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<pre><a name="line-1"></a><span class='comment'>-- ------------------------------------------------------------</span>
<a name="line-2"></a>
<a name="line-3"></a><span class='comment'>{- |
<a name="line-4"></a>   Module     : Text.XML.HXT.XPath.GetSimpleXPath
<a name="line-5"></a>   Copyright  : Copyright (C) 2008 Uwe Schmidt
<a name="line-6"></a>   License    : MIT
<a name="line-7"></a>
<a name="line-8"></a>   Maintainer : Uwe Schmidt (uwe@fh-wedel.de)
<a name="line-9"></a>   Stability  : experimental
<a name="line-10"></a>   Portability: portable
<a name="line-11"></a>
<a name="line-12"></a>   XPath selection for simple XPath expressions with list arrows
<a name="line-13"></a>   instead of navigatable trees.
<a name="line-14"></a>
<a name="line-15"></a>   It is recomended, that this module is imported qualified,
<a name="line-16"></a>   e.g like @Text.XML.HXT.Arrow.XPathSimple as XS@.
<a name="line-17"></a>
<a name="line-18"></a>   The arrows defined in this module have the same
<a name="line-19"></a>   functionality as the functions in 'Text.XML.HXT.Arrow.XPath'.
<a name="line-20"></a>
<a name="line-21"></a>   The computation modell in XPath is a navigatable tree,
<a name="line-22"></a>   that means a tree wicht can be traveresed in arbitrary directions,
<a name="line-23"></a>   not only from the root to the leafs. Sometimes this modell
<a name="line-24"></a>   leads to inefficent XPath processing for simple queries, which
<a name="line-25"></a>   only need a top down tree traversal.
<a name="line-26"></a>
<a name="line-27"></a>   When evaluating an XPath expression with these functions, first an attempt is made
<a name="line-28"></a>   to map the XPath expression to a pure arrow. If this is possible
<a name="line-29"></a>   due to the siplicity of the XPath expressions, the result is computed
<a name="line-30"></a>   directly, else the query is processed by the corresponding
<a name="line-31"></a>   function in 'Text.XML.HXT.Arrow.XPath'.
<a name="line-32"></a>
<a name="line-33"></a>   The simple evaluation is possible, when in the XPath expression
<a name="line-34"></a>   only the top down axis (self, child, descendant, descendant or self are used,
<a name="line-35"></a>   when no builtin functions concerning the position of a node are used,
<a name="line-36"></a>   and no comparison of nodes e.g. in node set union is required.
<a name="line-37"></a>
<a name="line-38"></a>-}</span>
<a name="line-39"></a>
<a name="line-40"></a><span class='comment'>-- ------------------------------------------------------------</span>
<a name="line-41"></a>
<a name="line-42"></a><span class='keyword'>module</span> <span class='conid'>Text</span><span class='varop'>.</span><span class='conid'>XML</span><span class='varop'>.</span><span class='conid'>HXT</span><span class='varop'>.</span><span class='conid'>Arrow</span><span class='varop'>.</span><span class='conid'>XPathSimple</span>
<a name="line-43"></a><span class='keyword'>where</span>
<a name="line-44"></a>
<a name="line-45"></a><span class='keyword'>import</span> <span class='conid'>Control</span><span class='varop'>.</span><span class='conid'>Monad</span>
<a name="line-46"></a><span class='keyword'>import</span> <span class='conid'>Control</span><span class='varop'>.</span><span class='conid'>Arrow</span><span class='varop'>.</span><span class='conid'>ListArrows</span>
<a name="line-47"></a>
<a name="line-48"></a><span class='keyword'>import</span> <span class='conid'>Data</span><span class='varop'>.</span><span class='conid'>Maybe</span>
<a name="line-49"></a>
<a name="line-50"></a><span class='keyword'>import</span> <span class='conid'>Text</span><span class='varop'>.</span><span class='conid'>ParserCombinators</span><span class='varop'>.</span><span class='conid'>Parsec</span>
<a name="line-51"></a>    <span class='layout'>(</span> <span class='varid'>runParser</span> <span class='layout'>)</span>
<a name="line-52"></a>
<a name="line-53"></a><span class='keyword'>import</span> <span class='conid'>Text</span><span class='varop'>.</span><span class='conid'>XML</span><span class='varop'>.</span><span class='conid'>HXT</span><span class='varop'>.</span><span class='conid'>DOM</span><span class='varop'>.</span><span class='conid'>Interface</span>
<a name="line-54"></a><span class='keyword'>import</span> <span class='conid'>Text</span><span class='varop'>.</span><span class='conid'>XML</span><span class='varop'>.</span><span class='conid'>HXT</span><span class='varop'>.</span><span class='conid'>Arrow</span><span class='varop'>.</span><span class='conid'>XmlArrow</span>
<a name="line-55"></a>
<a name="line-56"></a><span class='keyword'>import</span> <span class='keyword'>qualified</span> <span class='conid'>Text</span><span class='varop'>.</span><span class='conid'>XML</span><span class='varop'>.</span><span class='conid'>HXT</span><span class='varop'>.</span><span class='conid'>Arrow</span><span class='varop'>.</span><span class='conid'>XPath</span> <span class='keyword'>as</span> <span class='conid'>XP</span>
<a name="line-57"></a>    <span class='layout'>(</span> <span class='varid'>getXPathTreesWithNsEnv</span>
<a name="line-58"></a>    <span class='layout'>)</span>
<a name="line-59"></a>
<a name="line-60"></a><span class='keyword'>import</span> <span class='conid'>Text</span><span class='varop'>.</span><span class='conid'>XML</span><span class='varop'>.</span><span class='conid'>HXT</span><span class='varop'>.</span><span class='conid'>Arrow</span><span class='varop'>.</span><span class='conid'>Edit</span>
<a name="line-61"></a>    <span class='layout'>(</span> <span class='varid'>canonicalizeForXPath</span>
<a name="line-62"></a>    <span class='layout'>)</span>
<a name="line-63"></a>
<a name="line-64"></a><span class='keyword'>import</span> <span class='conid'>Text</span><span class='varop'>.</span><span class='conid'>XML</span><span class='varop'>.</span><span class='conid'>HXT</span><span class='varop'>.</span><span class='conid'>XPath</span><span class='varop'>.</span><span class='conid'>XPathDataTypes</span>
<a name="line-65"></a>    <span class='layout'>(</span> <span class='conid'>XPNumber</span> <span class='layout'>(</span><span class='keyglyph'>..</span><span class='layout'>)</span>
<a name="line-66"></a>    <span class='layout'>,</span> <span class='conid'>Expr</span> <span class='layout'>(</span><span class='keyglyph'>..</span><span class='layout'>)</span>
<a name="line-67"></a>    <span class='layout'>,</span> <span class='conid'>Op</span> <span class='layout'>(</span><span class='keyglyph'>..</span><span class='layout'>)</span>
<a name="line-68"></a>    <span class='layout'>,</span> <span class='conid'>XPathNode</span> <span class='layout'>(</span><span class='keyglyph'>..</span><span class='layout'>)</span>
<a name="line-69"></a>    <span class='layout'>,</span> <span class='conid'>LocationPath</span> <span class='layout'>(</span><span class='keyglyph'>..</span><span class='layout'>)</span>
<a name="line-70"></a>    <span class='layout'>,</span> <span class='conid'>Path</span> <span class='layout'>(</span><span class='keyglyph'>..</span><span class='layout'>)</span>
<a name="line-71"></a>    <span class='layout'>,</span> <span class='conid'>XStep</span> <span class='layout'>(</span><span class='keyglyph'>..</span><span class='layout'>)</span>
<a name="line-72"></a>    <span class='layout'>,</span> <span class='conid'>AxisSpec</span> <span class='layout'>(</span><span class='keyglyph'>..</span><span class='layout'>)</span>
<a name="line-73"></a>    <span class='layout'>,</span> <span class='conid'>NodeTest</span> <span class='layout'>(</span><span class='keyglyph'>..</span><span class='layout'>)</span>
<a name="line-74"></a>    <span class='layout'>,</span> <span class='conid'>XPathValue</span> <span class='layout'>(</span><span class='keyglyph'>..</span><span class='layout'>)</span>
<a name="line-75"></a>    <span class='layout'>)</span>
<a name="line-76"></a>
<a name="line-77"></a><span class='keyword'>import</span> <span class='conid'>Text</span><span class='varop'>.</span><span class='conid'>XML</span><span class='varop'>.</span><span class='conid'>HXT</span><span class='varop'>.</span><span class='conid'>XPath</span><span class='varop'>.</span><span class='conid'>XPathParser</span>
<a name="line-78"></a>    <span class='layout'>(</span> <span class='varid'>parseXPath</span>
<a name="line-79"></a>    <span class='layout'>,</span> <span class='varid'>parseNumber</span>
<a name="line-80"></a>    <span class='layout'>)</span>
<a name="line-81"></a>
<a name="line-82"></a><span class='comment'>-- ----------------------------------------</span>
<a name="line-83"></a>
<a name="line-84"></a><span class='comment'>-- |</span>
<a name="line-85"></a><span class='comment'>-- Same Functionality as 'Text.XML.HXT.Arrow.XPath.getXPathTreesInDoc'</span>
<a name="line-86"></a>
<a name="line-87"></a><a name="getXPathTreesInDoc"></a><span class='definition'>getXPathTreesInDoc</span>			<span class='keyglyph'>::</span> <span class='conid'>ArrowXml</span> <span class='varid'>a</span> <span class='keyglyph'>=&gt;</span> <span class='conid'>String</span> <span class='keyglyph'>-&gt;</span> <span class='varid'>a</span> <span class='conid'>XmlTree</span> <span class='conid'>XmlTree</span>
<a name="line-88"></a><span class='definition'>getXPathTreesInDoc</span>			<span class='keyglyph'>=</span> <span class='varid'>getXPathTreesInDocWithNsEnv</span> <span class='conid'>[]</span>
<a name="line-89"></a>
<a name="line-90"></a><span class='comment'>-- |</span>
<a name="line-91"></a><span class='comment'>-- Same Functionality as 'Text.XML.HXT.Arrow.XPath.getXPathTreesInDocWithNsEnv'</span>
<a name="line-92"></a>
<a name="line-93"></a><a name="getXPathTreesInDocWithNsEnv"></a><span class='definition'>getXPathTreesInDocWithNsEnv</span>		<span class='keyglyph'>::</span> <span class='conid'>ArrowXml</span> <span class='varid'>a</span> <span class='keyglyph'>=&gt;</span> <span class='conid'>NsEnv</span> <span class='keyglyph'>-&gt;</span> <span class='conid'>String</span> <span class='keyglyph'>-&gt;</span> <span class='varid'>a</span> <span class='conid'>XmlTree</span> <span class='conid'>XmlTree</span>
<a name="line-94"></a><span class='definition'>getXPathTreesInDocWithNsEnv</span> <span class='varid'>env</span> <span class='varid'>query</span>	<span class='keyglyph'>=</span> <span class='varid'>canonicalizeForXPath</span>
<a name="line-95"></a>					  <span class='varop'>&gt;&gt;&gt;</span>
<a name="line-96"></a>					  <span class='varid'>tryGetXPath</span> <span class='varid'>env</span> <span class='varid'>query</span>
<a name="line-97"></a><span class='comment'>-- |</span>
<a name="line-98"></a><span class='comment'>-- Same Functionality as 'Text.XML.HXT.Arrow.XPath.getXPathTrees'</span>
<a name="line-99"></a>
<a name="line-100"></a><a name="getXPathTrees"></a><span class='definition'>getXPathTrees</span>				<span class='keyglyph'>::</span> <span class='conid'>ArrowXml</span> <span class='varid'>a</span> <span class='keyglyph'>=&gt;</span> <span class='conid'>String</span> <span class='keyglyph'>-&gt;</span> <span class='varid'>a</span> <span class='conid'>XmlTree</span> <span class='conid'>XmlTree</span>
<a name="line-101"></a><span class='definition'>getXPathTrees</span>				<span class='keyglyph'>=</span> <span class='varid'>getXPathTreesWithNsEnv</span> <span class='conid'>[]</span>
<a name="line-102"></a>
<a name="line-103"></a><span class='comment'>-- |</span>
<a name="line-104"></a><span class='comment'>-- Same Functionality as 'Text.XML.HXT.Arrow.XPath.getXPathTreesWithNsEnv'</span>
<a name="line-105"></a>
<a name="line-106"></a><a name="getXPathTreesWithNsEnv"></a><span class='definition'>getXPathTreesWithNsEnv</span>			<span class='keyglyph'>::</span> <span class='conid'>ArrowXml</span> <span class='varid'>a</span> <span class='keyglyph'>=&gt;</span> <span class='conid'>NsEnv</span> <span class='keyglyph'>-&gt;</span> <span class='conid'>String</span> <span class='keyglyph'>-&gt;</span> <span class='varid'>a</span> <span class='conid'>XmlTree</span> <span class='conid'>XmlTree</span>
<a name="line-107"></a><span class='definition'>getXPathTreesWithNsEnv</span>			<span class='keyglyph'>=</span> <span class='varid'>tryGetXPath</span>
<a name="line-108"></a>
<a name="line-109"></a>
<a name="line-110"></a><a name="tryGetXPath"></a><span class='definition'>tryGetXPath</span>				<span class='keyglyph'>::</span> <span class='conid'>ArrowXml</span> <span class='varid'>a</span> <span class='keyglyph'>=&gt;</span> <span class='conid'>NsEnv</span> <span class='keyglyph'>-&gt;</span> <span class='conid'>String</span> <span class='keyglyph'>-&gt;</span> <span class='varid'>a</span> <span class='conid'>XmlTree</span> <span class='conid'>XmlTree</span>
<a name="line-111"></a><span class='definition'>tryGetXPath</span> <span class='varid'>env</span> <span class='varid'>query</span>			<span class='keyglyph'>=</span> <span class='layout'>(</span> <span class='varid'>listA</span> <span class='layout'>(</span><span class='varid'>getXPathTreesWithNsEnvSimple</span> <span class='varid'>env</span> <span class='varid'>query</span><span class='layout'>)</span>
<a name="line-112"></a>					    <span class='varop'>&amp;&amp;&amp;</span>
<a name="line-113"></a>					    <span class='varid'>listA</span> <span class='layout'>(</span>   <span class='conid'>XP</span><span class='varop'>.</span><span class='varid'>getXPathTreesWithNsEnv</span> <span class='varid'>env</span> <span class='varid'>query</span><span class='layout'>)</span>
<a name="line-114"></a>					  <span class='layout'>)</span>
<a name="line-115"></a>                                          <span class='varop'>&gt;&gt;&gt;</span>
<a name="line-116"></a>					  <span class='varid'>ifA</span> <span class='layout'>(</span><span class='varid'>arr</span> <span class='varid'>fst</span> <span class='varop'>&gt;&gt;&gt;</span> <span class='layout'>(</span><span class='varid'>unlistA</span> <span class='varop'>&gt;&gt;.</span> <span class='varid'>take</span> <span class='num'>1</span><span class='layout'>)</span> <span class='varop'>&gt;&gt;&gt;</span> <span class='varid'>isError</span><span class='layout'>)</span>
<a name="line-117"></a>					      <span class='layout'>(</span><span class='varid'>arr</span> <span class='varid'>snd</span> <span class='varop'>&gt;&gt;&gt;</span> <span class='varid'>unlistA</span><span class='layout'>)</span>
<a name="line-118"></a>					      <span class='layout'>(</span><span class='varid'>arr</span> <span class='varid'>fst</span> <span class='varop'>&gt;&gt;&gt;</span> <span class='varid'>unlistA</span><span class='layout'>)</span>
<a name="line-119"></a>
<a name="line-120"></a><span class='comment'>-- |</span>
<a name="line-121"></a><span class='comment'>-- The xpath interpreter for simple xpath expressions.</span>
<a name="line-122"></a><span class='comment'>--</span>
<a name="line-123"></a><span class='comment'>-- In case of a too complicated or illegal xpath expression an error</span>
<a name="line-124"></a><span class='comment'>-- node is returned, else the list of selected XML trees</span>
<a name="line-125"></a>
<a name="line-126"></a><a name="getXPathTreesWithNsEnvSimple"></a><span class='definition'>getXPathTreesWithNsEnvSimple</span>		<span class='keyglyph'>::</span> <span class='conid'>ArrowXml</span> <span class='varid'>a</span> <span class='keyglyph'>=&gt;</span> <span class='conid'>NsEnv</span> <span class='keyglyph'>-&gt;</span> <span class='conid'>String</span> <span class='keyglyph'>-&gt;</span> <span class='varid'>a</span> <span class='conid'>XmlTree</span> <span class='conid'>XmlTree</span>
<a name="line-127"></a><span class='definition'>getXPathTreesWithNsEnvSimple</span> <span class='varid'>env</span> <span class='varid'>s</span>	<span class='keyglyph'>=</span> <span class='varid'>fromLA</span> <span class='varop'>$</span> <span class='varid'>getXP</span> <span class='varid'>env</span> <span class='varid'>s</span>
<a name="line-128"></a>
<a name="line-129"></a><span class='comment'>-- ----------------------------------------</span>
<a name="line-130"></a>
<a name="line-131"></a><a name="getXP"></a><span class='definition'>getXP</span>			<span class='keyglyph'>::</span> <span class='conid'>NsEnv</span> <span class='keyglyph'>-&gt;</span> <span class='conid'>String</span> <span class='keyglyph'>-&gt;</span> <span class='conid'>LA</span> <span class='conid'>XmlTree</span> <span class='conid'>XmlTree</span>
<a name="line-132"></a><span class='definition'>getXP</span> <span class='varid'>env</span> <span class='varid'>s</span>		<span class='keyglyph'>=</span> <span class='varid'>either</span> <span class='layout'>(</span><span class='varid'>err</span>
<a name="line-133"></a>				  <span class='varop'>.</span>
<a name="line-134"></a>				  <span class='layout'>(</span><span class='layout'>(</span><span class='str'>"Syntax error in XPath expression "</span> <span class='varop'>++</span> <span class='varid'>show</span> <span class='varid'>s</span> <span class='varop'>++</span> <span class='str'>": "</span><span class='layout'>)</span> <span class='varop'>++</span><span class='layout'>)</span>
<a name="line-135"></a>				  <span class='varop'>.</span>
<a name="line-136"></a>				  <span class='varid'>show</span> <span class='varop'>.</span> <span class='varid'>show</span>
<a name="line-137"></a>				 <span class='layout'>)</span> <span class='layout'>(</span><span class='varid'>fromMaybe</span> <span class='layout'>(</span><span class='varid'>err</span> <span class='layout'>(</span> <span class='str'>"XPath expression "</span> <span class='varop'>++</span> <span class='varid'>show</span> <span class='varid'>s</span> <span class='varop'>++</span>
<a name="line-138"></a>						     <span class='str'>" too complicated for simple arrow evaluation"</span>
<a name="line-139"></a>						   <span class='layout'>)</span>
<a name="line-140"></a>					      <span class='layout'>)</span> <span class='varop'>.</span> <span class='varid'>compXPath</span>
<a name="line-141"></a>				   <span class='layout'>)</span>
<a name="line-142"></a>			  <span class='varop'>.</span>
<a name="line-143"></a>			  <span class='varid'>runParser</span> <span class='varid'>parseXPath</span> <span class='varid'>env</span> <span class='str'>""</span>
<a name="line-144"></a>			  <span class='varop'>$</span> <span class='varid'>s</span>
<a name="line-145"></a>
<a name="line-146"></a><span class='comment'>-- ----------------------------------------</span>
<a name="line-147"></a>
<a name="line-148"></a><a name="XPArrow"></a><span class='keyword'>type</span> <span class='conid'>XPArrow</span> <span class='varid'>b</span> <span class='varid'>c</span>		<span class='keyglyph'>=</span> <span class='conid'>Maybe</span> <span class='layout'>(</span><span class='conid'>LA</span> <span class='varid'>b</span> <span class='varid'>c</span><span class='layout'>)</span>
<a name="line-149"></a>
<a name="line-150"></a><a name="mk"></a><span class='definition'>mk</span>				<span class='keyglyph'>::</span> <span class='conid'>LA</span> <span class='varid'>b</span> <span class='varid'>c</span> <span class='keyglyph'>-&gt;</span> <span class='conid'>XPArrow</span> <span class='varid'>b</span> <span class='varid'>c</span>
<a name="line-151"></a><span class='definition'>mk</span>				<span class='keyglyph'>=</span> <span class='conid'>Just</span>
<a name="line-152"></a>
<a name="line-153"></a><a name="unwrap"></a><span class='definition'>unwrap</span>				<span class='keyglyph'>::</span> <span class='conid'>XPArrow</span> <span class='varid'>b</span> <span class='varid'>b</span> <span class='keyglyph'>-&gt;</span> <span class='conid'>LA</span> <span class='varid'>b</span> <span class='varid'>b</span>
<a name="line-154"></a><span class='definition'>unwrap</span>				<span class='keyglyph'>=</span> <span class='varid'>fromJust</span> <span class='varop'>.</span> <span class='varid'>toThis</span>
<a name="line-155"></a>
<a name="line-156"></a><a name=">>>>"></a><span class='layout'>(</span><span class='varop'>&gt;&gt;&gt;&gt;</span><span class='layout'>)</span>				<span class='keyglyph'>::</span> <span class='conid'>XPArrow</span> <span class='varid'>b</span> <span class='varid'>b</span> <span class='keyglyph'>-&gt;</span> <span class='conid'>XPArrow</span> <span class='varid'>b</span> <span class='varid'>b</span> <span class='keyglyph'>-&gt;</span> <span class='conid'>XPArrow</span> <span class='varid'>b</span> <span class='varid'>b</span>
<a name="line-157"></a><span class='conid'>Nothing</span>   <span class='varop'>&gt;&gt;&gt;&gt;</span> <span class='varid'>a2</span>		<span class='keyglyph'>=</span> <span class='varid'>a2</span>
<a name="line-158"></a><a name="a1"></a><span class='definition'>a1</span>        <span class='varop'>&gt;&gt;&gt;&gt;</span> <span class='conid'>Nothing</span>		<span class='keyglyph'>=</span> <span class='varid'>a1</span>
<a name="line-159"></a><span class='layout'>(</span><span class='conid'>Just</span> <span class='varid'>f1</span><span class='layout'>)</span> <span class='varop'>&gt;&gt;&gt;&gt;</span> <span class='layout'>(</span><span class='conid'>Just</span> <span class='varid'>f2</span><span class='layout'>)</span>	<span class='keyglyph'>=</span> <span class='varid'>return</span> <span class='varop'>$</span> <span class='varid'>f1</span> <span class='varop'>&gt;&gt;&gt;</span> <span class='varid'>f2</span>
<a name="line-160"></a>
<a name="line-161"></a><a name="&&&&"></a><span class='layout'>(</span><span class='varop'>&amp;&amp;&amp;&amp;</span><span class='layout'>)</span>				<span class='keyglyph'>::</span> <span class='conid'>XPArrow</span> <span class='varid'>b</span> <span class='varid'>b</span> <span class='keyglyph'>-&gt;</span> <span class='conid'>XPArrow</span> <span class='varid'>b</span> <span class='varid'>b</span> <span class='keyglyph'>-&gt;</span> <span class='conid'>XPArrow</span> <span class='varid'>b</span> <span class='layout'>(</span><span class='varid'>b</span><span class='layout'>,</span> <span class='varid'>b</span><span class='layout'>)</span>
<a name="line-162"></a><span class='conid'>Nothing</span>   <span class='varop'>&amp;&amp;&amp;&amp;</span> <span class='varid'>a2</span>		<span class='keyglyph'>=</span> <span class='varid'>this''</span> <span class='varop'>&amp;&amp;&amp;&amp;</span> <span class='varid'>a2</span>
<a name="line-163"></a><span class='definition'>a1</span>        <span class='varop'>&amp;&amp;&amp;&amp;</span> <span class='conid'>Nothing</span>		<span class='keyglyph'>=</span> <span class='varid'>a1</span>     <span class='varop'>&amp;&amp;&amp;&amp;</span> <span class='varid'>this''</span>
<a name="line-164"></a><span class='layout'>(</span><span class='conid'>Just</span> <span class='varid'>f1</span><span class='layout'>)</span> <span class='varop'>&amp;&amp;&amp;&amp;</span> <span class='layout'>(</span><span class='conid'>Just</span> <span class='varid'>f2</span><span class='layout'>)</span>	<span class='keyglyph'>=</span> <span class='varid'>return</span> <span class='varop'>$</span> <span class='varid'>f1</span> <span class='varop'>&amp;&amp;&amp;</span> <span class='varid'>f2</span>
<a name="line-165"></a>
<a name="line-166"></a><a name="<+>>"></a><span class='layout'>(</span><span class='varop'>&lt;+&gt;&gt;</span><span class='layout'>)</span>				<span class='keyglyph'>::</span> <span class='conid'>XPArrow</span> <span class='varid'>b</span> <span class='varid'>b</span> <span class='keyglyph'>-&gt;</span> <span class='conid'>XPArrow</span> <span class='varid'>b</span> <span class='varid'>b</span> <span class='keyglyph'>-&gt;</span> <span class='conid'>XPArrow</span> <span class='varid'>b</span> <span class='varid'>b</span>
<a name="line-167"></a><span class='conid'>Nothing</span>   <span class='varop'>&lt;+&gt;&gt;</span> <span class='sel'>_a2</span>		<span class='keyglyph'>=</span> <span class='conid'>Nothing</span>
<a name="line-168"></a><span class='sel'>_a1</span>       <span class='varop'>&lt;+&gt;&gt;</span> <span class='conid'>Nothing</span>		<span class='keyglyph'>=</span> <span class='conid'>Nothing</span>
<a name="line-169"></a><span class='layout'>(</span><span class='conid'>Just</span> <span class='varid'>f1</span><span class='layout'>)</span> <span class='varop'>&lt;+&gt;&gt;</span> <span class='layout'>(</span><span class='conid'>Just</span> <span class='varid'>f2</span><span class='layout'>)</span>	<span class='keyglyph'>=</span> <span class='varid'>return</span> <span class='varop'>$</span> <span class='varid'>f1</span> <span class='varop'>&lt;+&gt;</span> <span class='varid'>f2</span>
<a name="line-170"></a>
<a name="line-171"></a><a name="guards'"></a><span class='definition'>guards'</span>				<span class='keyglyph'>::</span> <span class='conid'>XPArrow</span> <span class='varid'>b</span> <span class='varid'>b</span> <span class='keyglyph'>-&gt;</span> <span class='conid'>XPArrow</span> <span class='varid'>b</span> <span class='varid'>b</span> <span class='keyglyph'>-&gt;</span> <span class='conid'>XPArrow</span> <span class='varid'>b</span> <span class='varid'>b</span>
<a name="line-172"></a><span class='conid'>Nothing</span>   <span class='varop'>`guards'`</span> <span class='varid'>a2</span>		<span class='keyglyph'>=</span> <span class='varid'>a2</span>
<a name="line-173"></a><a name="guards'"></a><span class='definition'>a1</span>        <span class='varop'>`guards'`</span> <span class='conid'>Nothing</span>	<span class='keyglyph'>=</span> <span class='varid'>a1</span> <span class='varop'>`guards'`</span> <span class='varid'>this''</span>
<a name="line-174"></a><a name="guards'"></a><span class='layout'>(</span><span class='conid'>Just</span> <span class='varid'>f1</span><span class='layout'>)</span> <span class='varop'>`guards'`</span> <span class='layout'>(</span><span class='conid'>Just</span> <span class='varid'>f2</span><span class='layout'>)</span>	<span class='keyglyph'>=</span> <span class='varid'>return</span> <span class='varop'>$</span> <span class='varid'>f1</span> <span class='varop'>`guards`</span> <span class='varid'>f2</span>
<a name="line-175"></a>
<a name="line-176"></a><a name="this'"></a><span class='definition'>this'</span>				<span class='keyglyph'>::</span> <span class='conid'>XPArrow</span> <span class='varid'>b</span> <span class='varid'>b</span>
<a name="line-177"></a><span class='definition'>this'</span>				<span class='keyglyph'>=</span> <span class='conid'>Nothing</span>
<a name="line-178"></a>
<a name="line-179"></a><a name="this''"></a><span class='definition'>this''</span>				<span class='keyglyph'>::</span> <span class='conid'>XPArrow</span> <span class='varid'>b</span> <span class='varid'>b</span>
<a name="line-180"></a><span class='definition'>this''</span>				<span class='keyglyph'>=</span> <span class='varid'>mk</span> <span class='varid'>this</span>
<a name="line-181"></a>
<a name="line-182"></a><a name="toThis"></a><span class='definition'>toThis</span>				<span class='keyglyph'>::</span> <span class='conid'>XPArrow</span> <span class='varid'>b</span> <span class='varid'>b</span> <span class='keyglyph'>-&gt;</span> <span class='conid'>XPArrow</span> <span class='varid'>b</span> <span class='varid'>b</span>
<a name="line-183"></a><span class='definition'>toThis</span> <span class='conid'>Nothing</span>			<span class='keyglyph'>=</span> <span class='varid'>this''</span>
<a name="line-184"></a><span class='definition'>toThis</span> <span class='varid'>a</span>			<span class='keyglyph'>=</span> <span class='varid'>a</span>
<a name="line-185"></a>
<a name="line-186"></a><a name="getChildren'"></a><span class='definition'>getChildren'</span>			<span class='keyglyph'>::</span> <span class='conid'>XPArrow</span> <span class='conid'>XmlTree</span> <span class='conid'>XmlTree</span> <span class='keyglyph'>-&gt;</span> <span class='conid'>XPArrow</span> <span class='conid'>XmlTree</span> <span class='conid'>XmlTree</span>
<a name="line-187"></a><span class='definition'>getChildren'</span> <span class='varid'>a</span>			<span class='keyglyph'>=</span> <span class='varid'>mk</span> <span class='varid'>getChildren</span> <span class='varop'>&gt;&gt;&gt;&gt;</span> <span class='varid'>a</span>
<a name="line-188"></a>
<a name="line-189"></a><a name="getAttrl'"></a><span class='definition'>getAttrl'</span>			<span class='keyglyph'>::</span> <span class='conid'>XPArrow</span> <span class='conid'>XmlTree</span> <span class='conid'>XmlTree</span> <span class='keyglyph'>-&gt;</span> <span class='conid'>XPArrow</span> <span class='conid'>XmlTree</span> <span class='conid'>XmlTree</span>
<a name="line-190"></a><span class='definition'>getAttrl'</span> <span class='varid'>a</span>			<span class='keyglyph'>=</span> <span class='varid'>mk</span> <span class='varid'>getAttrl</span> <span class='varop'>&gt;&gt;&gt;&gt;</span> <span class='varid'>a</span>
<a name="line-191"></a>
<a name="line-192"></a><a name="multi'"></a><span class='definition'>multi'</span>				<span class='keyglyph'>::</span> <span class='conid'>XPArrow</span> <span class='conid'>XmlTree</span> <span class='conid'>XmlTree</span> <span class='keyglyph'>-&gt;</span> <span class='conid'>XPArrow</span> <span class='conid'>XmlTree</span> <span class='conid'>XmlTree</span>
<a name="line-193"></a><span class='definition'>multi'</span> <span class='varid'>a</span>			<span class='keyglyph'>=</span> <span class='varid'>mk</span> <span class='varop'>$</span> <span class='varid'>multi</span> <span class='layout'>(</span><span class='varid'>unwrap</span> <span class='varid'>a</span><span class='layout'>)</span>
<a name="line-194"></a>
<a name="line-195"></a><a name="deep'"></a><span class='definition'>deep'</span>				<span class='keyglyph'>::</span> <span class='conid'>XPArrow</span> <span class='conid'>XmlTree</span> <span class='conid'>XmlTree</span> <span class='keyglyph'>-&gt;</span> <span class='conid'>XPArrow</span> <span class='conid'>XmlTree</span> <span class='conid'>XmlTree</span>
<a name="line-196"></a><span class='definition'>deep'</span> <span class='varid'>a</span>				<span class='keyglyph'>=</span> <span class='varid'>mk</span> <span class='varop'>$</span> <span class='varid'>deep</span> <span class='layout'>(</span><span class='varid'>unwrap</span> <span class='varid'>a</span><span class='layout'>)</span>
<a name="line-197"></a>
<a name="line-198"></a><a name="xIndex"></a><span class='definition'>xIndex</span>				<span class='keyglyph'>::</span> <span class='conid'>Int</span> <span class='keyglyph'>-&gt;</span> <span class='conid'>LA</span> <span class='keyglyph'>[</span><span class='varid'>b</span><span class='keyglyph'>]</span> <span class='varid'>b</span>
<a name="line-199"></a><span class='definition'>xIndex</span> <span class='varid'>i</span>
<a name="line-200"></a>    <span class='keyglyph'>|</span> <span class='varid'>i</span> <span class='varop'>&lt;=</span> <span class='num'>0</span>			<span class='keyglyph'>=</span> <span class='varid'>none</span>
<a name="line-201"></a>    <span class='keyglyph'>|</span> <span class='varid'>otherwise</span>			<span class='keyglyph'>=</span> <span class='varid'>arrL</span> <span class='layout'>(</span><span class='varid'>take</span> <span class='num'>1</span> <span class='varop'>.</span> <span class='varid'>drop</span> <span class='layout'>(</span><span class='varid'>i</span><span class='comment'>-</span><span class='num'>1</span><span class='layout'>)</span><span class='layout'>)</span>
<a name="line-202"></a>
<a name="line-203"></a><a name="xString"></a><span class='definition'>xString</span>				<span class='keyglyph'>::</span> <span class='conid'>XPArrow</span> <span class='conid'>XmlTree</span> <span class='conid'>XmlTree</span> <span class='keyglyph'>-&gt;</span> <span class='conid'>LA</span> <span class='conid'>XmlTree</span> <span class='conid'>String</span>
<a name="line-204"></a><span class='definition'>xString</span> <span class='varid'>a</span>			<span class='keyglyph'>=</span> <span class='varid'>unwrap</span> <span class='varid'>a</span> <span class='varop'>&gt;&gt;&gt;</span> <span class='varid'>xshow</span> <span class='layout'>(</span><span class='varid'>deep</span> <span class='varid'>isText</span><span class='layout'>)</span>
<a name="line-205"></a>
<a name="line-206"></a><a name="xNumber'"></a><span class='definition'>xNumber'</span>			<span class='keyglyph'>::</span> <span class='conid'>XPArrow</span> <span class='conid'>XmlTree</span> <span class='conid'>XmlTree</span> <span class='keyglyph'>-&gt;</span> <span class='conid'>LA</span> <span class='conid'>XmlTree</span> <span class='conid'>XPNumber</span>
<a name="line-207"></a><span class='definition'>xNumber'</span> <span class='varid'>a</span>			<span class='keyglyph'>=</span>  <span class='varid'>xString</span> <span class='varid'>a</span> <span class='varop'>&gt;&gt;&gt;</span> <span class='varid'>arr</span> <span class='varid'>toNumber</span>
<a name="line-208"></a>
<a name="line-209"></a><span class='comment'>-- ------------------------------</span>
<a name="line-210"></a>
<a name="line-211"></a><a name="deadEndStreet"></a><span class='definition'>deadEndStreet</span>			<span class='keyglyph'>::</span> <span class='conid'>Monad</span> <span class='varid'>m</span> <span class='keyglyph'>=&gt;</span> <span class='varid'>m</span> <span class='varid'>a</span>
<a name="line-212"></a><span class='definition'>deadEndStreet</span>			<span class='keyglyph'>=</span> <span class='varid'>fail</span> <span class='str'>"XPath expression too complicated for XmlArrows"</span>
<a name="line-213"></a>
<a name="line-214"></a><a name="compXPath"></a><span class='definition'>compXPath</span>			<span class='keyglyph'>::</span> <span class='conid'>MonadPlus</span> <span class='varid'>m</span> <span class='keyglyph'>=&gt;</span> <span class='conid'>Expr</span> <span class='keyglyph'>-&gt;</span> <span class='varid'>m</span> <span class='layout'>(</span><span class='conid'>LA</span> <span class='conid'>XmlTree</span> <span class='conid'>XmlTree</span><span class='layout'>)</span>
<a name="line-215"></a><span class='definition'>compXPath</span> <span class='varid'>e</span>			<span class='keyglyph'>=</span> <span class='keyword'>do</span>
<a name="line-216"></a>				  <span class='varid'>r</span> <span class='keyglyph'>&lt;-</span> <span class='varid'>compXP</span> <span class='varid'>e</span>
<a name="line-217"></a>				  <span class='varid'>return</span> <span class='varop'>$</span> <span class='varid'>unwrap</span> <span class='varid'>r</span>
<a name="line-218"></a>
<a name="line-219"></a><a name="compXP"></a><span class='definition'>compXP</span>				<span class='keyglyph'>::</span> <span class='conid'>MonadPlus</span> <span class='varid'>m</span> <span class='keyglyph'>=&gt;</span> <span class='conid'>Expr</span> <span class='keyglyph'>-&gt;</span> <span class='varid'>m</span> <span class='layout'>(</span><span class='conid'>XPArrow</span> <span class='conid'>XmlTree</span> <span class='conid'>XmlTree</span><span class='layout'>)</span>
<a name="line-220"></a><span class='definition'>compXP</span> <span class='layout'>(</span><span class='conid'>PathExpr</span> <span class='conid'>Nothing</span> <span class='layout'>(</span><span class='conid'>Just</span> <span class='layout'>(</span><span class='conid'>LocPath</span> <span class='conid'>Abs</span> <span class='varid'>lp</span><span class='layout'>)</span><span class='layout'>)</span><span class='layout'>)</span>
<a name="line-221"></a>				<span class='keyglyph'>=</span> <span class='varid'>compLP</span> <span class='varid'>lp</span> <span class='varid'>this'</span>
<a name="line-222"></a><span class='definition'>compXP</span> <span class='layout'>(</span><span class='conid'>FilterExpr</span> <span class='layout'>(</span><span class='varid'>e1</span><span class='conop'>:</span><span class='varid'>el</span><span class='layout'>)</span><span class='layout'>)</span>	<span class='keyglyph'>=</span> <span class='keyword'>do</span>
<a name="line-223"></a>				  <span class='varid'>r</span> <span class='keyglyph'>&lt;-</span> <span class='varid'>compXP</span> <span class='varid'>e1</span>
<a name="line-224"></a>				  <span class='varid'>compFP</span> <span class='varid'>el</span> <span class='varid'>r</span>
<a name="line-225"></a><span class='definition'>compXP</span> <span class='keyword'>_</span>			<span class='keyglyph'>=</span> <span class='varid'>deadEndStreet</span>
<a name="line-226"></a>
<a name="line-227"></a><a name="compFP"></a><span class='definition'>compFP</span>				<span class='keyglyph'>::</span> <span class='conid'>MonadPlus</span> <span class='varid'>m</span> <span class='keyglyph'>=&gt;</span> <span class='keyglyph'>[</span><span class='conid'>Expr</span><span class='keyglyph'>]</span> <span class='keyglyph'>-&gt;</span> <span class='conid'>XPArrow</span> <span class='conid'>XmlTree</span> <span class='conid'>XmlTree</span> <span class='keyglyph'>-&gt;</span> <span class='varid'>m</span> <span class='layout'>(</span><span class='conid'>XPArrow</span> <span class='conid'>XmlTree</span> <span class='conid'>XmlTree</span><span class='layout'>)</span>
<a name="line-228"></a><span class='definition'>compFP</span> <span class='conid'>[]</span>      <span class='varid'>r</span>		<span class='keyglyph'>=</span> <span class='varid'>return</span> <span class='varid'>r</span>
<a name="line-229"></a><span class='definition'>compFP</span> <span class='layout'>(</span><span class='varid'>e1</span><span class='conop'>:</span><span class='varid'>es</span><span class='layout'>)</span> <span class='varid'>r</span>		<span class='keyglyph'>=</span> <span class='keyword'>do</span>
<a name="line-230"></a>				  <span class='varid'>r1</span> <span class='keyglyph'>&lt;-</span> <span class='varid'>compPred</span> <span class='keyglyph'>[</span><span class='varid'>e1</span><span class='keyglyph'>]</span> <span class='varid'>r</span>
<a name="line-231"></a>				  <span class='varid'>compFP</span> <span class='varid'>es</span> <span class='varid'>r1</span>
<a name="line-232"></a>
<a name="line-233"></a><a name="compLP"></a><span class='definition'>compLP</span>				<span class='keyglyph'>::</span> <span class='conid'>MonadPlus</span> <span class='varid'>m</span> <span class='keyglyph'>=&gt;</span> <span class='keyglyph'>[</span><span class='conid'>XStep</span><span class='keyglyph'>]</span> <span class='keyglyph'>-&gt;</span> <span class='conid'>XPArrow</span> <span class='conid'>XmlTree</span> <span class='conid'>XmlTree</span> <span class='keyglyph'>-&gt;</span> <span class='varid'>m</span> <span class='layout'>(</span><span class='conid'>XPArrow</span> <span class='conid'>XmlTree</span> <span class='conid'>XmlTree</span><span class='layout'>)</span>
<a name="line-234"></a><span class='definition'>compLP</span> <span class='conid'>[]</span>     <span class='varid'>r</span>			<span class='keyglyph'>=</span> <span class='varid'>return</span> <span class='varid'>r</span>
<a name="line-235"></a><span class='definition'>compLP</span> <span class='layout'>(</span><span class='varid'>x</span><span class='conop'>:</span><span class='varid'>xs</span><span class='layout'>)</span> <span class='varid'>r</span>			<span class='keyglyph'>=</span> <span class='keyword'>do</span>
<a name="line-236"></a>				  <span class='varid'>a1</span> <span class='keyglyph'>&lt;-</span> <span class='varid'>compXS</span> <span class='varid'>x</span> <span class='varid'>r</span>
<a name="line-237"></a>				  <span class='keyword'>as</span> <span class='keyglyph'>&lt;-</span> <span class='varid'>compLP</span> <span class='varid'>xs</span> <span class='varid'>a1</span>
<a name="line-238"></a>				  <span class='varid'>return</span> <span class='keyword'>as</span>
<a name="line-239"></a>
<a name="line-240"></a><a name="compXS"></a><span class='definition'>compXS</span>				<span class='keyglyph'>::</span> <span class='conid'>MonadPlus</span> <span class='varid'>m</span> <span class='keyglyph'>=&gt;</span> <span class='conid'>XStep</span> <span class='keyglyph'>-&gt;</span> <span class='conid'>XPArrow</span> <span class='conid'>XmlTree</span> <span class='conid'>XmlTree</span> <span class='keyglyph'>-&gt;</span> <span class='varid'>m</span> <span class='layout'>(</span><span class='conid'>XPArrow</span> <span class='conid'>XmlTree</span> <span class='conid'>XmlTree</span><span class='layout'>)</span>
<a name="line-241"></a><span class='definition'>compXS</span> <span class='layout'>(</span><span class='conid'>Step</span> <span class='conid'>Child</span> <span class='varid'>nt</span> <span class='varid'>ps</span><span class='layout'>)</span> <span class='varid'>s</span>	<span class='keyglyph'>=</span> <span class='keyword'>do</span>
<a name="line-242"></a>				  <span class='varid'>an</span> <span class='keyglyph'>&lt;-</span> <span class='varid'>compNTE</span> <span class='varid'>nt</span>
<a name="line-243"></a>				  <span class='varid'>compPred</span> <span class='varid'>ps</span> <span class='layout'>(</span><span class='varid'>s</span> <span class='varop'>&gt;&gt;&gt;&gt;</span> <span class='varid'>mk</span> <span class='varid'>getChildren</span> <span class='varop'>&gt;&gt;&gt;&gt;</span> <span class='varid'>an</span><span class='layout'>)</span>
<a name="line-244"></a>
<a name="line-245"></a><span class='definition'>compXS</span> <span class='layout'>(</span><span class='conid'>Step</span> <span class='conid'>DescendantOrSelf</span> <span class='varid'>nt</span> <span class='varid'>ps</span><span class='layout'>)</span> <span class='varid'>s</span>
<a name="line-246"></a>				<span class='keyglyph'>=</span> <span class='keyword'>do</span>
<a name="line-247"></a>				  <span class='varid'>an</span> <span class='keyglyph'>&lt;-</span> <span class='varid'>compNTE</span> <span class='varid'>nt</span>
<a name="line-248"></a>				  <span class='varid'>compPred</span> <span class='varid'>ps</span> <span class='layout'>(</span><span class='varid'>s</span> <span class='varop'>&gt;&gt;&gt;&gt;</span> <span class='varid'>multi'</span> <span class='varid'>an</span><span class='layout'>)</span>
<a name="line-249"></a>
<a name="line-250"></a><span class='definition'>compXS</span> <span class='layout'>(</span><span class='conid'>Step</span> <span class='conid'>Descendant</span> <span class='varid'>nt</span> <span class='varid'>ps</span><span class='layout'>)</span> <span class='varid'>s</span>
<a name="line-251"></a>				<span class='keyglyph'>=</span> <span class='keyword'>do</span>
<a name="line-252"></a>				  <span class='varid'>an</span> <span class='keyglyph'>&lt;-</span> <span class='varid'>compNTE</span> <span class='varid'>nt</span>
<a name="line-253"></a>				  <span class='varid'>compPred</span> <span class='varid'>ps</span> <span class='layout'>(</span><span class='varid'>s</span> <span class='varop'>&gt;&gt;&gt;&gt;</span> <span class='varid'>mk</span> <span class='varid'>getChildren</span> <span class='varop'>&gt;&gt;&gt;&gt;</span> <span class='varid'>multi'</span> <span class='varid'>an</span><span class='layout'>)</span>
<a name="line-254"></a>
<a name="line-255"></a><span class='definition'>compXS</span> <span class='layout'>(</span><span class='conid'>Step</span> <span class='conid'>Self</span> <span class='varid'>nt</span> <span class='varid'>ps</span><span class='layout'>)</span> <span class='varid'>s</span>
<a name="line-256"></a>				<span class='keyglyph'>=</span> <span class='keyword'>do</span>
<a name="line-257"></a>				  <span class='varid'>an</span> <span class='keyglyph'>&lt;-</span> <span class='varid'>compNTE</span> <span class='varid'>nt</span>
<a name="line-258"></a>				  <span class='varid'>compPred</span> <span class='varid'>ps</span> <span class='layout'>(</span><span class='varid'>s</span> <span class='varop'>&gt;&gt;&gt;&gt;</span> <span class='varid'>an</span><span class='layout'>)</span>
<a name="line-259"></a><span class='definition'>compXS</span> <span class='layout'>(</span><span class='conid'>Step</span> <span class='conid'>Attribute</span> <span class='varid'>nt</span> <span class='varid'>ps</span><span class='layout'>)</span> <span class='varid'>s</span>
<a name="line-260"></a>				<span class='keyglyph'>=</span> <span class='keyword'>do</span>
<a name="line-261"></a>				  <span class='varid'>an</span> <span class='keyglyph'>&lt;-</span> <span class='varid'>compNTA</span> <span class='varid'>nt</span>
<a name="line-262"></a>				  <span class='varid'>compPred</span> <span class='varid'>ps</span> <span class='layout'>(</span><span class='varid'>s</span> <span class='varop'>&gt;&gt;&gt;&gt;</span> <span class='varid'>getAttrl'</span> <span class='varid'>an</span><span class='layout'>)</span>
<a name="line-263"></a>
<a name="line-264"></a><span class='definition'>compXS</span> <span class='keyword'>_</span> <span class='keyword'>_</span>			<span class='keyglyph'>=</span> <span class='varid'>deadEndStreet</span>
<a name="line-265"></a>
<a name="line-266"></a><a name="compNTE"></a><span class='definition'>compNTE</span>				<span class='keyglyph'>::</span> <span class='layout'>(</span><span class='conid'>Monad</span> <span class='varid'>m</span><span class='layout'>)</span> <span class='keyglyph'>=&gt;</span> <span class='conid'>NodeTest</span> <span class='keyglyph'>-&gt;</span> <span class='varid'>m</span> <span class='layout'>(</span><span class='conid'>XPArrow</span> <span class='conid'>XmlTree</span> <span class='conid'>XmlTree</span><span class='layout'>)</span>
<a name="line-267"></a><span class='definition'>compNTE</span> <span class='layout'>(</span><span class='conid'>NameTest</span> <span class='varid'>qn</span><span class='layout'>)</span>		<span class='keyglyph'>=</span> <span class='varid'>compNameT</span> <span class='varid'>isElem</span> <span class='varid'>qn</span>
<a name="line-268"></a><span class='definition'>compNTE</span> <span class='varid'>nt</span>			<span class='keyglyph'>=</span> <span class='varid'>compNT</span> <span class='varid'>nt</span>
<a name="line-269"></a>
<a name="line-270"></a><a name="compNTA"></a><span class='definition'>compNTA</span>				<span class='keyglyph'>::</span> <span class='layout'>(</span><span class='conid'>Monad</span> <span class='varid'>m</span><span class='layout'>)</span> <span class='keyglyph'>=&gt;</span> <span class='conid'>NodeTest</span> <span class='keyglyph'>-&gt;</span> <span class='varid'>m</span> <span class='layout'>(</span><span class='conid'>XPArrow</span> <span class='conid'>XmlTree</span> <span class='conid'>XmlTree</span><span class='layout'>)</span>
<a name="line-271"></a><span class='definition'>compNTA</span> <span class='layout'>(</span><span class='conid'>NameTest</span> <span class='varid'>qn</span><span class='layout'>)</span>		<span class='keyglyph'>=</span> <span class='varid'>compNameT</span> <span class='varid'>isAttr</span> <span class='varid'>qn</span>
<a name="line-272"></a><span class='definition'>compNTA</span> <span class='varid'>nt</span>			<span class='keyglyph'>=</span> <span class='varid'>compNT</span> <span class='varid'>nt</span>
<a name="line-273"></a>
<a name="line-274"></a><a name="compNameT"></a><span class='definition'>compNameT</span>			<span class='keyglyph'>::</span> <span class='conid'>Monad</span> <span class='varid'>m</span> <span class='keyglyph'>=&gt;</span> <span class='conid'>LA</span> <span class='conid'>XmlTree</span> <span class='conid'>XmlTree</span> <span class='keyglyph'>-&gt;</span> <span class='conid'>QName</span> <span class='keyglyph'>-&gt;</span> <span class='varid'>m</span> <span class='layout'>(</span><span class='conid'>XPArrow</span> <span class='conid'>XmlTree</span> <span class='conid'>XmlTree</span><span class='layout'>)</span>
<a name="line-275"></a><span class='definition'>compNameT</span> <span class='varid'>ist</span> <span class='varid'>qn</span>
<a name="line-276"></a>    <span class='keyglyph'>|</span> <span class='varid'>null</span> <span class='layout'>(</span><span class='varid'>namespaceUri</span> <span class='varid'>qn</span><span class='layout'>)</span>	<span class='keyglyph'>=</span> <span class='varid'>return</span> <span class='varop'>$</span> <span class='varid'>mk</span>
<a name="line-277"></a>				  <span class='layout'>(</span> <span class='keyword'>if</span> <span class='varid'>qualifiedName</span> <span class='varid'>qn</span> <span class='varop'>==</span> <span class='str'>"*"</span>
<a name="line-278"></a>				    <span class='keyword'>then</span> <span class='varid'>ist</span>
<a name="line-279"></a>				    <span class='keyword'>else</span> <span class='varid'>ist</span> <span class='varop'>&gt;&gt;&gt;</span> <span class='varid'>hasName</span> <span class='layout'>(</span><span class='varid'>qualifiedName</span> <span class='varid'>qn</span><span class='layout'>)</span>
<a name="line-280"></a>				  <span class='layout'>)</span>
<a name="line-281"></a>    <span class='keyglyph'>|</span> <span class='varid'>otherwise</span>			<span class='keyglyph'>=</span> <span class='varid'>return</span> <span class='varop'>$</span> <span class='varid'>mk</span>
<a name="line-282"></a>				  <span class='layout'>(</span> <span class='keyword'>if</span> <span class='varid'>localPart</span> <span class='varid'>qn</span> <span class='varop'>==</span> <span class='str'>"*"</span>
<a name="line-283"></a>				    <span class='keyword'>then</span> <span class='varid'>ist</span> <span class='varop'>&gt;&gt;&gt;</span> <span class='varid'>hasNamespaceUri</span> <span class='layout'>(</span><span class='varid'>namespaceUri</span> <span class='varid'>qn</span><span class='layout'>)</span>
<a name="line-284"></a>				    <span class='keyword'>else</span> <span class='varid'>ist</span> <span class='varop'>&gt;&gt;&gt;</span> <span class='varid'>hasQName</span> <span class='varid'>qn</span>
<a name="line-285"></a>
<a name="line-286"></a>				  <span class='layout'>)</span>
<a name="line-287"></a>
<a name="line-288"></a><a name="compNT"></a><span class='definition'>compNT</span>				<span class='keyglyph'>::</span> <span class='conid'>Monad</span> <span class='varid'>m</span> <span class='keyglyph'>=&gt;</span> <span class='conid'>NodeTest</span> <span class='keyglyph'>-&gt;</span> <span class='varid'>m</span> <span class='layout'>(</span><span class='conid'>XPArrow</span> <span class='conid'>XmlTree</span> <span class='conid'>XmlTree</span><span class='layout'>)</span>
<a name="line-289"></a><span class='definition'>compNT</span> <span class='layout'>(</span><span class='conid'>TypeTest</span> <span class='conid'>XPNode</span><span class='layout'>)</span>       	<span class='keyglyph'>=</span> <span class='varid'>return</span> <span class='varid'>this'</span>
<a name="line-290"></a><span class='definition'>compNT</span> <span class='layout'>(</span><span class='conid'>TypeTest</span> <span class='conid'>XPCommentNode</span><span class='layout'>)</span>	<span class='keyglyph'>=</span> <span class='varid'>return</span> <span class='varop'>$</span> <span class='varid'>mk</span> <span class='varid'>isCmt</span>
<a name="line-291"></a><span class='definition'>compNT</span> <span class='layout'>(</span><span class='conid'>TypeTest</span> <span class='conid'>XPPINode</span><span class='layout'>)</span>      <span class='keyglyph'>=</span> <span class='varid'>return</span> <span class='varop'>$</span> <span class='varid'>mk</span> <span class='varid'>isPi</span>
<a name="line-292"></a><span class='definition'>compNT</span> <span class='layout'>(</span><span class='conid'>TypeTest</span> <span class='conid'>XPTextNode</span><span class='layout'>)</span>    <span class='keyglyph'>=</span> <span class='varid'>return</span> <span class='varop'>$</span> <span class='varid'>mk</span> <span class='varid'>isText</span>
<a name="line-293"></a>
<a name="line-294"></a><span class='definition'>compNT</span> <span class='keyword'>_</span>			<span class='keyglyph'>=</span> <span class='varid'>deadEndStreet</span>
<a name="line-295"></a>
<a name="line-296"></a><a name="compPred"></a><span class='definition'>compPred</span>			<span class='keyglyph'>::</span> <span class='conid'>MonadPlus</span> <span class='varid'>m</span> <span class='keyglyph'>=&gt;</span> <span class='keyglyph'>[</span><span class='conid'>Expr</span><span class='keyglyph'>]</span> <span class='keyglyph'>-&gt;</span> <span class='conid'>XPArrow</span> <span class='conid'>XmlTree</span> <span class='conid'>XmlTree</span> <span class='keyglyph'>-&gt;</span> <span class='varid'>m</span> <span class='layout'>(</span><span class='conid'>XPArrow</span> <span class='conid'>XmlTree</span> <span class='conid'>XmlTree</span><span class='layout'>)</span>
<a name="line-297"></a><span class='definition'>compPred</span> <span class='conid'>[]</span>     <span class='varid'>r</span>		<span class='keyglyph'>=</span> <span class='varid'>return</span> <span class='varid'>r</span>
<a name="line-298"></a><span class='definition'>compPred</span> <span class='layout'>(</span><span class='varid'>e</span><span class='conop'>:</span><span class='varid'>es</span><span class='layout'>)</span>	<span class='varid'>r</span>		<span class='keyglyph'>=</span> <span class='keyword'>do</span>
<a name="line-299"></a>				  <span class='varid'>r1</span> <span class='keyglyph'>&lt;-</span> <span class='varid'>compPred1</span> <span class='varid'>e</span> <span class='varid'>r</span>
<a name="line-300"></a>				  <span class='varid'>compPred</span> <span class='varid'>es</span> <span class='varid'>r1</span>
<a name="line-301"></a>
<a name="line-302"></a><a name="compPred1"></a><span class='definition'>compPred1</span>			<span class='keyglyph'>::</span> <span class='conid'>MonadPlus</span> <span class='varid'>m</span> <span class='keyglyph'>=&gt;</span> <span class='conid'>Expr</span> <span class='keyglyph'>-&gt;</span> <span class='conid'>XPArrow</span> <span class='conid'>XmlTree</span> <span class='conid'>XmlTree</span> <span class='keyglyph'>-&gt;</span> <span class='varid'>m</span> <span class='layout'>(</span><span class='conid'>XPArrow</span> <span class='conid'>XmlTree</span> <span class='conid'>XmlTree</span><span class='layout'>)</span>
<a name="line-303"></a><span class='definition'>compPred1</span> <span class='varid'>e</span> <span class='varid'>r</span>			<span class='keyglyph'>=</span> <span class='layout'>(</span> <span class='keyword'>do</span>
<a name="line-304"></a>				    <span class='varid'>ix</span> <span class='keyglyph'>&lt;-</span> <span class='varid'>compIntExpr</span> <span class='varid'>e</span>
<a name="line-305"></a>				    <span class='varid'>return</span> <span class='varop'>.</span> <span class='varid'>mk</span> <span class='varop'>$</span> <span class='varid'>listA</span> <span class='layout'>(</span><span class='varid'>unwrap</span> <span class='varid'>r</span><span class='layout'>)</span> <span class='varop'>&gt;&gt;&gt;</span> <span class='varid'>xIndex</span> <span class='varid'>ix</span>
<a name="line-306"></a>				  <span class='layout'>)</span>
<a name="line-307"></a>				  <span class='varop'>`mplus`</span>
<a name="line-308"></a>				  <span class='layout'>(</span> <span class='keyword'>do</span>
<a name="line-309"></a>				    <span class='varid'>a1</span> <span class='keyglyph'>&lt;-</span> <span class='varid'>compRelPathExpr</span> <span class='varid'>e</span>
<a name="line-310"></a>				    <span class='varid'>return</span> <span class='varop'>$</span> <span class='varid'>r</span> <span class='varop'>&gt;&gt;&gt;&gt;</span> <span class='layout'>(</span><span class='varid'>a1</span> <span class='varop'>`guards'`</span> <span class='varid'>this'</span><span class='layout'>)</span>
<a name="line-311"></a>				  <span class='layout'>)</span>
<a name="line-312"></a>				  <span class='varop'>`mplus`</span>
<a name="line-313"></a>				  <span class='layout'>(</span> <span class='keyword'>do</span>
<a name="line-314"></a>				    <span class='varid'>a1</span> <span class='keyglyph'>&lt;-</span> <span class='varid'>compGenExpr</span> <span class='varid'>e</span>
<a name="line-315"></a>				    <span class='varid'>return</span> <span class='varop'>$</span> <span class='varid'>r</span> <span class='varop'>&gt;&gt;&gt;&gt;</span> <span class='layout'>(</span><span class='varid'>a1</span> <span class='varop'>`guards'`</span> <span class='varid'>this'</span><span class='layout'>)</span>
<a name="line-316"></a>				  <span class='layout'>)</span>
<a name="line-317"></a>				  <span class='varop'>`mplus`</span>
<a name="line-318"></a>				  <span class='layout'>(</span> <span class='keyword'>do</span>
<a name="line-319"></a>				    <span class='varid'>b1</span> <span class='keyglyph'>&lt;-</span> <span class='varid'>compBoolExpr</span> <span class='varid'>e</span>
<a name="line-320"></a>				    <span class='varid'>return</span> <span class='varop'>$</span> <span class='keyword'>if</span> <span class='varid'>b1</span> <span class='keyword'>then</span> <span class='varid'>r</span> <span class='keyword'>else</span> <span class='varid'>mk</span> <span class='varid'>none</span>
<a name="line-321"></a>				  <span class='layout'>)</span>
<a name="line-322"></a>
<a name="line-323"></a><a name="compRelPathExpr"></a><span class='definition'>compRelPathExpr</span>			<span class='keyglyph'>::</span> <span class='conid'>MonadPlus</span> <span class='varid'>m</span> <span class='keyglyph'>=&gt;</span> <span class='conid'>Expr</span> <span class='keyglyph'>-&gt;</span> <span class='varid'>m</span> <span class='layout'>(</span><span class='conid'>XPArrow</span> <span class='conid'>XmlTree</span> <span class='conid'>XmlTree</span><span class='layout'>)</span>
<a name="line-324"></a><span class='definition'>compRelPathExpr</span> <span class='layout'>(</span><span class='conid'>PathExpr</span> <span class='conid'>Nothing</span> <span class='layout'>(</span><span class='conid'>Just</span> <span class='layout'>(</span><span class='conid'>LocPath</span> <span class='conid'>Rel</span> <span class='varid'>lp</span><span class='layout'>)</span><span class='layout'>)</span><span class='layout'>)</span>
<a name="line-325"></a>				<span class='keyglyph'>=</span> <span class='varid'>compLP</span> <span class='varid'>lp</span> <span class='varid'>this'</span>
<a name="line-326"></a><span class='definition'>compRelPathExpr</span> <span class='keyword'>_</span>		<span class='keyglyph'>=</span> <span class='varid'>deadEndStreet</span>
<a name="line-327"></a>
<a name="line-328"></a><a name="compStringExpr"></a><span class='definition'>compStringExpr</span>			<span class='keyglyph'>::</span> <span class='conid'>MonadPlus</span> <span class='varid'>m</span> <span class='keyglyph'>=&gt;</span> <span class='conid'>Expr</span> <span class='keyglyph'>-&gt;</span> <span class='varid'>m</span> <span class='conid'>String</span>
<a name="line-329"></a><span class='definition'>compStringExpr</span> <span class='layout'>(</span><span class='conid'>LiteralExpr</span> <span class='varid'>s</span><span class='layout'>)</span>	<span class='keyglyph'>=</span> <span class='varid'>return</span> <span class='varid'>s</span>
<a name="line-330"></a><span class='definition'>compStringExpr</span> <span class='keyword'>_</span>		<span class='keyglyph'>=</span> <span class='varid'>deadEndStreet</span>
<a name="line-331"></a>
<a name="line-332"></a><a name="compNumberExpr"></a><span class='definition'>compNumberExpr</span>			<span class='keyglyph'>::</span> <span class='conid'>MonadPlus</span> <span class='varid'>m</span> <span class='keyglyph'>=&gt;</span> <span class='conid'>Expr</span> <span class='keyglyph'>-&gt;</span> <span class='varid'>m</span> <span class='conid'>XPNumber</span>
<a name="line-333"></a><span class='definition'>compNumberExpr</span> <span class='layout'>(</span><span class='conid'>NumberExpr</span> <span class='varid'>n</span><span class='layout'>)</span>	<span class='keyglyph'>=</span> <span class='varid'>return</span> <span class='varid'>n</span>
<a name="line-334"></a><span class='definition'>compNumberExpr</span> <span class='layout'>(</span><span class='conid'>FctExpr</span> <span class='str'>"number"</span> <span class='keyglyph'>[</span><span class='varid'>f1</span><span class='keyglyph'>]</span><span class='layout'>)</span>
<a name="line-335"></a>				<span class='keyglyph'>=</span> <span class='layout'>(</span> <span class='keyword'>do</span>
<a name="line-336"></a>				    <span class='varid'>b</span> <span class='keyglyph'>&lt;-</span> <span class='varid'>compBoolExpr</span> <span class='varid'>f1</span>
<a name="line-337"></a>				    <span class='varid'>return</span> <span class='varop'>$</span> <span class='keyword'>if</span> <span class='varid'>b</span> <span class='keyword'>then</span> <span class='layout'>(</span><span class='conid'>Float</span> <span class='num'>1</span><span class='layout'>)</span> <span class='keyword'>else</span> <span class='conid'>Pos0</span>
<a name="line-338"></a>				  <span class='layout'>)</span>
<a name="line-339"></a>				  <span class='varop'>`mplus`</span>
<a name="line-340"></a>				  <span class='layout'>(</span> <span class='keyword'>do</span>
<a name="line-341"></a>				    <span class='varid'>s</span> <span class='keyglyph'>&lt;-</span> <span class='varid'>compStringExpr</span> <span class='varid'>f1</span>
<a name="line-342"></a>				    <span class='varid'>return</span> <span class='varop'>$</span> <span class='varid'>toNumber</span> <span class='varid'>s</span>
<a name="line-343"></a>				  <span class='layout'>)</span>
<a name="line-344"></a><span class='definition'>compNumberExpr</span> <span class='keyword'>_</span>		<span class='keyglyph'>=</span> <span class='varid'>deadEndStreet</span>
<a name="line-345"></a>
<a name="line-346"></a><a name="compIntExpr"></a><span class='definition'>compIntExpr</span>			<span class='keyglyph'>::</span> <span class='conid'>MonadPlus</span> <span class='varid'>m</span> <span class='keyglyph'>=&gt;</span> <span class='conid'>Expr</span> <span class='keyglyph'>-&gt;</span> <span class='varid'>m</span> <span class='conid'>Int</span>
<a name="line-347"></a><span class='definition'>compIntExpr</span> <span class='varid'>e</span>			<span class='keyglyph'>=</span> <span class='layout'>(</span> <span class='keyword'>do</span>
<a name="line-348"></a>				    <span class='layout'>(</span><span class='conid'>Float</span> <span class='varid'>f</span><span class='layout'>)</span> <span class='keyglyph'>&lt;-</span> <span class='varid'>compNumberExpr</span> <span class='varid'>e</span>
<a name="line-349"></a>				    <span class='varid'>return</span> <span class='layout'>(</span><span class='varid'>round</span> <span class='varid'>f</span><span class='layout'>)</span>
<a name="line-350"></a>				  <span class='layout'>)</span>
<a name="line-351"></a>				  <span class='varop'>`mplus`</span>
<a name="line-352"></a>				  <span class='varid'>deadEndStreet</span>
<a name="line-353"></a>
<a name="line-354"></a>
<a name="line-355"></a><a name="compBoolExpr"></a><span class='definition'>compBoolExpr</span>			<span class='keyglyph'>::</span> <span class='conid'>MonadPlus</span> <span class='varid'>m</span> <span class='keyglyph'>=&gt;</span> <span class='conid'>Expr</span> <span class='keyglyph'>-&gt;</span> <span class='varid'>m</span> <span class='conid'>Bool</span>
<a name="line-356"></a><span class='definition'>compBoolExpr</span> <span class='layout'>(</span><span class='conid'>FctExpr</span> <span class='varid'>f</span> <span class='conid'>[]</span><span class='layout'>)</span>
<a name="line-357"></a>    <span class='keyglyph'>|</span> <span class='varid'>f</span> <span class='varop'>`elem`</span> <span class='keyglyph'>[</span><span class='str'>"true"</span><span class='layout'>,</span> <span class='str'>"false"</span><span class='keyglyph'>]</span>
<a name="line-358"></a>				<span class='keyglyph'>=</span> <span class='varid'>return</span> <span class='varop'>$</span> <span class='varid'>f</span> <span class='varop'>==</span> <span class='str'>"true"</span>
<a name="line-359"></a><span class='definition'>compBoolExpr</span> <span class='layout'>(</span><span class='conid'>FctExpr</span> <span class='str'>"not"</span> <span class='keyglyph'>[</span><span class='varid'>f1</span><span class='keyglyph'>]</span><span class='layout'>)</span>
<a name="line-360"></a>				<span class='keyglyph'>=</span> <span class='keyword'>do</span>
<a name="line-361"></a>				  <span class='varid'>v1</span> <span class='keyglyph'>&lt;-</span> <span class='varid'>compBoolExpr</span> <span class='varid'>f1</span>
<a name="line-362"></a>				  <span class='varid'>return</span> <span class='varop'>$</span> <span class='varid'>not</span> <span class='varid'>v1</span>
<a name="line-363"></a><span class='definition'>compBoolExpr</span> <span class='layout'>(</span><span class='conid'>LiteralExpr</span> <span class='varid'>s</span><span class='layout'>)</span>	<span class='keyglyph'>=</span> <span class='varid'>return</span> <span class='varop'>$</span> <span class='varid'>not</span> <span class='layout'>(</span><span class='varid'>null</span> <span class='varid'>s</span><span class='layout'>)</span>
<a name="line-364"></a><span class='definition'>compBoolExpr</span> <span class='layout'>(</span><span class='conid'>NumberExpr</span> <span class='varid'>n</span><span class='layout'>)</span>	<span class='keyglyph'>=</span> <span class='varid'>return</span> <span class='varop'>$</span> <span class='varid'>nz</span> <span class='varid'>n</span>
<a name="line-365"></a>				  <span class='keyword'>where</span>
<a name="line-366"></a>				  <span class='varid'>nz</span> <span class='layout'>(</span><span class='conid'>Float</span> <span class='varid'>f</span><span class='layout'>)</span> <span class='keyglyph'>=</span> <span class='varid'>f</span> <span class='varop'>/=</span> <span class='num'>0</span>
<a name="line-367"></a>				  <span class='varid'>nz</span> <span class='conid'>NegInf</span>    <span class='keyglyph'>=</span> <span class='conid'>True</span>
<a name="line-368"></a>				  <span class='varid'>nz</span> <span class='conid'>PosInf</span>    <span class='keyglyph'>=</span> <span class='conid'>True</span>
<a name="line-369"></a>				  <span class='varid'>nz</span> <span class='keyword'>_</span>         <span class='keyglyph'>=</span> <span class='conid'>False</span>
<a name="line-370"></a><span class='definition'>compBoolExpr</span> <span class='keyword'>_</span>			<span class='keyglyph'>=</span> <span class='varid'>deadEndStreet</span>
<a name="line-371"></a>
<a name="line-372"></a><a name="compGenExpr"></a><span class='definition'>compGenExpr</span>			<span class='keyglyph'>::</span> <span class='conid'>MonadPlus</span> <span class='varid'>m</span> <span class='keyglyph'>=&gt;</span> <span class='conid'>Expr</span> <span class='keyglyph'>-&gt;</span> <span class='varid'>m</span> <span class='layout'>(</span><span class='conid'>XPArrow</span> <span class='conid'>XmlTree</span> <span class='conid'>XmlTree</span><span class='layout'>)</span>
<a name="line-373"></a><span class='definition'>compGenExpr</span> <span class='layout'>(</span><span class='conid'>GenExpr</span> <span class='varid'>op</span> <span class='keyglyph'>[</span><span class='varid'>e1</span><span class='layout'>,</span><span class='varid'>e2</span><span class='keyglyph'>]</span><span class='layout'>)</span>
<a name="line-374"></a>				<span class='keyglyph'>=</span> <span class='varid'>compString</span> <span class='varid'>op</span> <span class='varid'>e1</span> <span class='varid'>e2</span>		<span class='comment'>-- on arg is a string expr</span>
<a name="line-375"></a>				  <span class='varop'>`mplus`</span>
<a name="line-376"></a>				  <span class='varid'>compNumber</span> <span class='varid'>op</span> <span class='varid'>e1</span> <span class='varid'>e2</span>		<span class='comment'>-- one arg is a number expr</span>
<a name="line-377"></a>				  <span class='varop'>`mplus`</span>
<a name="line-378"></a>				  <span class='varid'>compBool</span>   <span class='varid'>op</span> <span class='varid'>e1</span> <span class='varid'>e2</span>		<span class='comment'>-- and/or</span>
<a name="line-379"></a>				  <span class='varop'>`mplus`</span>
<a name="line-380"></a>				  <span class='varid'>compPath</span>   <span class='varid'>op</span> <span class='varid'>e1</span> <span class='varid'>e2</span>		<span class='comment'>-- nodeset equality</span>
<a name="line-381"></a>
<a name="line-382"></a><span class='definition'>compGenExpr</span> <span class='layout'>(</span><span class='conid'>GenExpr</span> <span class='varid'>op</span> <span class='layout'>(</span><span class='varid'>e1</span><span class='conop'>:</span><span class='varid'>el</span><span class='layout'>)</span><span class='layout'>)</span>
<a name="line-383"></a>    <span class='keyglyph'>|</span> <span class='varid'>op</span> <span class='varop'>`elem`</span> <span class='keyglyph'>[</span><span class='conid'>And</span><span class='layout'>,</span> <span class='conid'>Or</span><span class='keyglyph'>]</span>	<span class='keyglyph'>=</span> <span class='varid'>compGenExpr</span> <span class='layout'>(</span><span class='conid'>GenExpr</span> <span class='varid'>op</span> <span class='keyglyph'>[</span><span class='varid'>e1</span><span class='layout'>,</span> <span class='conid'>GenExpr</span> <span class='varid'>op</span> <span class='varid'>el</span><span class='keyglyph'>]</span><span class='layout'>)</span>
<a name="line-384"></a>
<a name="line-385"></a><span class='definition'>compGenExpr</span> <span class='keyword'>_</span>			<span class='keyglyph'>=</span> <span class='varid'>deadEndStreet</span>
<a name="line-386"></a>
<a name="line-387"></a><a name="compString"></a><span class='definition'>compString</span>			<span class='keyglyph'>::</span> <span class='conid'>MonadPlus</span> <span class='varid'>m</span> <span class='keyglyph'>=&gt;</span> <span class='conid'>Op</span> <span class='keyglyph'>-&gt;</span> <span class='conid'>Expr</span> <span class='keyglyph'>-&gt;</span> <span class='conid'>Expr</span> <span class='keyglyph'>-&gt;</span> <span class='varid'>m</span> <span class='layout'>(</span><span class='conid'>XPArrow</span> <span class='conid'>XmlTree</span> <span class='conid'>XmlTree</span><span class='layout'>)</span>
<a name="line-388"></a><span class='definition'>compString</span> <span class='varid'>op</span> <span class='varid'>e1</span> <span class='varid'>e2</span>
<a name="line-389"></a>    <span class='keyglyph'>|</span> <span class='varid'>op</span> <span class='varop'>`elem`</span> <span class='keyglyph'>[</span><span class='conid'>Eq</span><span class='layout'>,</span> <span class='conid'>NEq</span><span class='keyglyph'>]</span>	<span class='keyglyph'>=</span> <span class='layout'>(</span> <span class='keyword'>do</span>
<a name="line-390"></a>				    <span class='varid'>s</span> <span class='keyglyph'>&lt;-</span> <span class='varid'>compStringExpr</span>  <span class='varid'>e2</span>
<a name="line-391"></a>				    <span class='varid'>a</span> <span class='keyglyph'>&lt;-</span> <span class='varid'>compRelPathExpr</span> <span class='varid'>e1</span>
<a name="line-392"></a>				    <span class='varid'>return</span> <span class='varop'>$</span> <span class='varid'>mkEq'</span> <span class='varid'>a</span> <span class='varid'>s</span>
<a name="line-393"></a>				  <span class='layout'>)</span>
<a name="line-394"></a>				  <span class='varop'>`mplus`</span>
<a name="line-395"></a>				  <span class='layout'>(</span> <span class='keyword'>do</span>
<a name="line-396"></a>				    <span class='varid'>s</span> <span class='keyglyph'>&lt;-</span> <span class='varid'>compStringExpr</span>  <span class='varid'>e1</span>
<a name="line-397"></a>				    <span class='varid'>a</span> <span class='keyglyph'>&lt;-</span> <span class='varid'>compRelPathExpr</span> <span class='varid'>e2</span>
<a name="line-398"></a>				    <span class='varid'>return</span> <span class='varop'>$</span> <span class='varid'>mkEq'</span> <span class='varid'>a</span> <span class='varid'>s</span>
<a name="line-399"></a>				  <span class='layout'>)</span>
<a name="line-400"></a>				  <span class='keyword'>where</span>
<a name="line-401"></a>				  <span class='varid'>mkEq'</span> <span class='varid'>a'</span> <span class='varid'>s'</span> <span class='keyglyph'>=</span> <span class='varid'>mk</span> <span class='layout'>(</span> <span class='layout'>(</span> <span class='varid'>xString</span> <span class='varid'>a'</span>
<a name="line-402"></a>							<span class='varop'>&gt;&gt;&gt;</span>
<a name="line-403"></a>							<span class='varid'>isA</span> <span class='layout'>(</span> <span class='keyword'>if</span> <span class='varid'>op</span> <span class='varop'>==</span> <span class='conid'>Eq</span>
<a name="line-404"></a>							      <span class='keyword'>then</span> <span class='layout'>(</span><span class='varop'>==</span> <span class='varid'>s'</span><span class='layout'>)</span>
<a name="line-405"></a>							      <span class='keyword'>else</span> <span class='layout'>(</span><span class='varop'>/=</span> <span class='varid'>s'</span><span class='layout'>)</span>
<a name="line-406"></a>							    <span class='layout'>)</span>
<a name="line-407"></a>						      <span class='layout'>)</span>
<a name="line-408"></a>						      <span class='varop'>`guards`</span> <span class='varid'>this</span>	<span class='comment'>-- just for type match</span>
<a name="line-409"></a>						    <span class='layout'>)</span>
<a name="line-410"></a><span class='definition'>compString</span> <span class='keyword'>_</span> <span class='keyword'>_</span> <span class='keyword'>_</span>		<span class='keyglyph'>=</span> <span class='varid'>deadEndStreet</span>
<a name="line-411"></a>
<a name="line-412"></a><a name="compNumber"></a><span class='definition'>compNumber</span>			<span class='keyglyph'>::</span> <span class='conid'>MonadPlus</span> <span class='varid'>m</span> <span class='keyglyph'>=&gt;</span> <span class='conid'>Op</span> <span class='keyglyph'>-&gt;</span> <span class='conid'>Expr</span> <span class='keyglyph'>-&gt;</span> <span class='conid'>Expr</span> <span class='keyglyph'>-&gt;</span> <span class='varid'>m</span> <span class='layout'>(</span><span class='conid'>XPArrow</span> <span class='conid'>XmlTree</span> <span class='conid'>XmlTree</span><span class='layout'>)</span>
<a name="line-413"></a><span class='definition'>compNumber</span> <span class='varid'>op</span> <span class='varid'>e1</span> <span class='varid'>e2</span>
<a name="line-414"></a>    <span class='keyglyph'>|</span> <span class='varid'>op</span> <span class='varop'>`elem`</span> <span class='keyglyph'>[</span><span class='conid'>Eq</span><span class='layout'>,</span> <span class='conid'>NEq</span><span class='layout'>,</span> <span class='conid'>Less</span><span class='layout'>,</span> <span class='conid'>Greater</span><span class='layout'>,</span> <span class='conid'>LessEq</span><span class='layout'>,</span> <span class='conid'>GreaterEq</span><span class='keyglyph'>]</span>
<a name="line-415"></a>				<span class='keyglyph'>=</span> <span class='layout'>(</span> <span class='keyword'>do</span>
<a name="line-416"></a>				    <span class='varid'>n</span> <span class='keyglyph'>&lt;-</span> <span class='varid'>compNumberExpr</span>  <span class='varid'>e2</span>
<a name="line-417"></a>				    <span class='varid'>a</span> <span class='keyglyph'>&lt;-</span> <span class='varid'>compRelPathExpr</span> <span class='varid'>e1</span>
<a name="line-418"></a>				    <span class='varid'>return</span> <span class='varop'>$</span> <span class='varid'>mkEq'</span> <span class='varid'>a</span> <span class='varid'>n</span>
<a name="line-419"></a>				  <span class='layout'>)</span>
<a name="line-420"></a>				  <span class='varop'>`mplus`</span>
<a name="line-421"></a>				  <span class='layout'>(</span> <span class='keyword'>do</span>
<a name="line-422"></a>				    <span class='varid'>n</span> <span class='keyglyph'>&lt;-</span> <span class='varid'>compNumberExpr</span>  <span class='varid'>e1</span>
<a name="line-423"></a>				    <span class='varid'>a</span> <span class='keyglyph'>&lt;-</span> <span class='varid'>compRelPathExpr</span> <span class='varid'>e2</span>
<a name="line-424"></a>				    <span class='varid'>return</span> <span class='varop'>$</span> <span class='varid'>mkEq'</span> <span class='varid'>a</span> <span class='varid'>n</span>
<a name="line-425"></a>				  <span class='layout'>)</span>
<a name="line-426"></a>				  <span class='keyword'>where</span>
<a name="line-427"></a>				  <span class='varid'>mkEq'</span> <span class='varid'>a'</span> <span class='varid'>n'</span> <span class='keyglyph'>=</span> <span class='varid'>mk</span> <span class='layout'>(</span> <span class='layout'>(</span> <span class='varid'>xNumber'</span> <span class='varid'>a'</span>
<a name="line-428"></a>							<span class='varop'>&gt;&gt;&gt;</span>
<a name="line-429"></a>							<span class='varid'>isA</span> <span class='layout'>(</span><span class='varid'>flip</span> <span class='layout'>(</span> <span class='keyword'>case</span> <span class='varid'>op</span> <span class='keyword'>of</span>
<a name="line-430"></a>								    <span class='conid'>Eq</span>        <span class='keyglyph'>-&gt;</span> <span class='layout'>(</span><span class='varop'>==</span><span class='layout'>)</span>
<a name="line-431"></a>								    <span class='conid'>NEq</span>       <span class='keyglyph'>-&gt;</span> <span class='layout'>(</span><span class='varop'>/=</span><span class='layout'>)</span>
<a name="line-432"></a>								    <span class='conid'>Less</span>      <span class='keyglyph'>-&gt;</span> <span class='layout'>(</span><span class='varop'>&lt;</span><span class='layout'>)</span>
<a name="line-433"></a>								    <span class='conid'>Greater</span>   <span class='keyglyph'>-&gt;</span> <span class='layout'>(</span><span class='varop'>&gt;</span><span class='layout'>)</span>
<a name="line-434"></a>								    <span class='conid'>LessEq</span>    <span class='keyglyph'>-&gt;</span> <span class='layout'>(</span><span class='varop'>&lt;=</span><span class='layout'>)</span>
<a name="line-435"></a>								    <span class='conid'>GreaterEq</span> <span class='keyglyph'>-&gt;</span> <span class='layout'>(</span><span class='varop'>&gt;=</span><span class='layout'>)</span>
<a name="line-436"></a>								    <span class='keyword'>_</span>         <span class='keyglyph'>-&gt;</span> <span class='varid'>error</span> <span class='str'>"compNumber: wrong arg"</span>
<a name="line-437"></a>								  <span class='layout'>)</span> <span class='varid'>n'</span>
<a name="line-438"></a>							    <span class='layout'>)</span>
<a name="line-439"></a>						      <span class='layout'>)</span>
<a name="line-440"></a>						      <span class='varop'>`guards`</span> <span class='varid'>this</span>
<a name="line-441"></a>						    <span class='layout'>)</span>
<a name="line-442"></a><span class='definition'>compNumber</span> <span class='keyword'>_</span> <span class='keyword'>_</span> <span class='keyword'>_</span>		<span class='keyglyph'>=</span> <span class='varid'>deadEndStreet</span>
<a name="line-443"></a>
<a name="line-444"></a><a name="compBool"></a><span class='definition'>compBool</span>			<span class='keyglyph'>::</span> <span class='conid'>MonadPlus</span> <span class='varid'>m</span> <span class='keyglyph'>=&gt;</span> <span class='conid'>Op</span> <span class='keyglyph'>-&gt;</span> <span class='conid'>Expr</span> <span class='keyglyph'>-&gt;</span> <span class='conid'>Expr</span> <span class='keyglyph'>-&gt;</span> <span class='varid'>m</span> <span class='layout'>(</span><span class='conid'>XPArrow</span> <span class='conid'>XmlTree</span> <span class='conid'>XmlTree</span><span class='layout'>)</span>
<a name="line-445"></a><span class='definition'>compBool</span> <span class='conid'>And</span> <span class='varid'>e1</span> <span class='varid'>e2</span>		<span class='keyglyph'>=</span> <span class='layout'>(</span> <span class='keyword'>do</span>
<a name="line-446"></a>				    <span class='varid'>b</span> <span class='keyglyph'>&lt;-</span> <span class='varid'>compBoolExpr</span> <span class='varid'>e1</span>
<a name="line-447"></a>				    <span class='keyword'>if</span> <span class='varid'>b</span>
<a name="line-448"></a>				       <span class='keyword'>then</span> <span class='varid'>compGenExpr</span> <span class='varid'>e2</span>
<a name="line-449"></a>				       <span class='keyword'>else</span> <span class='varid'>return</span> <span class='varop'>$</span> <span class='varid'>mk</span> <span class='varid'>none</span>
<a name="line-450"></a>				  <span class='layout'>)</span>
<a name="line-451"></a>				  <span class='varop'>`mplus`</span>
<a name="line-452"></a>				  <span class='layout'>(</span> <span class='keyword'>do</span>
<a name="line-453"></a>				    <span class='varid'>b</span> <span class='keyglyph'>&lt;-</span> <span class='varid'>compBoolExpr</span> <span class='varid'>e2</span>
<a name="line-454"></a>				    <span class='keyword'>if</span> <span class='varid'>b</span>
<a name="line-455"></a>				       <span class='keyword'>then</span> <span class='varid'>compGenExpr</span> <span class='varid'>e1</span>
<a name="line-456"></a>				       <span class='keyword'>else</span> <span class='varid'>return</span> <span class='varop'>$</span> <span class='varid'>mk</span> <span class='varid'>none</span>
<a name="line-457"></a>				  <span class='layout'>)</span>
<a name="line-458"></a>				  <span class='varop'>`mplus`</span>
<a name="line-459"></a>				  <span class='layout'>(</span> <span class='keyword'>do</span>
<a name="line-460"></a>				    <span class='varid'>a1</span> <span class='keyglyph'>&lt;-</span> <span class='varid'>compGenExpr</span> <span class='varid'>e1</span>
<a name="line-461"></a>				    <span class='varid'>a2</span> <span class='keyglyph'>&lt;-</span> <span class='varid'>compGenExpr</span> <span class='varid'>e2</span>
<a name="line-462"></a>				    <span class='varid'>return</span> <span class='varop'>$</span> <span class='varid'>a1</span> <span class='varop'>`guards'`</span> <span class='varid'>a2</span>
<a name="line-463"></a>				  <span class='layout'>)</span>
<a name="line-464"></a><span class='definition'>compBool</span> <span class='conid'>Or</span> <span class='varid'>e1</span> <span class='varid'>e2</span>		<span class='keyglyph'>=</span> <span class='layout'>(</span> <span class='keyword'>do</span>
<a name="line-465"></a>				    <span class='varid'>b</span> <span class='keyglyph'>&lt;-</span> <span class='varid'>compBoolExpr</span> <span class='varid'>e1</span>
<a name="line-466"></a>				    <span class='keyword'>if</span> <span class='varid'>b</span>
<a name="line-467"></a>                                       <span class='keyword'>then</span> <span class='varid'>return</span> <span class='varid'>this'</span>
<a name="line-468"></a>				       <span class='keyword'>else</span> <span class='varid'>compGenExpr</span> <span class='varid'>e2</span>
<a name="line-469"></a>				  <span class='layout'>)</span>
<a name="line-470"></a>				  <span class='varop'>`mplus`</span>
<a name="line-471"></a>				  <span class='layout'>(</span> <span class='keyword'>do</span>
<a name="line-472"></a>				    <span class='varid'>b</span> <span class='keyglyph'>&lt;-</span> <span class='varid'>compBoolExpr</span> <span class='varid'>e2</span>
<a name="line-473"></a>				    <span class='keyword'>if</span> <span class='varid'>b</span>
<a name="line-474"></a>                                       <span class='keyword'>then</span> <span class='varid'>return</span> <span class='varid'>this'</span>
<a name="line-475"></a>				       <span class='keyword'>else</span> <span class='varid'>compGenExpr</span> <span class='varid'>e1</span>
<a name="line-476"></a>				  <span class='layout'>)</span>
<a name="line-477"></a>				  <span class='varop'>`mplus`</span>
<a name="line-478"></a>				  <span class='layout'>(</span> <span class='keyword'>do</span>
<a name="line-479"></a>				    <span class='varid'>a1</span> <span class='keyglyph'>&lt;-</span> <span class='varid'>compGenExpr</span> <span class='varid'>e1</span>
<a name="line-480"></a>				    <span class='varid'>a2</span> <span class='keyglyph'>&lt;-</span> <span class='varid'>compGenExpr</span> <span class='varid'>e2</span>
<a name="line-481"></a>				    <span class='varid'>return</span> <span class='varop'>$</span> <span class='varid'>a1</span> <span class='varop'>&lt;+&gt;&gt;</span> <span class='varid'>a2</span>
<a name="line-482"></a>				  <span class='layout'>)</span>
<a name="line-483"></a><span class='definition'>compBool</span> <span class='keyword'>_</span> <span class='keyword'>_</span> <span class='keyword'>_</span>			<span class='keyglyph'>=</span> <span class='varid'>deadEndStreet</span>
<a name="line-484"></a>
<a name="line-485"></a><a name="compPath"></a><span class='definition'>compPath</span>			<span class='keyglyph'>::</span> <span class='conid'>MonadPlus</span> <span class='varid'>m</span> <span class='keyglyph'>=&gt;</span> <span class='conid'>Op</span> <span class='keyglyph'>-&gt;</span> <span class='conid'>Expr</span> <span class='keyglyph'>-&gt;</span> <span class='conid'>Expr</span> <span class='keyglyph'>-&gt;</span> <span class='varid'>m</span> <span class='layout'>(</span><span class='conid'>XPArrow</span> <span class='conid'>XmlTree</span> <span class='conid'>XmlTree</span><span class='layout'>)</span>
<a name="line-486"></a><span class='definition'>compPath</span> <span class='varid'>op</span> <span class='varid'>e1</span> <span class='varid'>e2</span>
<a name="line-487"></a>    <span class='keyglyph'>|</span> <span class='varid'>op</span> <span class='varop'>`elem`</span> <span class='keyglyph'>[</span><span class='conid'>Eq</span><span class='layout'>,</span> <span class='conid'>NEq</span><span class='keyglyph'>]</span>	<span class='keyglyph'>=</span> <span class='layout'>(</span> <span class='keyword'>do</span>
<a name="line-488"></a>				    <span class='varid'>a1</span> <span class='keyglyph'>&lt;-</span> <span class='varid'>compRelPathExpr</span> <span class='varid'>e2</span>
<a name="line-489"></a>				    <span class='varid'>a2</span> <span class='keyglyph'>&lt;-</span> <span class='varid'>compRelPathExpr</span> <span class='varid'>e1</span>
<a name="line-490"></a>				    <span class='varid'>return</span> <span class='varop'>$</span> <span class='varid'>mk</span> <span class='varop'>.</span> <span class='varid'>cmp</span> <span class='varid'>op</span> <span class='varop'>$</span> <span class='layout'>(</span> <span class='layout'>(</span> <span class='varid'>listA</span> <span class='layout'>(</span><span class='varid'>xString</span> <span class='varid'>a1</span><span class='layout'>)</span> <span class='varop'>&amp;&amp;&amp;</span> <span class='varid'>listA</span> <span class='layout'>(</span><span class='varid'>xString</span> <span class='varid'>a2</span><span class='layout'>)</span><span class='layout'>)</span>
<a name="line-491"></a>							      <span class='varop'>&gt;&gt;&gt;</span>
<a name="line-492"></a>							      <span class='varid'>eqs</span>
<a name="line-493"></a>							    <span class='layout'>)</span>
<a name="line-494"></a>				  <span class='layout'>)</span>
<a name="line-495"></a>				  <span class='keyword'>where</span>
<a name="line-496"></a>				  <span class='varid'>eqs</span>		<span class='keyglyph'>=</span> <span class='varid'>arr2L</span> <span class='varid'>equalNodeSet</span>
<a name="line-497"></a>				  <span class='varid'>cmp</span> <span class='conid'>Eq</span>  <span class='varid'>a</span>	<span class='keyglyph'>=</span> <span class='varid'>a</span> <span class='varop'>`guards`</span> <span class='varid'>this</span>
<a name="line-498"></a>				  <span class='varid'>cmp</span> <span class='conid'>NEq</span> <span class='varid'>a</span>	<span class='keyglyph'>=</span> <span class='varid'>ifA</span> <span class='varid'>a</span> <span class='varid'>none</span> <span class='varid'>this</span>
<a name="line-499"></a>				  <span class='varid'>cmp</span> <span class='keyword'>_</span> <span class='keyword'>_</span>	<span class='keyglyph'>=</span> <span class='varid'>error</span> <span class='str'>"compPath: wrong agruments"</span>
<a name="line-500"></a>
<a name="line-501"></a><span class='definition'>compPath</span> <span class='keyword'>_</span> <span class='keyword'>_</span> <span class='keyword'>_</span>			<span class='keyglyph'>=</span> <span class='varid'>deadEndStreet</span>
<a name="line-502"></a>
<a name="line-503"></a><span class='comment'>-- ----------------------------------------</span>
<a name="line-504"></a>
<a name="line-505"></a><a name="toNumber"></a><span class='definition'>toNumber</span>		<span class='keyglyph'>::</span> <span class='conid'>String</span> <span class='keyglyph'>-&gt;</span> <span class='conid'>XPNumber</span>
<a name="line-506"></a><span class='definition'>toNumber</span> <span class='varid'>s</span>		<span class='keyglyph'>=</span> <span class='keyword'>let</span> <span class='layout'>(</span> <span class='conid'>XPVNumber</span> <span class='varid'>v</span><span class='layout'>)</span> <span class='keyglyph'>=</span> <span class='varid'>parseNumber</span> <span class='varid'>s</span> <span class='keyword'>in</span> <span class='varid'>v</span>
<a name="line-507"></a>
<a name="line-508"></a><a name="equalNodeSet"></a><span class='definition'>equalNodeSet</span>		<span class='keyglyph'>::</span> <span class='conid'>Eq</span> <span class='varid'>a</span> <span class='keyglyph'>=&gt;</span> <span class='keyglyph'>[</span><span class='varid'>a</span><span class='keyglyph'>]</span> <span class='keyglyph'>-&gt;</span> <span class='keyglyph'>[</span><span class='varid'>a</span><span class='keyglyph'>]</span> <span class='keyglyph'>-&gt;</span> <span class='keyglyph'>[</span><span class='varid'>a</span><span class='keyglyph'>]</span>
<a name="line-509"></a><span class='definition'>equalNodeSet</span> <span class='varid'>s1</span> <span class='varid'>s2</span>	<span class='keyglyph'>=</span> <span class='keyglyph'>[</span> <span class='varid'>x</span> <span class='keyglyph'>|</span> <span class='varid'>x</span> <span class='keyglyph'>&lt;-</span> <span class='varid'>s1</span><span class='layout'>,</span> <span class='varid'>y</span> <span class='keyglyph'>&lt;-</span> <span class='varid'>s2</span><span class='layout'>,</span> <span class='varid'>x</span> <span class='varop'>==</span> <span class='varid'>y</span><span class='keyglyph'>]</span>
<a name="line-510"></a>
<a name="line-511"></a><span class='comment'>-- ----------------------------------------</span>
</pre></body>
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