1 

     2 val EVIL_urban = SEQ(STAR(STAR(CHAR('a'))), CHAR('b'))

     3 

     4 //println("1")

     5 assert(ders("aaaaa".toList, EVIL_urban) == SEQ(SEQ(STAR(CHAR('a')),STAR(STAR(CHAR('a')))),CHAR('b')))

     6 //println("2")

     7 assert(ders(List('b'), EVIL_urban) == ONE)

     8 //println("3")

     9 assert(ders("bb".toList, EVIL_urban) == ZERO)

    10 //println("4")

    11 assert(matcher(EVIL_urban, "a" * 5 ++ "b") == true)

    12 //println("5")

    13 assert(matcher(EVIL_urban, "b") == true)

    14 //println("6") 

    15 assert(matcher(EVIL_urban, "bb") == false)

    16 //println("7")

    17 assert(matcher("abc", "abc") == true)

    18 //println("8")

    19 assert(matcher(("ab" | "a") ~ (ONE | "bc"), "abc") == true)

    20 //println("9")

    21 assert(matcher(ONE, "") == true)

    22 //println("10")

    23 assert(matcher(ZERO, "") == false)

    24 //println("11")

    25 assert(matcher(ONE | CHAR('a'), "") == true)

    26 //println("12")

    27 assert(matcher(ONE | CHAR('a'), "a") == true)