Rust basics

square_sum.rs

fn square_sum(n: isize) -> isize {
    (0..n)
        .filter(|i| i % 2 == 0)
        .map(|i| i * i)
        .sum()
}

fn main() {
    println!("{}", square_sum(10));
}

trait-sample.rs

trait WanLike {
    fn wan(&self);

    fn walk(&self) {
        println!("walking");
    }
}

struct Dog;

impl WanLike for Dog {
    fn wan(&self) {
        println!("wan");
    }
}

struct Nyan;

impl WanLike for Nyan {
    fn wan(&self) {
        println!("nyan");
    }
    
    fn walk(&self) {
        println!("nyaos");
    }
}

impl WanLike for i64 {
    fn wan(&self) {
        for _ in 0..*self {
            println!("nyanyanyan");
        }
    }
}

fn main() {
    let inu = Dog;
    let neko = Nyan;
    let i = 15;

    inu.wan();
    neko.wan();
    i.wan();
}