194     val (r_simp, f_simp) = simp(der(c, r))

   194     val (r_simp, f_simp) = simp(der(c, r))

   195     inj(r, c, f_simp(lex_simp(r_simp, cs)))

   195     inj(r, c, f_simp(lex_simp(r_simp, cs)))

   196   }

   196   }

   197 }

   197 }

   198 

   198 

   199 def lexing_simp(r: Rexp, s: String) = env(lex_simp(r, s.toList))

   204 def lexing_simp(r: Rexp, s: String) = env(lex_simp(r, s.toList))

   200 

   205 

   201 // Language specific code

   206 // Language specific code

   202 val KEYWORD : Rexp = "while" | "if" | "then" | "else" | "do" | "for" | "to" | "true" | "false" | "read" | "write" | "skip" 

   207 val KEYWORD : Rexp = "while" | "if" | "then" | "else" | "do" | "for" | "to" | "true" | "false" | "read" | "write" | "skip" 

   203 val OP : Rexp = "+" | "-" | "*" | "%" | "/" | "==" | "!=" | ">" | "<" | ">=" | "<=" | ":=" | "&&" | "||"

   208 val OP : Rexp = "+" | "-" | "*" | "%" | "/" | "==" | "!=" | ">" | "<" | ">=" | "<=" | ":=" | "&&" | "||"

   219                   ("p" $ PARENS) |

   224                   ("p" $ PARENS) |

   220                   ("s" $ SEMI) | 

   225                   ("s" $ SEMI) | 

   221                   ("w" $ WHITESPACE) | 

   226                   ("w" $ WHITESPACE) | 

   222                   ("i" $ ID) | 

   227                   ("i" $ ID) | 

   223                   ("n" $ NUM) |

   228                   ("n" $ NUM) |

   225 

   230 

   226 def esc(raw: String): String = {

   231 def esc(raw: String): String = {

   227   import scala.reflect.runtime.universe._

   232   import scala.reflect.runtime.universe._

   228   Literal(Constant(raw)).toString

   233   Literal(Constant(raw)).toString

   229 }

   234 }

   344   case ONE => 1

   349   case ONE => 1

   345   case CHAR(_) => 1

   350   case CHAR(_) => 1

   346   case ALT(r1, r2) => 1 + size(r1) + size (r2)

   351   case ALT(r1, r2) => 1 + size(r1) + size (r2)

   347   case SEQ(r1, r2) => 1 + size(r1) + size (r2)

   352   case SEQ(r1, r2) => 1 + size(r1) + size (r2)

   348   case STAR(r1) => 1 + size(r1)

   353   case STAR(r1) => 1 + size(r1)

   349   case NTIMES(r1, n) => 1 + size(r1)

   355   case NTIMES(r1, n) => 1 + size(r1)

   350 }

   358 }

   351 

   359 

   352 val reg = SEQ(STAR(STAR(CHAR('a'))), CHAR('b'))

   360 val reg = SEQ(STAR(STAR(CHAR('a'))), CHAR('b'))

   353 size(reg) // 5

   361 size(reg) // 5

   354 size(der('a', reg)) // 12

   362 size(der('a', reg)) // 12

   355 size(simp(der('a', reg))._1) // 8

   363 size(simp(der('a', reg))._1) // 8

   356 size(simp(der('a', der('a', reg)))._1) // 8

   364 size(simp(der('a', der('a', reg)))._1) // 8

   357 

   365