170       case (ONE, _) => (r2s, F_SEQ_Empty1(f1s, f2s))

   170       case (ONE, _) => (r2s, F_SEQ_Empty1(f1s, f2s))

   171       case (_, ONE) => (r1s, F_SEQ_Empty2(f1s, f2s))

   171       case (_, ONE) => (r1s, F_SEQ_Empty2(f1s, f2s))

   172       case _ => (SEQ(r1s,r2s), F_SEQ(f1s, f2s))

   172       case _ => (SEQ(r1s,r2s), F_SEQ(f1s, f2s))

   173     }

   173     }

   174   }

   174   }

   179   case r => (r, F_ID)

   175   case r => (r, F_ID)

   180 }

   176 }

   181 

   177 

   182 // lexing functions including simplification

   178 // lexing functions including simplification

   183 def lex_simp(r: Rexp, s: List[Char]) : Val = s match {

   179 def lex_simp(r: Rexp, s: List[Char]) : Val = s match {

   255   case ("n", s) => T_NUM(s.toInt)

   251   case ("n", s) => T_NUM(s.toInt)

   256   case ("k", s) => T_KWD(s)

   252   case ("k", s) => T_KWD(s)

   257   case ("str", s) => T_STR(s)

   253   case ("str", s) => T_STR(s)

   258 }

   254 }

   259 

   255 

   261 def tokenise(s: String) : List[Token] = 

   257 def tokenise(s: String) : List[Token] = 

   262   lexing_simp(WHILE_REGS, s).collect(token)

   258   lexing_simp(WHILE_REGS, s).collect(token)

   263 

   259 

   264 

   260 

   265 def serialise[T](fname: String, data: T) = {

   261 def serialise[T](fname: String, data: T) = {