rming_up.html#spirit.karma.tutorials.warming_up.trivial_example__4_generating_a_comma_delimited_list_of_numbers">Trivial
          Example #4 Generating a comma-delimited list of numbers</a>
        </h6>
<p>
          We follow the lead of <span class="emphasis"><em>Spirit.Qi</em></span>'s warming up section
          and will create a generator that produces a comma-delimited list of numbers.
        </p>
<pre class="programlisting"><span class="identifier">double_</span> <span class="special">&lt;&lt;</s