hpricot：An Hpricot Showcase：Hpricot Basics：Search for Elements

everyday Ruby 
>> require "hpricot"
=> true
>> require "open-uri"
=> true
>> doc = Hpricot(open("http://qwantz.com/"))
=> #<Hpricot::Doc {doctype "<!DOCTYPE html PUBLIC \"-//W3C//DTD XHTML 1.0 Transitional//EN\"\n" "                \"http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd\">"} "\n" {elem <html> "\n" {elem <head> "\n" {emptyelem <meta content="0; URL=/index.php" http-equiv="Refresh">} "\n" </head>} "\n" {elem <body> "\n" </body>} "\n" </html>} "\n\n">
>> doc.search("//p[@class='posted']")
=> #<Hpricot::Elements[]>
>> doc = Hpricot("<p>A simple <b>test</b> string.</p>")
=> #<Hpricot::Doc {elem <p> "A simple " {elem <b> "test" </b>} " string." </p>}>
>> doc.search("//p")
=> #<Hpricot::Elements[{elem <p> "A simple " {elem <b> "test" </b>} " string." </p>}]>
>> doc = Hpricot("<p>A simple <b>test</b> string.</p><p>foo<\p>")
=> #<Hpricot::Doc {elem <p> "A simple " {elem <b> "test" </b>} " string." </p>} {elem <p> "foo" {emptyelem <p>}}>
>> doc.search("//p")
=> #<Hpricot::Elements[{elem <p> "A simple " {elem <b> "test" </b>} " string." </p>}, {elem <p> "foo" {emptyelem <p>}}, {emptyelem <p>}]>
>> doc = Hpricot("<p>A simple <b>test</b> string.</p><p>foo</p>")
=> #<Hpricot::Doc {elem <p> "A simple " {elem <b> "test" </b>} " string." </p>} {elem <p> "foo" </p>}>
>> doc.search("//p")
=> #<Hpricot::Elements[{elem <p> "A simple " {elem <b> "test" </b>} " string." </p>}, {elem <p> "foo" </p>}]>
>> doc = Hpricot("<p class='posted'>A simple <b>test</b> string.</p>")
=> #<Hpricot::Doc {elem <p class="posted"> "A simple " {elem <b> "test" </b>} " string." </p>}>
>> doc.search("//p[@class='posted']")
=> #<Hpricot::Elements[{elem <p class="posted"> "A simple " {elem <b> "test" </b>} " string." </p>}]>
>> doc.search("//p")
=> #<Hpricot::Elements[{elem <p class="posted"> "A simple " {elem <b> "test" </b>} " string." </p>}]>
>> doc/"p.posted"
=> #<Hpricot::Elements[{elem <p class="posted"> "A simple " {elem <b> "test" </b>} " string." </p>}]>
>> doc/"p"
=> #<Hpricot::Elements[{elem <p class="posted"> "A simple " {elem <b> "test" </b>} " string." </p>}]>

再現可能な例を載せてほしいな〜