title: can regex alternation be used in replace?
body: <p>I doubt it's possible, but I haven't found anything to specifically say it's not possible.  But is there some way to construct a parallel alternation in a search and replace regex?  So, for example, if I wanted to replace street types with their abbreviations, could I do something like this:</p>
  
  <pre><code>s/(STREET|AVENUE|BOULEVARD)/(ST|AVE|BLVD)/ 
  </code></pre>
  
  <p>without having the entire rhs substituted in?  Or do I really have to do separate replaces for each street type?</p>