Expand description
98-008: Intro to the Rust Programming Language
Primer Lab
The goal of this homework is to make sure that you understand Rust’s basic syntax.
There is a markdown-rendered version of this writeup on our website that we would recommend using. It is automatically generated using Rust’s documentation tooling, and is very similar to Rust documentation that you will find in the wild!
We recommend you make use of the Rust Book chapters 1-3, as the “textbook” of this course. It’s generally easy to follow along with, and would make handy reference material for the homeworks in this course.
We’ve tried to calibrate this homework to take around an hour, so if you are spending much more than that, please let us know! However, this time bound does not include setting up Rust on your machine, so if you have trouble with installing Rust, make sure to ask for help!
Setup
Make sure you have Rust installed. You should have installed Rust through rustup.
To confirm, run:
$ rustup --version
rustup 1.27.1 (2023-11-14)
$ cargo --version
cargo 1.80.1 (ecb9851af 2023-10-18)
Make sure that both of those commands execute successfully,
and that they have relatively recent dates.
If the dates are not recent, you can update rustup by running rustup update.
If you want a local version of this writeup, you can generate it with cargo doc.
Once you have cargo installed, run cargo doc --open in this directory to generate documentation
for this homework.
$ cargo doc --open
Documenting primerlab v0.1.0 (<path>/primerlab)
Finished dev [unoptimized + debuginfo] target(s) in 0.11s
Opening <path>/primerlab/target/doc/primerlab/index.html
Either way, a version of this writeup will be up on our website!
Part 1: Exercises
For the first part of this homework, there are 8 files that do not compile under src/exercises.
You will need to modify each of them in some way to make them compile.
Run this command in the root of your project (parent directory of the src/ folder):
$ cargo test
What does the error say? Go into src/exercises/fixme1.rs and make the change.
When you are able to run cargo test without any errors,
move on to the next exercise by uncommenting pub mod fixme2 in src/exercises/mod.rs.
Go through all 8 of the exercises by uncommenting each of the pub mod fixme_;s,
and make sure that all the fixme_ test cases pass when you run cargo test.
At this point, you’ll see some other tests failing. You’ll fix those in the next section!
Part 2: Function implementations
You will now need to implement 4 relatively simple functions in Rust.
In src/functions.rs, you will find 4 functions with a todo!() inside of them.
Replace that todo!() with your implementation, according to the comment specification.
One of the functions requires you to implement it in a certain way, so make sure to read those comments carefully.
To test all of your functions, run:
$ cargo test
Note that cargo test will run the tests under src/tests.rs, as well as run each of the
code examples in the comments.
If you find that a test is running slowly, run cargo test --release,
which runs the tests in release mode. This runs the tests with
compiler optimizations (like the -O2 flag for C) and without debug symbols.
Also, if you want to run a specific test like fn it_works(), run cargo test -- it_works
with the name of the test instead of it_works.
Submission
Formatting and Style
The autograder will run these two commands on your code:
cargo clippy && cargo fmt --all -- --check
If the autograder detects any errors from the command above, you will not be able to receive any points. This may seem strict, but we have decided to follow standard best practices for Rust.
By following Rust’s style guidelines, you ensure that anybody reading your code (who is familiar with Rust) will be able to easily navigate your code. This can help with diving into an unfamiliar code base, and it also eliminates the need for debate with others over style rules, saving time and energy.
See the official guidelines for more information.
Unix
If you are on a unix system, we will try to create a handin.zip automatically for you,
but you will need to have zip already installed.
If you do not have zip installed on your system,
install zip on your machine or use the CMU Linux SSH machines.
If you need help with this, please reach out to us!
Once you have zip installed, we will create the handin.zip automatically for you
(take a peek into build.rs if you’re interested in how this works!).
Once you have the handin.zip file, submit it to Gradescope.
Windows
If you are on a windows system, you can zip the src/ folder manually
and upload that to Gradescope.
Note that you don’t need to name it handin.zip, you can name it whatever you’d like.
Collaboration
In general, feel free to discuss homeworks with other students! As long as you do not copy someone else’s work, any communication is fair game.
All formal questions should be asked on Piazza. Try to discuss on Piazza so that other students can see your questions and answers as well!
You can also discuss on Discord, but try to keep any technical questions on Piazza.
Feedback
We would like to reiterate that you should let us know if you spent anywhere in significant excess of an hour on this homework.
In addition, Rust has a notoriously steep learning curve, so if you find yourself not understanding the concepts, you should reach out to us and let us know as well — chances are, you’re not the only one!
Modules
- All examples taken from rustlings exercises