Sqlite regexp support

What’s the Right Way™ to implement regexp support in sqlite?
I’m doing this, but apparently it’s not working:

 db = SQLite3::Database.new("test.db")
 db.results_as_hash = true
 db.create_function('regexp', 2) do |func, v1, v2|
   r = Regexp.new(v1.to_s)
   if v2.to_s.match(r)
     func.result = true
     func.result = false

and i’m running a query like this:

select * from table where column REGEXP ‘(www.)?somedomain.com

any hints?
what should return the regexp function?