1 // for primitive definitions

     2 import $file.cw02

     3 import cw02._

     4 

     5 def sz(r: Rexp): Int = r match {

     6   case ZERO => 1

     7   case ONE => 1

     8   case CHAR(_) => 1

     9   case ALT(r1, r2) => 1 + sz(r1) + sz (r2)

    10   case SEQ(r1, r2) => 1 + sz(r1) + sz (r2)

    11   case STAR(r1) => 1 + sz(r1)

    12   case PLUS(r1) => 1 + sz(r1)

    13   case NTIMES(r1, n) => 1 + sz(r1)

    14   case OPTIONAL(r1) => 1 + sz(r1)

    15   case RECD(_, r1) => 1 + sz(r1)

    16   case RANGE(_) => 1

    17 }

    18 

    19 assert(sz(RANGE("abc")) != 1)

    20 

    21 

    22 

    23