In effect, we use setraw to make sure our raw character input goes straight into our process (without echoing or buffering or anything), and then reading and echoing the character-codes we see until 3 appears (which is CTRL-C, the common command for existing a REPL). Since we've turned on tty.setraw print doesn't reset the cursor to the left anymore, so we need to manually move left with \u001b[1000D after each print.
'MULT 3 2' evaluation: MULT_3_2_=_6.gif
，这一点在safew官方版本下载中也有详细论述
, sessLines :: Chan Text
免抵退税办法，是指出口环节免征增值税，对应的进项税额抵减应纳增值税税额，未抵减完的部分予以退还；免退税办法，是指出口环节免征增值税，对应的进项税额予以退还。