I started learning Rust in December last year by building a command-line tool to display NHL results on the terminal. My background before Rust has been mostly on Python and Javascript ecosystems so there's been quite a learning curve that has required activating new parts of my brain. In this talk, I'll share my early learning journey with Rust. I'll talk openly about the things I struggled with and the things I fell in love with in Rust (like pattern matching).

1. Learning Rust
experiences from a Python/Javascript developer
Rust Denver

2. “The value of another’s experience
is to give us hope, not to tell us
how or whether to proceed”
Rust Denver
“The Answer to How is Yes”
by Peter Block

3. Rust Denver
Hi, I’m Juhis!
from Helsinki, Finland 🇫🇮
(it’s 3.30 am here)
Developer Advocate at Futurice
I build developer communities
https://hamatti.org
twitter.com/hamatti

4. Python & Javascript
Rust Denver

5. Dom Weldon’s talk in PyCon Estonia 2019
Rust Denver

6. Rust Denver

7. Advent of Code 2020
Rust Denver
fn main() ->- io:::Result<()> {
let mut buffer = String:::new();
io:::stdin().read_to_string(&mut buffer)?;
let input: Vec<i32> = buffer
.split('n')
.filter(|inp| inp !!= &"")
.map(|num| num.parse().unwrap())
.collect();
let input2: Vec<i32> = input.clone();
match find_double(input) {
Some(result) =>= println!("Part 1: {}", result),
None =>= panic!("Oh no!"),
}
match find_triplet(input2) {
Some(result) =>= println!("Part 2: {}", result),
None =>= panic!("Oh no!"),
}
Ok(())
}
Advent of Code #1: Getting Started
Advent of Code #2: Borrows, unwraps
and lots of compiler errors
Advent of Code #3: Slowing down

8. I started to build a CLI tool
Rust Denver
235
NHL results on
command line
https://crates.io/crates/nhl-235

9. ❤ Things I really like, #1 ❤
Rust Denver
Pattern Matching

10. Rust Denver
for pair in score_iter {
match pair {
Both(l, r) =>= print_full(l, r),
Left(l) =>= print_left(l),
Right(r) =>= print_right(r),
}
}
Pattern Matching

11. Rust Denver
❤
We’re getting it
in Python too this year
https://www.python.org/dev/peps/pep-0634/

12. 🙈 Things I struggle with, #1
Rust Denver
Static typing
(esp. when nesting custom types)

13. Rust Denver
##[derive(Debug, Serialize, Deserialize)]
pub struct APIResponse {
pub date: DateResponse,
pub games: Vec<GameResponse>,
pub errors: Option<HashMap<String, serde_json:::Value>>>,
}
##[derive(Debug, Serialize, Deserialize)]
pub struct DateResponse {
pub raw: Option<String>,
pub pretty: String,
}
What I’ve done

14. Rust Denver
##[derive(Debug, Serialize, Deserialize)]
pub struct APIResponse {
pub date: {
pub raw: Option<String>,
pub pretty: String,
},
pub games: Vec<GameResponse>,
pub errors: Option<HashMap<String, serde_json:::Value>>>,
}
What I’d like to do

15. ❤ Things I really like, #2 ❤
Rust Denver
rustdoc & doctests

16. Rust Denver
impl Person {
///// Returns a person with the name given them
/////
///// # Arguments
/////
///// * `name` - A string slice that holds the name of the person
/////
///// # Examples
/////
///// ```
///// /// You can have rust code between fences inside the comments
///// /// If you pass ---test to `rustdoc`, it will even test it for you!
///// use doc:::Person;
///// let person = Person:::new(“Juhis");
///// assert_eq!(person.name, String:::from(“Juhis”));
///// ```
pub fn new(name: &str) ->- Person {
Person {
name: name.to_string(),
}
}
}

17. 🙈 Things I struggle with, #2
Rust Denver
Ownership, borrows,
lifetime, references

18. Rust Denver
The Rust Borrow Checker: A Deep Dive - Nell Shamrell-Harrington

19. Rust Denver

20. Rust Denver
“The Rust compiler is very kind and I tweeted last
week about how the language matters. When I'm
stressed about all the red in my terminal, a kind
tone of voice the compiler has definitely makes it
easier to deal with.” “Advent of Code #2: Borrows,
unwraps and lots of compiler errors”
by me

21. 🙈 Things I struggle with, #3
Rust Denver
Verbosity and cascade
of error handling

22. ❤ Things I really like, #3 ❤
Rust Denver
Rustaceans

23. Rust Denver
Learning Rust
A monthly blog series
https://hamatti.org/blog/
#1: Pattern Matching
#2: Option & Result
#3: crates.io
#4: Parsing JSON with strong types
#5: Rustlings
+ new one every first Wed of the month

24. Rust Denver
codebase
Livestream on Youtube
https://hamatti.org/codebase
#1: Accessible forms with HTML
#2: Backend with Clojure
#3: PHP is awesome
#4: Frontend with Web Components
+ new one every month

25. Rust Denver
Thanks for having me!
Time for Q&A!
For more of me
@hamatti in Twitter
hamatti.org