1 import CW9c._

     2 

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

     4 

     5 

     6 assert(simp(Iterator.iterate(ONE:Rexp)(r => SEQ(r, ONE | ONE)).drop(50).next) == ONE)

     7 assert(simp(Iterator.iterate(ONE:Rexp)(r => ALT(r, r)).drop(20).next) == ONE)

     8 assert(matcher(EVIL_urban, "a" * 1000000) == false)

     9 assert(matcher(EVIL_urban, "a" * 1000000 ++ "b") == true)