title: Ruby str.match(regex) returns MatchData containing only first matched item
body: <p><strong>Using Ruby 2.2</strong></p>
  
  <p>I have strings like following:</p>
  
  <ul>
  <li>Weekly on Tuesday and Friday</li>
  <li>Weekly on Monday, Wednesday and Saturday</li>
  <li>Monthly every 2 weeks on Monday</li>
  </ul>
  
  <p>To extract the days of week from above shown strings I have written following regex:</p>
  
  <pre><code>/\b(Monday|Tuesday|Wednesday|Thursday|Friday|Saturday|Sunday)\b/
  </code></pre>
  
  <p>When trying to use <code>String#match</code> instance method the match_data doesn't return all matches. For e.g. please refer the irb output shown below wherein when the string <code>Weekly on Tuesday and Friday</code> is matched against above shown regex the <code>MatchData</code> contains just <code>Tuesday</code>. I expected it to contain <code>Friday</code> too.</p>
  
  <pre><code>  2.2.1 :001 &gt; str = "Weekly on Tuesday and Friday"
    =&gt; "Weekly on Tuesday and Friday" 
    2.2.1 :002 &gt; regex = /\b(Monday|Tuesday|Wednesday|Thursday|Friday|Saturday|Sunday)\b/
    =&gt; /\b(Monday|Tuesday|Wednesday|Thursday|Friday|Saturday|Sunday)\b/ 
    2.2.1 :003 &gt; str.match(regex)
    =&gt; #&lt;MatchData "Tuesday" 1:"Tuesday"&gt; 
    2.2.1 :004 &gt; match_data = str.match(regex)
    =&gt; #&lt;MatchData "Tuesday" 1:"Tuesday"&gt; 
    2.2.1 :005 &gt; match_data.captures
    =&gt; ["Tuesday"] 
  </code></pre>
  
  <p>Can anybody please explain me why the MatchData contains only the first matched term when I haven't used any start/end anchors in my Regex? I am sure my regex misses something but I am unable to figure out.</p>
  
  <p><strong>Note</strong></p>
  
  <p>Rubular shows correct match groups for the same regex as can be seen at <a href="http://rubular.com/r/XZmrHPkjEk" rel="nofollow">http://rubular.com/r/XZmrHPkjEk</a></p>