Две-три думи за Rust (ТърновоКонф 2018)

Демонстрация на това защо Rust е интересен език, който си заслужава да се пробва.

Transcript

1. Две-три думи за ust
   

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2. @AndrewRadev
   

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3. “Много е готин”
   

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4. Ferris the Crustacean
   

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7. Какво толкова пренаписват
   тия ръстаджии?
   

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8. Redox
   

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9. Redox
   

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10. Alacritty
    

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11. Ripgrep
    

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12. Ripgrep
    

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13. Servo
    

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14. Игрички
    ●
    Piston
    ●
    SHAR
    ●
    ggez
    

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16. Защо?
    

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17. Защо?
    ●
    Скорост
    ●
    Съвместимост
    ●
    C, Ruby, Python, Erlang
    ●
    Микроконтролери
    ●
    Web Assembly
    ●
    Безопасност
    

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18. Rust винаги шофира
    

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19. Защо?
    ●
    Скорост
    ●
    Съвместимост
    ●
    Безопасност
    ●
    Елегантност
    ●
    Общност: документация, конференции,
    форуми, процес на разработка
    

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20. Малко код
    

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21. Zero-cost abstraction
    C++ implementations obey the zero-overhead
    principle: What you don’t use, you don’t pay for
    [Stroustrup, 1994]. And further: What you do use,
    you couldn’t hand code any better.
    – Stroustrup
    

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22. fn main() {
    let potato = "
    Любов, любов, варен картоф,
    разрежеш го, а той суров.
    ";
    println!("--\n{}\n--", potato);
    }
    // ===================
    ---
    Любов, любов, варен картоф,
    разрежеш го, а той суров.
    ---
    

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23. fn main() {
    let potato = "
    Любов, любов, варен картоф,
    разрежеш го, а той суров.
    ";
    let lines = potato.
    trim().
    lines().
    map(|l| l.trim());
    println!("---");
    for line in lines {
    println!("{}", line);
    }
    println!("---");
    }
    // ===================
    ---
    Любов, любов, варен картоф,
    разрежеш го, а той суров.
    ---
    

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24. fn main() {
    let potato = "
    Любов, любов, варен картоф,
    разрежеш го, а той суров.
    ";
    let lines = potato.
    trim().
    lines().
    map(|l| l.trim());
    println!("+-------------------------------+");
    for line in lines {
    println!("| {}\t|", line);
    }
    println!("+-------------------------------+");
    }
    // ===================
    +-------------------------------+
    | Любов, любов, варен картоф, |
    | разрежеш го, а той суров. |
    +-------------------------------+
    

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25. let lines = potato.
    trim().
    lines().
    map(|l| l.trim());
    for line in lines {
    println!("{}", line);
    }
    

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26. let lines = potato. // => &str
    trim().
    lines().
    map(|l| l.trim());
    for line in lines {
    println!("{}", line);
    }
    fn trim(&self) -> &str {
    //
    // " Любов, ала-бала, картоф "
    // ^___________________________^ -> текущия &str
    //
    // " Любов, ала-бала, картоф "
    // ^_____________________^ -> върнатия &str
    }
    

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27. let lines = potato.
    trim().
    lines(). // => Lines (std::str::Lines)
    map(|l| l.trim());
    for line in lines {
    println!("{}", line);
    }
    

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28. let lines = potato.
    trim().
    lines().
    map(|l| l.trim());
    for line in lines {
    println!("{}", line);
    }
    

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29. let lines = potato.
    trim().
    lines().
    map(|l| l.trim()); // => std::iter::Map,
    [closure@src/main.rs:10:13: 10:25]>
    for line in lines {
    println!("{}", line);
    }
    

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30. let lines = potato.
    trim().
    lines().
    map(|l| l.trim());
    for line in lines {
    println!("{}", line);
    }
    

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31. Zero-cost abstraction
    ●
    Удобен интерфейс
    ●
    Ефективна имплементация
    

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32. Error handling
    

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33. file, err := os.Open("filename.ext")
    if err != nil {
    return err
    }
    match File::open("filename.ext") {
    Ok(file) => file,
    Err(e) => return e,
    }
    enum Result {
    Ok(T),
    Err(E),
    }
    Result
    

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34. let mut fun = try! {
    File::open("fun.txt").
    or_else(|_| File::open("passable.txt")).
    or_else(|_| File::open("okay_i_guess.txt"))
    };
    

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35. use std::fs::File;
    use std::io::{self, Read};
    fn main() {
    match do_magic_stuff() {
    Ok(contents) => println!("{}", contents),
    Err(e) => panic!("OH, NO! {}", e),
    }
    }
    fn do_magic_stuff() -> Result {
    let mut boring = match File::open("boring.txt") {
    Ok(f) => f,
    Err(e) => return Err(e),
    };
    let mut fun = match File::open("fun.txt") {
    Ok(f) => f,
    Err(e) => return Err(e),
    };
    let mut contents = String::new();
    boring.read_to_string(&mut contents);
    fun.read_to_string(&mut contents);
    return Ok(contents);
    }
    

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36. use std::fs::File;
    use std::io::{self, Read};
    fn main() {
    match do_magic_stuff() {
    Ok(contents) => println!("{}", contents),
    Err(e) => panic!("OH, NO! {}", e),
    }
    }
    fn do_magic_stuff() -> Result {
    let mut boring = match File::open("boring.txt") {
    Ok(f) => f,
    Err(e) => return Err(e),
    };
    let mut fun = match File::open("fun.txt") {
    Ok(f) => f,
    Err(e) => return Err(e),
    };
    let mut contents = String::new();
    boring.read_to_string(&mut contents);
    fun.read_to_string(&mut contents);
    return Ok(contents);
    }
    

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37. macro_rules! try {
    ($expr:expr) => {
    match $expr {
    Ok(result) => result,
    Err(e) => return Err(e),
    }
    }
    }
    

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38. use std::fs::File;
    use std::io::{self, Read};
    fn main() {
    match do_magic_stuff() {
    Ok(contents) => println!("{}", contents),
    Err(e) => panic!("OH, NO! {}", e),
    }
    }
    fn do_magic_stuff() -> Result {
    let mut boring = match File::open("boring.txt") {
    Ok(f) => f,
    Err(e) => return Err(e),
    };
    let mut fun = match File::open("fun.txt") {
    Ok(f) => f,
    Err(e) => return Err(e),
    };
    let mut contents = String::new();
    boring.read_to_string(&mut contents);
    fun.read_to_string(&mut contents);
    return Ok(contents);
    }
    

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39. use std::fs::File;
    use std::io::{self, Read};
    fn main() {
    match do_magic_stuff() {
    Ok(contents) => println!("{}", contents),
    Err(e) => panic!("OH, NO! {}", e),
    }
    }
    fn do_magic_stuff() -> Result {
    let mut boring = try!(File::open("boring.txt"));
    let mut fun = try!(File::open("fun.txt"));
    let mut contents = String::new();
    boring.read_to_string(&mut contents);
    fun.read_to_string(&mut contents);
    return Ok(contents);
    }
    

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40. use std::fs::File;
    use std::io::{self, Read};
    fn main() {
    match do_magic_stuff() {
    Ok(contents) => println!("{}", contents),
    Err(e) => panic!("OH, NO! {}", e),
    }
    }
    fn do_magic_stuff() -> Result {
    let mut boring = File::open("boring.txt")?;
    let mut fun = File::open("fun.txt")?;
    let mut contents = String::new();
    boring.read_to_string(&mut contents);
    fun.read_to_string(&mut contents);
    return Ok(contents);
    }
    

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41. Безопасност
    

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42. Досадна безопасност
    ●
    Няма NULL
    ●
    3.14 * 2 е компилационна грешка
    ●
    Жонглиране на references (“псевдоними”)
    ●
    (demo)
    

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43. Полезна безопасност :)
    ●
    HashMap.entry()
    ●
    Има Result, Option – по-удобни от NULL
    ●
    Добре документирани и полезни операции с
    числа
    ●
    (demo)
    

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44. Learning curve
    ●
    “Това е ужасно, защо не мога да направя
    каквото си знам”?
    ●
    Крачка назад
    ●
    Четене на документация
    ●
    Различен (по-добър) подход
    

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45. Защо?
    ●
    Скорост
    ●
    Съвместимост
    ●
    Безопасност
    ●
    Елегантност
    ●
    Общност
    ●
    Труден, но си заслужава
    

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46. The Rust Book
    

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47. ?
    

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