title: find interval from value
body: <p>Suppose I've a list of intervals: <code>[1, 90], [104, 234], [235, 300], ...</code>. Every interval has a name <code>A1, B, B1, ...</code>. Given a value I want the name of the interval (<code>112 -&gt; B</code>, <code>100 -&gt; special_value</code>). What's the best and faster implentation? Something better than a list of <code>if</code> / <code>else if</code>.</p>
  
  <p>The intervals are sorted in order, and there is no overlap. I have a lot of values as input, but only one set of intervals. The size intervals are very different, some are very small, other are very large.</p>