//:load matcher.scala

// some regular expressions

val SYM = RANGE("""ABCDEFGHIJKLMNOPQRSTUVXYZabcdefghijklmnopqrstuvwxyz.,!?-{[()]}':;%0123456789""")

val WORD = PLUS(SYM)

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)