Grouping example: input

• Task: Arrange articles in a large, flat document like this by section:

  ---

  <?xml version="1.0"?>
  <backslash>
  
  <story>
  <title>ROX Desktop Update</title>
  <url>http://slashdot.org/article.pl?sid=02/02/18/180240</url>
  <time>2002-02-18 18:50:13</time>
  <author>timothy</author>
  <department>small-simple-swift</department>
  <topic>104</topic>
  <comments>32</comments>
  <section>developers</section>
  <image>topicx.jpg</image>
  </story>
  
  <story>
  <title>HP Selling Systems With Linux</title>
  <url>http://slashdot.org/article.pl?sid=02/02/18/1712241</url>
  <time>2002-02-18 17:37:20</time>
  <author>timothy</author>
  <department>wish-this-wasn't-remarkable</department>
  <topic>173</topic>
  <comments>188</comments>
  <section>articles</section>
  <image>topichp.gif</image>
  </story>
  
  <story>
  <title>Excellent Hacks to the ReplayTV 4000</title>
  <url>http://slashdot.org/article.pl?sid=02/02/18/1619213</url>
  <time>2002-02-18 16:46:04</time>
  <author>CmdrTaco</author>
  <department>hardware-I-lust-after</department>
  <topic>129</topic>
  <comments>117</comments>
  <section>articles</section>
  <image>topictv.jpg</image>
  </story>
  
  <story>
  <title>Peek-a-Boo(ty)</title>
  <url>http://slashdot.org/article.pl?sid=02/02/18/1546226</url>
  <time>2002-02-18 15:58:06</time>
  <author>Hemos</author>
  <department>pirate-treasure</department>
  <topic>158</topic>
  <comments>207</comments>
  <section>articles</section>
  <image>topicprivacy.gif</image>
  </story>
  
  <story>
  <title>Self-Shredding E-Mail</title>
  <url>http://slashdot.org/article.pl?sid=02/02/18/1343202</url>
  <time>2002-02-18 14:37:45</time>
  <author>timothy</author>
  <department>plausible-deniability</department>
  <topic>158</topic>
  <comments>170</comments>
  <section>articles</section>
  <image>topicprivacy.gif</image>
  </story>
  
  <story>
  <title>CIA &amp;amp; KGB Gadgets On Display</title>
  <url>http://slashdot.org/article.pl?sid=02/02/18/0252219</url>
  <time>2002-02-18 13:52:04</time>
  <author>Hemos</author>
  <department>looking-a-tthe-gear</department>
  <topic>126</topic>
  <comments>103</comments>
  <section>articles</section>
  <image>topictech2.gif</image>
  </story>
  
  <story>
  <title>Re-Building the Wright Flyer</title>
  <url>http://slashdot.org/article.pl?sid=02/02/18/060257</url>
  <time>2002-02-18 12:29:12</time>
  <author>timothy</author>
  <department>we-hope-they-wear-modern-helmets</department>
  <topic>126</topic>
  <comments>132</comments>
  <section>science</section>
  <image>topictech2.gif</image>
  </story>
  
  <story>
  <title>How to Fix the Unix Configuration Nightmare</title>
  <url>http://slashdot.org/article.pl?sid=02/02/18/0248248</url>
  <time>2002-02-18 10:48:36</time>
  <author>Hemos</author>
  <department>fixing-the-problem</department>
  <topic>130</topic>
  <comments>367</comments>
  <section>articles</section>
  <image>topicunix.jpg</image>
  </story>
  
  <story>
  <title>Sleep Less, Live Longer</title>
  <url>http://slashdot.org/article.pl?sid=02/02/18/0511253</url>
  <time>2002-02-18 07:38:15</time>
  <author>timothy</author>
  <department>if-you're-reading-this</department>
  <topic>134</topic>
  <comments>309</comments>
  <section>science</section>
  <image>topicscience.gif</image>
  </story>
  
  <story>
  <title>Warming and Slowing the World</title>
  <url>http://slashdot.org/article.pl?sid=02/02/18/0243253</url>
  <time>2002-02-18 04:39:39</time>
  <author>Hemos</author>
  <department>slowing-things-down</department>
  <topic>134</topic>
  <comments>312</comments>
  <section>science</section>
  <image>topicscience.gif</image>
  </story>
  
  </backslash>
  

  ---