1 

     2 //import scala.concurrent._

     3 //import scala.concurrent.duration._

     4 //import ExecutionContext.Implicits.global

     5 //import scala.language.postfixOps 

     6 //import scala.language.reflectiveCalls

     7 

     8 

     9 //lazy val f = Future {

    10   import CW8a._

    11 

    12   assert(der('a', ZERO | ONE) == (ZERO | ZERO))

    13   assert(der('a', (CHAR('a') | ONE) ~ CHAR('a')) == ALT((ONE | ZERO) ~ CHAR('a'), ONE))

    14   assert(der('a', STAR(CHAR('a'))) == (ONE ~ STAR(CHAR('a'))))

    15   assert(der('b', STAR(CHAR('a'))) == (ZERO ~ STAR(CHAR('a'))))

    16 //}

    17 

    18 //Await.result(f, 120 second)