Instructions

In this lab, you are required to complete the required problems described in section 3 and verify your answer with Ok.

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.