 class="identifier">first</span><span class="special">,</span> <span class="identifier">last</span><span class="special">,</span> <span class="identifier">skipper</span><span class="special">)</span></code>. The <span class="emphasis"><em>subject</em></span>, if
          it is a primitive, will do the pre-skip. If if it is another composite
          parser, it will eventually call a primitive parser somewhere down the line
          which will do the pre-skip. This makes it a lot more efficient than <a hr