如何以功能样式遍历2D向量? [英] How can I iterate over a 2D vector in functional style?

问题描述

不幸的是，以下操作无效:

The following doesn't work, unfortunately:

let vecs: Vec<Vec<i32>> = get_vectors();

let result = vecs
    .iter()
    .iter()
    .do_something()
    .do_something_else() // etc

编译时出现错误:

error[E0599]: no method named `iter` found for type`std::slice::Iter<'_, std::vec::Vec<i32>>` in the current scope
  --> src/main.rs:49:10
   |
49 |         .iter()
   | 

我可以避免

for row in vecs.iter() {
    for column in row.iter() {
        // do something
    }
}

我真的更喜欢.iter()方法.我该如何实现?

I'd really prefer the .iter() method. How could I achieve that?

推荐答案

使用 flatten :

fn main() {
    let v = vec![vec![1, 2], vec![3, 4], vec![5, 6]];

    for i in v.iter().flatten() {
        println!("{}", i); // 1 2 3 4 5 6
    }
}

flatten将嵌套的迭代器转换为一个迭代器.

flatten transforms nested iterators into one iterator.

这篇关于如何以功能样式遍历2D向量?的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！