title: How to skip unrelated lines when using Perl 6 Grammar to parse structurized text?
body: <p>I want to prase a <code>.sql</code> file using Perl 6 Grammar, I wonder if i can skip some unrelated lines when i'm parsing? </p>
  
  <p>For example: I want to skip the <code>DROP</code> lines, <code>/*!....!*/</code> lines, <code>--</code> lines, and the whitespace outside <code>CREATE TABLE</code> block in the following text.</p>
  
  <p>That is, I juse want to concentrate on <code>CREATE TABLE</code> blocks: </p>
  
  <pre><code>    DROP TABLE IF EXISTS `abcd`;
  /*!40101 SET @saved_cs_client     = @@character_set_client */;
  /*!40101 SET character_set_client = utf8 */;
  CREATE TABLE `abcd` (
    `id` int(11) NOT NULL AUTO_INCREMENT COMMENT 'app_id',
    `username` varchar(255) DEFAULT NULL COMMENT 'username',
    `url` varbinary(255) DEFAULT NULL COMMENT 'url',
    PRIMARY KEY (`id`),
    UNIQUE KEY `NewIndex1` (`username`)
  ) ENGINE=InnoDB AUTO_INCREMENT=954 DEFAULT CHARSET=utf8;
  /*!40101 SET character_set_client = @saved_cs_client */;
  
  --
  -- Table structure for table `temp`
  --
  
  DROP TABLE IF EXISTS `temp`;
  /*!40101 SET @saved_cs_client     = @@character_set_client */;
  /*!40101 SET character_set_client = utf8 */;
  CREATE TABLE `temp` (
    `id` int(11) NOT NULL AUTO_INCREMENT,
    `address` varchar(15) NOT NULL,
    `name` varchar(50) DEFAULT NULL,
    `phone_model` varchar(10) NOT NULL,
    `expire_time` varchar(15) NOT NULL,
    `created` varchar(15) NOT NULL,
    PRIMARY KEY (`id`)
  ) ENGINE=InnoDB AUTO_INCREMENT=1496 DEFAULT CHARSET=utf8;
  /*!40101 SET character_set_client = @saved_cs_client */;
  </code></pre>
  
  <p>Is there any suggestion?</p>