string - 未找到 str 的匹配方法

Question

我正在使用 rayon对文本执行并行迭代并尝试输出包含特定字符的字符串。我正在使用 matches() : playground

use rayon::prelude::*;

fn main() {
    let text =
        "Some are born great, some achieve greatness, and some have greatness thrust upon them."
            .to_string();
    check(text, 's');
}

fn check(text: String, ch: char) {
    let words: Vec<_> = text.split_whitespace().collect();
    let words_with_ch: Vec<_> = words.par_iter().map(|ch| words.matches(ch)).collect();
    println!(
        "The following words contain the letter {:?}: {:?}",
        ch, words_with_ch
    );
}

但它显示错误:

error[E0599]: no method named `matches` found for type `std::vec::Vec<&str>` in the current scope
  --> src/main.rs:12:65
   |
12 |     let words_with_ch: Vec<_> = words.par_iter().map(|ch| words.matches(ch)).collect();
   |                                                                 ^^^^^^^

如何解决这个编译错误？

Answer 1

正如@zerkms 所建议的，filter() 将是一个很好的函数来解决这个问题。

过滤器在迭代器上工作。 split_whitespace() 创建迭代器，然后可以将其传递给 filter()。

fn main() {
    let text =
        "Some are born great, some achieve greatness, and some have greatness thrust upon them."
            .to_string();
    check(text, 's');
}

fn check(text: String, ch: char) {
    let words_with_ch: Vec<_> = text
        .split_whitespace()
        .filter(|w| w.contains(ch))
        .collect();
    println!(
        "The following words contain the letter {:?}: {:?}",
        ch, words_with_ch
    );
}