REPL 支持类似于 ZSH 的双向反向搜索。 由 Ctrl+R 触发向后搜索，由 Ctrl+S 触发向前搜索。
只要按下与反向搜索不对应的任何键，条目就会被接受。 可以按 Esc 或 Ctrl+C 取消。
The REPL supports bi-directional reverse-i-search similar to ZSH. It is triggered with Ctrl+R to search backward and Ctrl+S to search forwards.
Duplicated history entries will be skipped.
Entries are accepted as soon as any key is pressed that doesn't correspond with the reverse search. Cancelling is possible by pressing Esc or Ctrl+C.
Changing the direction immediately searches for the next entry in the expected direction from the current position on.