你如何逐个字符地迭代 [英] How do you iterate over a string by character

问题描述

我有一个字符串，我需要扫描每次出现的foo并读取其后的所有文本，直到第二个。自Rust执行以来没有包含字符串的函数，我需要通过字符扫描来迭代它。我该怎么做？

I have a string and I need to scan for every occurrence of "foo" and read all the text following it until a second ". Since Rust does not have a contains function for strings, I need to iterate by characters scanning for it. How would I do this?

编辑：Rust的& str 有一个 包含（） 和 find（） method。

Edit: Rust's &str has a contains() and find() method.

推荐答案

我需要通过字符扫描来迭代它。

I need to iterate by characters scanning for it.

。 chars（）方法返回字符串中字符的迭代器。例如

The .chars() method returns an iterator over characters in a string. e.g.

for c in my_str.chars() { 
    // do something with `c`
}

for (i, c) in my_str.chars().enumerate() {
    // do something with character `c` and index `i`
}

如果你对每个字符的字节偏移感兴趣，你可以使用 char_indices 。

If you are interested in the byte offsets of each char, you can use char_indices.

查看 .peekable（），然后使用 peek（）展望未来。它是这样包装的，因为它支持UTF-8代码点而不是简单的字符向量。

Look into .peekable(), and use peek() for looking ahead. It's wrapped like this because it supports UTF-8 codepoints instead of being a simple vector of characters.

您还可以创建 char <的向量/ code> s并从那里开始工作，但这需要更多的时间和空间：

You could also create a vector of chars and work on it from there, but that's more time and space intensive:

let my_chars: Vec<_> = mystr.chars().collect();

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