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<title>Data/List/Split/Internals.hs</title>
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<pre><a name="line-1"></a><span class='hs-comment'>{-# LANGUAGE GADTs, Rank2Types #-}</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 : Data.List.Split.Internal</span>
<a name="line-5"></a><span class='hs-comment'>-- Copyright : (c) Brent Yorgey 2008</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'>-- Maintainer : byorgey@gmail.com</span>
<a name="line-8"></a><span class='hs-comment'>-- Stability : experimental</span>
<a name="line-9"></a><span class='hs-comment'>-- Portability : unportable (GADTs, Rank2Types)</span>
<a name="line-10"></a><span class='hs-comment'>--</span>
<a name="line-11"></a><span class='hs-comment'>-- Implementation module for "Data.List.Split", a combinator library</span>
<a name="line-12"></a><span class='hs-comment'>-- for splitting lists. See the "Data.List.Split" documentation for</span>
<a name="line-13"></a><span class='hs-comment'>-- more description and examples.</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'>Data</span><span class='hs-varop'>.</span><span class='hs-conid'>List</span><span class='hs-varop'>.</span><span class='hs-conid'>Split</span><span class='hs-varop'>.</span><span class='hs-conid'>Internals</span> <span class='hs-keyword'>where</span>
<a name="line-18"></a>
<a name="line-19"></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'>genericSplitAt</span><span class='hs-layout'>)</span>
<a name="line-20"></a>
<a name="line-21"></a><span class='hs-comment'>-- * Types and utilities</span>
<a name="line-22"></a>
<a name="line-23"></a><a name="Splitter"></a><span class='hs-comment'>-- | A splitting strategy.</span>
<a name="line-24"></a><a name="Splitter"></a><span class='hs-keyword'>data</span> <span class='hs-conid'>Splitter</span> <span class='hs-varid'>a</span> <span class='hs-keyglyph'>=</span> <span class='hs-conid'>Splitter</span> <span class='hs-layout'>{</span> <span class='hs-varid'>delimiter</span> <span class='hs-keyglyph'>::</span> <span class='hs-conid'>Delimiter</span> <span class='hs-varid'>a</span>
<a name="line-25"></a> <span class='hs-comment'>-- ^ What delimiter to split on</span>
<a name="line-26"></a> <span class='hs-layout'>,</span> <span class='hs-varid'>delimPolicy</span> <span class='hs-keyglyph'>::</span> <span class='hs-conid'>DelimPolicy</span>
<a name="line-27"></a> <span class='hs-comment'>-- ^ What to do with delimiters (drop</span>
<a name="line-28"></a> <span class='hs-comment'>-- from output, keep as separate</span>
<a name="line-29"></a> <span class='hs-comment'>-- elements in output, or merge with</span>
<a name="line-30"></a> <span class='hs-comment'>-- previous or following chunks)</span>
<a name="line-31"></a> <span class='hs-layout'>,</span> <span class='hs-varid'>condensePolicy</span> <span class='hs-keyglyph'>::</span> <span class='hs-conid'>CondensePolicy</span>
<a name="line-32"></a> <span class='hs-comment'>-- ^ What to do with multiple</span>
<a name="line-33"></a> <span class='hs-comment'>-- consecutive delimiters</span>
<a name="line-34"></a> <span class='hs-layout'>,</span> <span class='hs-varid'>initBlankPolicy</span> <span class='hs-keyglyph'>::</span> <span class='hs-conid'>EndPolicy</span>
<a name="line-35"></a> <span class='hs-comment'>-- ^ Drop an initial blank?</span>
<a name="line-36"></a> <span class='hs-layout'>,</span> <span class='hs-varid'>finalBlankPolicy</span> <span class='hs-keyglyph'>::</span> <span class='hs-conid'>EndPolicy</span>
<a name="line-37"></a> <span class='hs-comment'>-- ^ Drop a final blank?</span>
<a name="line-38"></a> <span class='hs-layout'>}</span>
<a name="line-39"></a>
<a name="line-40"></a><a name="defaultSplitter"></a><span class='hs-comment'>-- | The default splitting strategy: keep delimiters in the output</span>
<a name="line-41"></a><span class='hs-comment'>-- as separate chunks, don't condense multiple consecutive</span>
<a name="line-42"></a><span class='hs-comment'>-- delimiters into one, keep initial and final blank chunks.</span>
<a name="line-43"></a><span class='hs-comment'>-- Default delimiter is the constantly false predicate.</span>
<a name="line-44"></a><span class='hs-comment'>--</span>
<a name="line-45"></a><span class='hs-comment'>-- Note that 'defaultSplitter' should normally not be used; use</span>
<a name="line-46"></a><span class='hs-comment'>-- 'oneOf', 'onSublist', or 'whenElt' instead, which are the same as</span>
<a name="line-47"></a><span class='hs-comment'>-- the 'defaultSplitter' with just the delimiter overridden.</span>
<a name="line-48"></a><span class='hs-comment'>--</span>
<a name="line-49"></a><span class='hs-comment'>-- The 'defaultSplitter' strategy with any delimiter gives a</span>
<a name="line-50"></a><span class='hs-comment'>-- maximally information-preserving splitting strategy, in the sense</span>
<a name="line-51"></a><span class='hs-comment'>-- that (a) taking the 'concat' of the output yields the original</span>
<a name="line-52"></a><span class='hs-comment'>-- list, and (b) given only the output list, we can reconstruct a</span>
<a name="line-53"></a><span class='hs-comment'>-- 'Splitter' which would produce the same output list again given</span>
<a name="line-54"></a><span class='hs-comment'>-- the original input list. This default strategy can be overridden</span>
<a name="line-55"></a><span class='hs-comment'>-- to allow discarding various sorts of information.</span>
<a name="line-56"></a><span class='hs-definition'>defaultSplitter</span> <span class='hs-keyglyph'>::</span> <span class='hs-conid'>Splitter</span> <span class='hs-varid'>a</span>
<a name="line-57"></a><span class='hs-definition'>defaultSplitter</span> <span class='hs-keyglyph'>=</span> <span class='hs-conid'>Splitter</span> <span class='hs-layout'>{</span> <span class='hs-varid'>delimiter</span> <span class='hs-keyglyph'>=</span> <span class='hs-conid'>DelimEltPred</span> <span class='hs-layout'>(</span><span class='hs-varid'>const</span> <span class='hs-conid'>False</span><span class='hs-layout'>)</span>
<a name="line-58"></a> <span class='hs-layout'>,</span> <span class='hs-varid'>delimPolicy</span> <span class='hs-keyglyph'>=</span> <span class='hs-conid'>Keep</span>
<a name="line-59"></a> <span class='hs-layout'>,</span> <span class='hs-varid'>condensePolicy</span> <span class='hs-keyglyph'>=</span> <span class='hs-conid'>KeepBlankFields</span>
<a name="line-60"></a> <span class='hs-layout'>,</span> <span class='hs-varid'>initBlankPolicy</span> <span class='hs-keyglyph'>=</span> <span class='hs-conid'>KeepBlank</span>
<a name="line-61"></a> <span class='hs-layout'>,</span> <span class='hs-varid'>finalBlankPolicy</span> <span class='hs-keyglyph'>=</span> <span class='hs-conid'>KeepBlank</span>
<a name="line-62"></a> <span class='hs-layout'>}</span>
<a name="line-63"></a>
<a name="line-64"></a><span class='hs-comment'>-- | A delimiter can either be a predicate on elements, or a list of</span>
<a name="line-65"></a><span class='hs-comment'>-- elements to be matched as a subsequence.</span>
<a name="line-66"></a><span class='hs-keyword'>data</span> <span class='hs-conid'>Delimiter</span> <span class='hs-varid'>a</span> <span class='hs-keyword'>where</span>
<a name="line-67"></a> <span class='hs-conid'>DelimEltPred</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'>Delimiter</span> <span class='hs-varid'>a</span>
<a name="line-68"></a> <span class='hs-conid'>DelimSublist</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-keyglyph'>[</span><span class='hs-varid'>a</span><span class='hs-keyglyph'>]</span> <span class='hs-keyglyph'>-></span> <span class='hs-conid'>Delimiter</span> <span class='hs-varid'>a</span>
<a name="line-69"></a>
<a name="line-70"></a><a name="matchDelim"></a><span class='hs-comment'>-- | Try to match a delimiter at the start of a list, either failing</span>
<a name="line-71"></a><span class='hs-comment'>-- or decomposing the list into the portion which matched the delimiter</span>
<a name="line-72"></a><span class='hs-comment'>-- and the remainder.</span>
<a name="line-73"></a><span class='hs-definition'>matchDelim</span> <span class='hs-keyglyph'>::</span> <span class='hs-conid'>Delimiter</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-conid'>Maybe</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-keyglyph'>[</span><span class='hs-varid'>a</span><span class='hs-keyglyph'>]</span><span class='hs-layout'>)</span>
<a name="line-74"></a><span class='hs-definition'>matchDelim</span> <span class='hs-layout'>(</span><span class='hs-conid'>DelimEltPred</span> <span class='hs-varid'>p</span><span class='hs-layout'>)</span> <span class='hs-layout'>(</span><span class='hs-varid'>x</span><span class='hs-conop'>:</span><span class='hs-varid'>xs</span><span class='hs-layout'>)</span> <span class='hs-keyglyph'>|</span> <span class='hs-varid'>p</span> <span class='hs-varid'>x</span> <span class='hs-keyglyph'>=</span> <span class='hs-conid'>Just</span> <span class='hs-layout'>(</span><span class='hs-keyglyph'>[</span><span class='hs-varid'>x</span><span class='hs-keyglyph'>]</span><span class='hs-layout'>,</span><span class='hs-varid'>xs</span><span class='hs-layout'>)</span>
<a name="line-75"></a> <span class='hs-keyglyph'>|</span> <span class='hs-varid'>otherwise</span> <span class='hs-keyglyph'>=</span> <span class='hs-conid'>Nothing</span>
<a name="line-76"></a><span class='hs-definition'>matchDelim</span> <span class='hs-layout'>(</span><span class='hs-conid'>DelimEltPred</span> <span class='hs-keyword'>_</span><span class='hs-layout'>)</span> <span class='hs-conid'>[]</span> <span class='hs-keyglyph'>=</span> <span class='hs-conid'>Nothing</span>
<a name="line-77"></a><span class='hs-definition'>matchDelim</span> <span class='hs-layout'>(</span><span class='hs-conid'>DelimSublist</span> <span class='hs-conid'>[]</span><span class='hs-layout'>)</span> <span class='hs-varid'>xs</span> <span class='hs-keyglyph'>=</span> <span class='hs-conid'>Just</span> <span class='hs-layout'>(</span><span class='hs-conid'>[]</span><span class='hs-layout'>,</span><span class='hs-varid'>xs</span><span class='hs-layout'>)</span>
<a name="line-78"></a><span class='hs-definition'>matchDelim</span> <span class='hs-layout'>(</span><span class='hs-conid'>DelimSublist</span> <span class='hs-keyword'>_</span><span class='hs-layout'>)</span> <span class='hs-conid'>[]</span> <span class='hs-keyglyph'>=</span> <span class='hs-conid'>Nothing</span>
<a name="line-79"></a><span class='hs-definition'>matchDelim</span> <span class='hs-layout'>(</span><span class='hs-conid'>DelimSublist</span> <span class='hs-layout'>(</span><span class='hs-varid'>d</span><span class='hs-conop'>:</span><span class='hs-varid'>ds</span><span class='hs-layout'>)</span><span class='hs-layout'>)</span> <span class='hs-layout'>(</span><span class='hs-varid'>x</span><span class='hs-conop'>:</span><span class='hs-varid'>xs</span><span class='hs-layout'>)</span>
<a name="line-80"></a> <span class='hs-keyglyph'>|</span> <span class='hs-varid'>d</span> <span class='hs-varop'>==</span> <span class='hs-varid'>x</span> <span class='hs-keyglyph'>=</span> <span class='hs-varid'>matchDelim</span> <span class='hs-layout'>(</span><span class='hs-conid'>DelimSublist</span> <span class='hs-varid'>ds</span><span class='hs-layout'>)</span> <span class='hs-varid'>xs</span> <span class='hs-varop'>>>=</span> <span class='hs-keyglyph'>\</span><span class='hs-layout'>(</span><span class='hs-varid'>h</span><span class='hs-layout'>,</span><span class='hs-varid'>t</span><span class='hs-layout'>)</span> <span class='hs-keyglyph'>-></span> <span class='hs-conid'>Just</span> <span class='hs-layout'>(</span><span class='hs-varid'>d</span><span class='hs-conop'>:</span><span class='hs-varid'>h</span><span class='hs-layout'>,</span><span class='hs-varid'>t</span><span class='hs-layout'>)</span>
<a name="line-81"></a> <span class='hs-keyglyph'>|</span> <span class='hs-varid'>otherwise</span> <span class='hs-keyglyph'>=</span> <span class='hs-conid'>Nothing</span>
<a name="line-82"></a>
<a name="line-83"></a><a name="DelimPolicy"></a><span class='hs-comment'>-- | What to do with delimiters?</span>
<a name="line-84"></a><a name="DelimPolicy"></a><span class='hs-keyword'>data</span> <span class='hs-conid'>DelimPolicy</span> <span class='hs-keyglyph'>=</span> <span class='hs-conid'>Drop</span> <span class='hs-comment'>-- ^ Drop delimiters from the output.</span>
<a name="line-85"></a> <span class='hs-keyglyph'>|</span> <span class='hs-conid'>Keep</span> <span class='hs-comment'>-- ^ Keep delimiters as separate chunks</span>
<a name="line-86"></a> <span class='hs-comment'>-- of the output.</span>
<a name="line-87"></a> <span class='hs-keyglyph'>|</span> <span class='hs-conid'>KeepLeft</span> <span class='hs-comment'>-- ^ Keep delimiters in the output,</span>
<a name="line-88"></a> <span class='hs-comment'>-- prepending them to the following</span>
<a name="line-89"></a> <span class='hs-comment'>-- chunk.</span>
<a name="line-90"></a> <span class='hs-keyglyph'>|</span> <span class='hs-conid'>KeepRight</span> <span class='hs-comment'>-- ^ Keep delimiters in the output,</span>
<a name="line-91"></a> <span class='hs-comment'>-- appending them to the previous chunk.</span>
<a name="line-92"></a> <span class='hs-keyword'>deriving</span> <span class='hs-layout'>(</span><span class='hs-conid'>Eq</span><span class='hs-layout'>,</span> <span class='hs-conid'>Show</span><span class='hs-layout'>)</span>
<a name="line-93"></a>
<a name="line-94"></a><a name="CondensePolicy"></a><span class='hs-comment'>-- | What to do with multiple consecutive delimiters?</span>
<a name="line-95"></a><a name="CondensePolicy"></a><span class='hs-keyword'>data</span> <span class='hs-conid'>CondensePolicy</span> <span class='hs-keyglyph'>=</span> <span class='hs-conid'>Condense</span> <span class='hs-comment'>-- ^ Condense into a single delimiter.</span>
<a name="line-96"></a> <span class='hs-keyglyph'>|</span> <span class='hs-conid'>KeepBlankFields</span> <span class='hs-comment'>-- ^ Insert blank chunks</span>
<a name="line-97"></a> <span class='hs-comment'>-- between consecutive</span>
<a name="line-98"></a> <span class='hs-comment'>-- delimiters.</span>
<a name="line-99"></a> <span class='hs-keyword'>deriving</span> <span class='hs-layout'>(</span><span class='hs-conid'>Eq</span><span class='hs-layout'>,</span> <span class='hs-conid'>Show</span><span class='hs-layout'>)</span>
<a name="line-100"></a>
<a name="line-101"></a><a name="EndPolicy"></a><span class='hs-comment'>-- | What to do with a blank chunk at either end of the list</span>
<a name="line-102"></a><a name="EndPolicy"></a><span class='hs-comment'>-- (i.e. when the list begins or ends with a delimiter).</span>
<a name="line-103"></a><a name="EndPolicy"></a><span class='hs-keyword'>data</span> <span class='hs-conid'>EndPolicy</span> <span class='hs-keyglyph'>=</span> <span class='hs-conid'>DropBlank</span> <span class='hs-keyglyph'>|</span> <span class='hs-conid'>KeepBlank</span>
<a name="line-104"></a> <span class='hs-keyword'>deriving</span> <span class='hs-layout'>(</span><span class='hs-conid'>Eq</span><span class='hs-layout'>,</span> <span class='hs-conid'>Show</span><span class='hs-layout'>)</span>
<a name="line-105"></a>
<a name="line-106"></a><a name="Chunk"></a><span class='hs-comment'>-- | Tag chunks as delimiters or text.</span>
<a name="line-107"></a><a name="Chunk"></a><span class='hs-keyword'>data</span> <span class='hs-conid'>Chunk</span> <span class='hs-varid'>a</span> <span class='hs-keyglyph'>=</span> <span class='hs-conid'>Delim</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'>Text</span> <span class='hs-keyglyph'>[</span><span class='hs-varid'>a</span><span class='hs-keyglyph'>]</span>
<a name="line-108"></a> <span class='hs-keyword'>deriving</span> <span class='hs-layout'>(</span><span class='hs-conid'>Show</span><span class='hs-layout'>,</span> <span class='hs-conid'>Eq</span><span class='hs-layout'>)</span>
<a name="line-109"></a>
<a name="line-110"></a><a name="SplitList"></a><span class='hs-comment'>-- | Internal representation of a split list that tracks which pieces</span>
<a name="line-111"></a><a name="SplitList"></a><span class='hs-comment'>-- are delimiters and which aren't.</span>
<a name="line-112"></a><a name="SplitList"></a><span class='hs-keyword'>type</span> <span class='hs-conid'>SplitList</span> <span class='hs-varid'>a</span> <span class='hs-keyglyph'>=</span> <span class='hs-keyglyph'>[</span><span class='hs-conid'>Chunk</span> <span class='hs-varid'>a</span><span class='hs-keyglyph'>]</span>
<a name="line-113"></a>
<a name="line-114"></a><a name="fromElem"></a><span class='hs-comment'>-- | Untag a 'Chunk'.</span>
<a name="line-115"></a><span class='hs-definition'>fromElem</span> <span class='hs-keyglyph'>::</span> <span class='hs-conid'>Chunk</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>
<a name="line-116"></a><span class='hs-definition'>fromElem</span> <span class='hs-layout'>(</span><span class='hs-conid'>Text</span> <span class='hs-keyword'>as</span><span class='hs-layout'>)</span> <span class='hs-keyglyph'>=</span> <span class='hs-keyword'>as</span>
<a name="line-117"></a><span class='hs-definition'>fromElem</span> <span class='hs-layout'>(</span><span class='hs-conid'>Delim</span> <span class='hs-keyword'>as</span><span class='hs-layout'>)</span> <span class='hs-keyglyph'>=</span> <span class='hs-keyword'>as</span>
<a name="line-118"></a>
<a name="line-119"></a><a name="isDelim"></a><span class='hs-comment'>-- | Test whether a 'Chunk' is a delimiter.</span>
<a name="line-120"></a><span class='hs-definition'>isDelim</span> <span class='hs-keyglyph'>::</span> <span class='hs-conid'>Chunk</span> <span class='hs-varid'>a</span> <span class='hs-keyglyph'>-></span> <span class='hs-conid'>Bool</span>
<a name="line-121"></a><span class='hs-definition'>isDelim</span> <span class='hs-layout'>(</span><span class='hs-conid'>Delim</span> <span class='hs-keyword'>_</span><span class='hs-layout'>)</span> <span class='hs-keyglyph'>=</span> <span class='hs-conid'>True</span>
<a name="line-122"></a><span class='hs-definition'>isDelim</span> <span class='hs-keyword'>_</span> <span class='hs-keyglyph'>=</span> <span class='hs-conid'>False</span>
<a name="line-123"></a>
<a name="line-124"></a><a name="isText"></a><span class='hs-comment'>-- | Test whether a 'Chunk' is text.</span>
<a name="line-125"></a><span class='hs-definition'>isText</span> <span class='hs-keyglyph'>::</span> <span class='hs-conid'>Chunk</span> <span class='hs-varid'>a</span> <span class='hs-keyglyph'>-></span> <span class='hs-conid'>Bool</span>
<a name="line-126"></a><span class='hs-definition'>isText</span> <span class='hs-layout'>(</span><span class='hs-conid'>Text</span> <span class='hs-keyword'>_</span><span class='hs-layout'>)</span> <span class='hs-keyglyph'>=</span> <span class='hs-conid'>True</span>
<a name="line-127"></a><span class='hs-definition'>isText</span> <span class='hs-keyword'>_</span> <span class='hs-keyglyph'>=</span> <span class='hs-conid'>False</span>
<a name="line-128"></a>
<a name="line-129"></a><a name="build"></a><span class='hs-comment'>-- | Standard build function.</span>
<a name="line-130"></a><span class='hs-definition'>build</span> <span class='hs-keyglyph'>::</span> <span class='hs-layout'>(</span><span class='hs-keyword'>forall</span> <span class='hs-varid'>b</span><span class='hs-varop'>.</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-varid'>b</span><span class='hs-layout'>)</span> <span class='hs-keyglyph'>-></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'>build</span> <span class='hs-varid'>g</span> <span class='hs-keyglyph'>=</span> <span class='hs-varid'>g</span> <span class='hs-layout'>(</span><span class='hs-conop'>:</span><span class='hs-layout'>)</span> <span class='hs-conid'>[]</span>
<a name="line-132"></a>
<a name="line-133"></a><span class='hs-comment'>-- * Implementation</span>
<a name="line-134"></a>
<a name="line-135"></a><a name="splitInternal"></a><span class='hs-comment'>-- | Given a delimiter to use, split a list into an internal</span>
<a name="line-136"></a><span class='hs-comment'>-- representation with chunks tagged as delimiters or text. This</span>
<a name="line-137"></a><span class='hs-comment'>-- transformation is lossless; in particular, @'concatMap' 'fromElem'</span>
<a name="line-138"></a><span class='hs-comment'>-- ('splitInternal' d l) == l@.</span>
<a name="line-139"></a><span class='hs-definition'>splitInternal</span> <span class='hs-keyglyph'>::</span> <span class='hs-conid'>Delimiter</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-conid'>SplitList</span> <span class='hs-varid'>a</span>
<a name="line-140"></a><span class='hs-definition'>splitInternal</span> <span class='hs-keyword'>_</span> <span class='hs-conid'>[]</span> <span class='hs-keyglyph'>=</span> <span class='hs-conid'>[]</span>
<a name="line-141"></a><span class='hs-definition'>splitInternal</span> <span class='hs-varid'>d</span> <span class='hs-varid'>xxs</span><span class='hs-keyglyph'>@</span><span class='hs-layout'>(</span><span class='hs-varid'>x</span><span class='hs-conop'>:</span><span class='hs-varid'>xs</span><span class='hs-layout'>)</span> <span class='hs-keyglyph'>=</span> <span class='hs-keyword'>case</span> <span class='hs-varid'>matchDelim</span> <span class='hs-varid'>d</span> <span class='hs-varid'>xxs</span> <span class='hs-keyword'>of</span>
<a name="line-142"></a> <span class='hs-comment'>-- special case for blank delimiter</span>
<a name="line-143"></a> <span class='hs-conid'>Just</span> <span class='hs-layout'>(</span><span class='hs-conid'>[]</span><span class='hs-layout'>,</span> <span class='hs-layout'>(</span><span class='hs-varid'>r</span><span class='hs-conop'>:</span><span class='hs-varid'>rs</span><span class='hs-layout'>)</span><span class='hs-layout'>)</span> <span class='hs-keyglyph'>-></span> <span class='hs-conid'>Delim</span> <span class='hs-conid'>[]</span> <span class='hs-conop'>:</span> <span class='hs-conid'>Text</span> <span class='hs-keyglyph'>[</span><span class='hs-varid'>r</span><span class='hs-keyglyph'>]</span> <span class='hs-conop'>:</span> <span class='hs-varid'>splitInternal</span> <span class='hs-varid'>d</span> <span class='hs-varid'>rs</span>
<a name="line-144"></a> <span class='hs-conid'>Just</span> <span class='hs-layout'>(</span><span class='hs-varid'>match</span><span class='hs-layout'>,</span><span class='hs-varid'>rest</span><span class='hs-layout'>)</span> <span class='hs-keyglyph'>-></span> <span class='hs-conid'>Delim</span> <span class='hs-varid'>match</span> <span class='hs-conop'>:</span> <span class='hs-varid'>splitInternal</span> <span class='hs-varid'>d</span> <span class='hs-varid'>rest</span>
<a name="line-145"></a> <span class='hs-keyword'>_</span> <span class='hs-keyglyph'>-></span> <span class='hs-varid'>x</span> <span class='hs-varop'>`consText`</span> <span class='hs-varid'>splitInternal</span> <span class='hs-varid'>d</span> <span class='hs-varid'>xs</span>
<a name="line-146"></a> <span class='hs-keyword'>where</span> <span class='hs-varid'>consText</span> <span class='hs-varid'>z</span> <span class='hs-layout'>(</span><span class='hs-conid'>Text</span> <span class='hs-varid'>c</span> <span class='hs-conop'>:</span> <span class='hs-varid'>ys</span><span class='hs-layout'>)</span> <span class='hs-keyglyph'>=</span> <span class='hs-conid'>Text</span> <span class='hs-layout'>(</span><span class='hs-varid'>z</span><span class='hs-conop'>:</span><span class='hs-varid'>c</span><span class='hs-layout'>)</span> <span class='hs-conop'>:</span> <span class='hs-varid'>ys</span>
<a name="line-147"></a> <span class='hs-varid'>consText</span> <span class='hs-varid'>z</span> <span class='hs-varid'>ys</span> <span class='hs-keyglyph'>=</span> <span class='hs-conid'>Text</span> <span class='hs-keyglyph'>[</span><span class='hs-varid'>z</span><span class='hs-keyglyph'>]</span> <span class='hs-conop'>:</span> <span class='hs-varid'>ys</span>
<a name="line-148"></a>
<a name="line-149"></a><a name="postProcess"></a><span class='hs-comment'>-- | Given a split list in the internal tagged representation, produce</span>
<a name="line-150"></a><span class='hs-comment'>-- a new internal tagged representation corresponding to the final</span>
<a name="line-151"></a><span class='hs-comment'>-- output, according to the strategy defined by the given</span>
<a name="line-152"></a><span class='hs-comment'>-- 'Splitter'.</span>
<a name="line-153"></a><span class='hs-definition'>postProcess</span> <span class='hs-keyglyph'>::</span> <span class='hs-conid'>Splitter</span> <span class='hs-varid'>a</span> <span class='hs-keyglyph'>-></span> <span class='hs-conid'>SplitList</span> <span class='hs-varid'>a</span> <span class='hs-keyglyph'>-></span> <span class='hs-conid'>SplitList</span> <span class='hs-varid'>a</span>
<a name="line-154"></a><span class='hs-definition'>postProcess</span> <span class='hs-varid'>s</span> <span class='hs-keyglyph'>=</span> <span class='hs-varid'>dropFinal</span> <span class='hs-layout'>(</span><span class='hs-varid'>finalBlankPolicy</span> <span class='hs-varid'>s</span><span class='hs-layout'>)</span>
<a name="line-155"></a> <span class='hs-varop'>.</span> <span class='hs-varid'>dropInitial</span> <span class='hs-layout'>(</span><span class='hs-varid'>initBlankPolicy</span> <span class='hs-varid'>s</span><span class='hs-layout'>)</span>
<a name="line-156"></a> <span class='hs-varop'>.</span> <span class='hs-varid'>doMerge</span> <span class='hs-layout'>(</span><span class='hs-varid'>delimPolicy</span> <span class='hs-varid'>s</span><span class='hs-layout'>)</span>
<a name="line-157"></a> <span class='hs-varop'>.</span> <span class='hs-varid'>doDrop</span> <span class='hs-layout'>(</span><span class='hs-varid'>delimPolicy</span> <span class='hs-varid'>s</span><span class='hs-layout'>)</span>
<a name="line-158"></a> <span class='hs-varop'>.</span> <span class='hs-varid'>insertBlanks</span>
<a name="line-159"></a> <span class='hs-varop'>.</span> <span class='hs-varid'>doCondense</span> <span class='hs-layout'>(</span><span class='hs-varid'>condensePolicy</span> <span class='hs-varid'>s</span><span class='hs-layout'>)</span>
<a name="line-160"></a>
<a name="line-161"></a><a name="doDrop"></a><span class='hs-comment'>-- | Drop delimiters if the 'DelimPolicy' is 'Drop'.</span>
<a name="line-162"></a><span class='hs-definition'>doDrop</span> <span class='hs-keyglyph'>::</span> <span class='hs-conid'>DelimPolicy</span> <span class='hs-keyglyph'>-></span> <span class='hs-conid'>SplitList</span> <span class='hs-varid'>a</span> <span class='hs-keyglyph'>-></span> <span class='hs-conid'>SplitList</span> <span class='hs-varid'>a</span>
<a name="line-163"></a><span class='hs-definition'>doDrop</span> <span class='hs-conid'>Drop</span> <span class='hs-varid'>l</span> <span class='hs-keyglyph'>=</span> <span class='hs-keyglyph'>[</span> <span class='hs-varid'>c</span> <span class='hs-keyglyph'>|</span> <span class='hs-varid'>c</span><span class='hs-keyglyph'>@</span><span class='hs-layout'>(</span><span class='hs-conid'>Text</span> <span class='hs-keyword'>_</span><span class='hs-layout'>)</span> <span class='hs-keyglyph'><-</span> <span class='hs-varid'>l</span> <span class='hs-keyglyph'>]</span>
<a name="line-164"></a><span class='hs-definition'>doDrop</span> <span class='hs-keyword'>_</span> <span class='hs-varid'>l</span> <span class='hs-keyglyph'>=</span> <span class='hs-varid'>l</span>
<a name="line-165"></a>
<a name="line-166"></a><a name="doCondense"></a><span class='hs-comment'>-- | Condense multiple consecutive delimiters into one if the</span>
<a name="line-167"></a><span class='hs-comment'>-- 'CondensePolicy' is 'Condense'.</span>
<a name="line-168"></a><span class='hs-definition'>doCondense</span> <span class='hs-keyglyph'>::</span> <span class='hs-conid'>CondensePolicy</span> <span class='hs-keyglyph'>-></span> <span class='hs-conid'>SplitList</span> <span class='hs-varid'>a</span> <span class='hs-keyglyph'>-></span> <span class='hs-conid'>SplitList</span> <span class='hs-varid'>a</span>
<a name="line-169"></a><span class='hs-definition'>doCondense</span> <span class='hs-conid'>KeepBlankFields</span> <span class='hs-varid'>ls</span> <span class='hs-keyglyph'>=</span> <span class='hs-varid'>ls</span>
<a name="line-170"></a><span class='hs-definition'>doCondense</span> <span class='hs-conid'>Condense</span> <span class='hs-varid'>ls</span> <span class='hs-keyglyph'>=</span> <span class='hs-varid'>condense'</span> <span class='hs-varid'>ls</span>
<a name="line-171"></a> <span class='hs-keyword'>where</span> <span class='hs-varid'>condense'</span> <span class='hs-conid'>[]</span> <span class='hs-keyglyph'>=</span> <span class='hs-conid'>[]</span>
<a name="line-172"></a> <span class='hs-varid'>condense'</span> <span class='hs-layout'>(</span><span class='hs-varid'>c</span><span class='hs-keyglyph'>@</span><span class='hs-layout'>(</span><span class='hs-conid'>Text</span> <span class='hs-keyword'>_</span><span class='hs-layout'>)</span> <span class='hs-conop'>:</span> <span class='hs-varid'>l</span><span class='hs-layout'>)</span> <span class='hs-keyglyph'>=</span> <span class='hs-varid'>c</span> <span class='hs-conop'>:</span> <span class='hs-varid'>condense'</span> <span class='hs-varid'>l</span>
<a name="line-173"></a> <span class='hs-varid'>condense'</span> <span class='hs-varid'>l</span> <span class='hs-keyglyph'>=</span> <span class='hs-layout'>(</span><span class='hs-conid'>Delim</span> <span class='hs-varop'>$</span> <span class='hs-varid'>concatMap</span> <span class='hs-varid'>fromElem</span> <span class='hs-varid'>ds</span><span class='hs-layout'>)</span> <span class='hs-conop'>:</span> <span class='hs-varid'>condense'</span> <span class='hs-varid'>rest</span>
<a name="line-174"></a> <span class='hs-keyword'>where</span> <span class='hs-layout'>(</span><span class='hs-varid'>ds</span><span class='hs-layout'>,</span><span class='hs-varid'>rest</span><span class='hs-layout'>)</span> <span class='hs-keyglyph'>=</span> <span class='hs-varid'>span</span> <span class='hs-varid'>isDelim</span> <span class='hs-varid'>l</span>
<a name="line-175"></a>
<a name="line-176"></a><a name="insertBlanks"></a><span class='hs-comment'>-- | Insert blank chunks between any remaining consecutive delimiters,</span>
<a name="line-177"></a><span class='hs-comment'>-- and at the beginning or end if the first or last element is a</span>
<a name="line-178"></a><span class='hs-comment'>-- delimiter.</span>
<a name="line-179"></a><span class='hs-definition'>insertBlanks</span> <span class='hs-keyglyph'>::</span> <span class='hs-conid'>SplitList</span> <span class='hs-varid'>a</span> <span class='hs-keyglyph'>-></span> <span class='hs-conid'>SplitList</span> <span class='hs-varid'>a</span>
<a name="line-180"></a><span class='hs-definition'>insertBlanks</span> <span class='hs-conid'>[]</span> <span class='hs-keyglyph'>=</span> <span class='hs-keyglyph'>[</span><span class='hs-conid'>Text</span> <span class='hs-conid'>[]</span><span class='hs-keyglyph'>]</span>
<a name="line-181"></a><span class='hs-definition'>insertBlanks</span> <span class='hs-layout'>(</span><span class='hs-varid'>d</span><span class='hs-keyglyph'>@</span><span class='hs-layout'>(</span><span class='hs-conid'>Delim</span> <span class='hs-keyword'>_</span><span class='hs-layout'>)</span> <span class='hs-conop'>:</span> <span class='hs-varid'>l</span><span class='hs-layout'>)</span> <span class='hs-keyglyph'>=</span> <span class='hs-conid'>Text</span> <span class='hs-conid'>[]</span> <span class='hs-conop'>:</span> <span class='hs-varid'>insertBlanks'</span> <span class='hs-layout'>(</span><span class='hs-varid'>d</span><span class='hs-conop'>:</span><span class='hs-varid'>l</span><span class='hs-layout'>)</span>
<a name="line-182"></a><span class='hs-definition'>insertBlanks</span> <span class='hs-varid'>l</span> <span class='hs-keyglyph'>=</span> <span class='hs-varid'>insertBlanks'</span> <span class='hs-varid'>l</span>
<a name="line-183"></a>
<a name="line-184"></a><a name="insertBlanks'"></a><span class='hs-comment'>-- | Insert blank chunks between consecutive delimiters.</span>
<a name="line-185"></a><span class='hs-definition'>insertBlanks'</span> <span class='hs-keyglyph'>::</span> <span class='hs-conid'>SplitList</span> <span class='hs-varid'>a</span> <span class='hs-keyglyph'>-></span> <span class='hs-conid'>SplitList</span> <span class='hs-varid'>a</span>
<a name="line-186"></a><span class='hs-definition'>insertBlanks'</span> <span class='hs-conid'>[]</span> <span class='hs-keyglyph'>=</span> <span class='hs-conid'>[]</span>
<a name="line-187"></a><span class='hs-definition'>insertBlanks'</span> <span class='hs-layout'>(</span><span class='hs-varid'>d1</span><span class='hs-keyglyph'>@</span><span class='hs-layout'>(</span><span class='hs-conid'>Delim</span> <span class='hs-keyword'>_</span><span class='hs-layout'>)</span> <span class='hs-conop'>:</span> <span class='hs-varid'>d2</span><span class='hs-keyglyph'>@</span><span class='hs-layout'>(</span><span class='hs-conid'>Delim</span> <span class='hs-keyword'>_</span><span class='hs-layout'>)</span> <span class='hs-conop'>:</span> <span class='hs-varid'>l</span><span class='hs-layout'>)</span> <span class='hs-keyglyph'>=</span> <span class='hs-varid'>d1</span> <span class='hs-conop'>:</span> <span class='hs-conid'>Text</span> <span class='hs-conid'>[]</span> <span class='hs-conop'>:</span> <span class='hs-varid'>insertBlanks'</span> <span class='hs-layout'>(</span><span class='hs-varid'>d2</span><span class='hs-conop'>:</span><span class='hs-varid'>l</span><span class='hs-layout'>)</span>
<a name="line-188"></a><span class='hs-definition'>insertBlanks'</span> <span class='hs-keyglyph'>[</span><span class='hs-varid'>d</span><span class='hs-keyglyph'>@</span><span class='hs-layout'>(</span><span class='hs-conid'>Delim</span> <span class='hs-keyword'>_</span><span class='hs-layout'>)</span><span class='hs-keyglyph'>]</span> <span class='hs-keyglyph'>=</span> <span class='hs-keyglyph'>[</span><span class='hs-varid'>d</span><span class='hs-layout'>,</span> <span class='hs-conid'>Text</span> <span class='hs-conid'>[]</span><span class='hs-keyglyph'>]</span>
<a name="line-189"></a><span class='hs-definition'>insertBlanks'</span> <span class='hs-layout'>(</span><span class='hs-varid'>c</span> <span class='hs-conop'>:</span> <span class='hs-varid'>l</span><span class='hs-layout'>)</span> <span class='hs-keyglyph'>=</span> <span class='hs-varid'>c</span> <span class='hs-conop'>:</span> <span class='hs-varid'>insertBlanks'</span> <span class='hs-varid'>l</span>
<a name="line-190"></a>
<a name="line-191"></a><a name="doMerge"></a><span class='hs-comment'>-- | Merge delimiters into adjacent chunks according to the 'DelimPolicy'.</span>
<a name="line-192"></a><span class='hs-definition'>doMerge</span> <span class='hs-keyglyph'>::</span> <span class='hs-conid'>DelimPolicy</span> <span class='hs-keyglyph'>-></span> <span class='hs-conid'>SplitList</span> <span class='hs-varid'>a</span> <span class='hs-keyglyph'>-></span> <span class='hs-conid'>SplitList</span> <span class='hs-varid'>a</span>
<a name="line-193"></a><span class='hs-definition'>doMerge</span> <span class='hs-conid'>KeepLeft</span> <span class='hs-keyglyph'>=</span> <span class='hs-varid'>mergeLeft</span>
<a name="line-194"></a><span class='hs-definition'>doMerge</span> <span class='hs-conid'>KeepRight</span> <span class='hs-keyglyph'>=</span> <span class='hs-varid'>mergeRight</span>
<a name="line-195"></a><span class='hs-definition'>doMerge</span> <span class='hs-keyword'>_</span> <span class='hs-keyglyph'>=</span> <span class='hs-varid'>id</span>
<a name="line-196"></a>
<a name="line-197"></a><a name="mergeLeft"></a><span class='hs-comment'>-- | Merge delimiters with adjacent chunks to the right (yes, that's</span>
<a name="line-198"></a><span class='hs-comment'>-- not a typo: the delimiters should end up on the left of the</span>
<a name="line-199"></a><span class='hs-comment'>-- chunks, so they are merged with chunks to their right).</span>
<a name="line-200"></a><span class='hs-definition'>mergeLeft</span> <span class='hs-keyglyph'>::</span> <span class='hs-conid'>SplitList</span> <span class='hs-varid'>a</span> <span class='hs-keyglyph'>-></span> <span class='hs-conid'>SplitList</span> <span class='hs-varid'>a</span>
<a name="line-201"></a><span class='hs-definition'>mergeLeft</span> <span class='hs-conid'>[]</span> <span class='hs-keyglyph'>=</span> <span class='hs-conid'>[]</span>
<a name="line-202"></a><span class='hs-definition'>mergeLeft</span> <span class='hs-layout'>(</span><span class='hs-layout'>(</span><span class='hs-conid'>Delim</span> <span class='hs-varid'>d</span><span class='hs-layout'>)</span> <span class='hs-conop'>:</span> <span class='hs-layout'>(</span><span class='hs-conid'>Text</span> <span class='hs-varid'>c</span><span class='hs-layout'>)</span> <span class='hs-conop'>:</span> <span class='hs-varid'>l</span><span class='hs-layout'>)</span> <span class='hs-keyglyph'>=</span> <span class='hs-conid'>Text</span> <span class='hs-layout'>(</span><span class='hs-varid'>d</span><span class='hs-varop'>++</span><span class='hs-varid'>c</span><span class='hs-layout'>)</span> <span class='hs-conop'>:</span> <span class='hs-varid'>mergeLeft</span> <span class='hs-varid'>l</span>
<a name="line-203"></a><span class='hs-definition'>mergeLeft</span> <span class='hs-layout'>(</span><span class='hs-varid'>c</span> <span class='hs-conop'>:</span> <span class='hs-varid'>l</span><span class='hs-layout'>)</span> <span class='hs-keyglyph'>=</span> <span class='hs-varid'>c</span> <span class='hs-conop'>:</span> <span class='hs-varid'>mergeLeft</span> <span class='hs-varid'>l</span>
<a name="line-204"></a>
<a name="line-205"></a><a name="mergeRight"></a><span class='hs-comment'>-- | Merge delimiters with adjacent chunks to the left.</span>
<a name="line-206"></a><span class='hs-definition'>mergeRight</span> <span class='hs-keyglyph'>::</span> <span class='hs-conid'>SplitList</span> <span class='hs-varid'>a</span> <span class='hs-keyglyph'>-></span> <span class='hs-conid'>SplitList</span> <span class='hs-varid'>a</span>
<a name="line-207"></a><span class='hs-definition'>mergeRight</span> <span class='hs-conid'>[]</span> <span class='hs-keyglyph'>=</span> <span class='hs-conid'>[]</span>
<a name="line-208"></a><span class='hs-definition'>mergeRight</span> <span class='hs-layout'>(</span><span class='hs-layout'>(</span><span class='hs-conid'>Text</span> <span class='hs-varid'>c</span><span class='hs-layout'>)</span> <span class='hs-conop'>:</span> <span class='hs-layout'>(</span><span class='hs-conid'>Delim</span> <span class='hs-varid'>d</span><span class='hs-layout'>)</span> <span class='hs-conop'>:</span> <span class='hs-varid'>l</span><span class='hs-layout'>)</span> <span class='hs-keyglyph'>=</span> <span class='hs-conid'>Text</span> <span class='hs-layout'>(</span><span class='hs-varid'>c</span><span class='hs-varop'>++</span><span class='hs-varid'>d</span><span class='hs-layout'>)</span> <span class='hs-conop'>:</span> <span class='hs-varid'>mergeRight</span> <span class='hs-varid'>l</span>
<a name="line-209"></a><span class='hs-definition'>mergeRight</span> <span class='hs-layout'>(</span><span class='hs-varid'>c</span> <span class='hs-conop'>:</span> <span class='hs-varid'>l</span><span class='hs-layout'>)</span> <span class='hs-keyglyph'>=</span> <span class='hs-varid'>c</span> <span class='hs-conop'>:</span> <span class='hs-varid'>mergeRight</span> <span class='hs-varid'>l</span>
<a name="line-210"></a>
<a name="line-211"></a><a name="dropInitial"></a><span class='hs-comment'>-- | Drop an initial blank chunk according to the given 'EndPolicy'.</span>
<a name="line-212"></a><span class='hs-definition'>dropInitial</span> <span class='hs-keyglyph'>::</span> <span class='hs-conid'>EndPolicy</span> <span class='hs-keyglyph'>-></span> <span class='hs-conid'>SplitList</span> <span class='hs-varid'>a</span> <span class='hs-keyglyph'>-></span> <span class='hs-conid'>SplitList</span> <span class='hs-varid'>a</span>
<a name="line-213"></a><span class='hs-definition'>dropInitial</span> <span class='hs-conid'>DropBlank</span> <span class='hs-layout'>(</span><span class='hs-conid'>Text</span> <span class='hs-conid'>[]</span> <span class='hs-conop'>:</span> <span class='hs-varid'>l</span><span class='hs-layout'>)</span> <span class='hs-keyglyph'>=</span> <span class='hs-varid'>l</span>
<a name="line-214"></a><span class='hs-definition'>dropInitial</span> <span class='hs-keyword'>_</span> <span class='hs-varid'>l</span> <span class='hs-keyglyph'>=</span> <span class='hs-varid'>l</span>
<a name="line-215"></a>
<a name="line-216"></a><a name="dropFinal"></a><span class='hs-comment'>-- | Drop a final blank chunk according to the given 'EndPolicy'.</span>
<a name="line-217"></a><span class='hs-definition'>dropFinal</span> <span class='hs-keyglyph'>::</span> <span class='hs-conid'>EndPolicy</span> <span class='hs-keyglyph'>-></span> <span class='hs-conid'>SplitList</span> <span class='hs-varid'>a</span> <span class='hs-keyglyph'>-></span> <span class='hs-conid'>SplitList</span> <span class='hs-varid'>a</span>
<a name="line-218"></a><span class='hs-definition'>dropFinal</span> <span class='hs-keyword'>_</span> <span class='hs-conid'>[]</span> <span class='hs-keyglyph'>=</span> <span class='hs-conid'>[]</span>
<a name="line-219"></a><span class='hs-definition'>dropFinal</span> <span class='hs-conid'>DropBlank</span> <span class='hs-varid'>l</span> <span class='hs-keyglyph'>=</span> <span class='hs-varid'>dropFinal'</span> <span class='hs-varid'>l</span>
<a name="line-220"></a> <span class='hs-keyword'>where</span> <span class='hs-varid'>dropFinal'</span> <span class='hs-conid'>[]</span> <span class='hs-keyglyph'>=</span> <span class='hs-conid'>[]</span>
<a name="line-221"></a> <span class='hs-varid'>dropFinal'</span> <span class='hs-keyglyph'>[</span><span class='hs-conid'>Text</span> <span class='hs-conid'>[]</span><span class='hs-keyglyph'>]</span> <span class='hs-keyglyph'>=</span> <span class='hs-conid'>[]</span>
<a name="line-222"></a> <span class='hs-varid'>dropFinal'</span> <span class='hs-layout'>(</span><span class='hs-varid'>x</span><span class='hs-conop'>:</span><span class='hs-varid'>xs</span><span class='hs-layout'>)</span> <span class='hs-keyglyph'>=</span> <span class='hs-varid'>x</span><span class='hs-conop'>:</span><span class='hs-varid'>dropFinal'</span> <span class='hs-varid'>xs</span>
<a name="line-223"></a><span class='hs-definition'>dropFinal</span> <span class='hs-keyword'>_</span> <span class='hs-varid'>l</span> <span class='hs-keyglyph'>=</span> <span class='hs-varid'>l</span>
<a name="line-224"></a>
<a name="line-225"></a><span class='hs-comment'>-- * Combinators</span>
<a name="line-226"></a>
<a name="line-227"></a><a name="split"></a><span class='hs-comment'>-- | Split a list according to the given splitting strategy. This is</span>
<a name="line-228"></a><span class='hs-comment'>-- how to \"run\" a 'Splitter' that has been built using the other</span>
<a name="line-229"></a><span class='hs-comment'>-- combinators.</span>
<a name="line-230"></a><span class='hs-definition'>split</span> <span class='hs-keyglyph'>::</span> <span class='hs-conid'>Splitter</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-keyglyph'>[</span><span class='hs-keyglyph'>[</span><span class='hs-varid'>a</span><span class='hs-keyglyph'>]</span><span class='hs-keyglyph'>]</span>
<a name="line-231"></a><span class='hs-definition'>split</span> <span class='hs-varid'>s</span> <span class='hs-keyglyph'>=</span> <span class='hs-varid'>map</span> <span class='hs-varid'>fromElem</span> <span class='hs-varop'>.</span> <span class='hs-varid'>postProcess</span> <span class='hs-varid'>s</span> <span class='hs-varop'>.</span> <span class='hs-varid'>splitInternal</span> <span class='hs-layout'>(</span><span class='hs-varid'>delimiter</span> <span class='hs-varid'>s</span><span class='hs-layout'>)</span>
<a name="line-232"></a>
<a name="line-233"></a><span class='hs-comment'>-- ** Basic strategies</span>
<a name="line-234"></a><span class='hs-comment'>--</span>
<a name="line-235"></a><span class='hs-comment'>-- $ All these basic strategies have the same parameters as the</span>
<a name="line-236"></a><span class='hs-comment'>-- 'defaultSplitter' except for the delimiters.</span>
<a name="line-237"></a>
<a name="line-238"></a><a name="oneOf"></a><span class='hs-comment'>-- | A splitting strategy that splits on any one of the given</span>
<a name="line-239"></a><span class='hs-comment'>-- elements. For example:</span>
<a name="line-240"></a><span class='hs-comment'>--</span>
<a name="line-241"></a><span class='hs-comment'>-- > split (oneOf "xyz") "aazbxyzcxd" == ["aa","z","b","x","","y","","z","c","x","d"]</span>
<a name="line-242"></a><span class='hs-definition'>oneOf</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-keyglyph'>[</span><span class='hs-varid'>a</span><span class='hs-keyglyph'>]</span> <span class='hs-keyglyph'>-></span> <span class='hs-conid'>Splitter</span> <span class='hs-varid'>a</span>
<a name="line-243"></a><span class='hs-definition'>oneOf</span> <span class='hs-varid'>elts</span> <span class='hs-keyglyph'>=</span> <span class='hs-varid'>defaultSplitter</span> <span class='hs-layout'>{</span> <span class='hs-varid'>delimiter</span> <span class='hs-keyglyph'>=</span> <span class='hs-conid'>DelimEltPred</span> <span class='hs-layout'>(</span><span class='hs-varop'>`elem`</span> <span class='hs-varid'>elts</span><span class='hs-layout'>)</span> <span class='hs-layout'>}</span>
<a name="line-244"></a>
<a name="line-245"></a><a name="onSublist"></a><span class='hs-comment'>-- | A splitting strategy that splits on the given list, when it is</span>
<a name="line-246"></a><span class='hs-comment'>-- encountered as an exact subsequence. For example:</span>
<a name="line-247"></a><span class='hs-comment'>--</span>
<a name="line-248"></a><span class='hs-comment'>-- > split (onSublist "xyz") "aazbxyzcxd" == ["aazb","xyz","cxd"]</span>
<a name="line-249"></a><span class='hs-comment'>--</span>
<a name="line-250"></a><span class='hs-comment'>-- Note that splitting on the empty list is a special case, which</span>
<a name="line-251"></a><span class='hs-comment'>-- splits just before every element of the list being split. For example:</span>
<a name="line-252"></a><span class='hs-comment'>--</span>
<a name="line-253"></a><span class='hs-comment'>-- > split (onSublist "") "abc" == ["","","a","","b","","c"]</span>
<a name="line-254"></a><span class='hs-comment'>-- > split (dropDelims . dropBlanks $ onSublist "") "abc" == ["a","b","c"]</span>
<a name="line-255"></a><span class='hs-comment'>--</span>
<a name="line-256"></a><span class='hs-comment'>-- However, if you want to break a list into singleton elements like</span>
<a name="line-257"></a><span class='hs-comment'>-- this, you are better off using @'splitEvery' 1@, or better yet,</span>
<a name="line-258"></a><span class='hs-comment'>-- @'map' (:[])@.</span>
<a name="line-259"></a><span class='hs-definition'>onSublist</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-keyglyph'>[</span><span class='hs-varid'>a</span><span class='hs-keyglyph'>]</span> <span class='hs-keyglyph'>-></span> <span class='hs-conid'>Splitter</span> <span class='hs-varid'>a</span>
<a name="line-260"></a><span class='hs-definition'>onSublist</span> <span class='hs-varid'>lst</span> <span class='hs-keyglyph'>=</span> <span class='hs-varid'>defaultSplitter</span> <span class='hs-layout'>{</span> <span class='hs-varid'>delimiter</span> <span class='hs-keyglyph'>=</span> <span class='hs-conid'>DelimSublist</span> <span class='hs-varid'>lst</span> <span class='hs-layout'>}</span>
<a name="line-261"></a>
<a name="line-262"></a><a name="whenElt"></a><span class='hs-comment'>-- | A splitting strategy that splits on any elements that satisfy the</span>
<a name="line-263"></a><span class='hs-comment'>-- given predicate. For example:</span>
<a name="line-264"></a><span class='hs-comment'>--</span>
<a name="line-265"></a><span class='hs-comment'>-- > split (whenElt (<0)) [2,4,-3,6,-9,1] == [[2,4],[-3],[6],[-9],[1]]</span>
<a name="line-266"></a><span class='hs-definition'>whenElt</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'>Splitter</span> <span class='hs-varid'>a</span>
<a name="line-267"></a><span class='hs-definition'>whenElt</span> <span class='hs-varid'>p</span> <span class='hs-keyglyph'>=</span> <span class='hs-varid'>defaultSplitter</span> <span class='hs-layout'>{</span> <span class='hs-varid'>delimiter</span> <span class='hs-keyglyph'>=</span> <span class='hs-conid'>DelimEltPred</span> <span class='hs-varid'>p</span> <span class='hs-layout'>}</span>
<a name="line-268"></a>
<a name="line-269"></a><span class='hs-comment'>-- ** Strategy transformers</span>
<a name="line-270"></a>
<a name="line-271"></a><a name="dropDelims"></a><span class='hs-comment'>-- | Drop delimiters from the output (the default is to keep</span>
<a name="line-272"></a><span class='hs-comment'>-- them). For example,</span>
<a name="line-273"></a><span class='hs-comment'>--</span>
<a name="line-274"></a><span class='hs-comment'>-- > split (oneOf ":") "a:b:c" == ["a", ":", "b", ":", "c"]</span>
<a name="line-275"></a><span class='hs-comment'>-- > split (dropDelims $ oneOf ":") "a:b:c" == ["a", "b", "c"]</span>
<a name="line-276"></a><span class='hs-definition'>dropDelims</span> <span class='hs-keyglyph'>::</span> <span class='hs-conid'>Splitter</span> <span class='hs-varid'>a</span> <span class='hs-keyglyph'>-></span> <span class='hs-conid'>Splitter</span> <span class='hs-varid'>a</span>
<a name="line-277"></a><span class='hs-definition'>dropDelims</span> <span class='hs-varid'>s</span> <span class='hs-keyglyph'>=</span> <span class='hs-varid'>s</span> <span class='hs-layout'>{</span> <span class='hs-varid'>delimPolicy</span> <span class='hs-keyglyph'>=</span> <span class='hs-conid'>Drop</span> <span class='hs-layout'>}</span>
<a name="line-278"></a>
<a name="line-279"></a><a name="keepDelimsL"></a><span class='hs-comment'>-- | Keep delimiters in the output by prepending them to adjacent</span>
<a name="line-280"></a><span class='hs-comment'>-- chunks. For example:</span>
<a name="line-281"></a><span class='hs-comment'>--</span>
<a name="line-282"></a><span class='hs-comment'>-- > split (keepDelimsL $ oneOf "xyz") "aazbxyzcxd" == ["aa","zb","x","y","zc","xd"]</span>
<a name="line-283"></a><span class='hs-definition'>keepDelimsL</span> <span class='hs-keyglyph'>::</span> <span class='hs-conid'>Splitter</span> <span class='hs-varid'>a</span> <span class='hs-keyglyph'>-></span> <span class='hs-conid'>Splitter</span> <span class='hs-varid'>a</span>
<a name="line-284"></a><span class='hs-definition'>keepDelimsL</span> <span class='hs-varid'>s</span> <span class='hs-keyglyph'>=</span> <span class='hs-varid'>s</span> <span class='hs-layout'>{</span> <span class='hs-varid'>delimPolicy</span> <span class='hs-keyglyph'>=</span> <span class='hs-conid'>KeepLeft</span> <span class='hs-layout'>}</span>
<a name="line-285"></a>
<a name="line-286"></a><a name="keepDelimsR"></a><span class='hs-comment'>-- | Keep delimiters in the output by appending them to adjacent</span>
<a name="line-287"></a><span class='hs-comment'>-- chunks. For example:</span>
<a name="line-288"></a><span class='hs-comment'>--</span>
<a name="line-289"></a><span class='hs-comment'>-- > split (keepDelimsR $ oneOf "xyz") "aazbxyzcxd" == ["aaz","bx","y","z","cx","d"]</span>
<a name="line-290"></a><span class='hs-definition'>keepDelimsR</span> <span class='hs-keyglyph'>::</span> <span class='hs-conid'>Splitter</span> <span class='hs-varid'>a</span> <span class='hs-keyglyph'>-></span> <span class='hs-conid'>Splitter</span> <span class='hs-varid'>a</span>
<a name="line-291"></a><span class='hs-definition'>keepDelimsR</span> <span class='hs-varid'>s</span> <span class='hs-keyglyph'>=</span> <span class='hs-varid'>s</span> <span class='hs-layout'>{</span> <span class='hs-varid'>delimPolicy</span> <span class='hs-keyglyph'>=</span> <span class='hs-conid'>KeepRight</span> <span class='hs-layout'>}</span>
<a name="line-292"></a>
<a name="line-293"></a><a name="condense"></a><span class='hs-comment'>-- | Condense multiple consecutive delimiters into one. For example:</span>
<a name="line-294"></a><span class='hs-comment'>--</span>
<a name="line-295"></a><span class='hs-comment'>-- > split (condense $ oneOf "xyz") "aazbxyzcxd" == ["aa","z","b","xyz","c","x","d"]</span>
<a name="line-296"></a><span class='hs-comment'>-- > split (dropDelims $ oneOf "xyz") "aazbxyzcxd" == ["aa","b","","","c","d"]</span>
<a name="line-297"></a><span class='hs-comment'>-- > split (condense . dropDelims $ oneOf "xyz") "aazbxyzcxd" == ["aa","b","c","d"]</span>
<a name="line-298"></a><span class='hs-definition'>condense</span> <span class='hs-keyglyph'>::</span> <span class='hs-conid'>Splitter</span> <span class='hs-varid'>a</span> <span class='hs-keyglyph'>-></span> <span class='hs-conid'>Splitter</span> <span class='hs-varid'>a</span>
<a name="line-299"></a><span class='hs-definition'>condense</span> <span class='hs-varid'>s</span> <span class='hs-keyglyph'>=</span> <span class='hs-varid'>s</span> <span class='hs-layout'>{</span> <span class='hs-varid'>condensePolicy</span> <span class='hs-keyglyph'>=</span> <span class='hs-conid'>Condense</span> <span class='hs-layout'>}</span>
<a name="line-300"></a>
<a name="line-301"></a><a name="dropInitBlank"></a><span class='hs-comment'>-- | Don't generate a blank chunk if there is a delimiter at the</span>
<a name="line-302"></a><span class='hs-comment'>-- beginning. For example:</span>
<a name="line-303"></a><span class='hs-comment'>--</span>
<a name="line-304"></a><span class='hs-comment'>-- > split (oneOf ":") ":a:b" == ["",":","a",":","b"]</span>
<a name="line-305"></a><span class='hs-comment'>-- > split (dropInitBlank $ oneOf ":") ":a:b" == [":","a",":","b"]</span>
<a name="line-306"></a><span class='hs-definition'>dropInitBlank</span> <span class='hs-keyglyph'>::</span> <span class='hs-conid'>Splitter</span> <span class='hs-varid'>a</span> <span class='hs-keyglyph'>-></span> <span class='hs-conid'>Splitter</span> <span class='hs-varid'>a</span>
<a name="line-307"></a><span class='hs-definition'>dropInitBlank</span> <span class='hs-varid'>s</span> <span class='hs-keyglyph'>=</span> <span class='hs-varid'>s</span> <span class='hs-layout'>{</span> <span class='hs-varid'>initBlankPolicy</span> <span class='hs-keyglyph'>=</span> <span class='hs-conid'>DropBlank</span> <span class='hs-layout'>}</span>
<a name="line-308"></a>
<a name="line-309"></a><a name="dropFinalBlank"></a><span class='hs-comment'>-- | Don't generate a blank chunk if there is a delimiter at the end.</span>
<a name="line-310"></a><span class='hs-comment'>-- For example:</span>
<a name="line-311"></a><span class='hs-comment'>--</span>
<a name="line-312"></a><span class='hs-comment'>-- > split (oneOf ":") "a:b:" == ["a",":","b",":",""]</span>
<a name="line-313"></a><span class='hs-comment'>-- > split (dropFinalBlank $ oneOf ":") "a:b:" == ["a",":","b",":"]</span>
<a name="line-314"></a><span class='hs-definition'>dropFinalBlank</span> <span class='hs-keyglyph'>::</span> <span class='hs-conid'>Splitter</span> <span class='hs-varid'>a</span> <span class='hs-keyglyph'>-></span> <span class='hs-conid'>Splitter</span> <span class='hs-varid'>a</span>
<a name="line-315"></a><span class='hs-definition'>dropFinalBlank</span> <span class='hs-varid'>s</span> <span class='hs-keyglyph'>=</span> <span class='hs-varid'>s</span> <span class='hs-layout'>{</span> <span class='hs-varid'>finalBlankPolicy</span> <span class='hs-keyglyph'>=</span> <span class='hs-conid'>DropBlank</span> <span class='hs-layout'>}</span>
<a name="line-316"></a>
<a name="line-317"></a><span class='hs-comment'>-- ** Derived combinators</span>
<a name="line-318"></a>
<a name="line-319"></a><a name="dropBlanks"></a><span class='hs-comment'>-- | Drop all blank chunks from the output. Equivalent to</span>
<a name="line-320"></a><span class='hs-comment'>-- @'dropInitBlank' . 'dropFinalBlank' . 'condense'@. For example:</span>
<a name="line-321"></a><span class='hs-comment'>--</span>
<a name="line-322"></a><span class='hs-comment'>-- > split (oneOf ":") "::b:::a" == ["",":","",":","b",":","",":","",":","a"]</span>
<a name="line-323"></a><span class='hs-comment'>-- > split (dropBlanks $ oneOf ":") "::b:::a" == ["::","b",":::","a"]</span>
<a name="line-324"></a><span class='hs-definition'>dropBlanks</span> <span class='hs-keyglyph'>::</span> <span class='hs-conid'>Splitter</span> <span class='hs-varid'>a</span> <span class='hs-keyglyph'>-></span> <span class='hs-conid'>Splitter</span> <span class='hs-varid'>a</span>
<a name="line-325"></a><span class='hs-definition'>dropBlanks</span> <span class='hs-keyglyph'>=</span> <span class='hs-varid'>dropInitBlank</span> <span class='hs-varop'>.</span> <span class='hs-varid'>dropFinalBlank</span> <span class='hs-varop'>.</span> <span class='hs-varid'>condense</span>
<a name="line-326"></a>
<a name="line-327"></a><a name="startsWith"></a><span class='hs-comment'>-- | Make a strategy that splits a list into chunks that all start</span>
<a name="line-328"></a><span class='hs-comment'>-- with the given subsequence (except possibly the first).</span>
<a name="line-329"></a><span class='hs-comment'>-- Equivalent to @'dropInitBlank' . 'keepDelimsL' . 'onSublist'@.</span>
<a name="line-330"></a><span class='hs-comment'>-- For example:</span>
<a name="line-331"></a><span class='hs-comment'>--</span>
<a name="line-332"></a><span class='hs-comment'>-- > split (startsWith "app") "applyappicativeapplaudapproachapple" == ["apply","appicative","applaud","approach","apple"]</span>
<a name="line-333"></a><span class='hs-definition'>startsWith</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-keyglyph'>[</span><span class='hs-varid'>a</span><span class='hs-keyglyph'>]</span> <span class='hs-keyglyph'>-></span> <span class='hs-conid'>Splitter</span> <span class='hs-varid'>a</span>
<a name="line-334"></a><span class='hs-definition'>startsWith</span> <span class='hs-keyglyph'>=</span> <span class='hs-varid'>dropInitBlank</span> <span class='hs-varop'>.</span> <span class='hs-varid'>keepDelimsL</span> <span class='hs-varop'>.</span> <span class='hs-varid'>onSublist</span>
<a name="line-335"></a>
<a name="line-336"></a><a name="startsWithOneOf"></a><span class='hs-comment'>-- | Make a strategy that splits a list into chunks that all start</span>
<a name="line-337"></a><span class='hs-comment'>-- with one of the given elements (except possibly the first).</span>
<a name="line-338"></a><span class='hs-comment'>-- Equivalent to @'dropInitBlank' . 'keepDelimsL' . 'oneOf'@. For</span>
<a name="line-339"></a><span class='hs-comment'>-- example:</span>
<a name="line-340"></a><span class='hs-comment'>--</span>
<a name="line-341"></a><span class='hs-comment'>-- > split (startsWithOneOf ['A'..'Z']) "ACamelCaseIdentifier" == ["A","Camel","Case","Identifier"]</span>
<a name="line-342"></a><span class='hs-definition'>startsWithOneOf</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-keyglyph'>[</span><span class='hs-varid'>a</span><span class='hs-keyglyph'>]</span> <span class='hs-keyglyph'>-></span> <span class='hs-conid'>Splitter</span> <span class='hs-varid'>a</span>
<a name="line-343"></a><span class='hs-definition'>startsWithOneOf</span> <span class='hs-keyglyph'>=</span> <span class='hs-varid'>dropInitBlank</span> <span class='hs-varop'>.</span> <span class='hs-varid'>keepDelimsL</span> <span class='hs-varop'>.</span> <span class='hs-varid'>oneOf</span>
<a name="line-344"></a>
<a name="line-345"></a><a name="endsWith"></a><span class='hs-comment'>-- | Make a strategy that splits a list into chunks that all end with</span>
<a name="line-346"></a><span class='hs-comment'>-- the given subsequence, except possibly the last. Equivalent to</span>
<a name="line-347"></a><span class='hs-comment'>-- @'dropFinalBlank' . 'keepDelimsR' . 'onSublist'@. For example:</span>
<a name="line-348"></a><span class='hs-comment'>--</span>
<a name="line-349"></a><span class='hs-comment'>-- > split (endsWith "ly") "happilyslowlygnarlylily" == ["happily","slowly","gnarly","lily"]</span>
<a name="line-350"></a><span class='hs-definition'>endsWith</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-keyglyph'>[</span><span class='hs-varid'>a</span><span class='hs-keyglyph'>]</span> <span class='hs-keyglyph'>-></span> <span class='hs-conid'>Splitter</span> <span class='hs-varid'>a</span>
<a name="line-351"></a><span class='hs-definition'>endsWith</span> <span class='hs-keyglyph'>=</span> <span class='hs-varid'>dropFinalBlank</span> <span class='hs-varop'>.</span> <span class='hs-varid'>keepDelimsR</span> <span class='hs-varop'>.</span> <span class='hs-varid'>onSublist</span>
<a name="line-352"></a>
<a name="line-353"></a><a name="endsWithOneOf"></a><span class='hs-comment'>-- | Make a strategy that splits a list into chunks that all end with</span>
<a name="line-354"></a><span class='hs-comment'>-- one of the given elements, except possibly the last. Equivalent</span>
<a name="line-355"></a><span class='hs-comment'>-- to @'dropFinalBlank' . 'keepDelimsR' . 'oneOf'@. For example:</span>
<a name="line-356"></a><span class='hs-comment'>--</span>
<a name="line-357"></a><span class='hs-comment'>-- > split (condense $ endsWithOneOf ".,?! ") "Hi, there! How are you?" == ["Hi, ","there! ","How ","are ","you?"]</span>
<a name="line-358"></a><span class='hs-definition'>endsWithOneOf</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-keyglyph'>[</span><span class='hs-varid'>a</span><span class='hs-keyglyph'>]</span> <span class='hs-keyglyph'>-></span> <span class='hs-conid'>Splitter</span> <span class='hs-varid'>a</span>
<a name="line-359"></a><span class='hs-definition'>endsWithOneOf</span> <span class='hs-keyglyph'>=</span> <span class='hs-varid'>dropFinalBlank</span> <span class='hs-varop'>.</span> <span class='hs-varid'>keepDelimsR</span> <span class='hs-varop'>.</span> <span class='hs-varid'>oneOf</span>
<a name="line-360"></a>
<a name="line-361"></a><span class='hs-comment'>-- ** Convenience functions</span>
<a name="line-362"></a><span class='hs-comment'>--</span>
<a name="line-363"></a><span class='hs-comment'>-- These functions implement some common splitting strategies. Note</span>
<a name="line-364"></a><span class='hs-comment'>-- that all of the functions in this section drop delimiters from</span>
<a name="line-365"></a><span class='hs-comment'>-- the final output, since that is a more common use case even</span>
<a name="line-366"></a><span class='hs-comment'>-- though it is not the default.</span>
<a name="line-367"></a>
<a name="line-368"></a><a name="splitOneOf"></a><span class='hs-comment'>-- | Split on any of the given elements. Equivalent to @'split'</span>
<a name="line-369"></a><span class='hs-comment'>-- . 'dropDelims' . 'oneOf'@. For example:</span>
<a name="line-370"></a><span class='hs-comment'>--</span>
<a name="line-371"></a><span class='hs-comment'>-- > splitOneOf ";.," "foo,bar;baz.glurk" == ["foo","bar","baz","glurk"]</span>
<a name="line-372"></a><span class='hs-definition'>splitOneOf</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-keyglyph'>[</span><span class='hs-varid'>a</span><span class='hs-keyglyph'>]</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-keyglyph'>[</span><span class='hs-keyglyph'>[</span><span class='hs-varid'>a</span><span class='hs-keyglyph'>]</span><span class='hs-keyglyph'>]</span>
<a name="line-373"></a><span class='hs-definition'>splitOneOf</span> <span class='hs-keyglyph'>=</span> <span class='hs-varid'>split</span> <span class='hs-varop'>.</span> <span class='hs-varid'>dropDelims</span> <span class='hs-varop'>.</span> <span class='hs-varid'>oneOf</span>
<a name="line-374"></a>
<a name="line-375"></a><a name="splitOn"></a><span class='hs-comment'>-- | Split on the given sublist. Equivalent to @'split'</span>
<a name="line-376"></a><span class='hs-comment'>-- . 'dropDelims' . 'onSublist'@. For example:</span>
<a name="line-377"></a><span class='hs-comment'>--</span>
<a name="line-378"></a><span class='hs-comment'>-- > splitOn ".." "a..b...c....d.." == ["a","b",".c","","d",""]</span>
<a name="line-379"></a><span class='hs-definition'>splitOn</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-keyglyph'>[</span><span class='hs-varid'>a</span><span class='hs-keyglyph'>]</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-keyglyph'>[</span><span class='hs-keyglyph'>[</span><span class='hs-varid'>a</span><span class='hs-keyglyph'>]</span><span class='hs-keyglyph'>]</span>
<a name="line-380"></a><span class='hs-definition'>splitOn</span> <span class='hs-keyglyph'>=</span> <span class='hs-varid'>split</span> <span class='hs-varop'>.</span> <span class='hs-varid'>dropDelims</span> <span class='hs-varop'>.</span> <span class='hs-varid'>onSublist</span>
<a name="line-381"></a>
<a name="line-382"></a><a name="splitWhen"></a><span class='hs-comment'>-- | Split on elements satisfying the given predicate. Equivalent to</span>
<a name="line-383"></a><span class='hs-comment'>-- @'split' . 'dropDelims' . 'whenElt'@. For example:</span>
<a name="line-384"></a><span class='hs-comment'>--</span>
<a name="line-385"></a><span class='hs-comment'>-- > splitWhen (<0) [1,3,-4,5,7,-9,0,2] == [[1,3],[5,7],[0,2]]</span>
<a name="line-386"></a><span class='hs-definition'>splitWhen</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-keyglyph'>[</span><span class='hs-varid'>a</span><span class='hs-keyglyph'>]</span> <span class='hs-keyglyph'>-></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>
<a name="line-387"></a><span class='hs-definition'>splitWhen</span> <span class='hs-keyglyph'>=</span> <span class='hs-varid'>split</span> <span class='hs-varop'>.</span> <span class='hs-varid'>dropDelims</span> <span class='hs-varop'>.</span> <span class='hs-varid'>whenElt</span>
<a name="line-388"></a>
<a name="line-389"></a><a name="sepBy"></a><span class='hs-comment'>-- | A synonym for 'splitOn'.</span>
<a name="line-390"></a><span class='hs-definition'>sepBy</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-keyglyph'>[</span><span class='hs-varid'>a</span><span class='hs-keyglyph'>]</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-keyglyph'>[</span><span class='hs-keyglyph'>[</span><span class='hs-varid'>a</span><span class='hs-keyglyph'>]</span><span class='hs-keyglyph'>]</span>
<a name="line-391"></a><span class='hs-definition'>sepBy</span> <span class='hs-keyglyph'>=</span> <span class='hs-varid'>splitOn</span>
<a name="line-392"></a>
<a name="line-393"></a><a name="sepByOneOf"></a><span class='hs-comment'>-- | A synonym for 'splitOneOf'.</span>
<a name="line-394"></a><span class='hs-definition'>sepByOneOf</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-keyglyph'>[</span><span class='hs-varid'>a</span><span class='hs-keyglyph'>]</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-keyglyph'>[</span><span class='hs-keyglyph'>[</span><span class='hs-varid'>a</span><span class='hs-keyglyph'>]</span><span class='hs-keyglyph'>]</span>
<a name="line-395"></a><span class='hs-definition'>sepByOneOf</span> <span class='hs-keyglyph'>=</span> <span class='hs-varid'>splitOneOf</span>
<a name="line-396"></a>
<a name="line-397"></a><a name="endBy"></a><span class='hs-comment'>-- | Split into chunks terminated by the given subsequence.</span>
<a name="line-398"></a><span class='hs-comment'>-- Equivalent to @'split' . 'dropFinalBlank' . 'dropDelims'</span>
<a name="line-399"></a><span class='hs-comment'>-- . 'onSublist'@. For example:</span>
<a name="line-400"></a><span class='hs-comment'>--</span>
<a name="line-401"></a><span class='hs-comment'>-- > endBy ";" "foo;bar;baz;" == ["foo","bar","baz"]</span>
<a name="line-402"></a><span class='hs-comment'>--</span>
<a name="line-403"></a><span class='hs-comment'>-- Note also that the 'lines' function from "Data.List" is equivalent</span>
<a name="line-404"></a><span class='hs-comment'>-- to @'endBy' \"\\n\"@.</span>
<a name="line-405"></a><span class='hs-definition'>endBy</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-keyglyph'>[</span><span class='hs-varid'>a</span><span class='hs-keyglyph'>]</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-keyglyph'>[</span><span class='hs-keyglyph'>[</span><span class='hs-varid'>a</span><span class='hs-keyglyph'>]</span><span class='hs-keyglyph'>]</span>
<a name="line-406"></a><span class='hs-definition'>endBy</span> <span class='hs-keyglyph'>=</span> <span class='hs-varid'>split</span> <span class='hs-varop'>.</span> <span class='hs-varid'>dropFinalBlank</span> <span class='hs-varop'>.</span> <span class='hs-varid'>dropDelims</span> <span class='hs-varop'>.</span> <span class='hs-varid'>onSublist</span>
<a name="line-407"></a>
<a name="line-408"></a><a name="endByOneOf"></a><span class='hs-comment'>-- | Split into chunks terminated by one of the given elements.</span>
<a name="line-409"></a><span class='hs-comment'>-- Equivalent to @'split' . 'dropFinalBlank' . 'dropDelims' . 'oneOf'@.</span>
<a name="line-410"></a><span class='hs-definition'>endByOneOf</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-keyglyph'>[</span><span class='hs-varid'>a</span><span class='hs-keyglyph'>]</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-keyglyph'>[</span><span class='hs-keyglyph'>[</span><span class='hs-varid'>a</span><span class='hs-keyglyph'>]</span><span class='hs-keyglyph'>]</span>
<a name="line-411"></a><span class='hs-definition'>endByOneOf</span> <span class='hs-keyglyph'>=</span> <span class='hs-varid'>split</span> <span class='hs-varop'>.</span> <span class='hs-varid'>dropFinalBlank</span> <span class='hs-varop'>.</span> <span class='hs-varid'>dropDelims</span> <span class='hs-varop'>.</span> <span class='hs-varid'>oneOf</span>
<a name="line-412"></a>
<a name="line-413"></a><a name="unintercalate"></a><span class='hs-comment'>-- | A synonym for 'sepBy' \/ 'splitOn'.</span>
<a name="line-414"></a><span class='hs-comment'>--</span>
<a name="line-415"></a><span class='hs-comment'>-- Note that this is the right inverse of the 'intercalate' function</span>
<a name="line-416"></a><span class='hs-comment'>-- from "Data.List", that is, @'intercalate' x . 'unintercalate' x</span>
<a name="line-417"></a><span class='hs-comment'>-- == 'id'@. It is also the case that @'unintercalate' x</span>
<a name="line-418"></a><span class='hs-comment'>-- . 'intercalate' x@ is idempotent. @'unintercalate' x</span>
<a name="line-419"></a><span class='hs-comment'>-- . 'intercalate' x@ is the identity on certain lists, but it is</span>
<a name="line-420"></a><span class='hs-comment'>-- tricky to state the precise conditions under which this holds.</span>
<a name="line-421"></a><span class='hs-comment'>-- (For example, it is not enough to say that @x@ does not occur in</span>
<a name="line-422"></a><span class='hs-comment'>-- any elements of the input list. Working out why is left as an</span>
<a name="line-423"></a><span class='hs-comment'>-- exercise for the reader.)</span>
<a name="line-424"></a><span class='hs-definition'>unintercalate</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-keyglyph'>[</span><span class='hs-varid'>a</span><span class='hs-keyglyph'>]</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-keyglyph'>[</span><span class='hs-keyglyph'>[</span><span class='hs-varid'>a</span><span class='hs-keyglyph'>]</span><span class='hs-keyglyph'>]</span>
<a name="line-425"></a><span class='hs-definition'>unintercalate</span> <span class='hs-keyglyph'>=</span> <span class='hs-varid'>sepBy</span>
<a name="line-426"></a>
<a name="line-427"></a><a name="wordsBy"></a><span class='hs-comment'>-- | Split into words, with word boundaries indicated by the given</span>
<a name="line-428"></a><span class='hs-comment'>-- predicate. Satisfies @words === wordsBy isSpace@; equivalent to</span>
<a name="line-429"></a><span class='hs-comment'>-- @split . dropBlanks . dropDelims . whenElt@. For example:</span>
<a name="line-430"></a><span class='hs-comment'>--</span>
<a name="line-431"></a><span class='hs-comment'>-- > wordsBy (=='x') "dogxxxcatxbirdxx" == ["dog","cat","bird"]</span>
<a name="line-432"></a><span class='hs-definition'>wordsBy</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-keyglyph'>[</span><span class='hs-varid'>a</span><span class='hs-keyglyph'>]</span> <span class='hs-keyglyph'>-></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>
<a name="line-433"></a><span class='hs-definition'>wordsBy</span> <span class='hs-keyglyph'>=</span> <span class='hs-varid'>split</span> <span class='hs-varop'>.</span> <span class='hs-varid'>dropBlanks</span> <span class='hs-varop'>.</span> <span class='hs-varid'>dropDelims</span> <span class='hs-varop'>.</span> <span class='hs-varid'>whenElt</span>
<a name="line-434"></a>
<a name="line-435"></a><a name="linesBy"></a><span class='hs-comment'>-- | Split into lines, with line boundaries indicated by the given</span>
<a name="line-436"></a><span class='hs-comment'>-- predicate. Satisfies @lines === linesBy (=='\n')@; equivalent to</span>
<a name="line-437"></a><span class='hs-comment'>-- @split . dropFinalBlank . dropDelims . whenElt@. For example:</span>
<a name="line-438"></a><span class='hs-comment'>--</span>
<a name="line-439"></a><span class='hs-comment'>-- > linesBy (=='x') "dogxxxcatxbirdxx" == ["dog","","","cat","bird",""]</span>
<a name="line-440"></a><span class='hs-definition'>linesBy</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-keyglyph'>[</span><span class='hs-varid'>a</span><span class='hs-keyglyph'>]</span> <span class='hs-keyglyph'>-></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>
<a name="line-441"></a><span class='hs-definition'>linesBy</span> <span class='hs-keyglyph'>=</span> <span class='hs-varid'>split</span> <span class='hs-varop'>.</span> <span class='hs-varid'>dropFinalBlank</span> <span class='hs-varop'>.</span> <span class='hs-varid'>dropDelims</span> <span class='hs-varop'>.</span> <span class='hs-varid'>whenElt</span>
<a name="line-442"></a>
<a name="line-443"></a><span class='hs-comment'>-- * Other splitting methods</span>
<a name="line-444"></a>
<a name="line-445"></a><a name="splitEvery"></a><span class='hs-comment'>-- | @'splitEvery' n@ splits a list into length-n pieces. The last</span>
<a name="line-446"></a><span class='hs-comment'>-- piece will be shorter if @n@ does not evenly divide the length of</span>
<a name="line-447"></a><span class='hs-comment'>-- the list. If @n <= 0@, @'splitEvery' n l@ returns an infinite list</span>
<a name="line-448"></a><span class='hs-comment'>-- of empty lists.</span>
<a name="line-449"></a><span class='hs-comment'>--</span>
<a name="line-450"></a><span class='hs-comment'>-- Note that @'splitEvery' n []@ is @[]@, not @[[]]@. This is</span>
<a name="line-451"></a><span class='hs-comment'>-- intentional, and is consistent with a recursive definition of</span>
<a name="line-452"></a><span class='hs-comment'>-- 'splitEvery'; it satisfies the property that</span>
<a name="line-453"></a><span class='hs-comment'>--</span>
<a name="line-454"></a><span class='hs-comment'>-- @splitEvery n xs ++ splitEvery n ys == splitEvery n (xs ++ ys)@</span>
<a name="line-455"></a><span class='hs-comment'>--</span>
<a name="line-456"></a><span class='hs-comment'>-- whenever @n@ evenly divides the length of @xs@.</span>
<a name="line-457"></a><span class='hs-definition'>splitEvery</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'>e</span><span class='hs-keyglyph'>]</span> <span class='hs-keyglyph'>-></span> <span class='hs-keyglyph'>[</span><span class='hs-keyglyph'>[</span><span class='hs-varid'>e</span><span class='hs-keyglyph'>]</span><span class='hs-keyglyph'>]</span>
<a name="line-458"></a><span class='hs-definition'>splitEvery</span> <span class='hs-varid'>i</span> <span class='hs-varid'>ls</span> <span class='hs-keyglyph'>=</span> <span class='hs-varid'>map</span> <span class='hs-layout'>(</span><span class='hs-varid'>take</span> <span class='hs-varid'>i</span><span class='hs-layout'>)</span> <span class='hs-layout'>(</span><span class='hs-varid'>build</span> <span class='hs-layout'>(</span><span class='hs-varid'>splitter</span> <span class='hs-varid'>ls</span><span class='hs-layout'>)</span><span class='hs-layout'>)</span> <span class='hs-keyword'>where</span>
<a name="line-459"></a> <span class='hs-varid'>splitter</span> <span class='hs-conid'>[]</span> <span class='hs-keyword'>_</span> <span class='hs-varid'>n</span> <span class='hs-keyglyph'>=</span> <span class='hs-varid'>n</span>
<a name="line-460"></a> <span class='hs-varid'>splitter</span> <span class='hs-varid'>l</span> <span class='hs-varid'>c</span> <span class='hs-varid'>n</span> <span class='hs-keyglyph'>=</span> <span class='hs-varid'>l</span> <span class='hs-varop'>`c`</span> <span class='hs-varid'>splitter</span> <span class='hs-layout'>(</span><span class='hs-varid'>drop</span> <span class='hs-varid'>i</span> <span class='hs-varid'>l</span><span class='hs-layout'>)</span> <span class='hs-varid'>c</span> <span class='hs-varid'>n</span>
<a name="line-461"></a>
<a name="line-462"></a><a name="chunk"></a><span class='hs-comment'>-- | A common synonym for 'splitEvery'.</span>
<a name="line-463"></a><span class='hs-definition'>chunk</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'>e</span><span class='hs-keyglyph'>]</span> <span class='hs-keyglyph'>-></span> <span class='hs-keyglyph'>[</span><span class='hs-keyglyph'>[</span><span class='hs-varid'>e</span><span class='hs-keyglyph'>]</span><span class='hs-keyglyph'>]</span>
<a name="line-464"></a><span class='hs-definition'>chunk</span> <span class='hs-keyglyph'>=</span> <span class='hs-varid'>splitEvery</span>
<a name="line-465"></a>
<a name="line-466"></a><a name="splitPlaces"></a><span class='hs-comment'>-- | Split a list into chunks of the given lengths. For example:</span>
<a name="line-467"></a><span class='hs-comment'>--</span>
<a name="line-468"></a><span class='hs-comment'>-- > splitPlaces [2,3,4] [1..20] == [[1,2],[3,4,5],[6,7,8,9]]</span>
<a name="line-469"></a><span class='hs-comment'>-- > splitPlaces [4,9] [1..10] == [[1,2,3,4],[5,6,7,8,9,10]]</span>
<a name="line-470"></a><span class='hs-comment'>--</span>
<a name="line-471"></a><span class='hs-comment'>-- The behavior of @'splitPlaces' ls xs@ when @'sum' ls /= 'length' xs@ can</span>
<a name="line-472"></a><span class='hs-comment'>-- be inferred from the above examples and the fact that 'splitPlaces'</span>
<a name="line-473"></a><span class='hs-comment'>-- is total.</span>
<a name="line-474"></a><span class='hs-definition'>splitPlaces</span> <span class='hs-keyglyph'>::</span> <span class='hs-conid'>Integral</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-keyglyph'>[</span><span class='hs-varid'>e</span><span class='hs-keyglyph'>]</span> <span class='hs-keyglyph'>-></span> <span class='hs-keyglyph'>[</span><span class='hs-keyglyph'>[</span><span class='hs-varid'>e</span><span class='hs-keyglyph'>]</span><span class='hs-keyglyph'>]</span>
<a name="line-475"></a><span class='hs-definition'>splitPlaces</span> <span class='hs-varid'>is</span> <span class='hs-varid'>ys</span> <span class='hs-keyglyph'>=</span> <span class='hs-varid'>build</span> <span class='hs-layout'>(</span><span class='hs-varid'>splitPlacer</span> <span class='hs-varid'>is</span> <span class='hs-varid'>ys</span><span class='hs-layout'>)</span> <span class='hs-keyword'>where</span>
<a name="line-476"></a> <span class='hs-varid'>splitPlacer</span> <span class='hs-conid'>[]</span> <span class='hs-keyword'>_</span> <span class='hs-keyword'>_</span> <span class='hs-varid'>n</span> <span class='hs-keyglyph'>=</span> <span class='hs-varid'>n</span>
<a name="line-477"></a> <span class='hs-varid'>splitPlacer</span> <span class='hs-keyword'>_</span> <span class='hs-conid'>[]</span> <span class='hs-keyword'>_</span> <span class='hs-varid'>n</span> <span class='hs-keyglyph'>=</span> <span class='hs-varid'>n</span>
<a name="line-478"></a> <span class='hs-varid'>splitPlacer</span> <span class='hs-layout'>(</span><span class='hs-varid'>l</span><span class='hs-conop'>:</span><span class='hs-varid'>ls</span><span class='hs-layout'>)</span> <span class='hs-varid'>xs</span> <span class='hs-varid'>c</span> <span class='hs-varid'>n</span> <span class='hs-keyglyph'>=</span> <span class='hs-keyword'>let</span> <span class='hs-layout'>(</span><span class='hs-varid'>x1</span><span class='hs-layout'>,</span> <span class='hs-varid'>x2</span><span class='hs-layout'>)</span> <span class='hs-keyglyph'>=</span> <span class='hs-varid'>genericSplitAt</span> <span class='hs-varid'>l</span> <span class='hs-varid'>xs</span>
<a name="line-479"></a> <span class='hs-keyword'>in</span> <span class='hs-varid'>x1</span> <span class='hs-varop'>`c`</span> <span class='hs-varid'>splitPlacer</span> <span class='hs-varid'>ls</span> <span class='hs-varid'>x2</span> <span class='hs-varid'>c</span> <span class='hs-varid'>n</span>
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