 
  random access). Perhaps in the future, deterministic parsers when added to the 
  framework, will perform no backtracking and will need just a single token lookahead, 
  hence will require input iterators only.</p>
<p><img src="theme/lens.gif" width="15" height="16"><b> Why are subrules important?</b><br>
  <br>
  Subrules open up the opportunity to do aggressive meta programming as well because 
  they do not rely on virtual functions. The virtual function is the meta-programmer's 
  hell. Not only doe