stream to the 
  parser. The scanner extracts data from the input, parceling, potentially modifying 
  or filtering, and then finally relegating the result to individual parser elements 
  on demand until the input is exhausted. The scanner is composed of two STL conforming 
  forward iterators, first and last, where first is held by reference and last, 
  by value. The first iterator is held by reference to allow it to be re-positioned. 
  The following diagram illustrates what's happening:</p>
<table widt