Binary file slides08.pdf has changed

--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/while.scala	Wed Nov 21 02:34:37 2012 +0000
@@ -0,0 +1,60 @@
+
+//:load matcher.scala
+
+// some regular expressions
+val SYM = RANGE("""ABCDEFGHIJKLMNOPQRSTUVXYZabcdefghijklmnopqrstuvwxyz_""")
+val DIGIT = RANGE("0123456789")
+val ID = SEQ(PLUS(SYM)) ~ STAR(ALT(SYM, DIGIT)) 
+
+val BTAG = SEQS("<", WORD, ">") 
+val ETAG = SEQS("</", WORD, ">")
+
+val WHITESPACE = PLUS(RANGE(" \n"))
+
+// for classifying the strings that have been recognised
+abstract class Token
+case object T_WHITESPACE extends Token
+case class T_WORD(s: String) extends Token
+case class T_ETAG(s: String) extends Token
+case class T_BTAG(s: String) extends Token
+case class T_NT(s: String, rhs: List[Token]) extends Token
+
+val lexing_rules: List[Rule[Token]] = 
+  List((BTAG, (s) => T_BTAG(s.mkString)),
+       (ETAG, (s) => T_ETAG(s.mkString)),
+       (WORD, (s) => T_WORD(s.mkString)),
+       (WHITESPACE, (s) => T_WHITESPACE))
+
+// the tokenizer
+val T = Tokenizer(lexing_rules)
+
+// width for printing
+val WIDTH = 60
+
+
+def interpret(ts: List[Token], c: Int, ctr: List[String]) : Unit= ts match {
+  case Nil => println(Console.RESET)
+  case T_WHITESPACE::rest => print(Console.RESET + " "); interpret(rest, c + 1, ctr)
+  case T_WORD(s)::rest => {
+    val newstr = Console.RESET + ctr.reverse.mkString + s
+    if (c + s.length < WIDTH) {
+      print(newstr);
+      interpret(rest, c + s.length, ctr)
+    }
+    else {
+      print("\n" + newstr)
+      interpret(rest, s.length, ctr)
+    } 
+  }
+  case T_BTAG("<p>")::rest => print("\n"); interpret(rest, 0, ctr)
+  case T_ETAG("</p>")::rest => print("\n"); interpret(rest, 0, ctr)
+  case T_BTAG("<b>")::rest => interpret(rest, c, Console.BOLD :: ctr)
+  case T_BTAG("<a>")::rest => interpret(rest, c, Console.UNDERLINED :: ctr)
+  case T_BTAG("<cyan>")::rest => interpret(rest, c, Console.CYAN :: ctr)
+  case T_BTAG("<red>")::rest => interpret(rest, c, Console.RED :: ctr)
+  case T_BTAG("<blink>")::rest => interpret(rest, c, Console.BLINK :: ctr)
+  case T_ETAG(_)::rest => interpret(rest, c, ctr.tail)
+  case _::rest => interpret(rest, c, ctr)
+}
+ 
+interpret(T.fromFile("test.html"), 0, Nil)