ), sendMessage $ Move U)</span>
<a name="line-63"></a><span class='hs-comment'>-- > , ((modm .|. controlMask .|. shiftMask, xK_Down ), sendMessage $ Move D)</span>
<a name="line-64"></a><span class='hs-comment'>-- > , ((modm .|. controlMask .|. shiftMask, xK_s ), sendMessage $ SwapWindow)</span>
<a name="line-65"></a><span class='hs-comment'>--</span>
<a name="line-66"></a><span class='hs-comment'>-- For detailed instruction on editing the key binding see</span>
<a name="line-67"></a><span class='hs-comment'>-- "XMonad.Doc.Extending#Editing_key_bindings".</span>
<a name="line-68"></a>
<a name="line-69"></a><a name="SwapWindow"></a><span class='hs-keyword'>data</span> <span class='hs-conid'>SwapWindow</span> <span class='hs-keyglyph'>=</span> <span class='hs-conid'>SwapWindow</span> <span class='hs-comment'>-- ^ Swap window between panes</span>
<a name="line-70"></a> <span class='hs-keyglyph'>|</span> <span class='hs-conid'>SwapWindowN</span> <span class='hs-conid'>Int</span> <span class='hs-comment'>-- ^ Swap window between panes in the N-th nested ComboP. @SwapWindowN 0@ equals to SwapWindow</span>
<a name="line-71"></a> <span class='hs-keyword'>deriving</span> <span class='hs-layout'>(</span><span class='hs-conid'>Read</span><span class='hs-layout'>,</span> <span class='hs-conid'>Show</span><span class='hs-layout'>,</span> <span class='hs-conid'>Typeable</span><span class='hs-layout'>)</span>
<a name="line-72"></a><span class='hs-keyword'>instance</span> <span class='hs-conid'>Message</span> <span class='hs-conid'>SwapWindow</span>
<a name="line-73"></a>
<a name="line-74"></a><a name="CombineTwoP"></a><span class='hs-keyword'>data</span> <span class='hs-conid'>CombineTwoP</span> <span class='hs-varid'>l</span> <span class='hs-varid'>l1</span> <span class='hs-varid'>l2</span> <span class='hs-varid'>a</span> <span class='hs-keyglyph'>=</span> <span class='hs-conid'>C2P</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-varid'>a</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-varid'>l</span> <span class='hs-layout'>(</span><span class='hs-varid'>l1</span> <span class='hs-varid'>a</span><span class='hs-layout'>)</span> <span class='hs-layout'>(</span><span class='hs-varid'>l2</span> <span class='hs-varid'>a</span><span class='hs-layout'>)</span> <span class='hs-conid'>Property</span>
<a name="line-75"></a> <span class='hs-keyword'>deriving</span> <span class='hs-layout'>(</span><span class='hs-conid'>Read</span><span class='hs-layout'>,</span> <span class='hs-conid'>Show</span><span class='hs-layout'>)</span>
<a name="line-76"></a>
<a name="line-77"></a><a name="combineTwoP"></a><span class='hs-definition'>combineTwoP</span> <span class='hs-keyglyph'>::</span> <span class='hs-layout'>(</span><span class='hs-conid'>LayoutClass</span> <span class='hs-varid'>super</span><span class='hs-conid'>()</span><span class='hs-layout'>,</span> <span class='hs-conid'>LayoutClass</span> <span class='hs-varid'>l1</span> <span class='hs-conid'>Window</span><span class='hs-layout'>,</span> <span class='hs-conid'>LayoutClass</span> <span class='hs-varid'>l2</span> <span class='hs-conid'>Window</span><span class='hs-layout'>)</span> <span class='hs-keyglyph'>=></span>
<a name="line-78"></a> <span class='hs-varid'>super</span> <span class='hs-conid'>()</span> <span class='hs-keyglyph'>-></span> <span class='hs-varid'>l1</span> <span class='hs-conid'>Window</span> <span class='hs-keyglyph'>-></span> <span class='hs-varid'>l2</span> <span class='hs-conid'>Window</span> <span class='hs-keyglyph'>-></span> <span class='hs-conid'>Property</span> <span class='hs-keyglyph'>-></span> <span class='hs-conid'>CombineTwoP</span> <span class='hs-layout'>(</span><span class='hs-varid'>super</span> <span class='hs-conid'>()</span><span class='hs-layout'>)</span> <span class='hs-varid'>l1</span> <span class='hs-varid'>l2</span> <span class='hs-conid'>Window</span>
<a name="line-79"></a><span class='hs-definition'>combineTwoP</span> <span class='hs-keyglyph'>=</span> <span class='hs-conid'>C2P</span> <span class='hs-conid'>[]</span> <span class='hs-conid'>[]</span> <span class='hs-conid'>[]</span>
<a name="line-80"></a>
<a name="line-81"></a><span class='hs-keyword'>instance</span> <span class='hs-layout'>(</span><span class='hs-conid'>LayoutClass</span> <span class='hs-varid'>l</span> <span class='hs-conid'>()</span><span class='hs-layout'>,</span> <span class='hs-conid'>LayoutClass</span> <span class='hs-varid'>l1</span> <span class='hs-conid'>Window</span><span class='hs-layout'>,</span> <span class='hs-conid'>LayoutClass</span> <span class='hs-varid'>l2</span> <span class='hs-conid'>Window</span><span class='hs-layout'>)</span> <span class='hs-keyglyph'>=></span>
<a name="line-82"></a> <span class='hs-conid'>LayoutClass</span> <span class='hs-layout'>(</span><span class='hs-conid'>CombineTwoP</span> <span class='hs-layout'>(</span><span class='hs-varid'>l</span> <span class='hs-conid'>()</span><span class='hs-layout'>)</span> <span class='hs-varid'>l1</span> <span class='hs-varid'>l2</span><span class='hs-layout'>)</span> <span class='hs-conid'>Window</span> <span class='hs-keyword'>where</span>
<a name="line-83"></a> <span class='hs-varid'>doLayout</span> <span class='hs-layout'>(</span><span class='hs-conid'>C2P</span> <span class='hs-varid'>f</span> <span class='hs-varid'>w1</span> <span class='hs-varid'>w2</span> <span class='hs-varid'>super</span> <span class='hs-varid'>l1</span> <span class='hs-varid'>l2</span> <span class='hs-varid'>prop</span><span class='hs-layout'>)</span> <span class='hs-varid'>rinput</span> <span class='hs-varid'>s</span> <span class='hs-keyglyph'>=</span>
<a name="line-84"></a> <span class='hs-keyword'>let</span> <span class='hs-varid'>origws</span> <span class='hs-keyglyph'>=</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-comment'>-- passed in windows</span>
<a name="line-85"></a> <span class='hs-varid'>w1c</span> <span class='hs-keyglyph'>=</span> <span class='hs-varid'>origws</span> <span class='hs-varop'>`intersect`</span> <span class='hs-varid'>w1</span> <span class='hs-comment'>-- current windows in the first pane</span>
<a name="line-86"></a> <span class='hs-varid'>w2c</span> <span class='hs-keyglyph'>=</span> <span class='hs-varid'>origws</span> <span class='hs-varop'>`intersect`</span> <span class='hs-varid'>w2</span> <span class='hs-comment'>-- current windows in the second pane</span>
<a name="line-87"></a> <span class='hs-varid'>new</span> <span class='hs-keyglyph'>=</span> <span class='hs-varid'>origws</span> <span class='hs-varop'>\\</span> <span class='hs-layout'>(</span><span class='hs-varid'>w1c</span> <span class='hs-varop'>++</span> <span class='hs-varid'>w2c</span><span class='hs-layout'>)</span> <span class='hs-comment'>-- new windows</span>
<a name="line-88"></a> <span class='hs-varid'>superstack</span> <span class='hs-keyglyph'>=</span> <span class='hs-conid'>Just</span> <span class='hs-conid'>Stack</span> <span class='hs-layout'>{</span> <span class='hs-varid'>focus</span><span class='hs-keyglyph'>=</span><span class='hs-conid'>()</span><span class='hs-layout'>,</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-varid'>down</span><span class='hs-keyglyph'>=</span><span class='hs-keyglyph'>[</span><span class='hs-conid'>()</span><span class='hs-keyglyph'>]</span> <span class='hs-layout'>}</span>
<a name="line-89"></a> <span class='hs-varid'>f'</span> <span class='hs-keyglyph'>=</span> <span class='hs-varid'>focus</span> <span class='hs-varid'>s</span><span class='hs-conop'>:</span><span class='hs-varid'>delete</span> <span class='hs-layout'>(</span><span class='hs-varid'>focus</span> <span class='hs-varid'>s</span><span class='hs-layout'>)</span> <span class='hs-varid'>f</span> <span class='hs-comment'>-- list of focused windows, contains 2 elements at most</span>
<a name="line-90"></a> <span class='hs-keyword'>in</span> <span class='hs-keyword'>do</span>
<a name="line-91"></a> <span class='hs-varid'>matching</span> <span class='hs-keyglyph'><-</span> <span class='hs-layout'>(</span><span class='hs-varid'>hasProperty</span> <span class='hs-varid'>prop</span><span class='hs-layout'>)</span> <span class='hs-varop'>`filterM`</span> <span class='hs-varid'>new</span> <span class='hs-comment'>-- new windows matching predecate</span>
<a name="line-92"></a> <span class='hs-keyword'>let</span> <span class='hs-varid'>w1'</span> <span class='hs-keyglyph'>=</span> <span class='hs-varid'>w1c</span> <span class='hs-varop'>++</span> <span class='hs-varid'>matching</span> <span class='hs-comment'>-- updated first pane windows</span>
<a name="line-93"></a> <span class='hs-varid'>w2'</span> <span class='hs-keyglyph'>=</span> <span class='hs-varid'>w2c</span> <span class='hs-varop'>++</span> <span class='hs-layout'>(</span><span class='hs-varid'>new</span> <span class='hs-varop'>\\</span> <span class='hs-varid'>matching</span><span class='hs-layout'>)</span> <span class='hs-comment'>-- updated second pane windows</span>
<a name="line-94"></a> <span class='hs-varid'>s1</span> <span class='hs-keyglyph'>=</span> <span class='hs-varid'>differentiate</span> <span class='hs-varid'>f'</span> <span class='hs-varid'>w1'</span> <span class='hs-comment'>-- first pane stack</span>
<a name="line-95"></a> <span class='hs-varid'>s2</span> <span class='hs-keyglyph'>=</span> <span class='hs-varid'>differentiate</span> <span class='hs-varid'>f'</span> <span class='hs-varid'>w2'</span> <span class='hs-comment'>-- second pane stack</span>
<a name="line-96"></a> <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-varid'>r1</span><span class='hs-layout'>)</span><span class='hs-layout'>,</span><span class='hs-layout'>(</span><span class='hs-conid'>()</span><span class='hs-layout'>,</span><span class='hs-varid'>r2</span><span class='hs-layout'>)</span><span class='hs-keyglyph'>]</span><span class='hs-layout'>,</span> <span class='hs-varid'>msuper'</span><span class='hs-layout'>)</span> <span class='hs-keyglyph'><-</span> <span class='hs-varid'>runLayout</span> <span class='hs-layout'>(</span><span class='hs-conid'>Workspace</span> <span class='hs-str'>""</span> <span class='hs-varid'>super</span> <span class='hs-varid'>superstack</span><span class='hs-layout'>)</span> <span class='hs-varid'>rinput</span>
<a name="line-97"></a> <span class='hs-layout'>(</span><span class='hs-varid'>wrs1</span><span class='hs-layout'>,</span> <span class='hs-varid'>ml1'</span><span class='hs-layout'>)</span> <span class='hs-keyglyph'><-</span> <span class='hs-varid'>runLayout</span> <span class='hs-layout'>(</span><span class='hs-conid'>Workspace</span> <span class='hs-str'>""</span> <span class='hs-varid'>l1</span> <span class='hs-varid'>s1</span><span class='hs-layout'>)</span> <span class='hs-varid'>r1</span>
<a name="line-98"></a> <span class='hs-layout'>(</span><span class='hs-varid'>wrs2</span><span class='hs-layout'>,</span> <span class='hs-varid'>ml2'</span><span class='hs-layout'>)</span> <span class='hs-keyglyph'><-</span> <span class='hs-varid'>runLayout</span> <span class='hs-layout'>(</span><span class='hs-conid'>Workspace</span> <span class='hs-str'>""</span> <span class='hs-varid'>l2</span> <span class='hs-varid'>s2</span><span class='hs-layout'>)</span> <span class='hs-varid'>r2</span>
<a name="line-99"></a> <span class='hs-varid'>return</span> <span class='hs-layout'>(</span><span class='hs-varid'>wrs1</span><span class='hs-varop'>++</span><span class='hs-varid'>wrs2</span><span class='hs-layout'>,</span> <span class='hs-conid'>Just</span> <span class='hs-varop'>$</span> <span class='hs-conid'>C2P</span> <span class='hs-varid'>f'</span> <span class='hs-varid'>w1'</span> <span class='hs-varid'>w2'</span> <span class='hs-layout'>(</span><span class='hs-varid'>maybe</span> <span class='hs-varid'>super</span> <span class='hs-varid'>id</span> <span class='hs-varid'>msuper'</span><span class='hs-layout'>)</span>
<a name="line-100"></a> <span class='hs-layout'>(</span><span class='hs-varid'>maybe</span> <span class='hs-varid'>l1</span> <span class='hs-varid'>id</span> <span class='hs-varid'>ml1'</span><span class='hs-layout'>)</span> <span class='hs-layout'>(</span><span class='hs-varid'>maybe</span> <span class='hs-varid'>l2</span> <span class='hs-varid'>id</span> <span class='hs-varid'>ml2'</span><span class='hs-layout'>)</span> <span class='hs-varid'>prop</span><span class='hs-layout'>)</span>
<a name="line-101"></a>
<a name="line-102"></a> <span class='hs-varid'>handleMessage</span> <span class='hs-varid'>us</span><span class='hs-keyglyph'>@</span><span class='hs-layout'>(</span><span class='hs-conid'>C2P</span> <span class='hs-varid'>f</span> <span class='hs-varid'>ws1</span> <span class='hs-varid'>ws2</span> <span class='hs-varid'>super</span> <span class='hs-varid'>l1</span> <span class='hs-varid'>l2</span> <span class='hs-varid'>prop</span><span class='hs-layout'>)</span> <span class='hs-varid'>m</span>
<a name="line-103"></a> <span class='hs-keyglyph'>|</span> <span class='hs-conid'>Just</span> <span class='hs-conid'>SwapWindow</span> <span class='hs-keyglyph'><-</span> <span class='hs-varid'>fromMessage</span> <span class='hs-varid'>m</span> <span class='hs-keyglyph'>=</span> <span class='hs-varid'>swap</span> <span class='hs-varid'>us</span>
<a name="line-104"></a> <span class='hs-keyglyph'>|</span> <span class='hs-conid'>Just</span> <span class='hs-layout'>(</span><span class='hs-conid'>SwapWindowN</span> <span class='hs-num'>0</span><span class='hs-layout'>)</span> <span class='hs-keyglyph'><-</span> <span class='hs-varid'>fromMessage</span> <span class='hs-varid'>m</span> <span class='hs-keyglyph'>=</span> <span class='hs-varid'>swap</span> <span class='hs-varid'>us</span>
<a name="line-105"></a> <span class='hs-keyglyph'>|</span> <span class='hs-conid'>Just</span> <span class='hs-layout'>(</span><span class='hs-conid'>SwapWindowN</span> <span class='hs-varid'>n</span><span class='hs-layout'>)</span> <span class='hs-keyglyph'><-</span> <span class='hs-varid'>fromMessage</span> <span class='hs-varid'>m</span> <span class='hs-keyglyph'>=</span> <span class='hs-varid'>forwardToFocused</span> <span class='hs-varid'>us</span> <span class='hs-varop'>$</span> <span class='hs-conid'>SomeMessage</span> <span class='hs-varop'>$</span> <span class='hs-conid'>SwapWindowN</span> <span class='hs-varop'>$</span> <span class='hs-varid'>n</span><span class='hs-comment'>-</span><span class='hs-num'>1</span>
<a name="line-106"></a>
<a name="line-107"></a> <span class='hs-keyglyph'>|</span> <span class='hs-conid'>Just</span> <span class='hs-layout'>(</span><span class='hs-conid'>MoveWindowToWindow</span> <span class='hs-varid'>w1</span> <span class='hs-varid'>w2</span><span class='hs-layout'>)</span> <span class='hs-keyglyph'><-</span> <span class='hs-varid'>fromMessage</span> <span class='hs-varid'>m</span><span class='hs-layout'>,</span>
<a name="line-108"></a> <span class='hs-varid'>w1</span> <span class='hs-varop'>`elem`</span> <span class='hs-varid'>ws1</span><span class='hs-layout'>,</span>
<a name="line-109"></a> <span class='hs-varid'>w2</span> <span class='hs-varop'>`elem`</span> <span class='hs-varid'>ws2</span> <span class='hs-keyglyph'>=</span> <span class='hs-varid'>return</span> <span class='hs-varop'>$</span> <span class='hs-conid'>Just</span> <span class='hs-varop'>$</span> <span class='hs-conid'>C2P</span> <span class='hs-varid'>f</span> <span class='hs-layout'>(</span><span class='hs-varid'>delete</span> <span class='hs-varid'>w1</span> <span class='hs-varid'>ws1</span><span class='hs-layout'>)</span> <span class='hs-layout'>(</span><span class='hs-varid'>w1</span><span class='hs-conop'>:</span><span class='hs-varid'>ws2</span><span class='hs-layout'>)</span> <span class='hs-varid'>super</span> <span class='hs-varid'>l1</span> <span class='hs-varid'>l2</span> <span class='hs-varid'>prop</span>
<a name="line-110"></a>
<a name="line-111"></a> <span class='hs-keyglyph'>|</span> <span class='hs-conid'>Just</span> <span class='hs-layout'>(</span><span class='hs-conid'>MoveWindowToWindow</span> <span class='hs-varid'>w1</span> <span class='hs-varid'>w2</span><span class='hs-layout'>)</span> <span class='hs-keyglyph'><-</span> <span class='hs-varid'>fromMessage</span> <span class='hs-varid'>m</span><span class='hs-layout'>,</span>
<a name="line-112"></a> <span class='hs-varid'>w1</span> <span class='hs-varop'>`elem`</span> <span class='hs-varid'>ws2</span><span class='hs-layout'>,</span>
<a name="line-113"></a> <span class='hs-varid'>w2</span> <span class='hs-varop'>`elem`</span> <span class='hs-varid'>ws1</span> <span class='hs-keyglyph'>=</span> <span class='hs-varid'>return</span> <span class='hs-varop'>$</span> <span class='hs-conid'>Just</span> <span class='hs-varop'>$</span> <span class='hs-conid'>C2P</span> <span class='hs-varid'>f</span> <span class='hs-layout'>(</span><span class='hs-varid'>w1</span><span class='hs-conop'>:</span><span class='hs-varid'>ws1</span><span class='hs-layout'>)</span> <span class='hs-layout'>(</span><span class='hs-varid'>delete</span> <span class='hs-varid'>w1</span> <span class='hs-varid'>ws2</span><span class='hs-layout'>)</span> <span class='hs-varid'>super</span> <span class='hs-varid'>l1</span> <span class='hs-varid'>l2</span> <span class='hs-varid'>prop</span>
<a name="line-114"></a>
<a name="line-115"></a> <span class='hs-keyglyph'>|</span> <span class='hs-varid'>otherwise</span> <span class='hs-keyglyph'>=</span> <span class='hs-keyword'>do</span> <span class='hs-varid'>ml1'</span> <span class='hs-keyglyph'><-</span> <span class='hs-varid'>handleMessage</span> <span class='hs-varid'>l1</span> <span class='hs-varid'>m</span>
<a name="line-116"></a> <span class='hs-varid'>ml2'</span> <span class='hs-keyglyph'><-</span> <span class='hs-varid'>handleMessage</span> <span class='hs-varid'>l2</span> <span class='hs-varid'>m</span>
<a name="line-117"></a> <span class='hs-varid'>msuper'</span> <span class='hs-keyglyph'><-</span> <span class='hs-varid'>handleMessage</span> <span class='hs-varid'>super</span> <span class='hs-varid'>m</span>
<a name="line-118"></a> <span class='hs-keyword'>if</span> <span class='hs-varid'>isJust</span> <span class='hs-varid'>msuper'</span> <span class='hs-varop'>||</span> <span class='hs-varid'>isJust</span> <span class='hs-varid'>ml1'</span> <span class='hs-varop'>||</span> <span class='hs-varid'>isJust</span> <span class='hs-varid'>ml2'</span>
<a name="line-119"></a> <span class='hs-keyword'>then</span> <span class='hs-varid'>return</span> <span class='hs-varop'>$</span> <span class='hs-conid'>Just</span> <span class='hs-varop'>$</span> <span class='hs-conid'>C2P</span> <span class='hs-varid'>f</span> <span class='hs-varid'>ws1</span> <span class='hs-varid'>ws2</span>
<a name="line-120"></a> <span class='hs-layout'>(</span><span class='hs-varid'>maybe</span> <span class='hs-varid'>super</span> <span class='hs-varid'>id</span> <span class='hs-varid'>msuper'</span><span class='hs-layout'>)</span>
<a name="line-121"></a> <span class='hs-layout'>(</span><span class='hs-varid'>maybe</span> <span class='hs-varid'>l1</span> <span class='hs-varid'>id</span> <span class='hs-varid'>ml1'</span><span class='hs-layout'>)</span>
<a name="line-122"></a> <span class='hs-layout'>(</span><span class='hs-varid'>maybe</span> <span class='hs-varid'>l2</span> <span class='hs-varid'>id</span> <span class='hs-varid'>ml2'</span><span class='hs-layout'>)</span> <span class='hs-varid'>prop</span>
<a name="line-123"></a> <span class='hs-keyword'>else</span> <span class='hs-varid'>return</span> <span class='hs-conid'>Nothing</span>
<a name="line-124"></a>
<a name="line-125"></a> <span class='hs-varid'>description</span> <span class='hs-layout'>(</span><span class='hs-conid'>C2P</span> <span class='hs-keyword'>_</span> <span class='hs-keyword'>_</span> <span class='hs-keyword'>_</span> <span class='hs-varid'>super</span> <span class='hs-varid'>l1</span> <span class='hs-varid'>l2</span> <span class='hs-varid'>prop</span><span class='hs-layout'>)</span> <span class='hs-keyglyph'>=</span> <span class='hs-str'>"combining "</span> <span class='hs-varop'>++</span> <span class='hs-varid'>description</span> <span class='hs-varid'>l1</span> <span class='hs-varop'>++</span> <span class='hs-str'>" and "</span><span class='hs-varop'>++</span>
<a name="line-126"></a> <span class='hs-varid'>description</span> <span class='hs-varid'>l2</span> <span class='hs-varop'>++</span> <span class='hs-str'>" with "</span> <span class='hs-varop'>++</span> <span class='hs-varid'>description</span> <span class='hs-varid'>super</span> <span class='hs-varop'>++</span> <span class='hs-str'>" using "</span><span class='hs-varop'>++</span> <span class='hs-layout'>(</span><span class='hs-varid'>show</span> <span class='hs-varid'>prop</span><span class='hs-layout'>)</span>
<a name="line-127"></a>
<a name="line-128"></a><a name="swap"></a><span class='hs-comment'>-- send focused window to the other pane. Does nothing if we don't</span>
<a name="line-129"></a><span class='hs-comment'>-- own the focused window</span>
<a name="line-130"></a><span class='hs-definition'>swap</span> <span class='hs-keyglyph'>::</span> <span class='hs-layout'>(</span><span class='hs-conid'>LayoutClass</span> <span class='hs-varid'>s</span> <span class='hs-varid'>a</span><span class='hs-layout'>,</span> <span class='hs-conid'>LayoutClass</span> <span class='hs-varid'>l1</span> <span class='hs-conid'>Window</span><span class='hs-layout'>,</span> <span class='hs-conid'>LayoutClass</span> <span class='hs-varid'>l2</span> <span class='hs-conid'>Window</span><span class='hs-layout'>)</span> <span class='hs-keyglyph'>=></span>
<a name="line-131"></a> <span class='hs-conid'>CombineTwoP</span> <span class='hs-layout'>(</span><span class='hs-varid'>s</span> <span class='hs-varid'>a</span><span class='hs-layout'>)</span> <span class='hs-varid'>l1</span> <span class='hs-varid'>l2</span> <span class='hs-conid'>Window</span> <span class='hs-keyglyph'>-></span> <span class='hs-conid'>X</span> <span class='hs-layout'>(</span><span class='hs-conid'>Maybe</span> <span class='hs-layout'>(</span><span class='hs-conid'>CombineTwoP</span> <span class='hs-layout'>(</span><span class='hs-varid'>s</span> <span class='hs-varid'>a</span><span class='hs-layout'>)</span> <span class='hs-varid'>l1</span> <span class='hs-varid'>l2</span> <span class='hs-conid'>Window</span><span class='hs-layout'>)</span><span class='hs-layout'>)</span>
<a name="line-132"></a><span class='hs-definition'>swap</span> <span class='hs-layout'>(</span><span class='hs-conid'>C2P</span> <span class='hs-varid'>f</span> <span class='hs-varid'>ws1</span> <span class='hs-varid'>ws2</span> <span class='hs-varid'>super</span> <span class='hs-varid'>l1</span> <span class='hs-varid'>l2</span> <span class='hs-varid'>prop</span><span class='hs-layout'>)</span> <span class='hs-keyglyph'>=</span> <span class='hs-keyword'>do</span>
<a name="line-133"></a> <span class='hs-varid'>mst</span> <span class='hs-keyglyph'><-</span> <span class='hs-varid'>gets</span> <span class='hs-layout'>(</span><span class='hs-conid'>W</span><span class='hs-varop'>.</span><span class='hs-varid'>stack</span> <span class='hs-varop'>.</span> <span class='hs-conid'>W</span><span class='hs-varop'>.</span><span class='hs-varid'>workspace</span> <span class='hs-varop'>.</span> <span class='hs-conid'>W</span><span class='hs-varop'>.</span><span class='hs-varid'>current</span> <span class='hs-varop'>.</span> <span class='hs-varid'>windowset</span><span class='hs-layout'>)</span>
<a name="line-134"></a> <span class='hs-keyword'>let</span> <span class='hs-layout'>(</span><span class='hs-varid'>ws1'</span><span class='hs-layout'>,</span> <span class='hs-varid'>ws2'</span><span class='hs-layout'>)</span> <span class='hs-keyglyph'>=</span> <span class='hs-keyword'>case</span> <span class='hs-varid'>mst</span> <span class='hs-keyword'>of</span>
<a name="line-135"></a> <span class='hs-conid'>Nothing</span> <span class='hs-keyglyph'>-></span> <span class='hs-layout'>(</span><span class='hs-varid'>ws1</span><span class='hs-layout'>,</span> <span class='hs-varid'>ws2</span><span class='hs-layout'>)</span>
<a name="line-136"></a> <span class='hs-conid'>Just</span> <span class='hs-varid'>st</span> <span class='hs-keyglyph'>-></span> <span class='hs-keyword'>if</span> <span class='hs-varid'>foc</span> <span class='hs-varop'>`elem`</span> <span class='hs-varid'>ws1</span>
<a name="line-137"></a> <span class='hs-keyword'>then</span> <span class='hs-layout'>(</span><span class='hs-varid'>foc</span> <span class='hs-varop'>`delete`</span> <span class='hs-varid'>ws1</span><span class='hs-layout'>,</span> <span class='hs-varid'>foc</span><span class='hs-conop'>:</span><span class='hs-varid'>ws2</span><span class='hs-layout'>)</span>
<a name="line-138"></a> <span class='hs-keyword'>else</span> <span class='hs-keyword'>if</span> <span class='hs-varid'>foc</span> <span class='hs-varop'>`elem`</span> <span class='hs-varid'>ws2</span>
<a name="line-139"></a> <span class='hs-keyword'>then</span> <span class='hs-layout'>(</span><span class='hs-varid'>foc</span><span class='hs-conop'>:</span><span class='hs-varid'>ws1</span><span class='hs-layout'>,</span> <span class='hs-varid'>foc</span> <span class='hs-varop'>`delete`</span> <span class='hs-varid'>ws2</span><span class='hs-layout'>)</span>
<a name="line-140"></a> <span class='hs-keyword'>else</span> <span class='hs-layout'>(</span><span class='hs-varid'>ws1</span><span class='hs-layout'>,</span> <span class='hs-varid'>ws2</span><span class='hs-layout'>)</span>
<a name="line-141"></a> <span class='hs-keyword'>where</span> <span class='hs-varid'>foc</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'>st</span>
<a name="line-142"></a> <span class='hs-keyword'>if</span> <span class='hs-layout'>(</span><span class='hs-varid'>ws1</span><span class='hs-layout'>,</span><span class='hs-varid'>ws2</span><span class='hs-layout'>)</span> <span class='hs-varop'>==</span> <span class='hs-layout'>(</span><span class='hs-varid'>ws1'</span><span class='hs-layout'>,</span><span class='hs-varid'>ws2'</span><span class='hs-layout'>)</span>
<a name="line-143"></a> <span class='hs-keyword'>then</span> <span class='hs-varid'>return</span> <span class='hs-conid'>Nothing</span>
<a name="line-144"></a> <span class='hs-keyword'>else</span> <span class='hs-varid'>return</span> <span class='hs-varop'>$</span> <span class='hs-conid'>Just</span> <span class='hs-varop'>$</span> <span class='hs-conid'>C2P</span> <span class='hs-varid'>f</span> <span class='hs-varid'>ws1'</span> <span class='hs-varid'>ws2'</span> <span class='hs-varid'>super</span> <span class='hs-varid'>l1</span> <span class='hs-varid'>l2</span> <span class='hs-varid'>prop</span>
<a name="line-145"></a>
<a name="line-146"></a>
<a name="line-147"></a><a name="forwardToFocused"></a><span class='hs-comment'>-- forwards the message to the sublayout which contains the focused window</span>
<a name="line-148"></a><span class='hs-definition'>forwardToFocused</span> <span class='hs-keyglyph'>::</span> <span class='hs-layout'>(</span><span class='hs-conid'>LayoutClass</span> <span class='hs-varid'>l1</span> <span class='hs-conid'>Window</span><span class='hs-layout'>,</span> <span class='hs-conid'>LayoutClass</span> <span class='hs-varid'>l2</span> <span class='hs-conid'>Window</span><span class='hs-layout'>,</span> <span class='hs-conid'>LayoutClass</span> <span class='hs-varid'>s</span> <span class='hs-varid'>a</span><span class='hs-layout'>)</span> <span class='hs-keyglyph'>=></span>
<a name="line-149"></a> <span class='hs-conid'>CombineTwoP</span> <span class='hs-layout'>(</span><span class='hs-varid'>s</span> <span class='hs-varid'>a</span><span class='hs-layout'>)</span> <span class='hs-varid'>l1</span> <span class='hs-varid'>l2</span> <span class='hs-conid'>Window</span> <span class='hs-keyglyph'>-></span> <span class='hs-conid'>SomeMessage</span> <span class='hs-keyglyph'>-></span> <span class='hs-conid'>X</span> <span class='hs-layout'>(</span><span class='hs-conid'>Maybe</span> <span class='hs-layout'>(</span><span class='hs-conid'>CombineTwoP</span> <span class='hs-layout'>(</span><span class='hs-varid'>s</span> <span class='hs-varid'>a</span><span class='hs-layout'>)</span> <span class='hs-varid'>l1</span> <span class='hs-varid'>l2</span> <span class='hs-conid'>Window</span><span class='hs-layout'>)</span><span class='hs-layout'>)</span>
<a name="line-150"></a><span class='hs-definition'>forwardToFocused</span> <span class='hs-layout'>(</span><span class='hs-conid'>C2P</span> <span class='hs-varid'>f</span> <span class='hs-varid'>ws1</span> <span class='hs-varid'>ws2</span> <span class='hs-varid'>super</span> <span class='hs-varid'>l1</span> <span class='hs-varid'>l2</span> <span class='hs-varid'>prop</span><span class='hs-layout'>)</span> <span class='hs-varid'>m</span> <span class='hs-keyglyph'>=</span> <span class='hs-keyword'>do</span>
<a name="line-151"></a> <span class='hs-varid'>ml1</span> <span class='hs-keyglyph'><-</span> <span class='hs-varid'>forwardIfFocused</span> <span class='hs-varid'>l1</span> <span class='hs-varid'>ws1</span> <span class='hs-varid'>m</span>
<a name="line-152"></a> <span class='hs-varid'>ml2</span> <span class='hs-keyglyph'><-</span> <span class='hs-varid'>forwardIfFocused</span> <span class='hs-varid'>l2</span> <span class='hs-varid'>ws2</span> <span class='hs-varid'>m</span>
<a name="line-153"></a> <span class='hs-varid'>ms</span> <span class='hs-keyglyph'><-</span> <span class='hs-keyword'>if</span> <span class='hs-varid'>isJust</span> <span class='hs-varid'>ml1</span> <span class='hs-varop'>||</span> <span class='hs-varid'>isJust</span> <span class='hs-varid'>ml2</span>
<a name="line-154"></a> <span class='hs-keyword'>then</span> <span class='hs-varid'>return</span> <span class='hs-conid'>Nothing</span>
<a name="line-155"></a> <span class='hs-keyword'>else</span> <span class='hs-varid'>handleMessage</span> <span class='hs-varid'>super</span> <span class='hs-varid'>m</span>
<a name="line-156"></a> <span class='hs-keyword'>if</span> <span class='hs-varid'>isJust</span> <span class='hs-varid'>ml1</span> <span class='hs-varop'>||</span> <span class='hs-varid'>isJust</span> <span class='hs-varid'>ml2</span> <span class='hs-varop'>||</span> <span class='hs-varid'>isJust</span> <span class='hs-varid'>ms</span>
<a name="line-157"></a> <span class='hs-keyword'>then</span> <span class='hs-varid'>return</span> <span class='hs-varop'>$</span> <span class='hs-conid'>Just</span> <span class='hs-varop'>$</span> <span class='hs-conid'>C2P</span> <span class='hs-varid'>f</span> <span class='hs-varid'>ws1</span> <span class='hs-varid'>ws2</span> <span class='hs-layout'>(</span><span class='hs-varid'>maybe</span> <span class='hs-varid'>super</span> <span class='hs-varid'>id</span> <span class='hs-varid'>ms</span><span class='hs-layout'>)</span> <span class='hs-layout'>(</span><span class='hs-varid'>maybe</span> <span class='hs-varid'>l1</span> <span class='hs-varid'>id</span> <span class='hs-varid'>ml1</span><span class='hs-layout'>)</span> <span class='hs-layout'>(</span><span class='hs-varid'>maybe</span> <span class='hs-varid'>l2</span> <span class='hs-varid'>id</span> <span class='hs-varid'>ml2</span><span class='hs-layout'>)</span> <span class='hs-varid'>prop</span>
<a name="line-158"></a> <span class='hs-keyword'>else</span> <span class='hs-varid'>return</span> <span class='hs-conid'>Nothing</span>
<a name="line-159"></a>
<a name="line-160"></a><a name="forwardIfFocused"></a><span class='hs-comment'>-- forwards message m to layout l if focused window is among w</span>
<a name="line-161"></a><span class='hs-definition'>forwardIfFocused</span> <span class='hs-keyglyph'>::</span> <span class='hs-layout'>(</span><span class='hs-conid'>LayoutClass</span> <span class='hs-varid'>l</span> <span class='hs-conid'>Window</span><span class='hs-layout'>)</span> <span class='hs-keyglyph'>=></span> <span class='hs-varid'>l</span> <span class='hs-conid'>Window</span> <span class='hs-keyglyph'>-></span> <span class='hs-keyglyph'>[</span><span class='hs-conid'>Window</span><span class='hs-keyglyph'>]</span> <span class='hs-keyglyph'>-></span> <span class='hs-conid'>SomeMessage</span> <span class='hs-keyglyph'>-></span> <span class='hs-conid'>X</span> <span class='hs-layout'>(</span><span class='hs-conid'>Maybe</span> <span class='hs-layout'>(</span><span class='hs-varid'>l</span> <span class='hs-conid'>Window</span><span class='hs-layout'>)</span><span class='hs-layout'>)</span>
<a name="line-162"></a><span class='hs-definition'>forwardIfFocused</span> <span class='hs-varid'>l</span> <span class='hs-varid'>w</span> <span class='hs-varid'>m</span> <span class='hs-keyglyph'>=</span> <span class='hs-keyword'>do</span>
<a name="line-163"></a> <span class='hs-varid'>mst</span> <span class='hs-keyglyph'><-</span> <span class='hs-varid'>gets</span> <span class='hs-layout'>(</span><span class='hs-conid'>W</span><span class='hs-varop'>.</span><span class='hs-varid'>stack</span> <span class='hs-varop'>.</span> <span class='hs-conid'>W</span><span class='hs-varop'>.</span><span class='hs-varid'>workspace</span> <span class='hs-varop'>.</span> <span class='hs-conid'>W</span><span class='hs-varop'>.</span><span class='hs-varid'>current</span> <span class='hs-varop'>.</span> <span class='hs-varid'>windowset</span><span class='hs-layout'>)</span>
<a name="line-164"></a> <span class='hs-varid'>maybe</span> <span class='hs-layout'>(</span><span class='hs-varid'>return</span> <span class='hs-conid'>Nothing</span><span class='hs-layout'>)</span> <span class='hs-varid'>send</span> <span class='hs-varid'>mst</span> <span class='hs-keyword'>where</span>
<a name="line-165"></a> <span class='hs-varid'>send</span> <span class='hs-varid'>st</span> <span class='hs-keyglyph'>=</span> <span class='hs-keyword'>if</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'>st</span><span class='hs-layout'>)</span> <span class='hs-varop'>`elem`</span> <span class='hs-varid'>w</span>
<a name="line-166"></a> <span class='hs-keyword'>then</span> <span class='hs-varid'>handleMessage</span> <span class='hs-varid'>l</span> <span class='hs-varid'>m</span>
<a name="line-167"></a> <span class='hs-keyword'>else</span> <span class='hs-varid'>return</span> <span class='hs-conid'>Nothing</span>
<a name="line-168"></a>
<a name="line-169"></a><a name="differentiate"></a><span class='hs-comment'>-- code from CombineTwo</span>
<a name="line-170"></a><span class='hs-comment'>-- given two sets of zs and xs takes the first z from zs that also belongs to xs</span>
<a name="line-171"></a><span class='hs-comment'>-- and turns xs into a stack with z being current element. Acts as</span>
<a name="line-172"></a><span class='hs-comment'>-- StackSet.differentiate if zs and xs don't intersect</span>
<a name="line-173"></a><span class='hs-definition'>differentiate</span> <span class='hs-keyglyph'>::</span> <span class='hs-conid'>Eq</span> <span class='hs-varid'>q</span> <span class='hs-keyglyph'>=></span> <span class='hs-keyglyph'>[</span><span class='hs-varid'>q</span><span class='hs-keyglyph'>]</span> <span class='hs-keyglyph'>-></span> <span class='hs-keyglyph'>[</span><span class='hs-varid'>q</span><span class='hs-keyglyph'>]</span> <span class='hs-keyglyph'>-></span> <span class='hs-conid'>Maybe</span> <span class='hs-layout'>(</span><span class='hs-conid'>Stack</span> <span class='hs-varid'>q</span><span class='hs-layout'>)</span>
<a name="line-174"></a><span class='hs-definition'>differentiate</span> <span class='hs-layout'>(</span><span class='hs-varid'>z</span><span class='hs-conop'>:</span><span class='hs-varid'>zs</span><span class='hs-layout'>)</span> <span class='hs-varid'>xs</span> <span class='hs-keyglyph'>|</span> <span class='hs-varid'>z</span> <span class='hs-varop'>`elem`</span> <span class='hs-varid'>xs</span> <span class='hs-keyglyph'>=</span> <span class='hs-conid'>Just</span> <span class='hs-varop'>$</span> <span class='hs-conid'>Stack</span> <span class='hs-layout'>{</span> <span class='hs-varid'>focus</span><span class='hs-keyglyph'>=</span><span class='hs-varid'>z</span>
<a name="line-175"></a> <span class='hs-layout'>,</span> <span class='hs-varid'>up</span> <span class='hs-keyglyph'>=</span> <span class='hs-varid'>reverse</span> <span class='hs-varop'>$</span> <span class='hs-varid'>takeWhile</span> <span class='hs-layout'>(</span><span class='hs-varop'>/=</span><span class='hs-varid'>z</span><span class='hs-layout'>)</span> <span class='hs-varid'>xs</span>
<a name="line-176"></a> <span class='hs-layout'>,</span> <span class='hs-varid'>down</span> <span class='hs-keyglyph'>=</span> <span class='hs-varid'>tail</span> <span class='hs-varop'>$</span> <span class='hs-varid'>dropWhile</span> <span class='hs-layout'>(</span><span class='hs-varop'>/=</span><span class='hs-varid'>z</span><span class='hs-layout'>)</span> <span class='hs-varid'>xs</span> <span class='hs-layout'>}</span>
<a name="line-177"></a> <span class='hs-keyglyph'>|</span> <span class='hs-varid'>otherwise</span> <span class='hs-keyglyph'>=</span> <span class='hs-varid'>differentiate</span> <span class='hs-varid'>zs</span> <span class='hs-varid'>xs</span>
<a name="line-178"></a><span class='hs-definition'>differentiate</span> <span class='hs-conid'>[]</span> <span class='hs-varid'>xs</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-varid'>xs</span>
<a name="line-179"></a>
<a name="line-180"></a><span class='hs-comment'>-- vim:ts=4:shiftwidth=4:softtabstop=4:expandtab:foldlevel=20:</span>
</pre></body>
</html>
