https://clap.rs
use clap::App;
fn main() {
App::new("myapp")
.version("1.0")
.about("Does great things!")
.author("Kevin K.")
.get_matches();
}
$ myapp --help
myapp 1.0
Kevin K.
Does great things!
USAGE:
myapp [FLAGS]
FLAGS:
-h, --help Prints this message
-V, --version Prints version information
2、serde
和calp一样，serde是一个功能丰富且性能非常好的通用序列化库。
生产中不建议自己造轮子读写文件，你可以先定义你要的数据类型，然后使用serde库加载读写文件。另外serde库可以帮你完成YAML,JSON的序列化和反序化，非常的方便。
https://serde.rs
use serde::{Serialize, Deserialize};
#[derive(Serialize, Deserialize, Debug)]
struct Point {
x: i32,
y: i32,
}
fn main() {
let point = Point { x: 1, y: 2 };
// Convert the Point to a JSON string.
let serialized = serde_json::to_string(&point).unwrap();
// Prints serialized = {"x":1,"y":2}
println!("serialized = {}", serialized);
// Convert the JSON string back to a Point.
let deserialized: Point = serde_json::from_str(&serialized).unwrap();
// Prints deserialized = Point { x: 1, y: 2 }
println!("deserialized = {:?}", deserialized);
}3、reqwest
reqwest和request一样，是一个http协议的客户端库，帮大多数人做了一些希望HTTP客户端为他们做的许多事情,发请求，超时处理，多种格式支持，异步同步请求，代理等等。
https://docs.rs/reqwest/0.10.8/reqwest
// This will POST a body of `{"lang":"rust","body":"json"}`
let mut map = HashMap::new();
map.insert("lang", "rust");
map.insert("body", "json");
let client = reqwest::Client::new();
let res = client.post("http://httpbin.org/post")
.json(&map)
.send()
.await?;4、rayon
rayon是一个可以并行提供数据的库，它知道如何合理的拆分数据块并合理的使用cpu。比如你想在一个列表上并行使用map时就可以使用它。这就有意思了，在写一些CLI工具的时候很有用，并不是所有的编程语言都可以在命令行并行跑一些数据。
https://github.com/rayon-rs/rayon
use rayon::prelude::*;
fn sum_of_squares(input: &[i32]) -> i32 {
input.par_iter() // <-- just change that!
.map(|&i| i * i)
.sum()
}
5、slog and log
slog是Rust中非常完整的一个日志库。很多有名的库也使用它来做日志库，比如 term,json等等。但是log库正在成为Rust标准库的一部分，可以考虑切换到log库上。
https://github.com/slog-rs/slog
let decorator = slog_term::PlainSyncDecorator::new(std::io::stdout());
let drain = slog_term::FullFormat::new(decorator).build().fuse();
let root_log = slog::Logger::root(drain, o!("version" => "0.5"));
let server_log = root_log.new(o!("host" => "localhost", "port" => "8080"));
let peer1_log =
server_log.new(o!("peer_addr" => "8.8.8.8", "port" => "18230"));
let peer2_log =
server_log.new(o!("peer_addr" => "82.9.9.9", "port" => "42381"));
info!(server_log, "starting");
info!(server_log, "listening");
debug!(peer2_log, "connected");
debug!(peer2_log, "message received"; "length" => 2);
debug!(peer1_log, "connected");
debug!(peer2_log, "response sent"; "length" => 8);
debug!(peer2_log, "disconnected");
debug!(peer1_log, "message received"; "length" => 2);
debug!(peer1_log, "response sent"; "length" => 8);
debug!(peer1_log, "disconnected");
info!(server_log, "exit");
6、itertools
写代码的时候，在List上加N多个操作符非常的繁琐，幸好有itertools帮我们处理，方便的很，比如你要对一个list做map完后排序，排序完后分组，你要怎么做？
https://github.com/rust-itertools/itertools
// using Itertools::fold_results to create the result of parsing
let irises = DATA.lines()
.map(str::parse)
.fold_ok(Vec::new(), |mut v, iris: Iris| {
v.push(iris);
v
});
let mut irises = match irises {
Err(e) => {
println!("Error parsing: {:?}", e);
std::process::exit(1);
}
Ok(data) => data,
};
// Sort them and group them
irises.sort_by(|a, b| Ord::cmp(&a.name, &b.name));
