hxt-8.3.0: doc/hdoc/src/Text-XML-HXT-XPath-XPathEval.html
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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.XPathEval
<a name="line-5"></a> Copyright : Copyright (C) 2006 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> Version : $Id: XPathEval.hs,v 1.8 2006/10/12 11:51:29 hxml Exp $
<a name="line-12"></a>
<a name="line-13"></a> The core functions for evaluating the different types of XPath expressions.
<a name="line-14"></a> Each 'Expr'-constructor is mapped to an evaluation function.
<a name="line-15"></a>
<a name="line-16"></a>-}</span>
<a name="line-17"></a>
<a name="line-18"></a><span class='comment'>-- ------------------------------------------------------------</span>
<a name="line-19"></a>
<a name="line-20"></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'>XPath</span><span class='varop'>.</span><span class='conid'>XPathEval</span>
<a name="line-21"></a> <span class='layout'>(</span> <span class='varid'>getXPath</span>
<a name="line-22"></a> <span class='layout'>,</span> <span class='varid'>getXPathWithNsEnv</span>
<a name="line-23"></a> <span class='layout'>,</span> <span class='varid'>getXPathSubTrees</span>
<a name="line-24"></a> <span class='layout'>,</span> <span class='varid'>getXPathSubTreesWithNsEnv</span>
<a name="line-25"></a> <span class='layout'>,</span> <span class='varid'>getXPathNodeSet</span>
<a name="line-26"></a> <span class='layout'>,</span> <span class='varid'>getXPathNodeSetWithNsEnv</span>
<a name="line-27"></a> <span class='layout'>,</span> <span class='varid'>evalExpr</span>
<a name="line-28"></a> <span class='layout'>)</span>
<a name="line-29"></a><span class='keyword'>where</span>
<a name="line-30"></a>
<a name="line-31"></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'>XPathFct</span>
<a name="line-32"></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-33"></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'>XPathArithmetic</span>
<a name="line-34"></a> <span class='layout'>(</span> <span class='varid'>xPathAdd</span>
<a name="line-35"></a> <span class='layout'>,</span> <span class='varid'>xPathDiv</span>
<a name="line-36"></a> <span class='layout'>,</span> <span class='varid'>xPathMod</span>
<a name="line-37"></a> <span class='layout'>,</span> <span class='varid'>xPathMulti</span>
<a name="line-38"></a> <span class='layout'>,</span> <span class='varid'>xPathUnary</span>
<a name="line-39"></a> <span class='layout'>)</span>
<a name="line-40"></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-41"></a> <span class='layout'>(</span> <span class='varid'>parseXPath</span> <span class='layout'>)</span>
<a name="line-42"></a>
<a name="line-43"></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'>XPathToString</span>
<a name="line-44"></a> <span class='layout'>(</span> <span class='varid'>xPValue2XmlTrees</span> <span class='layout'>)</span>
<a name="line-45"></a>
<a name="line-46"></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'>XPathToNodeSet</span>
<a name="line-47"></a> <span class='layout'>(</span> <span class='varid'>xPValue2NodeSet</span>
<a name="line-48"></a> <span class='layout'>,</span> <span class='varid'>emptyNodeSet</span>
<a name="line-49"></a> <span class='layout'>)</span>
<a name="line-50"></a>
<a name="line-51"></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-52"></a> <span class='layout'>(</span> <span class='varid'>runParser</span> <span class='layout'>)</span>
<a name="line-53"></a>
<a name="line-54"></a><span class='keyword'>import</span> <span class='conid'>Data</span><span class='varop'>.</span><span class='conid'>Maybe</span>
<a name="line-55"></a> <span class='layout'>(</span> <span class='varid'>fromJust</span> <span class='layout'>)</span>
<a name="line-56"></a>
<a name="line-57"></a><span class='comment'>-- ----------------------------------------</span>
<a name="line-58"></a>
<a name="line-59"></a><span class='comment'>-- the DOM functions</span>
<a name="line-60"></a>
<a name="line-61"></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-62"></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'>DOM</span><span class='varop'>.</span><span class='conid'>XmlNode</span> <span class='keyword'>as</span> <span class='conid'>XN</span>
<a name="line-63"></a>
<a name="line-64"></a><span class='comment'>-- ----------------------------------------</span>
<a name="line-65"></a>
<a name="line-66"></a><span class='comment'>-- the list arrow functions</span>
<a name="line-67"></a>
<a name="line-68"></a><span class='keyword'>import</span> <span class='conid'>Control</span><span class='varop'>.</span><span class='conid'>Arrow</span> <span class='layout'>(</span> <span class='layout'>(</span><span class='varop'>>>></span><span class='layout'>)</span><span class='layout'>,</span> <span class='layout'>(</span><span class='varop'>>>^</span><span class='layout'>)</span> <span class='layout'>)</span>
<a name="line-69"></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'>ArrowList</span> <span class='layout'>(</span> <span class='varid'>arrL</span><span class='layout'>,</span> <span class='varid'>isA</span> <span class='layout'>)</span>
<a name="line-70"></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'>ArrowIf</span> <span class='layout'>(</span> <span class='varid'>filterA</span> <span class='layout'>)</span>
<a name="line-71"></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'>ListArrow</span> <span class='layout'>(</span> <span class='varid'>runLA</span> <span class='layout'>)</span>
<a name="line-72"></a><span class='keyword'>import</span> <span class='keyword'>qualified</span>
<a name="line-73"></a> <span class='conid'>Control</span><span class='varop'>.</span><span class='conid'>Arrow</span><span class='varop'>.</span><span class='conid'>ArrowTree</span> <span class='keyword'>as</span> <span class='conid'>AT</span>
<a name="line-74"></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> <span class='layout'>(</span> <span class='conid'>ArrowDTD</span><span class='layout'>,</span> <span class='varid'>isDTD</span><span class='layout'>,</span> <span class='varid'>getDTDAttrl</span> <span class='layout'>)</span>
<a name="line-75"></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> <span class='layout'>(</span> <span class='varid'>canonicalizeForXPath</span> <span class='layout'>)</span>
<a name="line-76"></a>
<a name="line-77"></a><span class='comment'>-- -----------------------------------------------------------------------------</span>
<a name="line-78"></a>
<a name="line-79"></a><span class='comment'>-- |</span>
<a name="line-80"></a><span class='comment'>-- Select parts of a document by an XPath expression.</span>
<a name="line-81"></a><span class='comment'>--</span>
<a name="line-82"></a><span class='comment'>-- The main filter for selecting parts of a document via XPath.</span>
<a name="line-83"></a><span class='comment'>-- The string argument must be a XPath expression with an absolute location path,</span>
<a name="line-84"></a><span class='comment'>-- the argument tree must be a complete document tree.</span>
<a name="line-85"></a><span class='comment'>-- Result is a possibly empty list of XmlTrees forming the set of selected XPath values.</span>
<a name="line-86"></a><span class='comment'>-- XPath values other than XmlTrees (numbers, attributes, tagnames, ...)</span>
<a name="line-87"></a><span class='comment'>-- are convertet to text nodes.</span>
<a name="line-88"></a>
<a name="line-89"></a><a name="getXPath"></a><span class='definition'>getXPath</span> <span class='keyglyph'>::</span> <span class='conid'>String</span> <span class='keyglyph'>-></span> <span class='conid'>XmlTree</span> <span class='keyglyph'>-></span> <span class='conid'>XmlTrees</span>
<a name="line-90"></a><span class='definition'>getXPath</span> <span class='keyglyph'>=</span> <span class='varid'>getXPathWithNsEnv</span> <span class='conid'>[]</span>
<a name="line-91"></a>
<a name="line-92"></a><span class='comment'>-- |</span>
<a name="line-93"></a><span class='comment'>-- Select parts of a document by a namespace aware XPath expression.</span>
<a name="line-94"></a><span class='comment'>--</span>
<a name="line-95"></a><span class='comment'>-- Works like 'getXPath' but the prefix:localpart names in the XPath expression</span>
<a name="line-96"></a><span class='comment'>-- are interpreted with respect to the given namespace environment</span>
<a name="line-97"></a>
<a name="line-98"></a><a name="getXPathWithNsEnv"></a><span class='definition'>getXPathWithNsEnv</span> <span class='keyglyph'>::</span> <span class='conid'>Attributes</span> <span class='keyglyph'>-></span> <span class='conid'>String</span> <span class='keyglyph'>-></span> <span class='conid'>XmlTree</span> <span class='keyglyph'>-></span> <span class='conid'>XmlTrees</span>
<a name="line-99"></a><span class='definition'>getXPathWithNsEnv</span> <span class='varid'>env</span> <span class='varid'>s</span> <span class='keyglyph'>=</span> <span class='varid'>runLA</span> <span class='layout'>(</span> <span class='varid'>canonicalizeForXPath</span>
<a name="line-100"></a> <span class='varop'>>>></span>
<a name="line-101"></a> <span class='varid'>arrL</span> <span class='layout'>(</span><span class='varid'>getXPathValues</span> <span class='varid'>xPValue2XmlTrees</span> <span class='varid'>xPathErr</span> <span class='layout'>(</span><span class='varid'>toNsEnv</span> <span class='varid'>env</span><span class='layout'>)</span> <span class='varid'>s</span><span class='layout'>)</span>
<a name="line-102"></a> <span class='layout'>)</span>
<a name="line-103"></a>
<a name="line-104"></a><span class='comment'>-- |</span>
<a name="line-105"></a><span class='comment'>-- Select parts of an XML tree by a XPath expression.</span>
<a name="line-106"></a><span class='comment'>--</span>
<a name="line-107"></a><span class='comment'>-- The main filter for selecting parts of an arbitrary XML tree via XPath.</span>
<a name="line-108"></a><span class='comment'>-- The string argument must be a XPath expression with an absolute location path,</span>
<a name="line-109"></a><span class='comment'>-- There are no restrictions on the arument tree.</span>
<a name="line-110"></a><span class='comment'>--</span>
<a name="line-111"></a><span class='comment'>-- No canonicalization is performed before evaluating the query</span>
<a name="line-112"></a><span class='comment'>--</span>
<a name="line-113"></a><span class='comment'>-- Result is a possibly empty list of XmlTrees forming the set of selected XPath values.</span>
<a name="line-114"></a><span class='comment'>-- XPath values other than XmlTrees (numbers, attributes, tagnames, ...)</span>
<a name="line-115"></a><span class='comment'>-- are convertet to text nodes.</span>
<a name="line-116"></a>
<a name="line-117"></a><a name="getXPathSubTrees"></a><span class='definition'>getXPathSubTrees</span> <span class='keyglyph'>::</span> <span class='conid'>String</span> <span class='keyglyph'>-></span> <span class='conid'>XmlTree</span> <span class='keyglyph'>-></span> <span class='conid'>XmlTrees</span>
<a name="line-118"></a><span class='definition'>getXPathSubTrees</span> <span class='keyglyph'>=</span> <span class='varid'>getXPathSubTreesWithNsEnv</span> <span class='conid'>[]</span>
<a name="line-119"></a>
<a name="line-120"></a><span class='comment'>-- | Same as 'getXPathSubTrees' but with namespace aware XPath expression</span>
<a name="line-121"></a>
<a name="line-122"></a><a name="getXPathSubTreesWithNsEnv"></a><span class='definition'>getXPathSubTreesWithNsEnv</span> <span class='keyglyph'>::</span> <span class='conid'>Attributes</span> <span class='keyglyph'>-></span> <span class='conid'>String</span> <span class='keyglyph'>-></span> <span class='conid'>XmlTree</span> <span class='keyglyph'>-></span> <span class='conid'>XmlTrees</span>
<a name="line-123"></a><span class='definition'>getXPathSubTreesWithNsEnv</span> <span class='varid'>nsEnv</span> <span class='varid'>xpStr</span>
<a name="line-124"></a> <span class='keyglyph'>=</span> <span class='varid'>getXPathValues</span> <span class='varid'>xPValue2XmlTrees</span> <span class='varid'>xPathErr</span> <span class='layout'>(</span><span class='varid'>toNsEnv</span> <span class='varid'>nsEnv</span><span class='layout'>)</span> <span class='varid'>xpStr</span>
<a name="line-125"></a>
<a name="line-126"></a><span class='comment'>-- | compute the node set of an XPath query</span>
<a name="line-127"></a>
<a name="line-128"></a><a name="getXPathNodeSet"></a><span class='definition'>getXPathNodeSet</span> <span class='keyglyph'>::</span> <span class='conid'>String</span> <span class='keyglyph'>-></span> <span class='conid'>XmlTree</span> <span class='keyglyph'>-></span> <span class='conid'>XmlNodeSet</span>
<a name="line-129"></a><span class='definition'>getXPathNodeSet</span> <span class='keyglyph'>=</span> <span class='varid'>getXPathNodeSetWithNsEnv</span> <span class='conid'>[]</span>
<a name="line-130"></a>
<a name="line-131"></a><span class='comment'>-- | compute the node set of a namespace aware XPath query</span>
<a name="line-132"></a>
<a name="line-133"></a><a name="getXPathNodeSetWithNsEnv"></a><span class='definition'>getXPathNodeSetWithNsEnv</span> <span class='keyglyph'>::</span> <span class='conid'>Attributes</span> <span class='keyglyph'>-></span> <span class='conid'>String</span> <span class='keyglyph'>-></span> <span class='conid'>XmlTree</span> <span class='keyglyph'>-></span> <span class='conid'>XmlNodeSet</span>
<a name="line-134"></a><span class='definition'>getXPathNodeSetWithNsEnv</span> <span class='varid'>nsEnv</span> <span class='varid'>xpStr</span>
<a name="line-135"></a> <span class='keyglyph'>=</span> <span class='varid'>getXPathValues</span> <span class='varid'>xPValue2NodeSet</span> <span class='layout'>(</span><span class='varid'>const</span> <span class='layout'>(</span><span class='varid'>const</span> <span class='varid'>emptyNodeSet</span><span class='layout'>)</span><span class='layout'>)</span> <span class='layout'>(</span><span class='varid'>toNsEnv</span> <span class='varid'>nsEnv</span><span class='layout'>)</span> <span class='varid'>xpStr</span>
<a name="line-136"></a>
<a name="line-137"></a><span class='comment'>-- | parse xpath, evaluate xpath expr and prepare results</span>
<a name="line-138"></a>
<a name="line-139"></a><a name="getXPathValues"></a><span class='definition'>getXPathValues</span> <span class='keyglyph'>::</span> <span class='layout'>(</span><span class='conid'>XPathValue</span> <span class='keyglyph'>-></span> <span class='varid'>a</span><span class='layout'>)</span> <span class='keyglyph'>-></span> <span class='layout'>(</span><span class='conid'>String</span> <span class='keyglyph'>-></span> <span class='conid'>String</span> <span class='keyglyph'>-></span> <span class='varid'>a</span><span class='layout'>)</span> <span class='keyglyph'>-></span> <span class='conid'>NsEnv</span> <span class='keyglyph'>-></span> <span class='conid'>String</span> <span class='keyglyph'>-></span> <span class='conid'>XmlTree</span> <span class='keyglyph'>-></span> <span class='varid'>a</span>
<a name="line-140"></a><span class='definition'>getXPathValues</span> <span class='varid'>cvRes</span> <span class='varid'>cvErr</span> <span class='varid'>nsEnv</span> <span class='varid'>xpStr</span> <span class='varid'>t</span>
<a name="line-141"></a> <span class='keyglyph'>=</span> <span class='keyword'>case</span> <span class='layout'>(</span><span class='varid'>runParser</span> <span class='varid'>parseXPath</span> <span class='varid'>nsEnv</span> <span class='str'>""</span> <span class='varid'>xpStr</span><span class='layout'>)</span> <span class='keyword'>of</span>
<a name="line-142"></a> <span class='conid'>Left</span> <span class='varid'>parseError</span>
<a name="line-143"></a> <span class='keyglyph'>-></span> <span class='varid'>cvErr</span> <span class='varid'>xpStr</span> <span class='layout'>(</span><span class='varid'>show</span> <span class='varid'>parseError</span><span class='layout'>)</span>
<a name="line-144"></a> <span class='conid'>Right</span> <span class='varid'>xpExpr</span>
<a name="line-145"></a> <span class='keyglyph'>-></span> <span class='varid'>evalXP</span> <span class='varid'>xpExpr</span>
<a name="line-146"></a> <span class='keyword'>where</span>
<a name="line-147"></a> <span class='varid'>evalXP</span> <span class='varid'>xpe</span>
<a name="line-148"></a> <span class='keyglyph'>=</span> <span class='varid'>cvRes</span> <span class='varid'>xpRes</span>
<a name="line-149"></a> <span class='keyword'>where</span>
<a name="line-150"></a> <span class='varid'>t'</span> <span class='keyglyph'>=</span> <span class='varid'>addRoot</span> <span class='varid'>t</span> <span class='comment'>-- we need a root node for starting xpath eval</span>
<a name="line-151"></a> <span class='varid'>idAttr</span> <span class='keyglyph'>=</span> <span class='layout'>(</span> <span class='layout'>(</span><span class='str'>""</span><span class='layout'>,</span> <span class='str'>"idAttr"</span><span class='layout'>)</span> <span class='comment'>-- id attributes from DTD (if there)</span>
<a name="line-152"></a> <span class='layout'>,</span> <span class='varid'>idAttributesToXPathValue</span> <span class='varop'>.</span> <span class='varid'>getIdAttributes</span> <span class='varop'>$</span> <span class='varid'>t'</span>
<a name="line-153"></a> <span class='layout'>)</span>
<a name="line-154"></a> <span class='varid'>navTD</span> <span class='keyglyph'>=</span> <span class='varid'>ntree</span> <span class='varid'>t'</span>
<a name="line-155"></a> <span class='varid'>xpRes</span> <span class='keyglyph'>=</span> <span class='varid'>evalExpr</span> <span class='layout'>(</span><span class='varid'>idAttr</span><span class='conop'>:</span><span class='layout'>(</span><span class='varid'>getVarTab</span> <span class='varid'>varEnv</span><span class='layout'>)</span><span class='layout'>,</span><span class='conid'>[]</span><span class='layout'>)</span> <span class='layout'>(</span><span class='num'>1</span><span class='layout'>,</span> <span class='num'>1</span><span class='layout'>,</span> <span class='varid'>navTD</span><span class='layout'>)</span> <span class='varid'>xpe</span> <span class='layout'>(</span><span class='conid'>XPVNode</span> <span class='keyglyph'>[</span><span class='varid'>navTD</span><span class='keyglyph'>]</span><span class='layout'>)</span>
<a name="line-156"></a>
<a name="line-157"></a><a name="addRoot"></a><span class='definition'>addRoot</span> <span class='keyglyph'>::</span> <span class='conid'>XmlTree</span> <span class='keyglyph'>-></span> <span class='conid'>XmlTree</span>
<a name="line-158"></a><span class='definition'>addRoot</span> <span class='varid'>t</span>
<a name="line-159"></a> <span class='keyglyph'>|</span> <span class='conid'>XN</span><span class='varop'>.</span><span class='varid'>isRoot</span> <span class='varid'>t</span>
<a name="line-160"></a> <span class='keyglyph'>=</span> <span class='varid'>t</span>
<a name="line-161"></a> <span class='keyglyph'>|</span> <span class='varid'>otherwise</span>
<a name="line-162"></a> <span class='keyglyph'>=</span> <span class='conid'>XN</span><span class='varop'>.</span><span class='varid'>mkRoot</span> <span class='conid'>[]</span> <span class='keyglyph'>[</span><span class='varid'>t</span><span class='keyglyph'>]</span>
<a name="line-163"></a>
<a name="line-164"></a><a name="xPathErr"></a><span class='definition'>xPathErr</span> <span class='keyglyph'>::</span> <span class='conid'>String</span> <span class='keyglyph'>-></span> <span class='conid'>String</span> <span class='keyglyph'>-></span> <span class='keyglyph'>[</span><span class='conid'>XmlTree</span><span class='keyglyph'>]</span>
<a name="line-165"></a><span class='definition'>xPathErr</span> <span class='varid'>xpStr</span> <span class='varid'>parseError</span>
<a name="line-166"></a> <span class='keyglyph'>=</span> <span class='keyglyph'>[</span><span class='conid'>XN</span><span class='varop'>.</span><span class='varid'>mkError</span> <span class='varid'>c_err</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'>xpStr</span> <span class='varop'>++</span> <span class='str'>": "</span> <span class='varop'>++</span> <span class='varid'>show</span> <span class='varid'>parseError</span><span class='layout'>)</span><span class='keyglyph'>]</span>
<a name="line-167"></a>
<a name="line-168"></a><span class='comment'>-- |</span>
<a name="line-169"></a><span class='comment'>-- The main evaluation entry point. </span>
<a name="line-170"></a><span class='comment'>-- Each XPath-'Expr' is mapped to an evaluation function. The 'Env'-parameter contains the set of global variables</span>
<a name="line-171"></a><span class='comment'>-- for the evaluator, the 'Context'-parameter the root of the tree in which the expression is evaluated.</span>
<a name="line-172"></a><span class='comment'>-- </span>
<a name="line-173"></a>
<a name="line-174"></a><a name="evalExpr"></a><span class='definition'>evalExpr</span> <span class='keyglyph'>::</span> <span class='conid'>Env</span> <span class='keyglyph'>-></span> <span class='conid'>Context</span> <span class='keyglyph'>-></span> <span class='conid'>Expr</span> <span class='keyglyph'>-></span> <span class='conid'>XPathFilter</span>
<a name="line-175"></a><span class='definition'>evalExpr</span> <span class='varid'>env</span> <span class='varid'>cont</span> <span class='layout'>(</span><span class='conid'>GenExpr</span> <span class='conid'>Or</span> <span class='varid'>ex</span><span class='layout'>)</span>
<a name="line-176"></a> <span class='keyglyph'>=</span> <span class='varid'>boolEval</span> <span class='varid'>env</span> <span class='varid'>cont</span> <span class='conid'>Or</span> <span class='varid'>ex</span>
<a name="line-177"></a><span class='definition'>evalExpr</span> <span class='varid'>env</span> <span class='varid'>cont</span> <span class='layout'>(</span><span class='conid'>GenExpr</span> <span class='conid'>And</span> <span class='varid'>ex</span><span class='layout'>)</span>
<a name="line-178"></a> <span class='keyglyph'>=</span> <span class='varid'>boolEval</span> <span class='varid'>env</span> <span class='varid'>cont</span> <span class='conid'>And</span> <span class='varid'>ex</span>
<a name="line-179"></a>
<a name="line-180"></a><span class='definition'>evalExpr</span> <span class='varid'>env</span> <span class='varid'>cont</span> <span class='layout'>(</span><span class='conid'>GenExpr</span> <span class='conid'>Eq</span> <span class='varid'>ex</span><span class='layout'>)</span>
<a name="line-181"></a> <span class='keyglyph'>=</span> <span class='varid'>relEqEval</span> <span class='varid'>env</span> <span class='varid'>cont</span> <span class='conid'>Eq</span> <span class='varop'>.</span> <span class='varid'>evalExprL</span> <span class='varid'>env</span> <span class='varid'>cont</span> <span class='varid'>ex</span>
<a name="line-182"></a><span class='definition'>evalExpr</span> <span class='varid'>env</span> <span class='varid'>cont</span> <span class='layout'>(</span><span class='conid'>GenExpr</span> <span class='conid'>NEq</span> <span class='varid'>ex</span><span class='layout'>)</span>
<a name="line-183"></a> <span class='keyglyph'>=</span> <span class='varid'>relEqEval</span> <span class='varid'>env</span> <span class='varid'>cont</span> <span class='conid'>NEq</span> <span class='varop'>.</span> <span class='varid'>evalExprL</span> <span class='varid'>env</span> <span class='varid'>cont</span> <span class='varid'>ex</span>
<a name="line-184"></a><span class='definition'>evalExpr</span> <span class='varid'>env</span> <span class='varid'>cont</span> <span class='layout'>(</span><span class='conid'>GenExpr</span> <span class='conid'>Less</span> <span class='varid'>ex</span><span class='layout'>)</span>
<a name="line-185"></a> <span class='keyglyph'>=</span> <span class='varid'>relEqEval</span> <span class='varid'>env</span> <span class='varid'>cont</span> <span class='conid'>Less</span> <span class='varop'>.</span> <span class='varid'>evalExprL</span> <span class='varid'>env</span> <span class='varid'>cont</span> <span class='varid'>ex</span>
<a name="line-186"></a><span class='definition'>evalExpr</span> <span class='varid'>env</span> <span class='varid'>cont</span> <span class='layout'>(</span><span class='conid'>GenExpr</span> <span class='conid'>LessEq</span> <span class='varid'>ex</span><span class='layout'>)</span>
<a name="line-187"></a> <span class='keyglyph'>=</span> <span class='varid'>relEqEval</span> <span class='varid'>env</span> <span class='varid'>cont</span> <span class='conid'>LessEq</span> <span class='varop'>.</span> <span class='varid'>evalExprL</span> <span class='varid'>env</span> <span class='varid'>cont</span> <span class='varid'>ex</span>
<a name="line-188"></a><span class='definition'>evalExpr</span> <span class='varid'>env</span> <span class='varid'>cont</span> <span class='layout'>(</span><span class='conid'>GenExpr</span> <span class='conid'>Greater</span> <span class='varid'>ex</span><span class='layout'>)</span>
<a name="line-189"></a> <span class='keyglyph'>=</span> <span class='varid'>relEqEval</span> <span class='varid'>env</span> <span class='varid'>cont</span> <span class='conid'>Greater</span> <span class='varop'>.</span> <span class='varid'>evalExprL</span> <span class='varid'>env</span> <span class='varid'>cont</span> <span class='varid'>ex</span>
<a name="line-190"></a><span class='definition'>evalExpr</span> <span class='varid'>env</span> <span class='varid'>cont</span> <span class='layout'>(</span><span class='conid'>GenExpr</span> <span class='conid'>GreaterEq</span> <span class='varid'>ex</span><span class='layout'>)</span>
<a name="line-191"></a> <span class='keyglyph'>=</span> <span class='varid'>relEqEval</span> <span class='varid'>env</span> <span class='varid'>cont</span> <span class='conid'>GreaterEq</span> <span class='varop'>.</span> <span class='varid'>evalExprL</span> <span class='varid'>env</span> <span class='varid'>cont</span> <span class='varid'>ex</span>
<a name="line-192"></a>
<a name="line-193"></a><span class='definition'>evalExpr</span> <span class='varid'>env</span> <span class='varid'>cont</span> <span class='layout'>(</span><span class='conid'>GenExpr</span> <span class='conid'>Plus</span> <span class='varid'>ex</span><span class='layout'>)</span>
<a name="line-194"></a> <span class='keyglyph'>=</span> <span class='varid'>numEval</span> <span class='varid'>xPathAdd</span> <span class='conid'>Plus</span> <span class='varop'>.</span> <span class='varid'>toXValue</span> <span class='varid'>xnumber</span> <span class='varid'>cont</span> <span class='varid'>env</span> <span class='varop'>.</span> <span class='varid'>evalExprL</span> <span class='varid'>env</span> <span class='varid'>cont</span> <span class='varid'>ex</span>
<a name="line-195"></a><span class='definition'>evalExpr</span> <span class='varid'>env</span> <span class='varid'>cont</span> <span class='layout'>(</span><span class='conid'>GenExpr</span> <span class='conid'>Minus</span> <span class='varid'>ex</span><span class='layout'>)</span>
<a name="line-196"></a> <span class='keyglyph'>=</span> <span class='varid'>numEval</span> <span class='varid'>xPathAdd</span> <span class='conid'>Minus</span> <span class='varop'>.</span> <span class='varid'>toXValue</span> <span class='varid'>xnumber</span> <span class='varid'>cont</span> <span class='varid'>env</span> <span class='varop'>.</span> <span class='varid'>evalExprL</span> <span class='varid'>env</span> <span class='varid'>cont</span> <span class='varid'>ex</span>
<a name="line-197"></a><span class='definition'>evalExpr</span> <span class='varid'>env</span> <span class='varid'>cont</span> <span class='layout'>(</span><span class='conid'>GenExpr</span> <span class='conid'>Div</span> <span class='varid'>ex</span><span class='layout'>)</span>
<a name="line-198"></a> <span class='keyglyph'>=</span> <span class='varid'>numEval</span> <span class='varid'>xPathDiv</span> <span class='conid'>Div</span> <span class='varop'>.</span> <span class='varid'>toXValue</span> <span class='varid'>xnumber</span> <span class='varid'>cont</span> <span class='varid'>env</span> <span class='varop'>.</span> <span class='varid'>evalExprL</span> <span class='varid'>env</span> <span class='varid'>cont</span> <span class='varid'>ex</span>
<a name="line-199"></a><span class='definition'>evalExpr</span> <span class='varid'>env</span> <span class='varid'>cont</span> <span class='layout'>(</span><span class='conid'>GenExpr</span> <span class='conid'>Mod</span> <span class='varid'>ex</span><span class='layout'>)</span>
<a name="line-200"></a> <span class='keyglyph'>=</span> <span class='varid'>numEval</span> <span class='varid'>xPathMod</span> <span class='conid'>Mod</span> <span class='varop'>.</span> <span class='varid'>toXValue</span> <span class='varid'>xnumber</span> <span class='varid'>cont</span> <span class='varid'>env</span> <span class='varop'>.</span> <span class='varid'>evalExprL</span> <span class='varid'>env</span> <span class='varid'>cont</span> <span class='varid'>ex</span>
<a name="line-201"></a><span class='definition'>evalExpr</span> <span class='varid'>env</span> <span class='varid'>cont</span> <span class='layout'>(</span><span class='conid'>GenExpr</span> <span class='conid'>Mult</span> <span class='varid'>ex</span><span class='layout'>)</span>
<a name="line-202"></a> <span class='keyglyph'>=</span> <span class='varid'>numEval</span> <span class='varid'>xPathMulti</span> <span class='conid'>Mult</span> <span class='varop'>.</span> <span class='varid'>toXValue</span> <span class='varid'>xnumber</span> <span class='varid'>cont</span> <span class='varid'>env</span> <span class='varop'>.</span> <span class='varid'>evalExprL</span> <span class='varid'>env</span> <span class='varid'>cont</span> <span class='varid'>ex</span>
<a name="line-203"></a>
<a name="line-204"></a><span class='definition'>evalExpr</span> <span class='varid'>env</span> <span class='varid'>cont</span> <span class='layout'>(</span><span class='conid'>GenExpr</span> <span class='conid'>Unary</span> <span class='varid'>ex</span><span class='layout'>)</span>
<a name="line-205"></a> <span class='keyglyph'>=</span> <span class='varid'>xPathUnary</span> <span class='varop'>.</span> <span class='varid'>xnumber</span> <span class='varid'>cont</span> <span class='varid'>env</span> <span class='varop'>.</span> <span class='varid'>evalExprL</span> <span class='varid'>env</span> <span class='varid'>cont</span> <span class='varid'>ex</span>
<a name="line-206"></a>
<a name="line-207"></a><span class='definition'>evalExpr</span> <span class='varid'>env</span> <span class='varid'>cont</span> <span class='layout'>(</span><span class='conid'>GenExpr</span> <span class='conid'>Union</span> <span class='varid'>ex</span><span class='layout'>)</span>
<a name="line-208"></a> <span class='keyglyph'>=</span> <span class='varid'>unionEval</span> <span class='varop'>.</span> <span class='varid'>evalExprL</span> <span class='varid'>env</span> <span class='varid'>cont</span> <span class='varid'>ex</span>
<a name="line-209"></a>
<a name="line-210"></a><span class='definition'>evalExpr</span> <span class='varid'>env</span> <span class='varid'>cont</span> <span class='layout'>(</span><span class='conid'>FctExpr</span> <span class='varid'>name</span> <span class='varid'>args</span><span class='layout'>)</span>
<a name="line-211"></a> <span class='keyglyph'>=</span> <span class='varid'>fctEval</span> <span class='varid'>env</span> <span class='varid'>cont</span> <span class='varid'>name</span> <span class='varid'>args</span>
<a name="line-212"></a>
<a name="line-213"></a><span class='definition'>evalExpr</span> <span class='varid'>env</span> <span class='keyword'>_</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='varid'>lp</span><span class='layout'>)</span><span class='layout'>)</span>
<a name="line-214"></a> <span class='keyglyph'>=</span> <span class='varid'>locPathEval</span> <span class='varid'>env</span> <span class='varid'>lp</span>
<a name="line-215"></a><span class='definition'>evalExpr</span> <span class='varid'>env</span> <span class='varid'>cont</span> <span class='layout'>(</span><span class='conid'>PathExpr</span> <span class='layout'>(</span><span class='conid'>Just</span> <span class='varid'>fe</span><span class='layout'>)</span> <span class='layout'>(</span><span class='conid'>Just</span> <span class='varid'>lp</span><span class='layout'>)</span><span class='layout'>)</span>
<a name="line-216"></a> <span class='keyglyph'>=</span> <span class='varid'>locPathEval</span> <span class='varid'>env</span> <span class='varid'>lp</span> <span class='varop'>.</span> <span class='varid'>evalExpr</span> <span class='varid'>env</span> <span class='varid'>cont</span> <span class='varid'>fe</span>
<a name="line-217"></a>
<a name="line-218"></a><span class='definition'>evalExpr</span> <span class='varid'>env</span> <span class='varid'>cont</span> <span class='layout'>(</span><span class='conid'>FilterExpr</span> <span class='varid'>ex</span><span class='layout'>)</span>
<a name="line-219"></a> <span class='keyglyph'>=</span> <span class='varid'>filterEval</span> <span class='varid'>env</span> <span class='varid'>cont</span> <span class='varid'>ex</span>
<a name="line-220"></a><span class='definition'>evalExpr</span> <span class='varid'>env</span> <span class='keyword'>_</span> <span class='varid'>ex</span>
<a name="line-221"></a> <span class='keyglyph'>=</span> <span class='varid'>evalSpezExpr</span> <span class='varid'>env</span> <span class='varid'>ex</span>
<a name="line-222"></a>
<a name="line-223"></a>
<a name="line-224"></a>
<a name="line-225"></a><a name="evalExprL"></a><span class='definition'>evalExprL</span> <span class='keyglyph'>::</span> <span class='conid'>Env</span> <span class='keyglyph'>-></span> <span class='conid'>Context</span> <span class='keyglyph'>-></span> <span class='keyglyph'>[</span><span class='conid'>Expr</span><span class='keyglyph'>]</span> <span class='keyglyph'>-></span> <span class='conid'>XPathValue</span> <span class='keyglyph'>-></span> <span class='keyglyph'>[</span><span class='conid'>XPathValue</span><span class='keyglyph'>]</span>
<a name="line-226"></a><span class='definition'>evalExprL</span> <span class='varid'>env</span> <span class='varid'>cont</span> <span class='varid'>ex</span> <span class='varid'>ns</span>
<a name="line-227"></a> <span class='keyglyph'>=</span> <span class='varid'>map</span> <span class='layout'>(</span><span class='keyglyph'>\</span><span class='varid'>e</span> <span class='keyglyph'>-></span> <span class='varid'>evalExpr</span> <span class='varid'>env</span> <span class='varid'>cont</span> <span class='varid'>e</span> <span class='varid'>ns</span><span class='layout'>)</span> <span class='varid'>ex</span>
<a name="line-228"></a>
<a name="line-229"></a><a name="evalSpezExpr"></a><span class='definition'>evalSpezExpr</span> <span class='keyglyph'>::</span> <span class='conid'>Env</span> <span class='keyglyph'>-></span> <span class='conid'>Expr</span> <span class='keyglyph'>-></span> <span class='conid'>XPathFilter</span>
<a name="line-230"></a><span class='definition'>evalSpezExpr</span> <span class='keyword'>_</span> <span class='layout'>(</span><span class='conid'>NumberExpr</span> <span class='layout'>(</span><span class='conid'>Float</span> <span class='num'>0</span><span class='layout'>)</span><span class='layout'>)</span> <span class='keyword'>_</span>
<a name="line-231"></a> <span class='keyglyph'>=</span> <span class='conid'>XPVNumber</span> <span class='conid'>Pos0</span>
<a name="line-232"></a><span class='definition'>evalSpezExpr</span> <span class='keyword'>_</span> <span class='layout'>(</span><span class='conid'>NumberExpr</span> <span class='layout'>(</span><span class='conid'>Float</span> <span class='varid'>f</span><span class='layout'>)</span><span class='layout'>)</span> <span class='keyword'>_</span>
<a name="line-233"></a> <span class='keyglyph'>=</span> <span class='conid'>XPVNumber</span> <span class='layout'>(</span><span class='conid'>Float</span> <span class='varid'>f</span><span class='layout'>)</span>
<a name="line-234"></a><span class='definition'>evalSpezExpr</span> <span class='keyword'>_</span> <span class='layout'>(</span><span class='conid'>LiteralExpr</span> <span class='varid'>s</span><span class='layout'>)</span> <span class='keyword'>_</span>
<a name="line-235"></a> <span class='keyglyph'>=</span> <span class='conid'>XPVString</span> <span class='varid'>s</span>
<a name="line-236"></a><span class='definition'>evalSpezExpr</span> <span class='varid'>env</span> <span class='layout'>(</span><span class='conid'>VarExpr</span> <span class='varid'>name</span><span class='layout'>)</span> <span class='varid'>v</span>
<a name="line-237"></a> <span class='keyglyph'>=</span> <span class='varid'>getVariable</span> <span class='varid'>env</span> <span class='varid'>name</span> <span class='varid'>v</span>
<a name="line-238"></a><span class='definition'>evalSpezExpr</span> <span class='keyword'>_</span> <span class='keyword'>_</span> <span class='keyword'>_</span>
<a name="line-239"></a> <span class='keyglyph'>=</span> <span class='conid'>XPVError</span> <span class='str'>"Call to evalExpr with a wrong argument"</span>
<a name="line-240"></a>
<a name="line-241"></a>
<a name="line-242"></a><span class='comment'>-- -----------------------------------------------------------------------------</span>
<a name="line-243"></a>
<a name="line-244"></a><a name="filterEval"></a><span class='comment'>-- |</span>
<a name="line-245"></a><span class='comment'>-- filter for evaluating a filter-expression</span>
<a name="line-246"></a><span class='definition'>filterEval</span> <span class='keyglyph'>::</span> <span class='conid'>Env</span> <span class='keyglyph'>-></span> <span class='conid'>Context</span> <span class='keyglyph'>-></span> <span class='keyglyph'>[</span><span class='conid'>Expr</span><span class='keyglyph'>]</span> <span class='keyglyph'>-></span> <span class='conid'>XPathFilter</span>
<a name="line-247"></a><span class='definition'>filterEval</span> <span class='varid'>env</span> <span class='varid'>cont</span> <span class='layout'>(</span><span class='varid'>prim</span><span class='conop'>:</span><span class='varid'>predicates</span><span class='layout'>)</span> <span class='varid'>ns</span>
<a name="line-248"></a> <span class='keyglyph'>=</span> <span class='keyword'>case</span> <span class='varid'>evalExpr</span> <span class='varid'>env</span> <span class='varid'>cont</span> <span class='varid'>prim</span> <span class='varid'>ns</span> <span class='keyword'>of</span>
<a name="line-249"></a> <span class='varid'>new_ns</span><span class='keyglyph'>@</span><span class='layout'>(</span><span class='conid'>XPVNode</span> <span class='keyword'>_</span><span class='layout'>)</span> <span class='keyglyph'>-></span> <span class='varid'>evalPredL</span> <span class='varid'>env</span> <span class='varid'>predicates</span> <span class='varid'>new_ns</span>
<a name="line-250"></a> <span class='keyword'>_</span> <span class='keyglyph'>-></span> <span class='conid'>XPVError</span> <span class='str'>"Return of a filterexpression is not a nodeset"</span>
<a name="line-251"></a><span class='definition'>filterEval</span> <span class='keyword'>_</span> <span class='keyword'>_</span> <span class='keyword'>_</span> <span class='keyword'>_</span>
<a name="line-252"></a> <span class='keyglyph'>=</span> <span class='conid'>XPVError</span> <span class='str'>"Call to filterEval without an expression"</span>
<a name="line-253"></a>
<a name="line-254"></a>
<a name="line-255"></a>
<a name="line-256"></a><a name="unionEval"></a><span class='comment'>-- |</span>
<a name="line-257"></a><span class='comment'>-- returns the union of its arguments, the arguments have to be node-sets.</span>
<a name="line-258"></a><span class='definition'>unionEval</span> <span class='keyglyph'>::</span> <span class='keyglyph'>[</span><span class='conid'>XPathValue</span><span class='keyglyph'>]</span> <span class='keyglyph'>-></span> <span class='conid'>XPathValue</span>
<a name="line-259"></a><span class='definition'>unionEval</span>
<a name="line-260"></a> <span class='keyglyph'>=</span> <span class='varid'>createDocumentOrder</span> <span class='varop'>.</span> <span class='varid'>remDups</span> <span class='varop'>.</span> <span class='varid'>unionEval'</span>
<a name="line-261"></a> <span class='keyword'>where</span>
<a name="line-262"></a> <span class='varid'>unionEval'</span> <span class='layout'>(</span><span class='varid'>e</span><span class='keyglyph'>@</span><span class='layout'>(</span><span class='conid'>XPVError</span> <span class='keyword'>_</span><span class='layout'>)</span><span class='conop'>:</span><span class='keyword'>_</span><span class='layout'>)</span> <span class='keyglyph'>=</span> <span class='varid'>e</span>
<a name="line-263"></a> <span class='varid'>unionEval'</span> <span class='layout'>(</span><span class='keyword'>_</span><span class='conop'>:</span><span class='varid'>e</span><span class='keyglyph'>@</span><span class='layout'>(</span><span class='conid'>XPVError</span> <span class='keyword'>_</span><span class='layout'>)</span><span class='conop'>:</span><span class='keyword'>_</span><span class='layout'>)</span> <span class='keyglyph'>=</span> <span class='varid'>e</span>
<a name="line-264"></a> <span class='varid'>unionEval'</span> <span class='keyglyph'>[</span><span class='varid'>n</span><span class='keyglyph'>@</span><span class='layout'>(</span><span class='conid'>XPVNode</span> <span class='keyword'>_</span><span class='layout'>)</span><span class='keyglyph'>]</span> <span class='keyglyph'>=</span> <span class='varid'>n</span>
<a name="line-265"></a> <span class='varid'>unionEval'</span> <span class='layout'>(</span><span class='layout'>(</span><span class='conid'>XPVNode</span> <span class='varid'>n</span><span class='layout'>)</span><span class='conop'>:</span><span class='layout'>(</span><span class='conid'>XPVNode</span> <span class='varid'>m</span><span class='layout'>)</span><span class='conop'>:</span><span class='varid'>xs</span><span class='layout'>)</span> <span class='keyglyph'>=</span> <span class='varid'>unionEval</span> <span class='layout'>(</span> <span class='layout'>(</span><span class='conid'>XPVNode</span> <span class='layout'>(</span><span class='varid'>n</span> <span class='varop'>++</span> <span class='varid'>m</span><span class='layout'>)</span><span class='layout'>)</span><span class='conop'>:</span><span class='varid'>xs</span><span class='layout'>)</span>
<a name="line-266"></a> <span class='varid'>unionEval'</span> <span class='keyword'>_</span> <span class='keyglyph'>=</span> <span class='conid'>XPVError</span> <span class='str'>"The value of a union ( | ) is not a nodeset"</span>
<a name="line-267"></a>
<a name="line-268"></a>
<a name="line-269"></a>
<a name="line-270"></a><a name="relEqEval"></a><span class='comment'>-- |</span>
<a name="line-271"></a><span class='comment'>-- Equality or relational test for node-sets, numbers, boolean values or strings,</span>
<a name="line-272"></a><span class='comment'>-- each computation of two operands is done by relEqEv'</span>
<a name="line-273"></a><span class='definition'>relEqEval</span> <span class='keyglyph'>::</span> <span class='conid'>Env</span> <span class='keyglyph'>-></span> <span class='conid'>Context</span> <span class='keyglyph'>-></span> <span class='conid'>Op</span> <span class='keyglyph'>-></span> <span class='keyglyph'>[</span><span class='conid'>XPathValue</span><span class='keyglyph'>]</span> <span class='keyglyph'>-></span> <span class='conid'>XPathValue</span>
<a name="line-274"></a><span class='definition'>relEqEval</span> <span class='varid'>env</span> <span class='varid'>cont</span> <span class='varid'>op</span>
<a name="line-275"></a> <span class='keyglyph'>=</span> <span class='varid'>foldl1</span> <span class='layout'>(</span><span class='varid'>relEqEv'</span> <span class='varid'>env</span> <span class='varid'>cont</span> <span class='varid'>op</span><span class='layout'>)</span>
<a name="line-276"></a>
<a name="line-277"></a>
<a name="line-278"></a>
<a name="line-279"></a><a name="relEqEv'"></a><span class='definition'>relEqEv'</span> <span class='keyglyph'>::</span> <span class='conid'>Env</span> <span class='keyglyph'>-></span> <span class='conid'>Context</span> <span class='keyglyph'>-></span> <span class='conid'>Op</span> <span class='keyglyph'>-></span> <span class='conid'>XPathValue</span> <span class='keyglyph'>-></span> <span class='conid'>XPathFilter</span>
<a name="line-280"></a><span class='definition'>relEqEv'</span> <span class='keyword'>_</span> <span class='keyword'>_</span> <span class='keyword'>_</span> <span class='varid'>e</span><span class='keyglyph'>@</span><span class='layout'>(</span><span class='conid'>XPVError</span> <span class='keyword'>_</span><span class='layout'>)</span> <span class='keyword'>_</span> <span class='keyglyph'>=</span> <span class='varid'>e</span>
<a name="line-281"></a><span class='definition'>relEqEv'</span> <span class='keyword'>_</span> <span class='keyword'>_</span> <span class='keyword'>_</span> <span class='keyword'>_</span> <span class='varid'>e</span><span class='keyglyph'>@</span><span class='layout'>(</span><span class='conid'>XPVError</span> <span class='keyword'>_</span><span class='layout'>)</span> <span class='keyglyph'>=</span> <span class='varid'>e</span>
<a name="line-282"></a>
<a name="line-283"></a><span class='comment'>-- two node-sets</span>
<a name="line-284"></a><span class='definition'>relEqEv'</span> <span class='varid'>env</span> <span class='varid'>cont</span> <span class='varid'>op</span> <span class='varid'>a</span><span class='keyglyph'>@</span><span class='layout'>(</span><span class='conid'>XPVNode</span> <span class='keyword'>_</span><span class='layout'>)</span> <span class='varid'>b</span><span class='keyglyph'>@</span><span class='layout'>(</span><span class='conid'>XPVNode</span> <span class='keyword'>_</span><span class='layout'>)</span>
<a name="line-285"></a> <span class='keyglyph'>=</span> <span class='varid'>relEqTwoNodes</span> <span class='varid'>env</span> <span class='varid'>cont</span> <span class='varid'>op</span> <span class='varid'>a</span> <span class='varid'>b</span>
<a name="line-286"></a>
<a name="line-287"></a><span class='comment'>-- one node-set</span>
<a name="line-288"></a><span class='definition'>relEqEv'</span> <span class='varid'>env</span> <span class='varid'>cont</span> <span class='varid'>op</span> <span class='varid'>a</span> <span class='varid'>b</span><span class='keyglyph'>@</span><span class='layout'>(</span><span class='conid'>XPVNode</span> <span class='keyword'>_</span><span class='layout'>)</span>
<a name="line-289"></a> <span class='keyglyph'>=</span> <span class='varid'>relEqOneNode</span> <span class='varid'>env</span> <span class='varid'>cont</span> <span class='layout'>(</span><span class='varid'>fromJust</span> <span class='varop'>$</span> <span class='varid'>getOpFct</span> <span class='varid'>op</span><span class='layout'>)</span> <span class='varid'>a</span> <span class='varid'>b</span>
<a name="line-290"></a><span class='definition'>relEqEv'</span> <span class='varid'>env</span> <span class='varid'>cont</span> <span class='varid'>op</span> <span class='varid'>a</span><span class='keyglyph'>@</span><span class='layout'>(</span><span class='conid'>XPVNode</span> <span class='keyword'>_</span><span class='layout'>)</span> <span class='varid'>b</span>
<a name="line-291"></a> <span class='keyglyph'>=</span> <span class='varid'>relEqOneNode</span> <span class='varid'>env</span> <span class='varid'>cont</span> <span class='layout'>(</span><span class='varid'>flip</span> <span class='varop'>$</span> <span class='varid'>fromJust</span> <span class='varop'>$</span> <span class='varid'>getOpFct</span> <span class='varid'>op</span><span class='layout'>)</span> <span class='varid'>b</span> <span class='varid'>a</span>
<a name="line-292"></a>
<a name="line-293"></a>
<a name="line-294"></a><span class='comment'>-- test without a node-set and equality or not-equality operator</span>
<a name="line-295"></a><span class='definition'>relEqEv'</span> <span class='varid'>env</span> <span class='varid'>cont</span> <span class='conid'>Eq</span> <span class='varid'>a</span> <span class='varid'>b</span> <span class='keyglyph'>=</span> <span class='varid'>eqEv</span> <span class='varid'>env</span> <span class='varid'>cont</span> <span class='layout'>(</span><span class='varop'>==</span><span class='layout'>)</span> <span class='varid'>a</span> <span class='varid'>b</span>
<a name="line-296"></a><span class='definition'>relEqEv'</span> <span class='varid'>env</span> <span class='varid'>cont</span> <span class='conid'>NEq</span> <span class='varid'>a</span> <span class='varid'>b</span> <span class='keyglyph'>=</span> <span class='varid'>eqEv</span> <span class='varid'>env</span> <span class='varid'>cont</span> <span class='layout'>(</span><span class='varop'>/=</span><span class='layout'>)</span> <span class='varid'>a</span> <span class='varid'>b</span>
<a name="line-297"></a>
<a name="line-298"></a><span class='comment'>-- test without a node-set and less, less-equal, greater or greater-equal operator</span>
<a name="line-299"></a><span class='definition'>relEqEv'</span> <span class='varid'>env</span> <span class='varid'>cont</span> <span class='varid'>op</span> <span class='varid'>a</span> <span class='varid'>b</span>
<a name="line-300"></a> <span class='keyglyph'>=</span> <span class='conid'>XPVBool</span> <span class='layout'>(</span><span class='layout'>(</span><span class='varid'>fromJust</span> <span class='varop'>$</span> <span class='varid'>getOpFct</span> <span class='varid'>op</span><span class='layout'>)</span> <span class='layout'>(</span><span class='varid'>toXNumber</span> <span class='varid'>a</span><span class='layout'>)</span> <span class='layout'>(</span><span class='varid'>toXNumber</span> <span class='varid'>b</span><span class='layout'>)</span><span class='layout'>)</span>
<a name="line-301"></a> <span class='keyword'>where</span>
<a name="line-302"></a> <span class='varid'>toXNumber</span> <span class='varid'>x</span> <span class='keyglyph'>=</span> <span class='varid'>xnumber</span> <span class='varid'>cont</span> <span class='varid'>env</span> <span class='keyglyph'>[</span><span class='varid'>x</span><span class='keyglyph'>]</span>
<a name="line-303"></a>
<a name="line-304"></a>
<a name="line-305"></a>
<a name="line-306"></a><a name="relEqTwoNodes"></a><span class='comment'>-- |</span>
<a name="line-307"></a><span class='comment'>-- Equality or relational test for two node-sets.</span>
<a name="line-308"></a><span class='comment'>-- The comparison will be true if and only if there is a node in the first node-set</span>
<a name="line-309"></a><span class='comment'>-- and a node in the second node-set such that the result of performing the</span>
<a name="line-310"></a><span class='comment'>-- comparison on the string-values of the two nodes is true</span>
<a name="line-311"></a><span class='definition'>relEqTwoNodes</span> <span class='keyglyph'>::</span> <span class='conid'>Env</span> <span class='keyglyph'>-></span> <span class='conid'>Context</span> <span class='keyglyph'>-></span> <span class='conid'>Op</span> <span class='keyglyph'>-></span> <span class='conid'>XPathValue</span> <span class='keyglyph'>-></span> <span class='conid'>XPathFilter</span>
<a name="line-312"></a><span class='definition'>relEqTwoNodes</span> <span class='keyword'>_</span> <span class='keyword'>_</span> <span class='varid'>op</span> <span class='layout'>(</span><span class='conid'>XPVNode</span> <span class='varid'>ns</span><span class='layout'>)</span> <span class='layout'>(</span><span class='conid'>XPVNode</span> <span class='varid'>ms</span><span class='layout'>)</span>
<a name="line-313"></a> <span class='keyglyph'>=</span> <span class='conid'>XPVBool</span> <span class='layout'>(</span><span class='varid'>foldr</span> <span class='layout'>(</span><span class='keyglyph'>\</span><span class='varid'>n</span> <span class='keyglyph'>-></span> <span class='layout'>(</span><span class='varid'>any</span> <span class='layout'>(</span><span class='varid'>fct</span> <span class='varid'>op</span> <span class='varid'>n</span><span class='layout'>)</span> <span class='layout'>(</span><span class='varid'>getStrValues</span> <span class='varid'>ms</span><span class='layout'>)</span> <span class='varop'>||</span><span class='layout'>)</span><span class='layout'>)</span> <span class='conid'>False</span> <span class='varid'>ns</span><span class='layout'>)</span>
<a name="line-314"></a> <span class='keyword'>where</span>
<a name="line-315"></a> <span class='varid'>fct</span> <span class='varid'>op'</span> <span class='varid'>n'</span> <span class='keyglyph'>=</span> <span class='layout'>(</span><span class='varid'>fromJust</span> <span class='varop'>$</span> <span class='varid'>getOpFct</span> <span class='varid'>op'</span><span class='layout'>)</span> <span class='layout'>(</span><span class='varid'>stringValue</span> <span class='varid'>n'</span><span class='layout'>)</span>
<a name="line-316"></a> <span class='varid'>getStrValues</span> <span class='keyglyph'>=</span> <span class='varid'>map</span> <span class='varid'>stringValue</span>
<a name="line-317"></a><span class='definition'>relEqTwoNodes</span> <span class='keyword'>_</span> <span class='keyword'>_</span> <span class='keyword'>_</span> <span class='keyword'>_</span> <span class='keyword'>_</span>
<a name="line-318"></a> <span class='keyglyph'>=</span> <span class='conid'>XPVError</span> <span class='str'>"Call to relEqTwoNodes without a nodeset"</span>
<a name="line-319"></a>
<a name="line-320"></a>
<a name="line-321"></a><a name="relEqOneNode"></a><span class='comment'>-- |</span>
<a name="line-322"></a><span class='comment'>-- Comparison between a node-set and different type.</span>
<a name="line-323"></a><span class='comment'>-- The node-set is converted in a boolean value if the second argument is of type boolean.</span>
<a name="line-324"></a><span class='comment'>-- If the argument is of type number, the node-set is converted in a number, otherwise it is converted</span>
<a name="line-325"></a><span class='comment'>-- in a string value.</span>
<a name="line-326"></a><span class='definition'>relEqOneNode</span> <span class='keyglyph'>::</span> <span class='conid'>Env</span> <span class='keyglyph'>-></span> <span class='conid'>Context</span> <span class='keyglyph'>-></span> <span class='layout'>(</span><span class='conid'>XPathValue</span> <span class='keyglyph'>-></span> <span class='conid'>XPathValue</span> <span class='keyglyph'>-></span> <span class='conid'>Bool</span><span class='layout'>)</span> <span class='keyglyph'>-></span> <span class='conid'>XPathValue</span> <span class='keyglyph'>-></span> <span class='conid'>XPathFilter</span>
<a name="line-327"></a><span class='definition'>relEqOneNode</span> <span class='varid'>env</span> <span class='varid'>cont</span> <span class='varid'>fct</span> <span class='varid'>arg</span> <span class='layout'>(</span><span class='conid'>XPVNode</span> <span class='varid'>ns</span><span class='layout'>)</span>
<a name="line-328"></a> <span class='keyglyph'>=</span> <span class='conid'>XPVBool</span> <span class='layout'>(</span><span class='varid'>any</span> <span class='layout'>(</span><span class='varid'>fct</span> <span class='varid'>arg</span><span class='layout'>)</span> <span class='layout'>(</span><span class='varid'>getStrValues</span> <span class='varid'>arg</span> <span class='varid'>ns</span><span class='layout'>)</span><span class='layout'>)</span>
<a name="line-329"></a> <span class='keyword'>where</span>
<a name="line-330"></a> <span class='varid'>getStrValues</span> <span class='varid'>arg'</span> <span class='keyglyph'>=</span> <span class='varid'>map</span> <span class='layout'>(</span><span class='layout'>(</span><span class='varid'>fromJust</span> <span class='varop'>$</span> <span class='varid'>getConvFct</span> <span class='varid'>arg'</span><span class='layout'>)</span> <span class='varid'>cont</span> <span class='varid'>env</span> <span class='varop'>.</span> <span class='varid'>wrap</span><span class='layout'>)</span> <span class='varop'>.</span> <span class='varid'>map</span> <span class='varid'>stringValue</span>
<a name="line-331"></a> <span class='varid'>wrap</span> <span class='varid'>x</span> <span class='keyglyph'>=</span> <span class='keyglyph'>[</span><span class='varid'>x</span><span class='keyglyph'>]</span>
<a name="line-332"></a><span class='definition'>relEqOneNode</span> <span class='keyword'>_</span> <span class='keyword'>_</span> <span class='keyword'>_</span> <span class='keyword'>_</span> <span class='keyword'>_</span>
<a name="line-333"></a> <span class='keyglyph'>=</span> <span class='conid'>XPVError</span> <span class='str'>"Call to relEqOneNode without a nodeset"</span>
<a name="line-334"></a>
<a name="line-335"></a>
<a name="line-336"></a>
<a name="line-337"></a><a name="eqEv"></a><span class='comment'>-- |</span>
<a name="line-338"></a><span class='comment'>-- No node-set is involved and the operator is equality or not-equality.</span>
<a name="line-339"></a><span class='comment'>-- The arguments are converted in a common type. If one argument is a boolean value</span>
<a name="line-340"></a><span class='comment'>-- then it is the boolean type. If a number is involved, the arguments have to converted in numbers,</span>
<a name="line-341"></a><span class='comment'>-- else the string type is the common type.</span>
<a name="line-342"></a><span class='definition'>eqEv</span> <span class='keyglyph'>::</span> <span class='conid'>Env</span> <span class='keyglyph'>-></span> <span class='conid'>Context</span> <span class='keyglyph'>-></span> <span class='layout'>(</span><span class='conid'>XPathValue</span> <span class='keyglyph'>-></span> <span class='conid'>XPathValue</span> <span class='keyglyph'>-></span> <span class='conid'>Bool</span><span class='layout'>)</span> <span class='keyglyph'>-></span> <span class='conid'>XPathValue</span> <span class='keyglyph'>-></span> <span class='conid'>XPathFilter</span>
<a name="line-343"></a><span class='definition'>eqEv</span> <span class='varid'>env</span> <span class='varid'>cont</span> <span class='varid'>fct</span> <span class='varid'>f</span><span class='keyglyph'>@</span><span class='layout'>(</span><span class='conid'>XPVBool</span> <span class='keyword'>_</span><span class='layout'>)</span> <span class='varid'>g</span>
<a name="line-344"></a> <span class='keyglyph'>=</span> <span class='conid'>XPVBool</span> <span class='layout'>(</span><span class='varid'>f</span> <span class='varop'>`fct`</span> <span class='varid'>xboolean</span> <span class='varid'>cont</span> <span class='varid'>env</span> <span class='keyglyph'>[</span><span class='varid'>g</span><span class='keyglyph'>]</span><span class='layout'>)</span>
<a name="line-345"></a><span class='definition'>eqEv</span> <span class='varid'>env</span> <span class='varid'>cont</span> <span class='varid'>fct</span> <span class='varid'>f</span> <span class='varid'>g</span><span class='keyglyph'>@</span><span class='layout'>(</span><span class='conid'>XPVBool</span> <span class='keyword'>_</span><span class='layout'>)</span>
<a name="line-346"></a> <span class='keyglyph'>=</span> <span class='conid'>XPVBool</span> <span class='layout'>(</span><span class='varid'>xboolean</span> <span class='varid'>cont</span> <span class='varid'>env</span> <span class='keyglyph'>[</span><span class='varid'>f</span><span class='keyglyph'>]</span> <span class='varop'>`fct`</span> <span class='varid'>g</span><span class='layout'>)</span>
<a name="line-347"></a>
<a name="line-348"></a><span class='definition'>eqEv</span> <span class='varid'>env</span> <span class='varid'>cont</span> <span class='varid'>fct</span> <span class='varid'>f</span><span class='keyglyph'>@</span><span class='layout'>(</span><span class='conid'>XPVNumber</span> <span class='keyword'>_</span><span class='layout'>)</span> <span class='varid'>g</span>
<a name="line-349"></a> <span class='keyglyph'>=</span> <span class='conid'>XPVBool</span> <span class='layout'>(</span><span class='varid'>f</span> <span class='varop'>`fct`</span> <span class='varid'>xnumber</span> <span class='varid'>cont</span> <span class='varid'>env</span> <span class='keyglyph'>[</span><span class='varid'>g</span><span class='keyglyph'>]</span><span class='layout'>)</span>
<a name="line-350"></a><span class='definition'>eqEv</span> <span class='varid'>env</span> <span class='varid'>cont</span> <span class='varid'>fct</span> <span class='varid'>f</span> <span class='varid'>g</span><span class='keyglyph'>@</span><span class='layout'>(</span><span class='conid'>XPVNumber</span> <span class='keyword'>_</span><span class='layout'>)</span>
<a name="line-351"></a> <span class='keyglyph'>=</span> <span class='conid'>XPVBool</span> <span class='layout'>(</span><span class='varid'>xnumber</span> <span class='varid'>cont</span> <span class='varid'>env</span> <span class='keyglyph'>[</span><span class='varid'>f</span><span class='keyglyph'>]</span> <span class='varop'>`fct`</span> <span class='varid'>g</span><span class='layout'>)</span>
<a name="line-352"></a>
<a name="line-353"></a><span class='definition'>eqEv</span> <span class='varid'>env</span> <span class='varid'>cont</span> <span class='varid'>fct</span> <span class='varid'>f</span> <span class='varid'>g</span>
<a name="line-354"></a> <span class='keyglyph'>=</span> <span class='conid'>XPVBool</span> <span class='layout'>(</span><span class='varid'>xstring</span> <span class='varid'>cont</span> <span class='varid'>env</span> <span class='keyglyph'>[</span><span class='varid'>f</span><span class='keyglyph'>]</span> <span class='varop'>`fct`</span> <span class='varid'>xstring</span> <span class='varid'>cont</span> <span class='varid'>env</span> <span class='keyglyph'>[</span><span class='varid'>g</span><span class='keyglyph'>]</span><span class='layout'>)</span>
<a name="line-355"></a>
<a name="line-356"></a>
<a name="line-357"></a><a name="getOpFct"></a><span class='definition'>getOpFct</span> <span class='keyglyph'>::</span> <span class='conid'>Op</span> <span class='keyglyph'>-></span> <span class='conid'>Maybe</span> <span class='layout'>(</span><span class='conid'>XPathValue</span> <span class='keyglyph'>-></span> <span class='conid'>XPathValue</span> <span class='keyglyph'>-></span> <span class='conid'>Bool</span><span class='layout'>)</span>
<a name="line-358"></a><span class='definition'>getOpFct</span> <span class='conid'>Eq</span> <span class='keyglyph'>=</span> <span class='conid'>Just</span> <span class='layout'>(</span><span class='varop'>==</span><span class='layout'>)</span>
<a name="line-359"></a><span class='definition'>getOpFct</span> <span class='conid'>NEq</span> <span class='keyglyph'>=</span> <span class='conid'>Just</span> <span class='layout'>(</span><span class='varop'>/=</span><span class='layout'>)</span>
<a name="line-360"></a><span class='definition'>getOpFct</span> <span class='conid'>Less</span> <span class='keyglyph'>=</span> <span class='conid'>Just</span> <span class='layout'>(</span><span class='varop'><</span><span class='layout'>)</span>
<a name="line-361"></a><span class='definition'>getOpFct</span> <span class='conid'>LessEq</span> <span class='keyglyph'>=</span> <span class='conid'>Just</span> <span class='layout'>(</span><span class='varop'><=</span><span class='layout'>)</span>
<a name="line-362"></a><span class='definition'>getOpFct</span> <span class='conid'>Greater</span> <span class='keyglyph'>=</span> <span class='conid'>Just</span> <span class='layout'>(</span><span class='varop'>></span><span class='layout'>)</span>
<a name="line-363"></a><span class='definition'>getOpFct</span> <span class='conid'>GreaterEq</span> <span class='keyglyph'>=</span> <span class='conid'>Just</span> <span class='layout'>(</span><span class='varop'>>=</span><span class='layout'>)</span>
<a name="line-364"></a><span class='definition'>getOpFct</span> <span class='keyword'>_</span> <span class='keyglyph'>=</span> <span class='conid'>Nothing</span>
<a name="line-365"></a>
<a name="line-366"></a>
<a name="line-367"></a>
<a name="line-368"></a><a name="getRoot"></a><span class='comment'>-- |</span>
<a name="line-369"></a><span class='comment'>-- Filter for accessing the root element of a document tree</span>
<a name="line-370"></a><span class='definition'>getRoot</span> <span class='keyglyph'>::</span> <span class='conid'>XPathFilter</span>
<a name="line-371"></a><span class='definition'>getRoot</span> <span class='layout'>(</span><span class='conid'>XPVNode</span> <span class='layout'>(</span><span class='varid'>n</span><span class='conop'>:</span><span class='keyword'>_</span><span class='layout'>)</span><span class='layout'>)</span>
<a name="line-372"></a> <span class='keyglyph'>=</span> <span class='conid'>XPVNode</span> <span class='keyglyph'>[</span><span class='varid'>getRoot'</span> <span class='varid'>n</span><span class='keyglyph'>]</span>
<a name="line-373"></a> <span class='keyword'>where</span>
<a name="line-374"></a> <span class='varid'>getRoot'</span> <span class='varid'>tree</span>
<a name="line-375"></a> <span class='keyglyph'>=</span> <span class='keyword'>case</span> <span class='varid'>upNT</span> <span class='varid'>tree</span> <span class='keyword'>of</span>
<a name="line-376"></a> <span class='conid'>Nothing</span> <span class='keyglyph'>-></span> <span class='varid'>tree</span>
<a name="line-377"></a> <span class='conid'>Just</span> <span class='varid'>t</span> <span class='keyglyph'>-></span> <span class='varid'>getRoot'</span> <span class='varid'>t</span>
<a name="line-378"></a><span class='definition'>getRoot</span> <span class='keyword'>_</span>
<a name="line-379"></a> <span class='keyglyph'>=</span> <span class='conid'>XPVError</span> <span class='str'>"Call to getRoot without a nodeset"</span>
<a name="line-380"></a>
<a name="line-381"></a>
<a name="line-382"></a>
<a name="line-383"></a><a name="getAxisNodes"></a><span class='comment'>-- |</span>
<a name="line-384"></a><span class='comment'>-- Filter for accessing all nodes of a XPath-axis</span>
<a name="line-385"></a><span class='comment'>--</span>
<a name="line-386"></a><span class='comment'>-- * 1.parameter as : axis specifier</span>
<a name="line-387"></a><span class='comment'>--</span>
<a name="line-388"></a><span class='definition'>getAxisNodes</span> <span class='keyglyph'>::</span> <span class='conid'>AxisSpec</span> <span class='keyglyph'>-></span> <span class='conid'>XPathFilter</span>
<a name="line-389"></a><span class='definition'>getAxisNodes</span> <span class='keyword'>as</span> <span class='layout'>(</span><span class='conid'>XPVNode</span> <span class='varid'>ns</span><span class='layout'>)</span>
<a name="line-390"></a> <span class='keyglyph'>=</span> <span class='conid'>XPVNode</span> <span class='layout'>(</span><span class='varid'>concat</span> <span class='varop'>$</span> <span class='varid'>map</span> <span class='layout'>(</span><span class='varid'>fromJust</span> <span class='varop'>$</span> <span class='varid'>lookup</span> <span class='keyword'>as</span> <span class='varid'>axisFctL</span><span class='layout'>)</span> <span class='varid'>ns</span><span class='layout'>)</span>
<a name="line-391"></a><span class='definition'>getAxisNodes</span> <span class='keyword'>_</span> <span class='keyword'>_</span>
<a name="line-392"></a> <span class='keyglyph'>=</span> <span class='conid'>XPVError</span> <span class='str'>"Call to getAxis without a nodeset"</span>
<a name="line-393"></a>
<a name="line-394"></a>
<a name="line-395"></a>
<a name="line-396"></a><a name="axisFctL"></a><span class='comment'>-- |</span>
<a name="line-397"></a><span class='comment'>-- Axis-Function-Table.</span>
<a name="line-398"></a><span class='comment'>-- Each XPath axis-specifier is mapped to the corresponding axis-function</span>
<a name="line-399"></a><span class='definition'>axisFctL</span> <span class='keyglyph'>::</span> <span class='keyglyph'>[</span><span class='layout'>(</span><span class='conid'>AxisSpec</span><span class='layout'>,</span> <span class='layout'>(</span><span class='conid'>NavXmlTree</span> <span class='keyglyph'>-></span> <span class='conid'>NavXmlTrees</span><span class='layout'>)</span><span class='layout'>)</span><span class='keyglyph'>]</span>
<a name="line-400"></a><span class='definition'>axisFctL</span> <span class='keyglyph'>=</span> <span class='keyglyph'>[</span> <span class='layout'>(</span><span class='conid'>Ancestor</span><span class='layout'>,</span> <span class='varid'>ancestorAxis</span><span class='layout'>)</span>
<a name="line-401"></a> <span class='layout'>,</span> <span class='layout'>(</span><span class='conid'>AncestorOrSelf</span><span class='layout'>,</span> <span class='varid'>ancestorOrSelfAxis</span><span class='layout'>)</span>
<a name="line-402"></a> <span class='layout'>,</span> <span class='layout'>(</span><span class='conid'>Attribute</span><span class='layout'>,</span> <span class='varid'>attributeAxis</span><span class='layout'>)</span>
<a name="line-403"></a> <span class='layout'>,</span> <span class='layout'>(</span><span class='conid'>Child</span><span class='layout'>,</span> <span class='varid'>childAxis</span><span class='layout'>)</span>
<a name="line-404"></a> <span class='layout'>,</span> <span class='layout'>(</span><span class='conid'>Descendant</span><span class='layout'>,</span> <span class='varid'>descendantAxis</span><span class='layout'>)</span>
<a name="line-405"></a> <span class='layout'>,</span> <span class='layout'>(</span><span class='conid'>DescendantOrSelf</span><span class='layout'>,</span> <span class='varid'>descendantOrSelfAxis</span><span class='layout'>)</span>
<a name="line-406"></a> <span class='layout'>,</span> <span class='layout'>(</span><span class='conid'>Following</span><span class='layout'>,</span> <span class='varid'>followingAxis</span><span class='layout'>)</span>
<a name="line-407"></a> <span class='layout'>,</span> <span class='layout'>(</span><span class='conid'>FollowingSibling</span><span class='layout'>,</span> <span class='varid'>followingSiblingAxis</span><span class='layout'>)</span>
<a name="line-408"></a> <span class='layout'>,</span> <span class='layout'>(</span><span class='conid'>Parent</span><span class='layout'>,</span> <span class='varid'>parentAxis</span><span class='layout'>)</span>
<a name="line-409"></a> <span class='layout'>,</span> <span class='layout'>(</span><span class='conid'>Preceding</span><span class='layout'>,</span> <span class='varid'>precedingAxis</span><span class='layout'>)</span>
<a name="line-410"></a> <span class='layout'>,</span> <span class='layout'>(</span><span class='conid'>PrecedingSibling</span><span class='layout'>,</span> <span class='varid'>precedingSiblingAxis</span><span class='layout'>)</span>
<a name="line-411"></a> <span class='layout'>,</span> <span class='layout'>(</span><span class='conid'>Self</span><span class='layout'>,</span> <span class='varid'>selfAxis</span><span class='layout'>)</span>
<a name="line-412"></a> <span class='keyglyph'>]</span>
<a name="line-413"></a>
<a name="line-414"></a>
<a name="line-415"></a><a name="locPathEval"></a><span class='comment'>-- |</span>
<a name="line-416"></a><span class='comment'>-- evaluates a location path,</span>
<a name="line-417"></a><span class='comment'>-- evaluation of an absolute path starts at the document root, </span>
<a name="line-418"></a><span class='comment'>-- the relative path at the context node</span>
<a name="line-419"></a><span class='definition'>locPathEval</span> <span class='keyglyph'>::</span> <span class='conid'>Env</span> <span class='keyglyph'>-></span> <span class='conid'>LocationPath</span> <span class='keyglyph'>-></span> <span class='conid'>XPathFilter</span>
<a name="line-420"></a><span class='definition'>locPathEval</span> <span class='varid'>env</span> <span class='layout'>(</span><span class='conid'>LocPath</span> <span class='conid'>Rel</span> <span class='varid'>steps</span><span class='layout'>)</span>
<a name="line-421"></a> <span class='keyglyph'>=</span> <span class='varid'>evalSteps</span> <span class='varid'>env</span> <span class='varid'>steps</span>
<a name="line-422"></a><span class='definition'>locPathEval</span> <span class='varid'>env</span> <span class='layout'>(</span><span class='conid'>LocPath</span> <span class='conid'>Abs</span> <span class='varid'>steps</span><span class='layout'>)</span>
<a name="line-423"></a> <span class='keyglyph'>=</span> <span class='varid'>evalSteps</span> <span class='varid'>env</span> <span class='varid'>steps</span> <span class='varop'>.</span> <span class='varid'>getRoot</span>
<a name="line-424"></a>
<a name="line-425"></a>
<a name="line-426"></a>
<a name="line-427"></a>
<a name="line-428"></a><a name="evalSteps"></a><span class='definition'>evalSteps</span> <span class='keyglyph'>::</span> <span class='conid'>Env</span> <span class='keyglyph'>-></span> <span class='keyglyph'>[</span><span class='conid'>XStep</span><span class='keyglyph'>]</span> <span class='keyglyph'>-></span> <span class='conid'>XPathFilter</span>
<a name="line-429"></a><span class='definition'>evalSteps</span> <span class='varid'>env</span> <span class='varid'>steps</span> <span class='varid'>ns</span>
<a name="line-430"></a> <span class='keyglyph'>=</span> <span class='varid'>foldl</span> <span class='layout'>(</span><span class='varid'>evalStep</span> <span class='varid'>env</span><span class='layout'>)</span> <span class='varid'>ns</span> <span class='varid'>steps</span>
<a name="line-431"></a>
<a name="line-432"></a>
<a name="line-433"></a><a name="evalStep"></a><span class='comment'>-- |</span>
<a name="line-434"></a><span class='comment'>-- evaluate a single XPath step</span>
<a name="line-435"></a><span class='comment'>-- namespace-axis is not supported</span>
<a name="line-436"></a><span class='definition'>evalStep</span> <span class='keyglyph'>::</span> <span class='conid'>Env</span> <span class='keyglyph'>-></span> <span class='conid'>XPathValue</span> <span class='keyglyph'>-></span> <span class='conid'>XStep</span> <span class='keyglyph'>-></span> <span class='conid'>XPathValue</span>
<a name="line-437"></a><span class='definition'>evalStep</span> <span class='keyword'>_</span> <span class='keyword'>_</span> <span class='layout'>(</span><span class='conid'>Step</span> <span class='conid'>Namespace</span> <span class='keyword'>_</span> <span class='keyword'>_</span><span class='layout'>)</span> <span class='keyglyph'>=</span> <span class='conid'>XPVError</span> <span class='str'>"namespace-axis not supported"</span>
<a name="line-438"></a><span class='definition'>evalStep</span> <span class='keyword'>_</span> <span class='varid'>ns</span> <span class='layout'>(</span><span class='conid'>Step</span> <span class='conid'>Attribute</span> <span class='varid'>nt</span> <span class='keyword'>_</span><span class='layout'>)</span> <span class='keyglyph'>=</span> <span class='varid'>evalAttr</span> <span class='varid'>nt</span> <span class='layout'>(</span><span class='varid'>getAxisNodes</span> <span class='conid'>Attribute</span> <span class='varid'>ns</span><span class='layout'>)</span>
<a name="line-439"></a><span class='definition'>evalStep</span> <span class='varid'>env</span> <span class='varid'>ns</span> <span class='layout'>(</span><span class='conid'>Step</span> <span class='varid'>axisSpec</span> <span class='varid'>nt</span> <span class='varid'>pr</span><span class='layout'>)</span> <span class='keyglyph'>=</span> <span class='varid'>evalStep'</span> <span class='varid'>env</span> <span class='varid'>pr</span> <span class='varid'>nt</span> <span class='layout'>(</span><span class='varid'>getAxisNodes</span> <span class='varid'>axisSpec</span> <span class='varid'>ns</span><span class='layout'>)</span>
<a name="line-440"></a>
<a name="line-441"></a>
<a name="line-442"></a>
<a name="line-443"></a><a name="evalAttr"></a><span class='definition'>evalAttr</span> <span class='keyglyph'>::</span> <span class='conid'>NodeTest</span> <span class='keyglyph'>-></span> <span class='conid'>XPathFilter</span>
<a name="line-444"></a><span class='definition'>evalAttr</span> <span class='varid'>nt</span> <span class='layout'>(</span><span class='conid'>XPVNode</span> <span class='varid'>ns</span><span class='layout'>)</span>
<a name="line-445"></a> <span class='keyglyph'>=</span> <span class='conid'>XPVNode</span> <span class='layout'>(</span><span class='varid'>foldr</span> <span class='layout'>(</span><span class='keyglyph'>\</span><span class='varid'>n</span> <span class='keyglyph'>-></span> <span class='layout'>(</span><span class='varid'>evalAttrNodeTest</span> <span class='varid'>nt</span> <span class='varid'>n</span> <span class='varop'>++</span><span class='layout'>)</span><span class='layout'>)</span> <span class='conid'>[]</span> <span class='varid'>ns</span><span class='layout'>)</span>
<a name="line-446"></a><span class='definition'>evalAttr</span> <span class='keyword'>_</span> <span class='keyword'>_</span>
<a name="line-447"></a> <span class='keyglyph'>=</span> <span class='conid'>XPVError</span> <span class='str'>"Call to evalAttr without a nodeset"</span>
<a name="line-448"></a>
<a name="line-449"></a>
<a name="line-450"></a><a name="evalAttrNodeTest"></a><span class='definition'>evalAttrNodeTest</span> <span class='keyglyph'>::</span> <span class='conid'>NodeTest</span> <span class='keyglyph'>-></span> <span class='conid'>NavXmlTree</span> <span class='keyglyph'>-></span> <span class='conid'>NavXmlTrees</span>
<a name="line-451"></a><span class='definition'>evalAttrNodeTest</span> <span class='layout'>(</span><span class='conid'>NameTest</span> <span class='varid'>qn</span><span class='layout'>)</span> <span class='varid'>ns</span><span class='keyglyph'>@</span><span class='layout'>(</span><span class='conid'>NT</span> <span class='layout'>(</span><span class='conid'>NTree</span> <span class='layout'>(</span><span class='conid'>XAttr</span> <span class='varid'>qn1</span><span class='layout'>)</span> <span class='keyword'>_</span><span class='layout'>)</span> <span class='keyword'>_</span> <span class='keyword'>_</span> <span class='keyword'>_</span><span class='layout'>)</span>
<a name="line-452"></a> <span class='keyglyph'>=</span> <span class='keyword'>if</span> <span class='layout'>(</span> <span class='layout'>(</span> <span class='varid'>uri</span> <span class='varop'>==</span> <span class='varid'>uri1</span> <span class='varop'>&&</span> <span class='varid'>lp</span> <span class='varop'>==</span> <span class='varid'>lp1</span><span class='layout'>)</span>
<a name="line-453"></a> <span class='varop'>||</span>
<a name="line-454"></a> <span class='layout'>(</span><span class='layout'>(</span><span class='varid'>uri</span> <span class='varop'>==</span> <span class='str'>""</span> <span class='varop'>||</span> <span class='varid'>uri</span> <span class='varop'>==</span> <span class='varid'>uri1</span><span class='layout'>)</span> <span class='varop'>&&</span> <span class='varid'>lp</span> <span class='varop'>==</span> <span class='str'>"*"</span><span class='layout'>)</span>
<a name="line-455"></a> <span class='layout'>)</span>
<a name="line-456"></a> <span class='keyword'>then</span> <span class='keyglyph'>[</span><span class='varid'>ns</span><span class='keyglyph'>]</span>
<a name="line-457"></a> <span class='keyword'>else</span> <span class='conid'>[]</span>
<a name="line-458"></a> <span class='keyword'>where</span>
<a name="line-459"></a> <span class='varid'>uri</span> <span class='keyglyph'>=</span> <span class='varid'>namespaceUri</span> <span class='varid'>qn</span>
<a name="line-460"></a> <span class='varid'>uri1</span> <span class='keyglyph'>=</span> <span class='varid'>namespaceUri</span> <span class='varid'>qn1</span>
<a name="line-461"></a> <span class='varid'>lp</span> <span class='keyglyph'>=</span> <span class='varid'>localPart</span> <span class='varid'>qn</span>
<a name="line-462"></a> <span class='varid'>lp1</span> <span class='keyglyph'>=</span> <span class='varid'>localPart</span> <span class='varid'>qn1</span>
<a name="line-463"></a>
<a name="line-464"></a><span class='definition'>evalAttrNodeTest</span> <span class='layout'>(</span><span class='conid'>TypeTest</span> <span class='conid'>XPNode</span><span class='layout'>)</span> <span class='varid'>ns</span><span class='keyglyph'>@</span><span class='layout'>(</span><span class='conid'>NT</span> <span class='layout'>(</span><span class='conid'>NTree</span> <span class='layout'>(</span><span class='conid'>XAttr</span> <span class='keyword'>_</span><span class='layout'>)</span> <span class='keyword'>_</span><span class='layout'>)</span> <span class='keyword'>_</span> <span class='keyword'>_</span> <span class='keyword'>_</span><span class='layout'>)</span>
<a name="line-465"></a> <span class='keyglyph'>=</span> <span class='keyglyph'>[</span><span class='varid'>ns</span><span class='keyglyph'>]</span>
<a name="line-466"></a>
<a name="line-467"></a><span class='definition'>evalAttrNodeTest</span> <span class='keyword'>_</span> <span class='keyword'>_</span>
<a name="line-468"></a> <span class='keyglyph'>=</span> <span class='conid'>[]</span>
<a name="line-469"></a>
<a name="line-470"></a><a name="evalStep'"></a><span class='definition'>evalStep'</span> <span class='keyglyph'>::</span> <span class='conid'>Env</span> <span class='keyglyph'>-></span> <span class='keyglyph'>[</span><span class='conid'>Expr</span><span class='keyglyph'>]</span> <span class='keyglyph'>-></span> <span class='conid'>NodeTest</span> <span class='keyglyph'>-></span> <span class='conid'>XPathFilter</span>
<a name="line-471"></a><span class='definition'>evalStep'</span> <span class='varid'>env</span> <span class='varid'>pr</span> <span class='varid'>nt</span>
<a name="line-472"></a> <span class='keyglyph'>=</span> <span class='varid'>evalPredL</span> <span class='varid'>env</span> <span class='varid'>pr</span> <span class='varop'>.</span> <span class='varid'>nodeTest</span> <span class='varid'>nt</span>
<a name="line-473"></a>
<a name="line-474"></a>
<a name="line-475"></a><a name="evalPredL"></a><span class='definition'>evalPredL</span> <span class='keyglyph'>::</span> <span class='conid'>Env</span> <span class='keyglyph'>-></span> <span class='keyglyph'>[</span><span class='conid'>Expr</span><span class='keyglyph'>]</span> <span class='keyglyph'>-></span> <span class='conid'>XPathFilter</span>
<a name="line-476"></a><span class='definition'>evalPredL</span> <span class='varid'>env</span> <span class='varid'>pr</span> <span class='varid'>n</span><span class='keyglyph'>@</span><span class='layout'>(</span><span class='conid'>XPVNode</span> <span class='varid'>ns</span><span class='layout'>)</span>
<a name="line-477"></a> <span class='keyglyph'>=</span> <span class='varid'>remDups</span> <span class='varop'>$</span> <span class='varid'>foldl</span> <span class='layout'>(</span><span class='varid'>evalPred</span> <span class='varid'>env</span> <span class='num'>1</span> <span class='layout'>(</span><span class='varid'>length</span> <span class='varid'>ns</span><span class='layout'>)</span><span class='layout'>)</span> <span class='varid'>n</span> <span class='varid'>pr</span>
<a name="line-478"></a><span class='definition'>evalPredL</span> <span class='keyword'>_</span> <span class='keyword'>_</span> <span class='keyword'>_</span>
<a name="line-479"></a> <span class='keyglyph'>=</span> <span class='conid'>XPVError</span> <span class='str'>"Call to evalPredL without a nodeset"</span>
<a name="line-480"></a>
<a name="line-481"></a>
<a name="line-482"></a><a name="evalPred"></a><span class='definition'>evalPred</span> <span class='keyglyph'>::</span> <span class='conid'>Env</span> <span class='keyglyph'>-></span> <span class='conid'>Int</span> <span class='keyglyph'>-></span> <span class='conid'>Int</span> <span class='keyglyph'>-></span> <span class='conid'>XPathValue</span> <span class='keyglyph'>-></span> <span class='conid'>Expr</span> <span class='keyglyph'>-></span> <span class='conid'>XPathValue</span>
<a name="line-483"></a><span class='definition'>evalPred</span> <span class='keyword'>_</span> <span class='keyword'>_</span> <span class='keyword'>_</span> <span class='varid'>ns</span><span class='keyglyph'>@</span><span class='layout'>(</span><span class='conid'>XPVNode</span> <span class='conid'>[]</span><span class='layout'>)</span> <span class='keyword'>_</span> <span class='keyglyph'>=</span> <span class='varid'>ns</span>
<a name="line-484"></a><span class='definition'>evalPred</span> <span class='varid'>env</span> <span class='varid'>pos</span> <span class='varid'>len</span> <span class='layout'>(</span><span class='conid'>XPVNode</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='layout'>)</span> <span class='varid'>ex</span>
<a name="line-485"></a> <span class='keyglyph'>=</span> <span class='keyword'>case</span> <span class='varid'>testPredicate</span> <span class='varid'>env</span> <span class='layout'>(</span><span class='varid'>pos</span><span class='layout'>,</span> <span class='varid'>len</span><span class='layout'>,</span> <span class='varid'>x</span><span class='layout'>)</span> <span class='varid'>ex</span> <span class='layout'>(</span><span class='conid'>XPVNode</span> <span class='keyglyph'>[</span><span class='varid'>x</span><span class='keyglyph'>]</span><span class='layout'>)</span> <span class='keyword'>of</span>
<a name="line-486"></a> <span class='varid'>e</span><span class='keyglyph'>@</span><span class='layout'>(</span><span class='conid'>XPVError</span> <span class='keyword'>_</span><span class='layout'>)</span> <span class='keyglyph'>-></span> <span class='varid'>e</span>
<a name="line-487"></a> <span class='conid'>XPVBool</span> <span class='conid'>True</span> <span class='keyglyph'>-></span> <span class='conid'>XPVNode</span> <span class='layout'>(</span><span class='varid'>x</span> <span class='conop'>:</span> <span class='varid'>n</span><span class='layout'>)</span>
<a name="line-488"></a> <span class='conid'>XPVBool</span> <span class='conid'>False</span> <span class='keyglyph'>-></span> <span class='varid'>nextNode</span>
<a name="line-489"></a> <span class='keyword'>_</span> <span class='keyglyph'>-></span> <span class='conid'>XPVError</span> <span class='str'>"Value of testPredicate is not a boolean"</span>
<a name="line-490"></a> <span class='keyword'>where</span> <span class='varid'>nextNode</span><span class='keyglyph'>@</span><span class='layout'>(</span><span class='conid'>XPVNode</span> <span class='varid'>n</span><span class='layout'>)</span> <span class='keyglyph'>=</span> <span class='varid'>evalPred</span> <span class='varid'>env</span> <span class='layout'>(</span><span class='varid'>pos</span><span class='varop'>+</span><span class='num'>1</span><span class='layout'>)</span> <span class='varid'>len</span> <span class='layout'>(</span><span class='conid'>XPVNode</span> <span class='varid'>xs</span><span class='layout'>)</span> <span class='varid'>ex</span>
<a name="line-491"></a><span class='definition'>evalPred</span> <span class='keyword'>_</span> <span class='keyword'>_</span> <span class='keyword'>_</span> <span class='keyword'>_</span> <span class='keyword'>_</span>
<a name="line-492"></a> <span class='keyglyph'>=</span> <span class='conid'>XPVError</span> <span class='str'>"Call to evalPred without a nodeset"</span>
<a name="line-493"></a>
<a name="line-494"></a>
<a name="line-495"></a>
<a name="line-496"></a><a name="testPredicate"></a><span class='definition'>testPredicate</span> <span class='keyglyph'>::</span> <span class='conid'>Env</span> <span class='keyglyph'>-></span> <span class='conid'>Context</span> <span class='keyglyph'>-></span> <span class='conid'>Expr</span> <span class='keyglyph'>-></span> <span class='conid'>XPathFilter</span>
<a name="line-497"></a><span class='definition'>testPredicate</span> <span class='varid'>env</span> <span class='varid'>context</span><span class='keyglyph'>@</span><span class='layout'>(</span><span class='varid'>pos</span><span class='layout'>,</span> <span class='keyword'>_</span><span class='layout'>,</span> <span class='keyword'>_</span><span class='layout'>)</span> <span class='varid'>ex</span> <span class='varid'>ns</span>
<a name="line-498"></a> <span class='keyglyph'>=</span> <span class='keyword'>case</span> <span class='varid'>evalExpr</span> <span class='varid'>env</span> <span class='varid'>context</span> <span class='varid'>ex</span> <span class='varid'>ns</span> <span class='keyword'>of</span>
<a name="line-499"></a> <span class='conid'>XPVNumber</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='conid'>XPVBool</span> <span class='layout'>(</span><span class='varid'>f</span> <span class='varop'>==</span> <span class='varid'>fromIntegral</span> <span class='varid'>pos</span><span class='layout'>)</span>
<a name="line-500"></a> <span class='conid'>XPVNumber</span> <span class='keyword'>_</span> <span class='keyglyph'>-></span> <span class='conid'>XPVBool</span> <span class='conid'>False</span>
<a name="line-501"></a> <span class='keyword'>_</span> <span class='keyglyph'>-></span> <span class='varid'>xboolean</span> <span class='varid'>context</span> <span class='varid'>env</span> <span class='keyglyph'>[</span><span class='varid'>evalExpr</span> <span class='varid'>env</span> <span class='varid'>context</span> <span class='varid'>ex</span> <span class='varid'>ns</span><span class='keyglyph'>]</span>
<a name="line-502"></a>
<a name="line-503"></a>
<a name="line-504"></a><span class='comment'>-- |</span>
<a name="line-505"></a><span class='comment'>-- filter for selecting a special type of nodes from the current fragment tree</span>
<a name="line-506"></a><span class='comment'>--</span>
<a name="line-507"></a><span class='comment'>-- the filter works with namespace activated and without namespaces.</span>
<a name="line-508"></a><span class='comment'>-- If namespaces occur in XPath names, the uris are used for matching,</span>
<a name="line-509"></a><span class='comment'>-- else the name prefix</span>
<a name="line-510"></a><span class='comment'>--</span>
<a name="line-511"></a><span class='comment'>-- Bugfix : "*" (or any other name-test) must not match the root node</span>
<a name="line-512"></a>
<a name="line-513"></a><a name="nodeTest"></a><span class='definition'>nodeTest</span> <span class='keyglyph'>::</span> <span class='conid'>NodeTest</span> <span class='keyglyph'>-></span> <span class='conid'>XPathFilter</span>
<a name="line-514"></a>
<a name="line-515"></a><span class='comment'>-- nodeTest (NameTest (QN "" "*" "")) = filterNodes (\n -> isXTagNode n && not (isRootNode n))</span>
<a name="line-516"></a><span class='comment'>-- nodeTest (NameTest (QN _ "*" uri)) = filterNodes (filterd uri)</span>
<a name="line-517"></a>
<a name="line-518"></a><span class='definition'>nodeTest</span> <span class='layout'>(</span><span class='conid'>NameTest</span> <span class='varid'>q</span><span class='layout'>)</span>
<a name="line-519"></a> <span class='keyglyph'>|</span> <span class='varid'>isWildcardTest</span>
<a name="line-520"></a> <span class='keyglyph'>=</span> <span class='varid'>filterNodes</span> <span class='layout'>(</span><span class='varid'>wildcardTest</span> <span class='varid'>q</span><span class='layout'>)</span>
<a name="line-521"></a> <span class='keyglyph'>|</span> <span class='varid'>otherwise</span>
<a name="line-522"></a> <span class='keyglyph'>=</span> <span class='varid'>filterNodes</span> <span class='layout'>(</span><span class='varid'>nameTest</span> <span class='varid'>q</span><span class='layout'>)</span> <span class='comment'>-- old: (isOfTagNode1 q)</span>
<a name="line-523"></a> <span class='keyword'>where</span>
<a name="line-524"></a> <span class='varid'>isWildcardTest</span> <span class='keyglyph'>=</span> <span class='varid'>localPart</span> <span class='varid'>q</span> <span class='varop'>==</span> <span class='str'>"*"</span>
<a name="line-525"></a>
<a name="line-526"></a><span class='definition'>nodeTest</span> <span class='layout'>(</span><span class='conid'>PI</span> <span class='varid'>n</span><span class='layout'>)</span> <span class='keyglyph'>=</span> <span class='varid'>filterNodes</span> <span class='varid'>isPiNode</span>
<a name="line-527"></a> <span class='keyword'>where</span>
<a name="line-528"></a> <span class='varid'>isPiNode</span> <span class='keyglyph'>=</span> <span class='varid'>maybe</span> <span class='conid'>False</span> <span class='layout'>(</span><span class='layout'>(</span><span class='varop'>==</span> <span class='varid'>n</span><span class='layout'>)</span> <span class='varop'>.</span> <span class='varid'>qualifiedName</span><span class='layout'>)</span> <span class='varop'>.</span> <span class='conid'>XN</span><span class='varop'>.</span><span class='varid'>getPiName</span>
<a name="line-529"></a>
<a name="line-530"></a><span class='definition'>nodeTest</span> <span class='layout'>(</span><span class='conid'>TypeTest</span> <span class='varid'>t</span><span class='layout'>)</span> <span class='keyglyph'>=</span> <span class='varid'>typeTest</span> <span class='varid'>t</span>
<a name="line-531"></a>
<a name="line-532"></a><a name="nameTest"></a><span class='definition'>nameTest</span> <span class='keyglyph'>::</span> <span class='conid'>QName</span> <span class='keyglyph'>-></span> <span class='conid'>XNode</span> <span class='keyglyph'>-></span> <span class='conid'>Bool</span>
<a name="line-533"></a><span class='definition'>nameTest</span> <span class='varid'>xpName</span> <span class='layout'>(</span><span class='conid'>XTag</span> <span class='varid'>elemName</span> <span class='keyword'>_</span><span class='layout'>)</span>
<a name="line-534"></a> <span class='keyglyph'>|</span> <span class='varid'>namespaceAware</span>
<a name="line-535"></a> <span class='keyglyph'>=</span> <span class='varid'>localPart</span> <span class='varid'>xpName</span> <span class='varop'>==</span> <span class='varid'>localPart</span> <span class='varid'>elemName</span>
<a name="line-536"></a> <span class='varop'>&&</span>
<a name="line-537"></a> <span class='varid'>namespaceUri</span> <span class='varid'>xpName</span> <span class='varop'>==</span> <span class='varid'>namespaceUri</span> <span class='varid'>elemName</span>
<a name="line-538"></a> <span class='keyglyph'>|</span> <span class='varid'>otherwise</span>
<a name="line-539"></a> <span class='keyglyph'>=</span> <span class='varid'>qualifiedName</span> <span class='varid'>xpName</span> <span class='varop'>==</span> <span class='varid'>qualifiedName</span> <span class='varid'>elemName</span>
<a name="line-540"></a> <span class='keyword'>where</span>
<a name="line-541"></a> <span class='varid'>namespaceAware</span> <span class='keyglyph'>=</span> <span class='varid'>not</span> <span class='varop'>.</span> <span class='varid'>null</span> <span class='varop'>.</span> <span class='varid'>namespaceUri</span> <span class='varop'>$</span> <span class='varid'>xpName</span>
<a name="line-542"></a>
<a name="line-543"></a><span class='definition'>nameTest</span> <span class='keyword'>_</span> <span class='keyword'>_</span> <span class='keyglyph'>=</span> <span class='conid'>False</span>
<a name="line-544"></a>
<a name="line-545"></a><a name="wildcardTest"></a><span class='definition'>wildcardTest</span> <span class='keyglyph'>::</span> <span class='conid'>QName</span> <span class='keyglyph'>-></span> <span class='conid'>XNode</span> <span class='keyglyph'>-></span> <span class='conid'>Bool</span>
<a name="line-546"></a><span class='definition'>wildcardTest</span> <span class='varid'>xpName</span> <span class='layout'>(</span><span class='conid'>XTag</span> <span class='varid'>elemName</span> <span class='keyword'>_</span><span class='layout'>)</span>
<a name="line-547"></a> <span class='keyglyph'>|</span> <span class='varid'>namespaceAware</span>
<a name="line-548"></a> <span class='keyglyph'>=</span> <span class='varid'>namespaceUri</span> <span class='varid'>xpName</span> <span class='varop'>==</span> <span class='varid'>namespaceUri</span> <span class='varid'>elemName</span>
<a name="line-549"></a> <span class='keyglyph'>|</span> <span class='varid'>prefixMatch</span>
<a name="line-550"></a> <span class='keyglyph'>=</span> <span class='varid'>namePrefix</span> <span class='varid'>xpName</span> <span class='varop'>==</span> <span class='varid'>namePrefix</span> <span class='varid'>elemName</span>
<a name="line-551"></a> <span class='keyglyph'>|</span> <span class='varid'>otherwise</span>
<a name="line-552"></a> <span class='keyglyph'>=</span> <span class='varid'>localPart</span> <span class='varid'>elemName</span> <span class='varop'>/=</span> <span class='varid'>t_root</span> <span class='comment'>-- all names except the root name "/"</span>
<a name="line-553"></a> <span class='keyword'>where</span>
<a name="line-554"></a> <span class='varid'>namespaceAware</span> <span class='keyglyph'>=</span> <span class='varid'>not</span> <span class='varop'>.</span> <span class='varid'>null</span> <span class='varop'>.</span> <span class='varid'>namespaceUri</span> <span class='varop'>$</span> <span class='varid'>xpName</span>
<a name="line-555"></a> <span class='varid'>prefixMatch</span> <span class='keyglyph'>=</span> <span class='varid'>not</span> <span class='varop'>.</span> <span class='varid'>null</span> <span class='varop'>.</span> <span class='varid'>namePrefix</span> <span class='varop'>$</span> <span class='varid'>xpName</span>
<a name="line-556"></a>
<a name="line-557"></a><span class='definition'>wildcardTest</span> <span class='keyword'>_</span> <span class='keyword'>_</span> <span class='keyglyph'>=</span> <span class='conid'>False</span>
<a name="line-558"></a>
<a name="line-559"></a><a name="typeTest"></a><span class='comment'>-- |</span>
<a name="line-560"></a><span class='comment'>-- tests whether a node is of a special type</span>
<a name="line-561"></a><span class='comment'>--</span>
<a name="line-562"></a><span class='definition'>typeTest</span> <span class='keyglyph'>::</span> <span class='conid'>XPathNode</span> <span class='keyglyph'>-></span> <span class='conid'>XPathFilter</span>
<a name="line-563"></a><span class='definition'>typeTest</span> <span class='conid'>XPNode</span> <span class='keyglyph'>=</span> <span class='varid'>id</span>
<a name="line-564"></a><span class='definition'>typeTest</span> <span class='conid'>XPCommentNode</span> <span class='keyglyph'>=</span> <span class='varid'>filterNodes</span> <span class='conid'>XN</span><span class='varop'>.</span><span class='varid'>isCmt</span>
<a name="line-565"></a><span class='definition'>typeTest</span> <span class='conid'>XPPINode</span> <span class='keyglyph'>=</span> <span class='varid'>filterNodes</span> <span class='conid'>XN</span><span class='varop'>.</span><span class='varid'>isPi</span>
<a name="line-566"></a><span class='definition'>typeTest</span> <span class='conid'>XPTextNode</span> <span class='keyglyph'>=</span> <span class='varid'>filterNodes</span> <span class='conid'>XN</span><span class='varop'>.</span><span class='varid'>isText</span>
<a name="line-567"></a>
<a name="line-568"></a><a name="filterNodes"></a><span class='comment'>-- |</span>
<a name="line-569"></a><span class='comment'>-- the filter selects the NTree part of a navigable tree and</span>
<a name="line-570"></a><span class='comment'>-- tests whether the node is of the necessary type</span>
<a name="line-571"></a><span class='comment'>--</span>
<a name="line-572"></a><span class='comment'>-- * 1.parameter fct : filter function from the XmlTreeFilter module which tests the type of a node</span>
<a name="line-573"></a><span class='comment'>--</span>
<a name="line-574"></a><span class='definition'>filterNodes</span> <span class='keyglyph'>::</span> <span class='layout'>(</span><span class='conid'>XNode</span> <span class='keyglyph'>-></span> <span class='conid'>Bool</span><span class='layout'>)</span> <span class='keyglyph'>-></span> <span class='conid'>XPathFilter</span>
<a name="line-575"></a><span class='definition'>filterNodes</span> <span class='varid'>fct</span> <span class='layout'>(</span><span class='conid'>XPVNode</span> <span class='varid'>ns</span><span class='layout'>)</span>
<a name="line-576"></a> <span class='keyglyph'>=</span> <span class='conid'>XPVNode</span> <span class='layout'>(</span><span class='keyglyph'>[</span><span class='varid'>n</span> <span class='keyglyph'>|</span> <span class='varid'>n</span><span class='keyglyph'>@</span><span class='layout'>(</span><span class='conid'>NT</span> <span class='layout'>(</span><span class='conid'>NTree</span> <span class='varid'>node</span> <span class='keyword'>_</span><span class='layout'>)</span> <span class='keyword'>_</span> <span class='keyword'>_</span> <span class='keyword'>_</span><span class='layout'>)</span> <span class='keyglyph'><-</span> <span class='varid'>ns</span> <span class='layout'>,</span> <span class='varid'>fct</span> <span class='varid'>node</span><span class='keyglyph'>]</span><span class='layout'>)</span>
<a name="line-577"></a><span class='definition'>filterNodes</span> <span class='keyword'>_</span> <span class='keyword'>_</span>
<a name="line-578"></a> <span class='keyglyph'>=</span> <span class='conid'>XPVError</span> <span class='str'>"Call to filterNodes without a nodeset"</span>
<a name="line-579"></a>
<a name="line-580"></a><a name="boolEval"></a><span class='comment'>-- |</span>
<a name="line-581"></a><span class='comment'>-- evaluates a boolean expression, the evaluation is non-strict</span>
<a name="line-582"></a><span class='definition'>boolEval</span> <span class='keyglyph'>::</span> <span class='conid'>Env</span> <span class='keyglyph'>-></span> <span class='conid'>Context</span> <span class='keyglyph'>-></span> <span class='conid'>Op</span> <span class='keyglyph'>-></span> <span class='keyglyph'>[</span><span class='conid'>Expr</span><span class='keyglyph'>]</span> <span class='keyglyph'>-></span> <span class='conid'>XPathFilter</span>
<a name="line-583"></a><span class='definition'>boolEval</span> <span class='keyword'>_</span> <span class='keyword'>_</span> <span class='varid'>op</span> <span class='conid'>[]</span> <span class='keyword'>_</span>
<a name="line-584"></a> <span class='keyglyph'>=</span> <span class='conid'>XPVBool</span> <span class='layout'>(</span><span class='varid'>op</span><span class='varop'>==</span><span class='conid'>And</span><span class='layout'>)</span>
<a name="line-585"></a><span class='definition'>boolEval</span> <span class='varid'>env</span> <span class='varid'>cont</span> <span class='conid'>Or</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'>ns</span>
<a name="line-586"></a> <span class='keyglyph'>=</span> <span class='keyword'>case</span> <span class='varid'>xboolean</span> <span class='varid'>cont</span> <span class='varid'>env</span> <span class='keyglyph'>[</span><span class='varid'>evalExpr</span> <span class='varid'>env</span> <span class='varid'>cont</span> <span class='varid'>x</span> <span class='varid'>ns</span><span class='keyglyph'>]</span> <span class='keyword'>of</span>
<a name="line-587"></a> <span class='varid'>e</span><span class='keyglyph'>@</span><span class='layout'>(</span><span class='conid'>XPVError</span> <span class='keyword'>_</span><span class='layout'>)</span> <span class='keyglyph'>-></span> <span class='varid'>e</span>
<a name="line-588"></a> <span class='conid'>XPVBool</span> <span class='conid'>True</span> <span class='keyglyph'>-></span> <span class='conid'>XPVBool</span> <span class='conid'>True</span>
<a name="line-589"></a> <span class='keyword'>_</span> <span class='keyglyph'>-></span> <span class='varid'>boolEval</span> <span class='varid'>env</span> <span class='varid'>cont</span> <span class='conid'>Or</span> <span class='varid'>xs</span> <span class='varid'>ns</span>
<a name="line-590"></a>
<a name="line-591"></a><span class='definition'>boolEval</span> <span class='varid'>env</span> <span class='varid'>cont</span> <span class='conid'>And</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'>ns</span>
<a name="line-592"></a> <span class='keyglyph'>=</span> <span class='keyword'>case</span> <span class='varid'>xboolean</span> <span class='varid'>cont</span> <span class='varid'>env</span> <span class='keyglyph'>[</span><span class='varid'>evalExpr</span> <span class='varid'>env</span> <span class='varid'>cont</span> <span class='varid'>x</span> <span class='varid'>ns</span><span class='keyglyph'>]</span> <span class='keyword'>of</span>
<a name="line-593"></a> <span class='varid'>e</span><span class='keyglyph'>@</span><span class='layout'>(</span><span class='conid'>XPVError</span> <span class='keyword'>_</span><span class='layout'>)</span> <span class='keyglyph'>-></span> <span class='varid'>e</span>
<a name="line-594"></a> <span class='conid'>XPVBool</span> <span class='conid'>True</span> <span class='keyglyph'>-></span> <span class='varid'>boolEval</span> <span class='varid'>env</span> <span class='varid'>cont</span> <span class='conid'>And</span> <span class='varid'>xs</span> <span class='varid'>ns</span>
<a name="line-595"></a> <span class='keyword'>_</span> <span class='keyglyph'>-></span> <span class='conid'>XPVBool</span> <span class='conid'>False</span>
<a name="line-596"></a><span class='definition'>boolEval</span> <span class='keyword'>_</span> <span class='keyword'>_</span> <span class='keyword'>_</span> <span class='keyword'>_</span> <span class='keyword'>_</span>
<a name="line-597"></a> <span class='keyglyph'>=</span> <span class='conid'>XPVError</span> <span class='str'>"Call to boolEval with a wrong argument"</span>
<a name="line-598"></a>
<a name="line-599"></a>
<a name="line-600"></a>
<a name="line-601"></a><a name="getVariable"></a><span class='comment'>-- |</span>
<a name="line-602"></a><span class='comment'>-- returns the value of a variable</span>
<a name="line-603"></a><span class='definition'>getVariable</span> <span class='keyglyph'>::</span> <span class='conid'>Env</span> <span class='keyglyph'>-></span> <span class='conid'>VarName</span> <span class='keyglyph'>-></span> <span class='conid'>XPathFilter</span>
<a name="line-604"></a><span class='definition'>getVariable</span> <span class='varid'>env</span> <span class='varid'>name</span> <span class='keyword'>_</span>
<a name="line-605"></a> <span class='keyglyph'>=</span> <span class='keyword'>case</span> <span class='varid'>lookup</span> <span class='varid'>name</span> <span class='layout'>(</span><span class='varid'>getVarTab</span> <span class='varid'>env</span><span class='layout'>)</span> <span class='keyword'>of</span>
<a name="line-606"></a> <span class='conid'>Nothing</span> <span class='keyglyph'>-></span> <span class='conid'>XPVError</span> <span class='layout'>(</span><span class='str'>"Variable: "</span> <span class='varop'>++</span> <span class='varid'>show</span> <span class='varid'>name</span> <span class='varop'>++</span> <span class='str'>" not found"</span><span class='layout'>)</span>
<a name="line-607"></a> <span class='conid'>Just</span> <span class='varid'>v</span> <span class='keyglyph'>-></span> <span class='varid'>v</span>
<a name="line-608"></a>
<a name="line-609"></a>
<a name="line-610"></a><a name="fctEval"></a><span class='comment'>-- |</span>
<a name="line-611"></a><span class='comment'>-- evaluates a function, </span>
<a name="line-612"></a><span class='comment'>-- computation is done by 'XPathFct.evalFct' which is defined in "XPathFct".</span>
<a name="line-613"></a><span class='definition'>fctEval</span> <span class='keyglyph'>::</span> <span class='conid'>Env</span> <span class='keyglyph'>-></span> <span class='conid'>Context</span> <span class='keyglyph'>-></span> <span class='conid'>FctName</span> <span class='keyglyph'>-></span> <span class='keyglyph'>[</span><span class='conid'>Expr</span><span class='keyglyph'>]</span> <span class='keyglyph'>-></span> <span class='conid'>XPathFilter</span>
<a name="line-614"></a><span class='definition'>fctEval</span> <span class='varid'>env</span> <span class='varid'>cont</span> <span class='varid'>name</span> <span class='varid'>args</span>
<a name="line-615"></a> <span class='keyglyph'>=</span> <span class='varid'>evalFct</span> <span class='varid'>name</span> <span class='varid'>env</span> <span class='varid'>cont</span> <span class='varop'>.</span> <span class='varid'>evalExprL</span> <span class='varid'>env</span> <span class='varid'>cont</span> <span class='varid'>args</span>
<a name="line-616"></a>
<a name="line-617"></a>
<a name="line-618"></a>
<a name="line-619"></a><a name="numEval"></a><span class='comment'>-- |</span>
<a name="line-620"></a><span class='comment'>-- evaluates an arithmetic operation.</span>
<a name="line-621"></a><span class='comment'>--</span>
<a name="line-622"></a><span class='comment'>-- 1.parameter f : arithmetic function from "XPathArithmetic"</span>
<a name="line-623"></a><span class='comment'>--</span>
<a name="line-624"></a><span class='definition'>numEval</span> <span class='keyglyph'>::</span> <span class='layout'>(</span><span class='conid'>Op</span> <span class='keyglyph'>-></span> <span class='conid'>XPathValue</span> <span class='keyglyph'>-></span> <span class='conid'>XPathValue</span> <span class='keyglyph'>-></span> <span class='conid'>XPathValue</span><span class='layout'>)</span> <span class='keyglyph'>-></span> <span class='conid'>Op</span> <span class='keyglyph'>-></span> <span class='keyglyph'>[</span><span class='conid'>XPathValue</span><span class='keyglyph'>]</span> <span class='keyglyph'>-></span> <span class='conid'>XPathValue</span>
<a name="line-625"></a><span class='definition'>numEval</span> <span class='varid'>f</span> <span class='varid'>op</span> <span class='keyglyph'>=</span> <span class='varid'>foldl1</span> <span class='layout'>(</span><span class='varid'>f</span> <span class='varid'>op</span><span class='layout'>)</span>
<a name="line-626"></a>
<a name="line-627"></a>
<a name="line-628"></a>
<a name="line-629"></a><span class='comment'>-- |</span>
<a name="line-630"></a><span class='comment'>-- Convert list of ID attributes from DTD into a space separated 'XPVString'</span>
<a name="line-631"></a><span class='comment'>--</span>
<a name="line-632"></a>
<a name="line-633"></a><a name="idAttributesToXPathValue"></a><span class='definition'>idAttributesToXPathValue</span> <span class='keyglyph'>::</span> <span class='conid'>XmlTrees</span> <span class='keyglyph'>-></span> <span class='conid'>XPathValue</span>
<a name="line-634"></a><span class='definition'>idAttributesToXPathValue</span> <span class='varid'>ts</span>
<a name="line-635"></a> <span class='keyglyph'>=</span> <span class='conid'>XPVString</span> <span class='layout'>(</span><span class='varid'>foldr</span> <span class='layout'>(</span><span class='keyglyph'>\</span> <span class='varid'>n</span> <span class='keyglyph'>-></span> <span class='layout'>(</span> <span class='layout'>(</span><span class='varid'>valueOfDTD</span> <span class='varid'>a_value</span> <span class='varid'>n</span> <span class='varop'>++</span> <span class='str'>" "</span><span class='layout'>)</span> <span class='varop'>++</span><span class='layout'>)</span><span class='layout'>)</span> <span class='conid'>[]</span> <span class='varid'>ts</span><span class='layout'>)</span>
<a name="line-636"></a>
<a name="line-637"></a><span class='comment'>-- |</span>
<a name="line-638"></a><span class='comment'>-- Extracts all ID-attributes from the document type definition (DTD).</span>
<a name="line-639"></a><span class='comment'>--</span>
<a name="line-640"></a>
<a name="line-641"></a><a name="getIdAttributes"></a><span class='definition'>getIdAttributes</span> <span class='keyglyph'>::</span> <span class='conid'>XmlTree</span> <span class='keyglyph'>-></span> <span class='conid'>XmlTrees</span>
<a name="line-642"></a><span class='definition'>getIdAttributes</span>
<a name="line-643"></a> <span class='keyglyph'>=</span> <span class='varid'>runLA</span> <span class='varop'>$</span>
<a name="line-644"></a> <span class='conid'>AT</span><span class='varop'>.</span><span class='varid'>getChildren</span>
<a name="line-645"></a> <span class='varop'>>>></span>
<a name="line-646"></a> <span class='varid'>isDTD</span>
<a name="line-647"></a> <span class='varop'>>>></span>
<a name="line-648"></a> <span class='conid'>AT</span><span class='varop'>.</span><span class='varid'>deep</span> <span class='layout'>(</span><span class='varid'>isIdAttrType</span><span class='layout'>)</span>
<a name="line-649"></a>
<a name="line-650"></a><span class='comment'>-- ----------------------------------------</span>
<a name="line-651"></a>
<a name="line-652"></a><a name="isIdAttrType"></a><span class='definition'>isIdAttrType</span> <span class='keyglyph'>::</span> <span class='conid'>ArrowDTD</span> <span class='varid'>a</span> <span class='keyglyph'>=></span> <span class='varid'>a</span> <span class='conid'>XmlTree</span> <span class='conid'>XmlTree</span>
<a name="line-653"></a><span class='definition'>isIdAttrType</span> <span class='keyglyph'>=</span> <span class='varid'>hasDTDAttrValue</span> <span class='varid'>a_type</span> <span class='layout'>(</span><span class='varop'>==</span> <span class='varid'>k_id</span><span class='layout'>)</span>
<a name="line-654"></a>
<a name="line-655"></a><a name="valueOfDTD"></a><span class='definition'>valueOfDTD</span> <span class='keyglyph'>::</span> <span class='conid'>String</span> <span class='keyglyph'>-></span> <span class='conid'>XmlTree</span> <span class='keyglyph'>-></span> <span class='conid'>String</span>
<a name="line-656"></a><span class='definition'>valueOfDTD</span> <span class='varid'>n</span> <span class='keyglyph'>=</span> <span class='varid'>concat</span> <span class='varop'>.</span> <span class='varid'>runLA</span> <span class='layout'>(</span> <span class='varid'>getDTDAttrl</span> <span class='varop'>>>^</span> <span class='varid'>lookup1</span> <span class='varid'>n</span> <span class='layout'>)</span>
<a name="line-657"></a>
<a name="line-658"></a><a name="hasDTDAttrValue"></a><span class='definition'>hasDTDAttrValue</span> <span class='keyglyph'>::</span> <span class='conid'>ArrowDTD</span> <span class='varid'>a</span> <span class='keyglyph'>=></span> <span class='conid'>String</span> <span class='keyglyph'>-></span> <span class='layout'>(</span><span class='conid'>String</span> <span class='keyglyph'>-></span> <span class='conid'>Bool</span><span class='layout'>)</span> <span class='keyglyph'>-></span> <span class='varid'>a</span> <span class='conid'>XmlTree</span> <span class='conid'>XmlTree</span>
<a name="line-659"></a><span class='definition'>hasDTDAttrValue</span> <span class='varid'>an</span> <span class='varid'>p</span> <span class='keyglyph'>=</span> <span class='varid'>filterA</span> <span class='varop'>$</span>
<a name="line-660"></a> <span class='varid'>getDTDAttrl</span> <span class='varop'>>>></span> <span class='varid'>isA</span> <span class='layout'>(</span><span class='varid'>p</span> <span class='varop'>.</span> <span class='varid'>lookup1</span> <span class='varid'>an</span><span class='layout'>)</span>
<a name="line-661"></a>
<a name="line-662"></a><span class='comment'>-- ------------------------------------------------------------</span>
</pre></body>
</html>