equivalent of mysql's SET type?

[Reece Hart <reece@xxxxxxxxx>]

I'm considering porting a MySQL database to PostgreSQL. That database uses MySQL's SET type. Does anyone have advice about representing this type in PostgreSQL?

MySQL DDL excerpt:

CREATE TABLE `transcript_variation` (

  `transcript_variation_id` int(10) unsigned NOT NULL AUTO_INCREMENT,

  `transcript_stable_id` varchar(128) NOT NULL,

   ...

  `consequence_type` set('ESSENTIAL_SPLICE_SITE','STOP_GAINED','STOP_LOST','COMPLEX_INDEL','SPLICE_SITE')

) ENGINE=MyISAM AUTO_INCREMENT=174923212 DEFAULT CHARSET=latin1;

I'm considering implementing this as a new type based on a bit vector, but I wonder if anyone has a more flexible general solution.

Thanks,

Reece