--- a/matcher.scala	Sun Dec 23 00:38:56 2012 +0000
+++ /dev/null	Thu Jan 01 00:00:00 1970 +0000
@@ -1,130 +0,0 @@
-package object matcher {
-
-// regular expressions 
-// including constructors for NOT and ALLC
-abstract class Rexp
-
-case object NULL extends Rexp
-case object EMPTY extends Rexp
-case object ALLC extends Rexp            // recognises any character
-case class CHAR(c: Char) extends Rexp
-case class ALT(r1: Rexp, r2: Rexp) extends Rexp
-case class SEQ(r1: Rexp, r2: Rexp) extends Rexp
-case class STAR(r: Rexp) extends Rexp
-case class NOT(r: Rexp) extends Rexp     // negation of a regular expression
-
-
-// nullable function: tests whether the regular 
-// expression can recognise the empty string
-def nullable (r: Rexp) : Boolean = r match {
-  case NULL => false
-  case EMPTY => true
-  case ALLC => false
-  case CHAR(_) => false
-  case ALT(r1, r2) => nullable(r1) || nullable(r2)
-  case SEQ(r1, r2) => nullable(r1) && nullable(r2)
-  case STAR(_) => true
-  case NOT(r) => !(nullable(r))
-}
-
-// tests whether a regular expression 
-// cannot recognise more
-def no_more (r: Rexp) : Boolean = r match {
-  case NULL => true
-  case EMPTY => false
-  case ALLC => false
-  case CHAR(_) => false
-  case ALT(r1, r2) => no_more(r1) && no_more(r2)
-  case SEQ(r1, r2) => if (nullable(r1)) (no_more(r1) && no_more(r2)) else no_more(r1)
-  case STAR(_) => false
-  case NOT(r) => !(no_more(r))
-}
-
-
-// derivative of a regular expression w.r.t. a character
-def der (c: Char, r: Rexp) : Rexp = r match {
-  case NULL => NULL
-  case EMPTY => NULL  
-  case ALLC => EMPTY
-  case CHAR(d) => if (c == d) EMPTY else NULL
-  case ALT(r1, r2) => ALT(der(c, r1), der(c, r2))
-  case SEQ(r1, r2) => 
-    if (nullable(r1)) ALT(SEQ(der(c, r1), r2), der(c, r2))
-    else SEQ(der(c, r1), r2)
-  case STAR(r) => SEQ(der(c, r), STAR(r))
-  case NOT(r) => NOT(der (c, r))
-}
-
-// main class for the tokenizer
-case class Tokenizer[T](rules: List[(Rexp, List[Char] => T)], excl: List[T] = Nil) {
-
-def munch(r: Rexp, action: List[Char] => T, s: List[Char], t: List[Char]) : Option[(List[Char], T)] = 
-  s match {
-    case Nil if (nullable(r)) => Some(Nil, action(t))
-    case Nil => None
-    case c::s if (no_more(der (c, r)) && nullable(r)) => Some(c::s, action(t))
-    case c::s if (no_more(der (c, r))) => None
-    case c::s => munch(der (c, r), action, s, t ::: List(c))
-  }
-
-def one_token(s: List[Char]) : Either[(List[Char], T), String] = {
-  val somes = rules.map { (r) => munch(r._1, r._2, s, Nil) }.flatten
-  if (somes == Nil) Right(s.mkString) 
-  else Left(somes sortBy (_._1.length) head)
-}
-
-def tokenize(cs: List[Char]) : List[T] = cs match {
-  case Nil => Nil
-  case _ => one_token(cs) match {
-    case Left((rest, token)) => token :: tokenize(rest)
-    case Right(s) => { println("Cannot tokenize: \"" + s + "\""); Nil } 
-  }
-}
-
-def fromString(s: String) : List[T] = 
-  tokenize(s.toList).filterNot(excl.contains(_))
-
-def fromFile(name: String) : List[T] = 
-  fromString(io.Source.fromFile(name).mkString)
-
-}
-
-
-// regular expression for specifying 
-// ranges of characters
-def Range(s : List[Char]) : Rexp = s match {
-  case Nil => NULL
-  case c::Nil => CHAR(c)
-  case c::s => ALT(CHAR(c), Range(s))
-}
-def RANGE(s: String) = Range(s.toList)
-
-
-// one or more
-def PLUS(r: Rexp) = SEQ(r, STAR(r))
-
-// many alternatives
-def Alts(rs: List[Rexp]) : Rexp = rs match {
-  case Nil => NULL
-  case r::Nil => r
-  case r::rs => ALT(r, Alts(rs))
-}
-def ALTS(rs: Rexp*) = Alts(rs.toList)
-
-// repetitions
-def Seqs(rs: List[Rexp]) : Rexp = rs match {
-  case Nil => NULL
-  case r::Nil => r
-  case r::rs => SEQ(r, Seqs(rs))
-}
-def SEQS(rs: Rexp*) = Seqs(rs.toList)
-
-// some convenience for typing in regular expressions
-def charlist2rexp(s : List[Char]) : Rexp = s match {
-  case Nil => EMPTY
-  case c::Nil => CHAR(c)
-  case c::s => SEQ(CHAR(c), charlist2rexp(s))
-}
-implicit def string2rexp(s : String) : Rexp = charlist2rexp(s.toList)
-
-}