rust - 在Rust中将文本数字解析为UTF-8字符？

Question

我有一个字节数组，其中的UTF8字节为str。
我想将此数组转换为UTF8字符。

像这样

["21", "22", "23", "24"]: [&str]

到

!"#$

Answer 1

use std::convert::TryFrom;

fn main() {
    let input = ["21", "22", "23", "24"];

    let result: String = input
        .iter()
        .map(|s| u32::from_str_radix(s, 16).unwrap()) // HEX string to unsigned int
        .map(|u| char::try_from(u).unwrap()) // unsigned int to char (unicode verification)
        .collect();

    assert_eq!(result, "!\"#$");
}

然后，如果需要，可以添加错误验证，而不是 unwrap。我会用一个迭代器来做到这一点:

use std::convert::TryFrom;
use std::error::Error;

struct HexSliceToChars<'a> {
    slice: &'a [&'a str],
    index: usize,
}

impl<'a> HexSliceToChars<'a> {
    fn new(slice: &'a [&'a str]) -> Self {
        HexSliceToChars {slice, index: 0 }
    }
}

impl<'a> Iterator for HexSliceToChars<'a> {
    type Item = Result<char, Box<dyn Error>>;

    fn next(&mut self) -> Option<Self::Item> {
        self.slice.get(self.index).map(|s| {
            let u = u32::from_str_radix(s, 16)?;
            let c = char::try_from(u)?;

            self.index += 1;

            Ok(c)
        })
    }
}

fn main() {
    let input = ["21", "22", "23", "24"];
    let result: Result<String, _> = HexSliceToChars::new(&input).collect();
    // Error handling
    let result = result.unwrap();

    assert_eq!(result, "!\"#$");
}