如何在循环中将 lines() 迭代器作为参数传递给函数

Question

这是开头：

    let fb = BufReader::new(&f);
    let lines = fb.lines();

        let bank_sequence = read_1_sequence(&mut count, lines);
        print_seq(&bank_sequence);

这里是 read_1_sequence 函数：

    fn read_1_sequence<B: BufRead>(count: &mut u8, lines: Lines<B>)
// ...

    for line in lines {
        let the_line = line.unwrap();
        if the_line.len() > 0 {
        let first = &the_line[0..1];
        if first == ">" {
// etc.

但是，如果对 read_1_sequence 的调用处于循环中，如下所示：

    loop {
        let bank_sequence = read_1_sequence(&mut count, lines);
        print_seq(&bank_sequence);
    }

我收到（显然）消息：

26 |     let lines = fb.lines();
   |         ----- move occurs because `lines` has type `std::io::Lines<BufReader<&File>>`, which does not implement the `Copy` trait
...
29 |         let bank_sequence = read_1_sequence(&mut count, lines);
   |                                                         ^^^^^ value moved here, in previous iteration of loop

有解决办法吗？感谢您的任何提示。

祝你（编程）愉快！

Answer 1

其他答案建议克隆 lines，但这行不通，因为 Lines 没有实现 Clone（如果实现了，它可能会从每个循环中文件的开头）。相反，您应该将函数更改为 &mut Lines<B>:

fn read_1_sequence<B: BufRead>(count: &mut u8, lines: &mut Lines<B>)

并这样称呼它：

loop {
    let bank_sequence = read_1_sequence(&mut count, &mut lines);
    print_seq(&bank_sequence);
}

如何在循环中将 lines() 迭代器作为参数传递给函数

How to pass lines() iterator as an argument to a function, in a loop

iterator

arguments

loops

function

rust