title: Print all Lua reserved keywords
body: <p>With this code:</p>
  
  <pre><code>for n in pairs(_G) do print(n) end
  </code></pre>
  
  <p>I print the names of all global variables defined in the current environment. </p>
  
  <p>Is there any way to print all Lua keywords (<code>and</code>,<code>break</code>,<code>do</code>,<code>else</code>,<code>elseif</code>,<code>end</code>,<code>false</code>,<code>for</code>,<code>function</code>,<code>if</code>,<code>in</code>,<code>local</code>,<code>nil</code>,<code>not</code>,<code>or</code>,<code>repeat</code>,<code>return</code>,<code>then</code>,<code>true</code>,<code>until</code>,<code>while</code>)?</p>