RosettaCodeData/Task/First-class-environments/Zkl/first-class-environments-1.zkl

class Env{
   var n,cnt=0;
   fcn init(_n){n=_n; returnClass(self.f)}
   fcn f{
      if(n!=1){
         cnt += 1;
         if(n.isEven) n=n/2; else n=n*3+1;
      }
      n
   }
}