FPSE

Assignment 2: List module, special integers, and the Towers game.

This assignment is split into three separate files, each unrelated to the other.

• src/reimplementation.ml: you write new solutions to some problems from Assignment 1, but you can only use the List module and cannot use explicit recursion (i.e., no let rec).
• src/divisors.ml: you write a few functions around divisors of integers.
• src/towers.ml: you verify that the solution to a Towers game is correct.

File structure and requirements

• Use this zip file as the starting point for your assignment. Download and unzip it.
• Your code will go in three files, each of which contains a full description of the requirements for that file:
  • src/reimplementation.ml
  • src/divisors.ml
  • src/towers.ml
• Thoroughly read the instructions in each of these files and write your code to follow the instructions.
• You must add five non-redundant assert_equal statements to the tests in test/tests.ml.
  • Note there are other provided tests in the following files:
    • tests/reimplementation_tests.ml
    • tests/divisors_tests.ml
    • tests/towers_tests.ml
  • Your new assert_equal statements must be complementary to all tests in these files. Your tests can be on any part of this assignment (e.g. on divisors, towers, etc.).
• There are corresponding .mli files that state which functions you must have in your submission. You will not submit these files, so do not edit them. If you edit them, then Gradescope may fail to run your code. Note that for this assignment we also list all functions you need to define in the .ml files, so you can largely ignore them now; it is more of a warm-up to how real OCaml development works.
• The dune files are set up for you. They allow you to run dune build and dune test from the top level directory assignment2/.

Resources to help you

Here is a reminder of some resources at your disposal.

• Consult the Course Coding page for information on installing OCaml and getting a good toolchain setup for development.
• Consult the OCaml Intro lecture notes, and if you want to re-watch any lecture they are on Panopto as per the link pinned on Courselore.
• Real World OCaml Chapter 1 is another tutorial introduction in a somewhat different order than we are doing. They use the Core standard library overlay, so their library functions may look different than yours.
• If you are looking for how some standard library function is expressed in OCaml, like not equal, etc, consult the Caml Stdlib which are the predefined functions available in OCaml.
• You are encouraged to work with other people on the assignment. You just need to list the names of people you worked with. However, remember that you should submit your own write up of the answers. Copying of solutions is not allowed. For the full collaboration policy see here.
• Come to office hours to get help from Prof and CAs. Office hours are posted on Courselore.
• Use Courselore for online help and question clarification.

Coding Methods

• There are two ways to test your code.
  • Run it in the top loop with utop. To load all of your functions into the top loop in one go you can use the OCaml top-loop directive #use "src/submission.ml";; which is the same as copy/pasting that file into the top loop as input. Make sure you started utop from the assignment2/ directory for this to work. Alternatively, you can use the dune utop command to load your code upon starting.
  • Run dune test from the main directory (assignment2/). All of these tests should pass because we will run it when you submit your code. Remember to add five of your own tests.
• Note that all dune commands should be run directly from the assignment2/ directory ONLY. dune automatically will also run the build files in any sub-directories by default, so this will run the dune files in src/ and test/ if required. Also note that dune test will implicitly invoke dune build if your code is not compiled yet.

Submission and Grading

• Follow the same procedure as Assignment 1 to upload to Gradescope.
  • Run dune build and submit the zip file at _build/default/assignment2.zip.
• The autograder will run the tests we gave you and any additional tests you add.
  • You will be graded on adding five additional tests.
• The autograder will also run our own tests that you might not see (yet). Ensure your own tests are complete to pass all of our hidden tests.
• We will hand-inspect your code, but we won’t enforce style guidelines until the next assignment.
• You can submit the assignment as many times as you want up to the deadline. Any submissions after the deadline will fall under the late submission policy.
• Please submit your draft assignment at least once well ahead of the deadline, so you do not find some problem right at the deadline.