progs/app03.scala
author Christian Urban <christian dot urban at kcl dot ac dot uk>
Tue, 18 Oct 2016 10:43:26 +0100
changeset 453 36e5752fa191
parent 400 e4afe3f46c29
permissions -rw-r--r--
updated

abstract class Rexp
case object ZERO extends Rexp
case object ONE extends Rexp
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 REC(x: String, r: Rexp) extends Rexp