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Welcome to the third installment of stupid coding tricks! As we learned from the T-SQL Mandelbrot and A Batch of Pi, stupid coding tricks aren't really about obfuscation per se... just, well, stupid awesomeness. Kinda like a quine, except even more useless.Got a trick of your own? I'd love to see it, so send it on in.
If you were to use The Daily WTF as a guide, your impression of XSL Transformations (XSLT) would probably be fairly low. I mean, seeing article after article after article might have given the impression that XSLT is often not the right tool for the job... or, perhaps, maybe not even a right tool. Period.
But regardless of your opinions on XSLT, I'm certain you'll have a new appreciation after seeing what magic it can work on a boring old piece of XML. Even if its variables are write-once and cannot vary.
<?xml version="1.0" encoding="UTF-8"?> <!-- XSLT Mandelbrot - written by Joel Yliluoma 2007, http://iki.fi/bisqwit/ --> <?xml-stylesheet type='text/xsl' href='mandelbrot.xsl'?> <fractal> <scale>100</scale> <y><min>-120</min> <max>120</max> <step>3.9</step></y> <x><min>-203</min> <max>100</max> <step>1.4</step></x> <maxiter>28</maxiter> <background>#500</background> <magnitude value="0"><symbol>░</symbol><color>#115</color></magnitude> <magnitude value="1"><symbol>░</symbol><color>#228</color></magnitude> <magnitude value="2"><symbol>░</symbol><color>#22B</color></magnitude> <magnitude value="3"><symbol>░</symbol><color>#33D</color></magnitude> <magnitude value="4"><symbol>░</symbol><color>#44F</color></magnitude> <magnitude value="5"><symbol>▒</symbol><color>#55C</color></magnitude> <magnitude value="6"><symbol>▒</symbol><color>#55D</color></magnitude> <magnitude value="7"><symbol>▒</symbol><color>#55E</color></magnitude> <magnitude value="8"><symbol>▓</symbol><color>#55F</color></magnitude> <magnitude value="9"><symbol>▓</symbol><color>#66F</color></magnitude> <magnitude value="10"><symbol>▓</symbol><color>#77F</color></magnitude> <magnitude value="11"><symbol>▓</symbol><color>#88F</color></magnitude> <magnitude value="12"><symbol>█</symbol><color>#88F</color></magnitude> <magnitude value="13"><symbol>▓</symbol><color>#99F</color></magnitude> <magnitude value="14"><symbol>█</symbol><color>#99F</color></magnitude> <magnitude value="15"><symbol>▓</symbol><color>#AAF</color></magnitude> <magnitude value="16"><symbol>█</symbol><color>#AAF</color></magnitude> <magnitude value="17"><symbol>▓</symbol><color>#BBF</color></magnitude> <magnitude value="18"><symbol>█</symbol><color>#BBF</color></magnitude> <magnitude value="19"><symbol>▓</symbol><color>#CCF</color></magnitude> <magnitude value="20"><symbol>█</symbol><color>#CCF</color></magnitude> <magnitude value="21"><symbol>▓</symbol><color>#DDF</color></magnitude> <magnitude value="22"><symbol>█</symbol><color>#DDF</color></magnitude> <magnitude value="23"><symbol>▓</symbol><color>#EEF</color></magnitude> <magnitude value="24"><symbol>█</symbol><color>#EEF</color></magnitude> <magnitude value="25"><symbol>▓</symbol><color>#FFF</color></magnitude> <magnitude value="26"><symbol>█</symbol><color>#FFF</color></magnitude> <magnitude value="27"><symbol>░</symbol><color>#000</color></magnitude> </fractal>
Simple XML, right? Now let's apply a little templating...
<?xml version="1.0" encoding="UTF-8"?>
<xsl:stylesheet version="1.0" xmlns:xsl="http://www.w3.org/1999/XSL/Transform">
<!-- XSLT Mandelbrot - written by Joel Yliluoma 2007, http://iki.fi/bisqwit/ -->
<xsl:output method="html" indent="no"
doctype-public="-//W3C//DTD HTML 4.01//EN"
doctype-system="http://www.w3.org/TR/REC-html40/strict.dtd"
/>
<xsl:template match="/fractal">
<html>
<head>
<title>XSLT fractal</title>
<style type="text/css">
body { color:#55F; background:#000 }
pre { font-family:monospace; font-size:7px }
pre span { background:<xsl:value-of select="background" /> }
</style>
</head>
<body>
<div style="position:absolute;top:20px;left:20em">
Copyright © 1992,2007 Joel Yliluoma
(<a href="http://iki.fi/bisqwit/">http://iki.fi/bisqwit/</a>)
</div>
<h1 style="margin:0px">XSLT fractal</h1>
<pre><xsl:call-template name="bisqwit-mandelbrot" /></pre>
</body>
</html>
</xsl:template>
<xsl:template name="bisqwit-mandelbrot"
><xsl:call-template name="bisqwit-mandelbrot-line">
<xsl:with-param name="y" select="y/min"/>
</xsl:call-template
></xsl:template>
<xsl:template name="bisqwit-mandelbrot-line"
><xsl:param name="y"
/><xsl:call-template name="bisqwit-mandelbrot-column">
<xsl:with-param name="x" select="x/min"/>
<xsl:with-param name="y" select="$y"/>
</xsl:call-template
><xsl:if test="$y < y/max"
><br
/><xsl:call-template name="bisqwit-mandelbrot-line">
<xsl:with-param name="y" select="$y + y/step"/>
</xsl:call-template
></xsl:if
></xsl:template>
<xsl:template name="bisqwit-mandelbrot-column"
><xsl:param name="x"
/><xsl:param name="y"
/><xsl:call-template name="bisqwit-mandelbrot-slot">
<xsl:with-param name="x" select="$x" />
<xsl:with-param name="y" select="$y" />
<xsl:with-param name="zr" select="$x" />
<xsl:with-param name="zi" select="$y" />
</xsl:call-template
><xsl:if test="$x < x/max"
><xsl:call-template name="bisqwit-mandelbrot-column">
<xsl:with-param name="x" select="$x + x/step"/>
<xsl:with-param name="y" select="$y" />
</xsl:call-template
></xsl:if
></xsl:template>
<xsl:template name="bisqwit-mandelbrot-slot"
><xsl:param name="x"
/><xsl:param name="y"
/><xsl:param name="zr"
/><xsl:param name="zi"
/><xsl:param name="iter" select="0"
/><xsl:variable name="zrsqr" select="($zr * $zr)"
/><xsl:variable name="zisqr" select="($zi * $zi)"
/><xsl:choose>
<xsl:when test="(4*scale*scale >= $zrsqr + $zisqr) and (maxiter > $iter+1)"
><xsl:call-template name="bisqwit-mandelbrot-slot">
<xsl:with-param name="x" select="$x" />
<xsl:with-param name="y" select="$y" />
<xsl:with-param name="zi" select="(2 * $zr * $zi) div scale + $y" />
<xsl:with-param name="zr" select="($zrsqr - $zisqr) div scale + $x" />
<xsl:with-param name="iter" select="$iter + 1" />
</xsl:call-template
></xsl:when>
<xsl:otherwise
><xsl:variable name="magnitude" select="magnitude[@value=$iter]"
/><span style="color:{$magnitude/color}"
><xsl:value-of select="$magnitude/symbol"
/></span></xsl:otherwise>
</xsl:choose
></xsl:template>
</xsl:stylesheet>
Open it in a browser (go ahead, try it yourself), and voilà! You get XSLT Mandelbrot.
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