title: Regular Expression for single line comments
body: <p>What is the regular expression for single line java comments:
  I am trying the following grammar : </p>
  
  <pre><code>     def single_comment(t):
            r'\/\/.~(\n)'
            #r'//.*$'
            pass
  </code></pre>
  
  <p>but, I am unable to ignore the single line comments how can I do it?</p>