diff -r e3c64f22dd31 -r 14914b57e207 Attic/crawler2.scala
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/Attic/crawler2.scala	Wed May 06 15:37:31 2020 +0100
@@ -0,0 +1,44 @@
+// This version of the crawler only
+// checks links in the "domain" urbanc
+
+import io.Source
+import scala.util.matching.Regex
+import scala.util._
+
+// gets the first 10K of a web-page
+def get_page(url: String) : String = {
+  Try(Source.fromURL(url)("ISO-8859-1").take(10000).mkString). 
+    getOrElse { println(s"  Problem with: $url"); ""}
+}
+
+// regexes for URLs and "my" domain
+val http_pattern = """"https?://[^"]*"""".r
+val my_urls = """urban""".r       /*@\label{myurlline}@*/
+//val my_urls = """kcl.ac.uk""".r 
+
+def unquote(s: String) = s.drop(1).dropRight(1)
+
+def get_all_URLs(page: String) : Set[String] = 
+  http_pattern.findAllIn(page).map(unquote).toSet
+
+def crawl(url: String, n: Int) : Unit = {
+  if (n == 0) ()                   /*@\label{changestartline}@*/
+  else if (my_urls.findFirstIn(url) == None) { 
+    println(s"Visiting: $n $url")
+    get_page(url); () 
+  }                                /*@\label{changeendline}@*/
+  else {
+    println(s"Visiting: $n $url")
+    for (u <- get_all_URLs(get_page(url)).par) crawl(u, n - 1)
+  }
+}
+
+// starting URL for the crawler
+val startURL = """https://nms.kcl.ac.uk/christian.urban/"""
+//val startURL = """https://nms.kcl.ac.uk/christian.urban/bsc-projects-17.html"""
+
+
+// can now deal with depth 3 and beyond
+crawl(startURL, 3)
+
+