s have two forms. The first form works on the <b>character level</b>. 
  The second works on the <b>phrase level</b> and asks for a <b>skip parser</b>.</p>
<p>The <b>skip parser</b> is just about any parser primitive or composite. Its 
  purpose is to move the scanner's <tt>first</tt> iterator to valid tokens by 
  skipping white spaces. In C for instance, the tab <tt class="quotes">'\t'</tt>, 
  the newline <tt class="quotes">'\n'</tt>, return <tt><span class="quotes">'\r'</span></tt>, 
  space <tt class="