Rust101_Session3

Rust101_Session3.md

Rust 101 - Session 3

Recap

Ownership

fn main() {
    let nums = vec![2, 4, 6];
    let nums2 = nums;

    println!("{:?}", nums2);
}

Immutable Borrow

fn main() {
    let nums = vec![2, 4, 6];
    print_nums(nums);

    println!("{:?}", nums);
}

fn print_nums(nums: Vec<i32>) {
    for num in nums.iter() {
        println!("{}", num)
    }
}

Multiple immutable borrow

fn main() {
    let nums = vec![2, 4, 6];
    let nums2 = &nums;
    let nums3 = &nums;
    let nums4 = &nums;

    println!("{:?} {:?} {:?}", nums2, nums3, nums4);
}

Mutable borrow

fn main() {
    let nums = vec![2, 4, 6];
    extend_nums(nums);

    println!("{:?}", nums);
}

fn extend_nums(mut nums: Vec<i32>) {
    nums.push(8);
}

Structs

• Classic struct - Color
• Create object and access values
• Debug print
• Mutability of values
• Update for Tuple Struct
• Unit Struct
• Struct of a package with strings and weight
• Impl of ownership
• Impl of reference
• How to call a reference?
• Impl of add weight
• How to call a mut reference?

Enums

• Example of Message - Echo, Move, ChangeColor, Quit
• If else enum and PartialEq

impl PartialEq for Message {
    fn eq(&self, other: &Self) -> bool {
        match (self, other) {
            (Message::Quit, Message::Quit) => true,
            (Message::Echo, Message::Echo) => true,
            (Message::Move, Message::Move) => true,
            (Message::ChangeColor, Message::ChangeColor) => true,
            _ => false,
        }
    }
}

• Enum with values
• Print - Debug
• Impl for call
• Match

String

• String::from for foobar
• How to get a slice from a string
• Trim string
• Replace bar with baz
• Replacement needs a new String. Why?
• String concatenation
  • push_str
  • format!

Modules

• Crate root
• mod foo and how to call
• mod bar and how to call foo from there
• export and import
• Separate into files
• Separate into folders