title: How to split a multibyte string into words in Php?
body: <p>How to split a multibyte string into words in Php? 
  Here is what I have done so far, but I would like to improve the code...</p>
  
  <pre><code>   mb_internal_encoding( 'UTF-8');
     mb_regex_encoding( 'UTF-8');
     $arr = mb_split( '[\s\[\]().,;:-_]', $str );
  </code></pre>
  
  <p>Is there a way to say that a <em>word</em> is a sequence of "alpha"-characters (not using the notation a-z, since I would like to include non-latin characters)</p>