: calcPiDigits
| q r t k n l |
   1 ->q 0 ->r 1 ->t 1 ->k 3 ->n 3 -> l

   while( true ) [
      4 q * r + t - n t * < ifTrue: [
         n print
         r n t * - 10 *
         3 q * r + 10 * t / n 10 * - ->n ->r
         q 10 * ->q
         ]
      else: [
         2 q * r + l *
         7 k * q * 2 + r l * + t l * / ->n ->r
         k q * ->q
         t l * ->t
         l 2 + ->l
         k 1+  ->k
         ]
       ] ;