Finite Loop

Finite loops of the Repeat class execute their body a fixed number of times. Unlike infinite loops, an instantaneously terminating body is not a problem, as it does not prevent the loop to terminate. Therefore, there is no detection of instantaneously terminating bodies of Repeat instructions. Repeat  contains two integer field: num which is the initial number of cycles, and counter which is the number of cycles performed so far.

 
public class Repeat extends UnaryInstruction
{

  protected int num, counter;

  public Repeat(int num,Instruction body) 
  { 
    super.body = body; 
    this.num = num; 
    counter = num;
  }

  public void reset(){ super.reset(); counter = num; }

  final public boolean equals(Instruction inst){
    return  super.equals(inst) && num == ((Repeat)inst).num;
  }

  final public String toString(){ 
    return "loop {" + num + "} times " + body + " end"; 
  }

  final protected byte activation(Machine machine)
  {
    while (counter > 0){
     byte res = body.activ(machine);
     if (res == TERM){ 
       counter--;
       body.reset();
     }else{
       return res;
     }
    }
    return TERM;
  }
}