在一个字符串向量上,连接运算符的等价物是什么？

Question

我无法在Strings 的向量上找到"join"运算符的Rust等价物.我有一个Vec<String>,我想加入他们作为一个单身String:

let string_list = vec!["Foo".to_string(),"Bar".to_string()];
let joined = something::join(string_list,"-");
assert_eq!("Foo-Bar", joined);

Answer 1

在Rust 1.3.0及更高版本中,SliceConcatExt::join可用:

fn main() {
    let string_list = vec!["Foo".to_string(),"Bar".to_string()];
    let joined = string_list.join("-");
    assert_eq!("Foo-Bar", joined);
}

在1.3.0之前,您可以使用SliceConcatExt::connect:

let joined = string_list.connect("-");

请注意,您不需要任何导入,因为标准库前缀会自动导入方法.

Answer 2

正如Wilfred所述,SliceConcatExt::connect自版本1.3.0以来已被弃用,赞成SliceConcatExt::join:

let joined = string_list.join("-");

Answer 3

itertools板条箱中有一个函数也称为join迭代器：

extern crate itertools; // 0.7.8

use itertools::free::join;
use std::fmt;

pub struct MyScores {
    scores: Vec<i16>,
}

impl fmt::Display for MyScores {
    fn fmt(&self, fmt: &mut fmt::Formatter) -> fmt::Result {
        fmt.write_str("MyScores(")?;
        fmt.write_str(&join(&self.scores[..], &","))?;
        fmt.write_str(")")?;
        Ok(())
    }
}

fn main() {
    let my_scores = MyScores {
        scores: vec![12, 23, 34, 45],
    };
    println!("{}", my_scores); // outputs MyScores(12,23,34,45)
}