title: regex double white space separation problem
body: <p>I want a regex to match words that are delimited by double or more space characters, e.g.</p>
  
  <pre><code>ABC  DE  FGHIJ   KLM    NO  P  QRST
  </code></pre>
  
  <p>Notice double or more spaces between the alphabets. Writing regex for such a problem is easy as I only need the first 4 words, as we may search for a word by using <code>\S+</code> or <code>\S+?</code></p>
  
  <p>However, for my problem, only 1 white space CAN occur in a word, for example</p>
  
  <pre><code>AB C  DE  FG HIJ   KLM    NO  P  QRST
  </code></pre>
  
  <p>Here AB C is a word and FG HIJ is a word as well. In short we want to isolate characters that are spearated by double or more white spaces, I tried using this regex,</p>
  
  <pre><code>.+?  +.+?  +.+?  +.+?  +
  </code></pre>
  
  <p>it matches very swiftly, but it takes too much time for strings it doesn't match. (4 matches are given as an example here, in practice I need to match more).</p>
  
  <p>I am in a need of a better regex to accomplish this, so that all the backtracking can be avoided. <code>[^ ]*</code> is a regex which will match uptill a space is encountered. Can't we specify a negated character set where we continue matching in case of a single space and break when 2 are encountered? I've tried using positive lookahead but failed miserably.</p>
  
  <p>I would really appreciate your help. Thanks in advance.</p>
  
  <p>Saad</p>