val my_urls = """urban""".r+− +− def crawl(url: String, n: Int) : Unit = {+− if (n == 0) ()+− else if (my_urls.findFirstIn(url) == None) { +− println(s"Visiting: $n $url")+− get_page(url); () +− }+− else {+− println(s"Visiting: $n $url")+− for (u <- get_all_URLs(get_page(url))) crawl(u, n - 1)+− }+− }+−