>>> basic link
before <http://foo.com/> after

<<<
<p>before <a href="http://foo.com/">http://foo.com/</a> after</p>
>>> handles ampersand in url
<http://foo.com/?a=1&b=2>

<<<
<p><a href="http://foo.com/?a=1&amp;b=2">http://foo.com/?a=1&amp;b=2</a></p>