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【Rust5】基础包
source link: https://www.guofei.site/2022/09/13/rust5.html
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rand随机
rand = "0.8.3"
use rand::Rng;
// 每个线程都有一个初始化的生成器
let mut rng = rand::thread_rng();
// 整数范围是该类型的范围
let n1: u8 = rng.gen();
let n2: u16 = rng.gen();
// 浮点数的范围是0到1，但不包括1
let f1: f64 = rng.gen();
生成一个范围内的随机数
let f2_rnd: f64 = rng.gen_range(0.0..10.0);
let i2_rnd: i32 = rng.gen_range(0..10);
// 整数
Uniform::from(1..7);
// 浮点数
Uniform::from(1.0..7.0);
// 更复杂的类型用 rand_distr
use rand_distr::{Normal, Binomial, Gamma};
// mean 2, standard deviation 3
let mut normal = Normal::new(2.0, 3.0).unwrap();
let val = normal.sample(&mut rand::thread_rng());
案例：随机生成密码
use rand::Rng;
const CHARSET: &[u8] = b"ABCDEFGHIJKLMNOPQRSTUVWXYZ\
abcdefghijklmnopqrstuvwxyz\
0123456789)(*&^%$#@!~";
const PASSWORD_LEN: usize = 30;
let mut rng = rand::thread_rng();
let password: String = (0..PASSWORD_LEN)
.map(|_| {
let idx = rng.gen_range(0..CHARSET.len());
CHARSET[idx] as char
})
.collect();sort
vec.sort 可以用于 int, &str 但不能用于 float
let mut vec = vec![1, 5, 10, 2, 15];
let mut vec = vec!["aa", "ab", "b"];
vec.sort();
print!("{:?}", vec);
下面这种写法很通用
let mut vec = vec![1.1, 1.15, 5.5, 1.123, 2.0];
vec.sort_by(|a, b| a.partial_cmp(b).unwrap());
案例：对 vec<struct> 排序
struct Person {
name: String,
age: u32,
}
impl Person {
fn new(name: String, age: u32) -> Self {
Person { name, age }
}
}
fn main() {
let mut people = vec![
Person::new("Zoe".to_string(), 25),
Person::new("Al".to_string(), 60),
Person::new("John".to_string(), 1),
];
people.sort_by(|a, b| b.age.cmp(&a.age));
}
命令行
// clap = "*"
use clap::{Arg, App};
fn main() {
let matches = App::new("app名称")
.version("0.0.1")
.author("guofei9987 <[email protected]>")
.about("关于，这个app是干什么的")
.arg(Arg::with_name("file")
.short('f')
.long("file")
.takes_value(true)
.help("A cool file"))
.arg(Arg::with_name("num")
.short('n')
.long("number")
.takes_value(true)
.help("Five less than your favorite number"))
.get_matches();
let myfile = matches.value_of("file").unwrap_or("input.txt");
println!("The file passed is: {}", myfile);
let num_str = matches.value_of("num");
match num_str {
None => println!("No idea what your favorite number is."),
Some(s) => {
match s.parse::<i32>() {
Ok(n) => println!("Your favorite number must be {}.", n + 5),
Err(_) => println!("That's not a number! {}", s),
}
}
}
}# 正经使用
cargo run -- -f myfile.txt -n 251
# -V 和 --version 显示app名称+版本
cargo run -- -V
# -h, --help 显示详细的帮助信息
cargo run -- -h
ANSI：彩色命令行
// ansi_term = "*"
use ansi_term::Colour;
use ansi_term::Style;
fn main() {
println!("This is {}, {}, {} and {}. This is {}.",
Colour::Red.paint("red"),
Colour::Blue.paint("blue"),
Colour::Green.paint("green"),
Colour::Yellow.paint("yellow"),
Style::new().bold().paint("bold"),
);
}time
let start = Instant::now();
thread::sleep(Duration::from_secs(1));
let duration = start.elapsed();
// duration 可以转化为很多种数字格式
// duration.as_secs_f32(); // 返回 f32，
// std::time::Duration 重复了，所以做个别名
use chrono::Duration as Duration2;
let now = Utc::now();
now.checked_add_signed(Duration2::days(-1))
// 还可以用checked_sub_signed
// Duration2:: 可以是:
// days, weeks,
// hours, minutes, milliseconds, microseconds时区（略）
生成时间对象
let now = Utc::now();
let date_time = chrono::NaiveDate::from_ymd(2017, 11, 12).and_hms(17, 33, 44);时间对象格式转字符串
let now = Utc::now();
// 标准格式时间
let time_str = format!("{}-{:02}-{:02} {:02}:{:02}:{:02}",
now.year(), now.month(), now.day(),
now.hour(), now.minute(), now.second());
// 其它格式时间
let (is_common_era, year) = now.year_ce();
println!(
"The current UTC date is {}-{:02}-{:02} {:?} ({})",
year,
now.month(),
now.day(),
now.weekday(),
if is_common_era { "CE" } else { "BCE" }
);
let (is_pm, hour) = now.hour12();
println!(
"The current UTC time is {:02}:{:02}:{:02} {}",
hour,
now.minute(),
now.second(),
if is_pm { "PM" } else { "AM" }
);
时间对象转 timestamp
now.timestamp()
字符串转日期
let no_timezone = chrono::NaiveDateTime::parse_from_str("2015-09-05 23:56:04", "%Y-%m-%d %H:%M:%S")
.unwrap();
正则
[dependencies]
regex = "*"
// 编译正则
let re = Regex::new("\\b[\\w\\-\\+\\.]+@[\\w\\-\\+\\.]+\\.\\w{2,18}\\b").unwrap();
let text = "aaa [email protected] [email protected]";
// 是否有匹配，
let res: bool = re.is_match(text);
// true
// 单匹配
let mut res = Vec::new();
match re.captures(text) {
// 这里面的序号0代表整体，序号1代表分组1
Some(i) => { res.push(String::from(&i[0])) }
None => {}
}
// 多匹配
let mut res = Vec::new();
for cap in re.captures_iter(text) {
res.push(String::from(&cap[0]));
}
// 匹配并替换
let text_new = re.replace_all(text, "你");关于分组运算
// 编译正则，定义老公两个组，分别命名为 user_name 和 domain
let re = Regex::new("\\b(?P<name>[\\w\\-\\+\\.]+)@[\\w\\-\\+\\.]+\\.(?P<domain>\\w{2,18})\\b").unwrap();
let text = "aaa [email protected] [email protected]";
let text2 = "aaaaaaa";
// 单匹配：上面用 index 方便一些，如果想用name：
// re.captures(text) 是一个 `<Option<Captures<"user_name":Option>>>` 这种嵌套
let mut res: Vec<String> = Vec::new();
match re.captures(text) {
Some(i) => {
res.push(String::from(i.name("user_name").unwrap().as_str()));
}
None => {}
}
// 还可以这样，但是匹配不到的时候直接 Panic 了
let res: &str = cap.unwrap().name("user_name").unwrap().as_str();
// 多匹配
let mut res = Vec::new();
for cap in re.captures_iter(&text) {
match cap.name("user_name") {
None => {}
Some(i) => { res.push(String::from(i.as_str())) }
}
}
// 替换
let text_new = re.replace_all(text, "$user_name/$domain");参考：https://blog.csdn.net/wsp_1138886114/article/details/116519242 （rust的正则和python的正则有些区别，功能更多）
字符串临时
用的pcre
fn get_mod_match(&self, text: &str) -> Vec<String> {
let text = text.as_bytes();
let mut res = Vec::new();
for re in &self.re_set {
for cap in re.captures_iter(text) {
match cap {
Ok(cap) => res.push(String::from_utf8_lossy(cap.index(0)).parse().unwrap()),
Error => {}
}
}
}
return res;
}
let my_str_u: &[u8] = b"hello";
let my_str: &str = "hello";
// 互相转换
let new_my_str_u: &[u8] = my_str.as_bytes();
String::from_utf8_lossy(my_str_u);
String::from(my_str);
<String>.as_str()
<String>.as_bytes()
测试性能
[dependencies]
bench = "*"
lib.rs
#![feature(test)]
pub mod benchmarks;
benchmarks.rs
#![feature(test)]
extern crate test;
use test::Bencher;
#[bench]
fn bench_pcre2_is_match(b: &mut Bencher) {
let pcre_re: pcre2::bytes::Regex = pcre2::bytes::Regex::new(r#"he.{0,2}o"#).unwrap();
b.iter(|| pcre2_is_match(&pcre_re));
}
额外
// 如何匹配 Option
match opt {
Some(i)=>{},
None=>{}
}
// 如何匹配 Result
match res {
Ok{t}=>{}
Err(e)=>{}
}改一个数字
fn myfun(a: &mut i32){
*a+=1;
}
fn main() {
let mut a=1;
myfun(&mut a);
println!("{}",a); // 为 2
}tar（待补充）
https://rust-lang-nursery.github.io/rust-cookbook/compression/tar.html
密码学（待补充）
https://rust-lang-nursery.github.io/rust-cookbook/cryptography/encryption.html
ring::pbkdf2
SQLite 和 Postgres（待补充）
https://rust-lang-nursery.github.io/rust-cookbook/database/sqlite.html
如何打log（待补充）
https://rust-lang-nursery.github.io/rust-cookbook/development_tools.html
参考资料
https://llever.com/rust-cookbook-zh/
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