127 def lexing(r: Rexp, s: String) : Val = lex(r, s.toList)

   127 def lexing(r: Rexp, s: String) : Val = lex(r, s.toList)

   128 

   128 

   129 

   129 

   130 lexing(("ab" | "a") ~ ("b" | ONE), "ab")

   130 lexing(("ab" | "a") ~ ("b" | ONE), "ab")

   131 

   131 

   134 // some "rectification" functions for simplification

   132 // some "rectification" functions for simplification

   135 def F_ID(v: Val): Val = v

   133 def F_ID(v: Val): Val = v

   136 def F_RIGHT(f: Val => Val) = (v:Val) => Right(f(v))

   134 def F_RIGHT(f: Val => Val) = (v:Val) => Right(f(v))

   137 def F_LEFT(f: Val => Val) = (v:Val) => Left(f(v))

   135 def F_LEFT(f: Val => Val) = (v:Val) => Left(f(v))

   138 def F_ALT(f1: Val => Val, f2: Val => Val) = (v:Val) => v match {

   136 def F_ALT(f1: Val => Val, f2: Val => Val) = (v:Val) => v match {