title: Javacc parser option LOOKAHEAD, Java
body: <p>I've recently started to play around with grammatical analyzers using javacc and one of the fields is the options one...I have a code like the folowing:</p>
  
  <pre><code>options
  {
    LOOKAHEAD=1;
  }
  PARSER_BEGIN(Calculator)
  
  public class Calculator
  {
   ...
  }
  PARSER_END(Calculator)
  </code></pre>
  
  <p>What exactly does it mean the LOOKAHEAD option?
  Thanks</p>