hxt-8.0.0: doc/hdoc/src/Text-XML-HXT-XPath-XPathArithmetic.html
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<pre><a name="line-1"></a><span class='comment'>-- |</span>
<a name="line-2"></a><span class='comment'>-- The module contains arithmetic calculations according the IEEE 754 standard</span>
<a name="line-3"></a><span class='comment'>-- for plus, minus, unary minus, multiplication, modulo and division.</span>
<a name="line-4"></a><span class='comment'>--</span>
<a name="line-5"></a>
<a name="line-6"></a>
<a name="line-7"></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'>XPathArithmetic</span>
<a name="line-8"></a> <span class='layout'>(</span> <span class='varid'>xPathMulti</span>
<a name="line-9"></a> <span class='layout'>,</span> <span class='varid'>xPathMod</span>
<a name="line-10"></a> <span class='layout'>,</span> <span class='varid'>xPathDiv</span>
<a name="line-11"></a> <span class='layout'>,</span> <span class='varid'>xPathAdd</span>
<a name="line-12"></a> <span class='layout'>,</span> <span class='varid'>xPathUnary</span>
<a name="line-13"></a> <span class='layout'>)</span>
<a name="line-14"></a><span class='keyword'>where</span>
<a name="line-15"></a>
<a name="line-16"></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-17"></a>
<a name="line-18"></a>
<a name="line-19"></a><span class='comment'>-- |</span>
<a name="line-20"></a><span class='comment'>-- Unary minus: the value 'NaN' is not calculatable and returned unchanged,</span>
<a name="line-21"></a><span class='comment'>-- all other values can be denied.</span>
<a name="line-22"></a><span class='comment'>--</span>
<a name="line-23"></a>
<a name="line-24"></a><a name="xPathUnary"></a><span class='definition'>xPathUnary</span> <span class='keyglyph'>::</span> <span class='conid'>XPathFilter</span>
<a name="line-25"></a><span class='definition'>xPathUnary</span> <span class='layout'>(</span><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='layout'>)</span> <span class='keyglyph'>=</span> <span class='conid'>XPVNumber</span> <span class='layout'>(</span><span class='conid'>Float</span> <span class='layout'>(</span><span class='comment'>-</span><span class='varid'>f</span><span class='layout'>)</span><span class='layout'>)</span>
<a name="line-26"></a><span class='definition'>xPathUnary</span> <span class='layout'>(</span><span class='conid'>XPVError</span> <span class='varid'>e</span><span class='layout'>)</span> <span class='keyglyph'>=</span> <span class='conid'>XPVError</span> <span class='varid'>e</span>
<a name="line-27"></a><span class='definition'>xPathUnary</span> <span class='layout'>(</span><span class='conid'>XPVNumber</span> <span class='conid'>NaN</span><span class='layout'>)</span> <span class='keyglyph'>=</span> <span class='conid'>XPVNumber</span> <span class='conid'>NaN</span>
<a name="line-28"></a><span class='definition'>xPathUnary</span> <span class='layout'>(</span><span class='conid'>XPVNumber</span> <span class='conid'>Pos0</span><span class='layout'>)</span> <span class='keyglyph'>=</span> <span class='conid'>XPVNumber</span> <span class='conid'>Neg0</span>
<a name="line-29"></a><span class='definition'>xPathUnary</span> <span class='layout'>(</span><span class='conid'>XPVNumber</span> <span class='conid'>Neg0</span><span class='layout'>)</span> <span class='keyglyph'>=</span> <span class='conid'>XPVNumber</span> <span class='conid'>Pos0</span>
<a name="line-30"></a><span class='definition'>xPathUnary</span> <span class='layout'>(</span><span class='conid'>XPVNumber</span> <span class='conid'>PosInf</span><span class='layout'>)</span> <span class='keyglyph'>=</span> <span class='conid'>XPVNumber</span> <span class='conid'>NegInf</span>
<a name="line-31"></a><span class='definition'>xPathUnary</span> <span class='layout'>(</span><span class='conid'>XPVNumber</span> <span class='conid'>NegInf</span><span class='layout'>)</span> <span class='keyglyph'>=</span> <span class='conid'>XPVNumber</span> <span class='conid'>PosInf</span>
<a name="line-32"></a><span class='definition'>xPathUnary</span> <span class='keyword'>_</span> <span class='keyglyph'>=</span> <span class='conid'>XPVError</span> <span class='str'>"Call to unaryEval without a number"</span>
<a name="line-33"></a>
<a name="line-34"></a>
<a name="line-35"></a><span class='comment'>-- |</span>
<a name="line-36"></a><span class='comment'>-- Multiplication</span>
<a name="line-37"></a><span class='comment'>--</span>
<a name="line-38"></a>
<a name="line-39"></a><a name="xPathMulti"></a><span class='definition'>xPathMulti</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-40"></a><span class='definition'>xPathMulti</span> <span class='keyword'>_</span> <span class='layout'>(</span><span class='conid'>XPVNumber</span> <span class='layout'>(</span><span class='conid'>Float</span> <span class='varid'>a</span><span class='layout'>)</span><span class='layout'>)</span> <span class='layout'>(</span><span class='conid'>XPVNumber</span> <span class='layout'>(</span><span class='conid'>Float</span> <span class='varid'>b</span><span class='layout'>)</span><span class='layout'>)</span>
<a name="line-41"></a> <span class='keyglyph'>=</span> <span class='conid'>XPVNumber</span> <span class='layout'>(</span><span class='conid'>Float</span> <span class='layout'>(</span><span class='varid'>a</span> <span class='varop'>*</span> <span class='varid'>b</span><span class='layout'>)</span><span class='layout'>)</span>
<a name="line-42"></a><span class='definition'>xPathMulti</span> <span class='keyword'>_</span> <span class='layout'>(</span><span class='conid'>XPVNumber</span> <span class='conid'>NegInf</span><span class='layout'>)</span> <span class='layout'>(</span><span class='conid'>XPVNumber</span> <span class='layout'>(</span><span class='conid'>Float</span> <span class='varid'>a</span><span class='layout'>)</span><span class='layout'>)</span>
<a name="line-43"></a> <span class='keyglyph'>|</span> <span class='varid'>a</span> <span class='varop'><</span> <span class='num'>0</span> <span class='keyglyph'>=</span> <span class='conid'>XPVNumber</span> <span class='conid'>PosInf</span>
<a name="line-44"></a> <span class='keyglyph'>|</span> <span class='varid'>otherwise</span> <span class='keyglyph'>=</span> <span class='conid'>XPVNumber</span> <span class='conid'>NegInf</span>
<a name="line-45"></a><span class='definition'>xPathMulti</span> <span class='keyword'>_</span> <span class='layout'>(</span><span class='conid'>XPVNumber</span> <span class='conid'>PosInf</span><span class='layout'>)</span> <span class='layout'>(</span><span class='conid'>XPVNumber</span> <span class='layout'>(</span><span class='conid'>Float</span> <span class='varid'>a</span><span class='layout'>)</span><span class='layout'>)</span>
<a name="line-46"></a> <span class='keyglyph'>|</span> <span class='varid'>a</span> <span class='varop'><</span> <span class='num'>0</span> <span class='keyglyph'>=</span> <span class='conid'>XPVNumber</span> <span class='conid'>NegInf</span>
<a name="line-47"></a> <span class='keyglyph'>|</span> <span class='varid'>otherwise</span> <span class='keyglyph'>=</span> <span class='conid'>XPVNumber</span> <span class='conid'>PosInf</span>
<a name="line-48"></a><span class='definition'>xPathMulti</span> <span class='keyword'>_</span> <span class='layout'>(</span><span class='conid'>XPVNumber</span> <span class='layout'>(</span><span class='conid'>Float</span> <span class='varid'>a</span><span class='layout'>)</span><span class='layout'>)</span> <span class='layout'>(</span><span class='conid'>XPVNumber</span> <span class='conid'>NegInf</span><span class='layout'>)</span>
<a name="line-49"></a> <span class='keyglyph'>|</span> <span class='varid'>a</span> <span class='varop'><</span> <span class='num'>0</span> <span class='keyglyph'>=</span> <span class='conid'>XPVNumber</span> <span class='conid'>PosInf</span>
<a name="line-50"></a> <span class='keyglyph'>|</span> <span class='varid'>otherwise</span> <span class='keyglyph'>=</span> <span class='conid'>XPVNumber</span> <span class='conid'>NegInf</span>
<a name="line-51"></a><span class='definition'>xPathMulti</span> <span class='keyword'>_</span> <span class='layout'>(</span><span class='conid'>XPVNumber</span> <span class='layout'>(</span><span class='conid'>Float</span> <span class='varid'>a</span><span class='layout'>)</span><span class='layout'>)</span> <span class='layout'>(</span><span class='conid'>XPVNumber</span> <span class='conid'>PosInf</span><span class='layout'>)</span>
<a name="line-52"></a> <span class='keyglyph'>|</span> <span class='varid'>a</span> <span class='varop'><</span> <span class='num'>0</span> <span class='keyglyph'>=</span> <span class='conid'>XPVNumber</span> <span class='conid'>NegInf</span>
<a name="line-53"></a> <span class='keyglyph'>|</span> <span class='varid'>otherwise</span> <span class='keyglyph'>=</span> <span class='conid'>XPVNumber</span> <span class='conid'>PosInf</span>
<a name="line-54"></a><span class='definition'>xPathMulti</span> <span class='keyword'>_</span> <span class='layout'>(</span><span class='conid'>XPVNumber</span> <span class='conid'>Pos0</span><span class='layout'>)</span> <span class='layout'>(</span><span class='conid'>XPVNumber</span> <span class='layout'>(</span><span class='conid'>Float</span> <span class='varid'>a</span><span class='layout'>)</span><span class='layout'>)</span>
<a name="line-55"></a> <span class='keyglyph'>|</span> <span class='varid'>a</span> <span class='varop'><</span> <span class='num'>0</span> <span class='keyglyph'>=</span> <span class='conid'>XPVNumber</span> <span class='conid'>Neg0</span>
<a name="line-56"></a> <span class='keyglyph'>|</span> <span class='varid'>otherwise</span> <span class='keyglyph'>=</span> <span class='conid'>XPVNumber</span> <span class='conid'>Pos0</span>
<a name="line-57"></a><span class='definition'>xPathMulti</span> <span class='keyword'>_</span> <span class='layout'>(</span><span class='conid'>XPVNumber</span> <span class='conid'>Neg0</span><span class='layout'>)</span> <span class='layout'>(</span><span class='conid'>XPVNumber</span> <span class='layout'>(</span><span class='conid'>Float</span> <span class='varid'>a</span><span class='layout'>)</span><span class='layout'>)</span>
<a name="line-58"></a> <span class='keyglyph'>|</span> <span class='varid'>a</span> <span class='varop'><</span> <span class='num'>0</span> <span class='keyglyph'>=</span> <span class='conid'>XPVNumber</span> <span class='conid'>Pos0</span>
<a name="line-59"></a> <span class='keyglyph'>|</span> <span class='varid'>otherwise</span> <span class='keyglyph'>=</span> <span class='conid'>XPVNumber</span> <span class='conid'>Neg0</span>
<a name="line-60"></a><span class='definition'>xPathMulti</span> <span class='keyword'>_</span> <span class='layout'>(</span><span class='conid'>XPVNumber</span> <span class='layout'>(</span><span class='conid'>Float</span> <span class='varid'>a</span><span class='layout'>)</span><span class='layout'>)</span> <span class='layout'>(</span><span class='conid'>XPVNumber</span> <span class='conid'>Pos0</span><span class='layout'>)</span>
<a name="line-61"></a> <span class='keyglyph'>|</span> <span class='varid'>a</span> <span class='varop'><</span> <span class='num'>0</span> <span class='keyglyph'>=</span> <span class='conid'>XPVNumber</span> <span class='conid'>Neg0</span>
<a name="line-62"></a> <span class='keyglyph'>|</span> <span class='varid'>otherwise</span> <span class='keyglyph'>=</span> <span class='conid'>XPVNumber</span> <span class='conid'>Pos0</span>
<a name="line-63"></a><span class='definition'>xPathMulti</span> <span class='keyword'>_</span> <span class='layout'>(</span><span class='conid'>XPVNumber</span> <span class='layout'>(</span><span class='conid'>Float</span> <span class='varid'>a</span><span class='layout'>)</span><span class='layout'>)</span> <span class='layout'>(</span><span class='conid'>XPVNumber</span> <span class='conid'>Neg0</span><span class='layout'>)</span>
<a name="line-64"></a> <span class='keyglyph'>|</span> <span class='varid'>a</span> <span class='varop'><</span> <span class='num'>0</span> <span class='keyglyph'>=</span> <span class='conid'>XPVNumber</span> <span class='conid'>Pos0</span>
<a name="line-65"></a> <span class='keyglyph'>|</span> <span class='varid'>otherwise</span> <span class='keyglyph'>=</span> <span class='conid'>XPVNumber</span> <span class='conid'>Neg0</span>
<a name="line-66"></a><span class='definition'>xPathMulti</span> <span class='varid'>a</span> <span class='varid'>b</span> <span class='varid'>c</span> <span class='keyglyph'>=</span> <span class='varid'>xPathSpez</span> <span class='varid'>a</span> <span class='varid'>b</span> <span class='varid'>c</span>
<a name="line-67"></a>
<a name="line-68"></a>
<a name="line-69"></a><span class='comment'>-- |</span>
<a name="line-70"></a><span class='comment'>-- Modulo</span>
<a name="line-71"></a><span class='comment'>--</span>
<a name="line-72"></a>
<a name="line-73"></a><a name="xPathMod"></a><span class='definition'>xPathMod</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-74"></a><span class='definition'>xPathMod</span> <span class='keyword'>_</span> <span class='layout'>(</span><span class='conid'>XPVNumber</span> <span class='layout'>(</span><span class='conid'>Float</span> <span class='varid'>a</span><span class='layout'>)</span><span class='layout'>)</span> <span class='layout'>(</span><span class='conid'>XPVNumber</span> <span class='layout'>(</span><span class='conid'>Float</span> <span class='varid'>b</span><span class='layout'>)</span><span class='layout'>)</span>
<a name="line-75"></a> <span class='keyglyph'>|</span> <span class='varid'>floatMod</span> <span class='varid'>a</span> <span class='varid'>b</span> <span class='varop'>==</span> <span class='num'>0</span> <span class='keyglyph'>=</span> <span class='conid'>XPVNumber</span> <span class='conid'>Pos0</span>
<a name="line-76"></a> <span class='keyglyph'>|</span> <span class='varid'>otherwise</span> <span class='keyglyph'>=</span> <span class='conid'>XPVNumber</span> <span class='layout'>(</span><span class='conid'>Float</span> <span class='layout'>(</span><span class='varid'>floatMod</span> <span class='varid'>a</span> <span class='varid'>b</span><span class='layout'>)</span><span class='layout'>)</span>
<a name="line-77"></a> <span class='keyword'>where</span>
<a name="line-78"></a> <span class='varid'>floatMod</span> <span class='varid'>x</span> <span class='varid'>y</span>
<a name="line-79"></a> <span class='keyglyph'>|</span> <span class='varid'>x</span><span class='varop'>/</span><span class='varid'>y</span> <span class='varop'>>=</span> <span class='num'>0</span> <span class='keyglyph'>=</span> <span class='varid'>x</span> <span class='comment'>-</span> <span class='varid'>y</span> <span class='varop'>*</span> <span class='varid'>fromInteger</span><span class='layout'>(</span><span class='varid'>floor</span> <span class='layout'>(</span><span class='varid'>x</span> <span class='varop'>/</span> <span class='varid'>y</span><span class='layout'>)</span><span class='layout'>)</span>
<a name="line-80"></a> <span class='keyglyph'>|</span> <span class='varid'>otherwise</span> <span class='keyglyph'>=</span><span class='varid'>x</span> <span class='comment'>-</span> <span class='varid'>y</span> <span class='varop'>*</span> <span class='varid'>fromInteger</span><span class='layout'>(</span><span class='varid'>ceiling</span> <span class='layout'>(</span><span class='varid'>x</span> <span class='varop'>/</span> <span class='varid'>y</span><span class='layout'>)</span><span class='layout'>)</span>
<a name="line-81"></a>
<a name="line-82"></a><span class='definition'>xPathMod</span> <span class='keyword'>_</span> <span class='layout'>(</span><span class='conid'>XPVNumber</span> <span class='layout'>(</span><span class='conid'>Float</span> <span class='varid'>a</span><span class='layout'>)</span><span class='layout'>)</span> <span class='layout'>(</span><span class='conid'>XPVNumber</span> <span class='conid'>NegInf</span><span class='layout'>)</span>
<a name="line-83"></a> <span class='keyglyph'>=</span> <span class='conid'>XPVNumber</span> <span class='layout'>(</span><span class='conid'>Float</span> <span class='varid'>a</span><span class='layout'>)</span>
<a name="line-84"></a><span class='definition'>xPathMod</span> <span class='keyword'>_</span> <span class='layout'>(</span><span class='conid'>XPVNumber</span> <span class='layout'>(</span><span class='conid'>Float</span> <span class='varid'>a</span><span class='layout'>)</span><span class='layout'>)</span> <span class='layout'>(</span><span class='conid'>XPVNumber</span> <span class='conid'>PosInf</span><span class='layout'>)</span>
<a name="line-85"></a> <span class='keyglyph'>=</span> <span class='conid'>XPVNumber</span> <span class='layout'>(</span><span class='conid'>Float</span> <span class='varid'>a</span><span class='layout'>)</span>
<a name="line-86"></a><span class='definition'>xPathMod</span> <span class='keyword'>_</span> <span class='layout'>(</span><span class='conid'>XPVNumber</span> <span class='conid'>Neg0</span><span class='layout'>)</span> <span class='layout'>(</span><span class='conid'>XPVNumber</span> <span class='conid'>Pos0</span><span class='layout'>)</span>
<a name="line-87"></a> <span class='keyglyph'>=</span> <span class='conid'>XPVNumber</span> <span class='conid'>Neg0</span>
<a name="line-88"></a><span class='definition'>xPathMod</span> <span class='varid'>a</span> <span class='varid'>b</span> <span class='varid'>c</span> <span class='keyglyph'>=</span> <span class='varid'>xPathSpez</span> <span class='varid'>a</span> <span class='varid'>b</span> <span class='varid'>c</span>
<a name="line-89"></a>
<a name="line-90"></a>
<a name="line-91"></a><span class='comment'>-- |</span>
<a name="line-92"></a><span class='comment'>-- Division: the divison-operator is not according the IEEE 754 standard,</span>
<a name="line-93"></a><span class='comment'>-- it calculates the same as the % operator in Java and ECMAScript</span>
<a name="line-94"></a><span class='comment'>--</span>
<a name="line-95"></a>
<a name="line-96"></a><a name="xPathDiv"></a><span class='definition'>xPathDiv</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-97"></a><span class='definition'>xPathDiv</span> <span class='keyword'>_</span> <span class='layout'>(</span><span class='conid'>XPVNumber</span> <span class='layout'>(</span><span class='conid'>Float</span> <span class='varid'>a</span><span class='layout'>)</span><span class='layout'>)</span> <span class='layout'>(</span><span class='conid'>XPVNumber</span> <span class='layout'>(</span><span class='conid'>Float</span> <span class='varid'>b</span><span class='layout'>)</span><span class='layout'>)</span>
<a name="line-98"></a> <span class='keyglyph'>=</span> <span class='conid'>XPVNumber</span> <span class='layout'>(</span><span class='conid'>Float</span> <span class='layout'>(</span><span class='varid'>a</span> <span class='varop'>/</span> <span class='varid'>b</span><span class='layout'>)</span><span class='layout'>)</span>
<a name="line-99"></a><span class='definition'>xPathDiv</span> <span class='keyword'>_</span> <span class='layout'>(</span><span class='conid'>XPVNumber</span> <span class='conid'>NegInf</span><span class='layout'>)</span> <span class='layout'>(</span><span class='conid'>XPVNumber</span> <span class='layout'>(</span><span class='conid'>Float</span> <span class='varid'>a</span><span class='layout'>)</span><span class='layout'>)</span>
<a name="line-100"></a> <span class='keyglyph'>|</span> <span class='varid'>a</span> <span class='varop'><</span> <span class='num'>0</span> <span class='keyglyph'>=</span> <span class='conid'>XPVNumber</span> <span class='conid'>PosInf</span>
<a name="line-101"></a> <span class='keyglyph'>|</span> <span class='varid'>otherwise</span> <span class='keyglyph'>=</span> <span class='conid'>XPVNumber</span> <span class='conid'>NegInf</span>
<a name="line-102"></a><span class='definition'>xPathDiv</span> <span class='keyword'>_</span> <span class='layout'>(</span><span class='conid'>XPVNumber</span> <span class='conid'>PosInf</span><span class='layout'>)</span> <span class='layout'>(</span><span class='conid'>XPVNumber</span> <span class='layout'>(</span><span class='conid'>Float</span> <span class='varid'>a</span><span class='layout'>)</span><span class='layout'>)</span>
<a name="line-103"></a> <span class='keyglyph'>|</span> <span class='varid'>a</span> <span class='varop'><</span> <span class='num'>0</span> <span class='keyglyph'>=</span> <span class='conid'>XPVNumber</span> <span class='conid'>NegInf</span>
<a name="line-104"></a> <span class='keyglyph'>|</span> <span class='varid'>otherwise</span> <span class='keyglyph'>=</span> <span class='conid'>XPVNumber</span> <span class='conid'>PosInf</span>
<a name="line-105"></a><span class='definition'>xPathDiv</span> <span class='keyword'>_</span> <span class='layout'>(</span><span class='conid'>XPVNumber</span> <span class='layout'>(</span><span class='conid'>Float</span> <span class='varid'>a</span><span class='layout'>)</span><span class='layout'>)</span> <span class='layout'>(</span><span class='conid'>XPVNumber</span> <span class='conid'>NegInf</span><span class='layout'>)</span>
<a name="line-106"></a> <span class='keyglyph'>|</span> <span class='varid'>a</span> <span class='varop'><</span> <span class='num'>0</span> <span class='keyglyph'>=</span> <span class='conid'>XPVNumber</span> <span class='conid'>Pos0</span>
<a name="line-107"></a> <span class='keyglyph'>|</span> <span class='varid'>otherwise</span> <span class='keyglyph'>=</span> <span class='conid'>XPVNumber</span> <span class='conid'>Neg0</span>
<a name="line-108"></a><span class='definition'>xPathDiv</span> <span class='keyword'>_</span> <span class='layout'>(</span><span class='conid'>XPVNumber</span> <span class='layout'>(</span><span class='conid'>Float</span> <span class='varid'>a</span><span class='layout'>)</span><span class='layout'>)</span> <span class='layout'>(</span><span class='conid'>XPVNumber</span> <span class='conid'>PosInf</span><span class='layout'>)</span>
<a name="line-109"></a> <span class='keyglyph'>|</span> <span class='varid'>a</span> <span class='varop'><</span> <span class='num'>0</span> <span class='keyglyph'>=</span> <span class='conid'>XPVNumber</span> <span class='conid'>Neg0</span>
<a name="line-110"></a> <span class='keyglyph'>|</span> <span class='varid'>otherwise</span> <span class='keyglyph'>=</span> <span class='conid'>XPVNumber</span> <span class='conid'>Pos0</span>
<a name="line-111"></a><span class='definition'>xPathDiv</span> <span class='keyword'>_</span> <span class='layout'>(</span><span class='conid'>XPVNumber</span> <span class='conid'>Neg0</span><span class='layout'>)</span> <span class='layout'>(</span><span class='conid'>XPVNumber</span> <span class='layout'>(</span><span class='conid'>Float</span> <span class='varid'>a</span><span class='layout'>)</span><span class='layout'>)</span>
<a name="line-112"></a> <span class='keyglyph'>|</span> <span class='varid'>a</span> <span class='varop'><</span> <span class='num'>0</span> <span class='keyglyph'>=</span> <span class='conid'>XPVNumber</span> <span class='conid'>Pos0</span>
<a name="line-113"></a> <span class='keyglyph'>|</span> <span class='varid'>otherwise</span> <span class='keyglyph'>=</span> <span class='conid'>XPVNumber</span> <span class='conid'>Neg0</span>
<a name="line-114"></a><span class='definition'>xPathDiv</span> <span class='keyword'>_</span> <span class='layout'>(</span><span class='conid'>XPVNumber</span> <span class='layout'>(</span><span class='conid'>Float</span> <span class='varid'>a</span><span class='layout'>)</span><span class='layout'>)</span> <span class='layout'>(</span><span class='conid'>XPVNumber</span> <span class='conid'>Neg0</span><span class='layout'>)</span>
<a name="line-115"></a> <span class='keyglyph'>|</span> <span class='varid'>a</span> <span class='varop'><</span> <span class='num'>0</span> <span class='keyglyph'>=</span> <span class='conid'>XPVNumber</span> <span class='conid'>PosInf</span>
<a name="line-116"></a> <span class='keyglyph'>|</span> <span class='varid'>otherwise</span> <span class='keyglyph'>=</span> <span class='conid'>XPVNumber</span> <span class='conid'>NegInf</span>
<a name="line-117"></a><span class='definition'>xPathDiv</span> <span class='keyword'>_</span> <span class='layout'>(</span><span class='conid'>XPVNumber</span> <span class='layout'>(</span><span class='conid'>Float</span> <span class='varid'>a</span><span class='layout'>)</span><span class='layout'>)</span> <span class='layout'>(</span><span class='conid'>XPVNumber</span> <span class='conid'>Pos0</span><span class='layout'>)</span>
<a name="line-118"></a> <span class='keyglyph'>|</span> <span class='varid'>a</span> <span class='varop'><</span> <span class='num'>0</span> <span class='keyglyph'>=</span> <span class='conid'>XPVNumber</span> <span class='conid'>NegInf</span>
<a name="line-119"></a> <span class='keyglyph'>|</span> <span class='varid'>otherwise</span> <span class='keyglyph'>=</span> <span class='conid'>XPVNumber</span> <span class='conid'>PosInf</span>
<a name="line-120"></a><span class='definition'>xPathDiv</span> <span class='varid'>a</span> <span class='varid'>b</span> <span class='varid'>c</span> <span class='keyglyph'>=</span> <span class='varid'>xPathSpez</span> <span class='varid'>a</span> <span class='varid'>b</span> <span class='varid'>c</span>
<a name="line-121"></a>
<a name="line-122"></a>
<a name="line-123"></a><span class='comment'>-- |</span>
<a name="line-124"></a><span class='comment'>-- Plus and minus</span>
<a name="line-125"></a><span class='comment'>--</span>
<a name="line-126"></a><span class='comment'>-- 1.parameter op : plus or minus operation</span>
<a name="line-127"></a><span class='comment'>--</span>
<a name="line-128"></a>
<a name="line-129"></a><a name="xPathAdd"></a><span class='definition'>xPathAdd</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-130"></a><span class='definition'>xPathAdd</span> <span class='conid'>Plus</span> <span class='layout'>(</span><span class='conid'>XPVNumber</span> <span class='layout'>(</span><span class='conid'>Float</span> <span class='varid'>a</span><span class='layout'>)</span><span class='layout'>)</span> <span class='layout'>(</span><span class='conid'>XPVNumber</span> <span class='layout'>(</span><span class='conid'>Float</span> <span class='varid'>b</span><span class='layout'>)</span><span class='layout'>)</span>
<a name="line-131"></a> <span class='keyglyph'>=</span> <span class='keyword'>if</span> <span class='varid'>a</span> <span class='varop'>+</span> <span class='varid'>b</span> <span class='varop'>==</span> <span class='num'>0</span>
<a name="line-132"></a> <span class='keyword'>then</span> <span class='conid'>XPVNumber</span> <span class='conid'>Pos0</span>
<a name="line-133"></a> <span class='keyword'>else</span> <span class='conid'>XPVNumber</span> <span class='layout'>(</span><span class='conid'>Float</span> <span class='layout'>(</span><span class='varid'>a</span><span class='varop'>+</span><span class='varid'>b</span><span class='layout'>)</span><span class='layout'>)</span>
<a name="line-134"></a><span class='definition'>xPathAdd</span> <span class='conid'>Minus</span> <span class='layout'>(</span><span class='conid'>XPVNumber</span> <span class='layout'>(</span><span class='conid'>Float</span> <span class='varid'>a</span><span class='layout'>)</span><span class='layout'>)</span> <span class='layout'>(</span><span class='conid'>XPVNumber</span> <span class='layout'>(</span><span class='conid'>Float</span> <span class='varid'>b</span><span class='layout'>)</span><span class='layout'>)</span>
<a name="line-135"></a> <span class='keyglyph'>=</span> <span class='keyword'>if</span> <span class='varid'>a</span> <span class='comment'>-</span> <span class='varid'>b</span> <span class='varop'>==</span> <span class='num'>0</span>
<a name="line-136"></a> <span class='keyword'>then</span> <span class='conid'>XPVNumber</span> <span class='conid'>Pos0</span>
<a name="line-137"></a> <span class='keyword'>else</span> <span class='conid'>XPVNumber</span> <span class='layout'>(</span><span class='conid'>Float</span> <span class='layout'>(</span><span class='varid'>a</span><span class='comment'>-</span><span class='varid'>b</span><span class='layout'>)</span><span class='layout'>)</span>
<a name="line-138"></a><span class='definition'>xPathAdd</span> <span class='keyword'>_</span> <span class='layout'>(</span><span class='conid'>XPVNumber</span> <span class='conid'>PosInf</span><span class='layout'>)</span> <span class='layout'>(</span><span class='conid'>XPVNumber</span> <span class='conid'>NegInf</span><span class='layout'>)</span> <span class='keyglyph'>=</span> <span class='conid'>XPVNumber</span> <span class='conid'>NaN</span>
<a name="line-139"></a><span class='definition'>xPathAdd</span> <span class='keyword'>_</span> <span class='layout'>(</span><span class='conid'>XPVNumber</span> <span class='conid'>NegInf</span><span class='layout'>)</span> <span class='layout'>(</span><span class='conid'>XPVNumber</span> <span class='conid'>PosInf</span><span class='layout'>)</span> <span class='keyglyph'>=</span> <span class='conid'>XPVNumber</span> <span class='conid'>NaN</span>
<a name="line-140"></a><span class='definition'>xPathAdd</span> <span class='keyword'>_</span> <span class='layout'>(</span><span class='conid'>XPVNumber</span> <span class='conid'>PosInf</span><span class='layout'>)</span> <span class='keyword'>_</span> <span class='keyglyph'>=</span> <span class='conid'>XPVNumber</span> <span class='conid'>PosInf</span>
<a name="line-141"></a><span class='definition'>xPathAdd</span> <span class='keyword'>_</span> <span class='layout'>(</span><span class='conid'>XPVNumber</span> <span class='conid'>NegInf</span><span class='layout'>)</span> <span class='keyword'>_</span> <span class='keyglyph'>=</span> <span class='conid'>XPVNumber</span> <span class='conid'>NegInf</span>
<a name="line-142"></a><span class='definition'>xPathAdd</span> <span class='keyword'>_</span> <span class='keyword'>_</span> <span class='layout'>(</span><span class='conid'>XPVNumber</span> <span class='conid'>PosInf</span><span class='layout'>)</span> <span class='keyglyph'>=</span> <span class='conid'>XPVNumber</span> <span class='conid'>PosInf</span>
<a name="line-143"></a><span class='definition'>xPathAdd</span> <span class='keyword'>_</span> <span class='keyword'>_</span> <span class='layout'>(</span><span class='conid'>XPVNumber</span> <span class='conid'>NegInf</span><span class='layout'>)</span> <span class='keyglyph'>=</span> <span class='conid'>XPVNumber</span> <span class='conid'>NegInf</span>
<a name="line-144"></a><span class='definition'>xPathAdd</span> <span class='keyword'>_</span> <span class='layout'>(</span><span class='conid'>XPVNumber</span> <span class='layout'>(</span><span class='conid'>Float</span> <span class='varid'>a</span><span class='layout'>)</span><span class='layout'>)</span> <span class='layout'>(</span><span class='conid'>XPVNumber</span> <span class='conid'>Pos0</span><span class='layout'>)</span> <span class='keyglyph'>=</span> <span class='conid'>XPVNumber</span> <span class='layout'>(</span><span class='conid'>Float</span> <span class='varid'>a</span><span class='layout'>)</span>
<a name="line-145"></a><span class='definition'>xPathAdd</span> <span class='varid'>op</span> <span class='layout'>(</span><span class='conid'>XPVNumber</span> <span class='conid'>Pos0</span><span class='layout'>)</span> <span class='layout'>(</span><span class='conid'>XPVNumber</span> <span class='layout'>(</span><span class='conid'>Float</span> <span class='varid'>a</span><span class='layout'>)</span><span class='layout'>)</span>
<a name="line-146"></a> <span class='keyglyph'>|</span> <span class='varid'>op</span> <span class='varop'>==</span> <span class='conid'>Minus</span> <span class='keyglyph'>=</span> <span class='conid'>XPVNumber</span> <span class='layout'>(</span><span class='conid'>Float</span> <span class='layout'>(</span><span class='comment'>-</span><span class='varid'>a</span><span class='layout'>)</span><span class='layout'>)</span>
<a name="line-147"></a> <span class='keyglyph'>|</span> <span class='varid'>otherwise</span> <span class='keyglyph'>=</span> <span class='conid'>XPVNumber</span> <span class='layout'>(</span><span class='conid'>Float</span> <span class='varid'>a</span><span class='layout'>)</span>
<a name="line-148"></a><span class='definition'>xPathAdd</span> <span class='varid'>op</span> <span class='layout'>(</span><span class='conid'>XPVNumber</span> <span class='conid'>Neg0</span><span class='layout'>)</span> <span class='layout'>(</span><span class='conid'>XPVNumber</span> <span class='layout'>(</span><span class='conid'>Float</span> <span class='varid'>a</span><span class='layout'>)</span><span class='layout'>)</span>
<a name="line-149"></a> <span class='keyglyph'>|</span> <span class='varid'>op</span> <span class='varop'>==</span> <span class='conid'>Minus</span> <span class='keyglyph'>=</span> <span class='conid'>XPVNumber</span> <span class='layout'>(</span><span class='conid'>Float</span> <span class='layout'>(</span><span class='comment'>-</span><span class='varid'>a</span><span class='layout'>)</span><span class='layout'>)</span>
<a name="line-150"></a> <span class='keyglyph'>|</span> <span class='varid'>otherwise</span> <span class='keyglyph'>=</span> <span class='conid'>XPVNumber</span> <span class='layout'>(</span><span class='conid'>Float</span> <span class='varid'>a</span><span class='layout'>)</span>
<a name="line-151"></a><span class='definition'>xPathAdd</span> <span class='keyword'>_</span> <span class='layout'>(</span><span class='conid'>XPVNumber</span> <span class='layout'>(</span><span class='conid'>Float</span> <span class='varid'>a</span><span class='layout'>)</span><span class='layout'>)</span> <span class='layout'>(</span><span class='conid'>XPVNumber</span> <span class='conid'>Neg0</span><span class='layout'>)</span> <span class='keyglyph'>=</span> <span class='conid'>XPVNumber</span> <span class='layout'>(</span><span class='conid'>Float</span> <span class='varid'>a</span><span class='layout'>)</span>
<a name="line-152"></a><span class='definition'>xPathAdd</span> <span class='keyword'>_</span> <span class='layout'>(</span><span class='conid'>XPVNumber</span> <span class='conid'>Neg0</span><span class='layout'>)</span> <span class='layout'>(</span><span class='conid'>XPVNumber</span> <span class='conid'>Pos0</span><span class='layout'>)</span> <span class='keyglyph'>=</span> <span class='conid'>XPVNumber</span> <span class='conid'>Neg0</span>
<a name="line-153"></a><span class='definition'>xPathAdd</span> <span class='keyword'>_</span> <span class='layout'>(</span><span class='conid'>XPVNumber</span> <span class='conid'>Pos0</span><span class='layout'>)</span> <span class='layout'>(</span><span class='conid'>XPVNumber</span> <span class='conid'>Neg0</span><span class='layout'>)</span> <span class='keyglyph'>=</span> <span class='conid'>XPVNumber</span> <span class='conid'>Neg0</span>
<a name="line-154"></a><span class='definition'>xPathAdd</span> <span class='keyword'>_</span> <span class='layout'>(</span><span class='conid'>XPVNumber</span> <span class='conid'>Neg0</span><span class='layout'>)</span> <span class='layout'>(</span><span class='conid'>XPVNumber</span> <span class='conid'>Neg0</span><span class='layout'>)</span> <span class='keyglyph'>=</span> <span class='conid'>XPVNumber</span> <span class='conid'>Neg0</span>
<a name="line-155"></a><span class='definition'>xPathAdd</span> <span class='keyword'>_</span> <span class='layout'>(</span><span class='conid'>XPVNumber</span> <span class='conid'>Pos0</span><span class='layout'>)</span> <span class='layout'>(</span><span class='conid'>XPVNumber</span> <span class='conid'>Pos0</span><span class='layout'>)</span> <span class='keyglyph'>=</span> <span class='conid'>XPVNumber</span> <span class='conid'>Pos0</span>
<a name="line-156"></a><span class='definition'>xPathAdd</span> <span class='varid'>a</span> <span class='varid'>b</span> <span class='varid'>c</span> <span class='keyglyph'>=</span> <span class='varid'>xPathSpez</span> <span class='varid'>a</span> <span class='varid'>b</span> <span class='varid'>c</span>
<a name="line-157"></a>
<a name="line-158"></a>
<a name="line-159"></a><a name="xPathSpez"></a><span class='comment'>-- |</span>
<a name="line-160"></a><span class='comment'>-- Identically results of the operators are combined to get</span>
<a name="line-161"></a><span class='comment'>-- as few as possible combinations of the special IEEE values</span>
<a name="line-162"></a><span class='comment'>--</span>
<a name="line-163"></a><span class='definition'>xPathSpez</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-164"></a><span class='definition'>xPathSpez</span> <span class='keyword'>_</span> <span class='layout'>(</span><span class='conid'>XPVError</span> <span class='varid'>e</span><span class='layout'>)</span> <span class='keyword'>_</span> <span class='keyglyph'>=</span> <span class='conid'>XPVError</span> <span class='varid'>e</span>
<a name="line-165"></a><span class='definition'>xPathSpez</span> <span class='keyword'>_</span> <span class='keyword'>_</span> <span class='layout'>(</span><span class='conid'>XPVError</span> <span class='varid'>e</span><span class='layout'>)</span> <span class='keyglyph'>=</span> <span class='conid'>XPVError</span> <span class='varid'>e</span>
<a name="line-166"></a><span class='definition'>xPathSpez</span> <span class='keyword'>_</span> <span class='keyword'>_</span> <span class='keyword'>_</span> <span class='keyglyph'>=</span> <span class='conid'>XPVNumber</span> <span class='conid'>NaN</span>
</pre></body>
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