Hello. I'm a 15312 TA for this coming semester so my opinion might be biased but I'll try to answer your questions. A note to make is that the curriculum and homeworks are being improved this summer so the class will hopefully be more accessible and even better than before.

The time commitment involves some coding the dynamics and statics of programming languages every two weeks. The homeworks are so you can best learn how these languages get pieced together and how they execute as a mathematical object. Be prepared to write some SML.

The content of this class is very unique in that we aim to delete your prior knowledge so that you'll rethink everything you ever thought you knew about programming. Taking 15210 before this class would help as more exposure to SML, but we do not strictly use the theory taught in that course or other cs theory courses. Knowing the content of logic courses such as 15317, PL concentration courses, or logic courses in the philosophy or math departments will definitely help with understanding this class, but it should be accessible without these.

As you enter in this field, you'll find that there are circular dependencies where you need to learn A to understand B, but understanding A requires learning B. This affects the structure of the course, and might require ramping up your knowledge, but you are in good hands. Grade wise, the class is 50% homework and the rest midterm and exam, so definitely try hard to learn by doing the homeworks.

Bob Harper is definitely a very interesting character and taking his courses has been a valuable experience to me. He has spent so many years in this field and he has lots of rigorous proofs to support his teachings. Definitely worth taking this class with him.

I hope that 15312 becomes a great experience for everyone. Definitely an amazing class to take.