float->float feedbackloop Echo
    (int n, float f) {
  join roundrobin(1,1);
  body FloatAdderBypass();
  loop float->float filter {
    work pop 1 push 1 {
      push(pop() * f);
    }
  };
  split roundrobin;
  for (int i = 0; i < n; i++)
    enqueue(0);
}
float->float filter FloatAdderBypass {
  work pop 2 push 2 {
    push(peek(0) + peek(1));
    push(peek(0));
    pop();
    pop();
  }
}

void->void pipeline EchoProgram {
  add FloatSource();
  add Echo(3, 0.5);
  add FloatPrinter();
}

void->float filter FloatSource {
  float x;
  init { x = 1; }
  work push 1 {
    push(x);
    x = 0;
  }
}

float->void filter FloatPrinter {
  work pop 1 { println(pop()); }
}