backward method

void backward()

Moves the Bar Backward

Implementation

void backward() {
  final out = StringBuffer('[');
  final width = console.columns - 2;
  final before = width - position;
  final after = width - before - 1;
  for (int i = 1; i <= before; i++) {
    out.write(' ');
  }
  out.write('=');
  for (int i = 1; i <= after; i++) {
    out.write(' ');
  }
  out.write(']');
  console.overwrite_line(out.toString());
}