Rust中的迭代器

Posted 2022-09-13 aguncn

和闭包一样，练代码

struct Counter 
    count: u32,


impl Counter 
    fn new() -> Counter 
        Counter count: 0 
    


impl Iterator for Counter 
    type Item = u32;

    fn next(&mut self) -> Option<Self::Item> 
        self.count += 1;

        if self.count < 6 
            Some(self.count)
         else 
            None
        
    


#[test]
fn using_other_iterator_trait_methods() 
    let sum: u32 = Counter::new().zip(Counter::new().skip(1))
                    .map(|(a, b)| a * b)
                    .filter(|x| x % 3 == 0)
                    .sum();
    assert_eq!(18, sum);