use crate::stack::Stack;
impl<T> Stack<T> {
pub fn left(&mut self) -> &mut Stack<T> {
if ! self.stack.is_empty() {
self.stack.rotate_left(1);
}
self
}
pub fn right(&mut self) -> &mut Stack<T> {
if ! self.stack.is_empty() {
self.stack.rotate_right(1);
}
self
}
}