Instructions

Please download lab materials lab09.zip from our QQ group if you don't have one.

In this lab, you are required to complete the required problems described in section 3 and submit your code to our OJ website.

The starter code for these problems is provided in expr.py, repl.py, reader.py and buffer.py. You only have to make changes to expr.py and repl.py in this lab.

Submission: As instructed before, you need to submit your work with Ok by python ok --submit. You may submit more than once before the deadline, and your score of this assignment will be the highest one of all your submissions.