windows下的终端版2048，因为我没有找到调用winAPI合适的crate，无法进行清屏处理。所以游戏大概是如下这样的。
+------+------+------+------+
| | | | |
+------+------+------+------+
| | | | |
+------+------+------+------+
| | | | |
+------+------+------+------+
| 2 | | | |
+------+------+------+------+
'w'
+------+------+------+------+
| 2 | | | |
+------+------+------+------+
| | | | |
+------+------+------+------+
| | 4 | | |
+------+------+------+------+
| | | | |
+------+------+------+------+
但是我的游戏虽然简陋，但是逻辑完备。包含测试代码在内代码量极少，充分利用了rust语法。处理上下左右移动逻辑，只用到如下一个函数。
fn rs_move(&mut self, x: i8, y: i8, c: i8, r: i8) {
...
match (current, target) {
(None, _) => {}
(Some(v1), Some(v2)) if v1 == v2 => {
...
}
(Some(v1), None) => {
...
}
(Some(_), Some(_)) => {
....
}
}