title: Why does Incanter return number instead of sequence when result is one value?
body: <p>I am having an issue that can be reduced to the following problem: When the result of a query is one value, <code>sel / $</code> returns a number, when it is more than one value, it is a sequence:</p>
  
  <pre><code>(with-data (to-dataset [[1 2] [3 4]])
      ($ :col-1))
  </code></pre>
  
  <p>yields (2 4), but</p>
  
  <pre><code>(with-data (to-dataset [[1 2]])
      ($ :col-1))
  </code></pre>
  
  <p>yields 2.</p>
  
  <p>I would like it to be a sequence at all times, since I want to e. g. apply + to the sequence.  I want to avoid checking for the type using (seq?). Any ideas? Is this behaviour of Incanter reasonable?</p>
  
  <p>This is my workaround:</p>
  
  <pre><code>(let [seq-it (fn [a] (if (seq? a) a (list a)))]
    (with-data (to-dataset [[1 2]])
      (-&gt;&gt; ($ :col-1) 
           (seq-it))))
  </code></pre>
  
  <p>which yields (2).</p>