# Syllabus

### Collaborative Course Construction and Feedback

We are together in unprecedented times. The typical course structure implicitly assumes regular whole-class in-person meetings. We will not have that this semester. No student will be physically present in class on all days. Some students may not be physically present in class at all, or on campus period. This change affects much of the course infrastructure. As such, I want you all’s feedback and input. I am open to suggestions and changes; I consider this preliminary until the end of the first week of class. You can see any and all changes on the course website’s repository.

I cannot promise that we will act on all suggestions, and even those we find compelling may not be implementable as we go.

## Purpose and Objectives

This course introduces programming languages concepts with a hands-on, “learn by doing” approach. This means both writing working programs and understanding programming languages’ behaviors by implementing those behaviors in interpreters. Through this we will understand both the commonalities between languages and the impact of various language-design decisions. To summarize, in this course you will:

After this course you will know how to:

1. Learn and utilize central PL concepts such as evaluation, scope, binding, and defunctionalization.
2. Implement interpreters and extend them to evaluate new syntactic forms.
3. Apply correctness-preserving program transformation techniques to guarantee program properties.
4. Evaluate and critique the impact of language design decisions.

This course is fast paced. The course’s material accumulates, building to a must-pass final project. Weekly programming assignments help situate lectures and provide opportunities to engage and practice concepts prior to the exams. Grades from these assignments give you early feedback on your understanding and performance. Further, these assignments ensure your final grade will not be solely determined by your project and exams. These will be discussed in detail below.

This syllabus contains policies and expectations I have established for CS4400 and CS5400. Please read carefully the entire syllabus before continuing in this course. These policies and expectations are intended to create a productive learning atmosphere for all students. Unless you are prepared to abide by these policies and expectations, you risk losing the opportunity to participate further in the course. Policies and expectations as set forth in this syllabus may be modified at any time by the course instructor. Notice of such changes will be made by announcement in class, by written or email notice, or by changes to this syllabus posted on the course website.

## Contact

The best way to get in contact for personal, private (FERPA, etc) messages is via my email address jhemann@northeastern.edu. You should expect a response within 48 hours. You will find that I am faster with Piazza or our public forums. If I deem it even potentially useful to others, I will likely anonymize your letter, re-post it on Piazza, answer it there, and forward you the link.

A great regular way to reach out for help is via our office hours.

## Grade Breakdown

I will assign overall course grades as follows:

 | Category                  | Weight (%) |
|---------------------------+------------|
| Participation             |         10 |
| Exams                     |         50 |
| Homework*                 |         40 |
| TRACE                     |          2 |
| Total                     |        102 |


We (I) will calculate overall numeric grade according to this grading scheme. Your final grades will be at least as good as the standard calculation for As, Bs, Cs, etc. To assign final letter grades at the end of the term I sum and chart the numeric scores, and break students’ grades where we see inflection points (with no students’ grade worse than their raw calculation). This means I cannot give you a more precise estimate of your grade than what you calculate from the raw score.

I will base some portions of your lab, homework, and lecture quiz grades on completion and submission of the relevant exercises. I will base the remaining portion of each on correctness.

### Total Running Grade Calculation

We will track the completion portions of your exam and homework grades, as well as your project grades, in handins. We will maintain a record of the remaining grades, and will update you with the current status of that before the Add/Drop deadline. Please ignore the grade tracker on Canvas.

## Participation

I expect you to attend each lecture. Your attendance is a prerequisite for a substantial portion of the course’s grade. Students are expected to attend every class and remain in class for the duration of the session. Your absence or tardiness will impact your ability to achieve course objectives which could hurt your course grade. An absence, excused or unexcused, does not relieve a student of any course requirement. We will not take attendance as such, but some reading and lecture content quizzes will serve as proxies for participation and thus attendance.

### Lecture Quizzes/Polls

There may be quick pop quizzes during the session. These act as a forcing function for the readings, for lecture notes and to alert me to students’ difficulties.

## Homework

Homework, consisting of weekly programming assignments, is an essential part of the course. Assignments are available by at least Thursday evening, and unless otherwise indicated, homework submissions are due by 10pm on the Wednesday after I have assigned them. We give a few (randomly-varying) extra minutes to account for network time disagreements, but beyond this homework assignments are due strictly on the day and time listed on the assignment.

To universally, uniformly and preemptively account for any number of situations that arise, I will drop every student’s lowest homework assignment grade. You will also have an opportunity for a bonus assignment to replace your lowest remaining assignment. This absolution for one assignment and optional bonus is our late/etc homework clemency; but for exceptional circumstances, I shall not accept late homework otherwise; we are, however happy to go over your submissions with you at office hours.

You should make every effort to complete and submit each assignment. If you are struggling with an assignment, it best to turn in what you can complete and to seek help. Homework assignments will build on one other conceptually, and some later assignments require the successful completion of problems from earlier ones. Do not fall behind. If you feel yourself falling behind, seek help immediately and take advantage of both lab sessions and additional support. Follow both the general homework guidelines, as well as any special instructions given on the assignment itself.

Your submission will be evaluated under the following rubric. We provide you a test suite for each assignment. A submission that does not load in Racket and execute the test suite without warning or exception will automatically receive no better than a U. To avoid this, ensure that sure your submission runs and passes the test suites provide you. We allow an unlimited number of submissions per assignment, up to the deadline.

Your work is evaluated both for correctness and for style. The autograder merely ensures that your programs compute the correct answers. Our homework problems are are as much about how you solve the problems as that you solve them. You should use the suggested style as demonstrated in class. We are teaching, especially early in the course, a particular way of thinking through and solving problems. This technique generalizes to the course’s subsequent, larger problems, and programs in this style serve as input for program transformation techniques we will learn.

You should aim for a grade of S or better on homework assignments. If you receive a lower grade, make sure to carefully revisit that assignment before the next exam. I encourage you to contact an instructor for help, even on prior assignments.

Homework assignments will almost always contain extra “just dessert” problems. These are not required and do not impact your homework grade–they are there for your fun and excitement. Often, these problems explore interesting topics we will not have get to in class, but we would be remiss in skipping them entirely.

### Exams

You will have two long-form in-class exams. You will also have a final, that takes place at the date, time, and location given by the registrar. Thus there are three exams in total. We calibrate our exams to make full use of the grading spectrum, and assume you fully understand the lecture material and the skills and techniques practiced on homework, and that you can apply them in new ways. They are not intended to be “easy” for even accomplished students. We will provide you a practice exam, and before each exam we will use the full period for an exam review session. Exams offer bonus questions that can help improve your score, potentially above 100 points.

Due to the present changes in the education landscape, it is not obvious how to administer exams faithfully. If you have suggestions on how to improve the workflow, then I am by all means open to it. At a minimum, we will ask you to adopt an honor code and sign your name by it. Exams are strictly individual. Make sure to avoid even the appearance of misconduct. Instructors reserve the right to at any point in time call students individually to explain their work.

### TRACE evaluations

I encourage students to take time and submit TRACE evaluations. Your time is busy at the end of the term when these are available. In order to fairly compensate you for that time, if 85% or more of the enrolled students complete these TRACE evaluations, then I shall add 2 points onto the class-wide final average.

## Recent Changes

I’m also planning to use some of the last part of the course, while students are working on these larger projects, to talk about a different area in programming languages: logic programming. We can also get into the “guts” of an implementation of such a system. If in fact you’re interested in PL research, logic, logic programming, automated theorem proving or the like, please let me know on that too! I’m excited to talk more about it all :-)

## Project

This course culminates in a final project. This project also presumes an understanding of the prior material in the course, and acts as a final test of your ability to understand and apply this material. To complete this assignment you must: 1) submit a working version of your interpreter written in C 2) keep copies of your program at each stage of this transformation 3) successfully pass a code review, to be scheduled with one of the instructors. We will provide a tool to schedule a code review with an instructor. You may take as many code reviews as you need, without penalty. This project is given as an assignment, and graded for completion—you will receive 100\% if you complete it successfully by the scheduled time. However, you must complete all portions of this assignment before the date and time of the final exam. You must complete this assignment to receive a passing grade in this course.

## Lecture

The vast majority of course content will come from in-class lecture, supplemented with notes distributed online. Therefore, attending lecture is of the utmost importance. You should make every effort to attend each lecture, and take vigorous notes. We will often provide directly the answers to homework problems in lecture, and this course is made significantly more difficult by missing one or more lectures. We will often distribute electronic transcripts of the in-class code, but this is no substitute for careful notes and understanding its development. I will not be taking attendance. Regular class attendance is a student’s obligation, as is responsibility for all the content of class meetings, including tests.

Regardless of your attendance modality, you should plan to have with you pencil and paper to take notes. Take vigorous notes. This first day of lecture you may not have these materials, but for subsequent classes, students’ use of laptops in class is strictly forbidden. The use of cell phones, smart phones, or other mobile communication devices is disruptive, and is therefore prohibited during class.

I do not permit electronic video and/or audio recording of class in either modality. Unless the student obtains permission from the instructor electronic video and/or audio recording of class is prohibited. If permission is granted, any distribution of the recording is prohibited. Students with specific electronic recording accommodations authorized by the DRC do not require instructor permission; however, the instructor must be notified of any such accommodation prior to recording. Any distribution of such recordings is prohibited. Obviously I cannot stop you, but it’s to both our benefits.

## Additional Support

In addition to lecture, we provide the following additional resources for students to avail themselves. Do consider taking regular advantage of them.

### Scheduled Office Hours

Course personnel will make ourselves available for 8-10 hours of office hours available weekly, concentrated toward assignment due dates. If our office hours schedule in particularly ill-suited to your class schedule, let me know and we may be able to adjust them.

### Piazza Forums

Outside of office hours, you should utilize the class’s Piazza forums for questions. We have disabled private messages to instructors, but you can choose to remain anonymous to the class when asking questions. We prefer Piazza over email, as it gives other students the opportunity to learn from those same anwers. Please restrict your questions to those that do not give away the punchline’’ to a homework question. For more sensitive questions, or administrative issues that should addressed in private, please email me at the address listed on the front of this syllabus.

### Optional Texts

There are no required texts for this class. Simply put, no companion textbooks mirror this course’s development of these topics. For students who prefer to have readings to supplement lecture material, we suggest the following two optional texts, which we refer to as SAOP and EOPL. Each covers portions of material from this course, and together the two texts contain supplementary material for almost every lecture. The schedule lists optional readings from each when they contain supplementary material that complements that lecture. Both are available at the campus bookstore.

Neither will cover topics precisely the way we do in lecture. Their implementations will also differ in technical details and particulars of syntax. However, both provide material that translates to what we do in class. Some students may choose to use these readings after lectures to supplement their understanding. Especially diligent students may use them to preview the lecture and be that much farther ahead. In the rare circumstance you must miss lecture, these may help supplement your understanding from lab, our additional support, and perhaps lecture notes from a friend.

## Academic Integrity Policy

Students of course play an integral part in ensuring they receive the full benefit of their coursework. The students of 2800 are certainly beholden to the academic integrity policies of Northeastern University, the Khoury College.

## Academic Accommodations

If you have accommodations from the Disability Resource Center (DRC) please submit your Professor Notification Letter to me by email, preferably within the first two weeks of the quarter, so I can do my part to help you achieve equal access in this course. I am eager to discuss ways we can ensure your full participation.

I encourage all students who may benefit from learning more about DRC services to contact the DRC.

## Technology and Platforms

As a course and a student body, we are more remote than usual, and preferable. We will leverage a number of Northeastern’s technology platforms to help bridge the chasm. Your first lab assignment will walk you through installing and configuring these.

We will use a variety of tools and platforms to facilitate teaching and learning at a somewhat remote distance and to compensate for this unconventional semester. These include Racket, Khoury Office Hours, PollEverywhere, and Piazza. Please see the technology page for more details.

## Health and Safety

The university has put into place a robust plan to make the campus healthy and safe for all — but you must do your part. On August 22, all students received an email from Senior Vice Chancellor for Student Affairs Madeleine Estabrook on the expectations for behavior both on campus and off campus. Please read it carefully today.

To summarize:

• Gatherings on or off campus must conform to healthy practices as outlined by university and Massachusetts state guidance. If you host or attend an inappropriate party or gathering, you run the very real risk of immediate removal from the community.

• Wear a mask indoors and outdoors as you maintain a 6-foot distance from everyone.

• Get tested every three days using the COVID-19 Test Scheduler (covid19-testing.northeastern.edu.) We may require more frequent testing as the semester progresses. It’s quick, easy and will help us to quickly identify and care for anyone who tests positive. I will not be told the identity of anyone who tests positive, and you do not need to share that information with me or anyone else unless you want to. If you receive a positive test result, you will be contacted by a member of the university’s telehealth team who will provide you with next steps.

• Do a Daily Wellness Check (wellness-check.northeastern.edu), wash your hands well and regularly, and disinfect high-touch surfaces and spaces.

• I will be wearing a face covering or mask as I teach and expect that you will do the same in class. If you come to class without a mask, I’ll ask you to go and get one on campus. You can get a mask at the Visitor Center or at the Curry Student Center Help Desk. If you refuse to wear a mask in class, I won’t be able to continue the class. If you are not sitting six feet apart from your classmate, I’ll ask you to do so. We won’t be able to eat or drink in class (except water). If you test positive, you will need to enter isolation as directed by the university’s telehealth team. I expect that you will not come in-person to class and that you will follow the guidance from the university telehealth team to isolate and get appropriate healthcare if needed.

• Staying safe is a responsibility that we all must take seriously. Keep in mind the “Protect the Pack” theme. Remember that our individual actions will help everyone stay safe this fall.”

## Acknowledgments

I derived many of our course’s lecture’s contents and topics, as well as assignments, from Dan Friedman’s 311 at Indiana University. Lindsey Kuper inspires some of this site as well as being all-around inspirational.