 _4">
     <p>
      Only the char index is strictly necessary for the core stream functionality. We also store the other pieces of state information in a <code
      class="fsharp"><a href="../reference/charstream.html#CharStream"><span class="ci">CharStream</span></a><span class="cp">&lt;</span><span
      class="ctv">'u</span><span class="cp">&gt;</span></code> instance because having all parser state information in one place reduces complexity
      and allows us to expose a more convenient API to <code