{"id":3432,"date":"2023-06-03T18:34:18","date_gmt":"2023-06-03T10:34:18","guid":{"rendered":"http:\/\/192.168.31.200\/?p=3432"},"modified":"2023-06-03T18:34:19","modified_gmt":"2023-06-03T10:34:19","slug":"rust-basic-grammar","status":"publish","type":"post","link":"http:\/\/g1n29wqq.ipyingshe.net:5347\/?p=3432","title":{"rendered":"Rust basic grammar"},"content":{"rendered":"\n

expression grammar<\/strong><\/p>\n\n\n\n

expression: literal identifier operator expression function_call tuple vector map reference range<\/p>\n\n\n\n

literal: integer float string boolean character<\/p>\n\n\n\n

identifier: identifier_name<\/p>\n\n\n\n

operator: arithmetic_operator logical_operator comparison_operator<\/p>\n\n\n\n

function_call: function_name arguments<\/p>\n\n\n\n

arguments: expression expression arguments<\/p>\n\n\n\n

tuple: ( expression , )*<\/p>\n\n\n\n

vector: [ expression , ]*<\/p>\n\n\n\n

map: { key_value_pair , }<\/p>\n\n\n\n

key_value_pair: identifier : expression<\/p>\n\n\n\n

reference: & expression<\/p>\n\n\n\n

range: expression .. expression<\/p>\n\n\n\n

123 \/\/ integer literal
1.23 \/\/ float literal
\"hello world\" \/\/ string literal
true \/\/ boolean literal
'a' \/\/ character literal
\u200b
add_one = |x| x + 1 \/\/ function declaration
add_one(10) \/\/ function call
\u200b
(1, 2, 3) \/\/ tuple literal
[1, 2, 3] \/\/ vector literal
{ 1: \"one\", 2: \"two\" } \/\/ map literal
&10 \/\/ reference to the value 10
1..10 \/\/ range from 1 to 10
\u200b
let number: i32 = 10; \/\/ Signed integer
let another_number: u32 = 20; \/\/ Unsigned integer
\u200b
let decimal_number: f32 = 1.5; \/\/ Single-precision float
let another_decimal_number: f64 = 2.3; \/\/ Double-precision float
\u200b
let is_even: bool = true; \/\/ Boolean value `true`
let is_odd: bool = false; \/\/ Boolean value `false`
\u200b
let character: char = 'a';<\/pre>\n\n\n\n
rust control grammar example<\/strong><\/h3>\n\n\n\n
let number = 10;
\u200b
if number > 5 {
    println!(\"The number is greater than 5.\");
} else if number < 5 {
    println!(\"The number is less than 5.\");
} else {
    println!(\"The number is equal to 5.\");
}
\/\/The number is greater than 5.<\/pre>\n\n\n\n
rust while grammar example<\/h2>\n\n\n\n
fn main() {
    let mut i = 0;
    while i < 10 {
        println!(\"The number is {}\", i);
        i += 1;
    }
}<\/pre>\n\n\n\n
In Rust, the while<\/code> loop can be used to iterate over a collection of items. For example, the following code will print the names of all the files in the current directory:<\/p>\n\n\n\n
fn main() {
    for file in std::fs::read_dir(\".\").unwrap() {
        let file = file.unwrap();
        println!(\"The file is {}\", file.file_name().unwrap().to_str().unwrap());
    }
}
\/\/-------------------
for i in 1..10 {
    println!(\"{}\", i);
}
\/\/select
\u200b
let x = 10;
let y = 20;
\u200b
let z = select(x, y) {
    when x > y => x,
    when x < y => y,
    otherwise => 0,
};
\u200b
println!(\"{}\", z);
\u200b
\/\/loop grammar
loop {
    println!(\"{}\", i);
    i += 1;
    if i > 10 {
        break;
    }
}
\u200b<\/pre>\n\n\n\n
Rust match grammar example<\/p>\n\n\n\n
let number = 10;
\u200b
match number {
    1 => println!(\"One\"),
    2 => println!(\"Two\"),
    3 => println!(\"Three\"),
    _ => println!(\"Other\"),
}
\u200b<\/pre>\n\n\n\n
rust how to write data to fle in example<\/h2>\n\n\n\n
use std::fs::File;
use std::io::Write;
\u200b
fn main() {
    let mut file = File::create(\"data.txt\").expect(\"Could not create file\");
\u200b
    file.write_all(\"Hello, world!\".as_bytes()).expect(\"Could not write to file\");
}
\u200b<\/pre>\n\n\n\n
rust structure data type example<\/h3>\n\n\n\n
struct Person {
    name: String,
    age: u8,
}
\u200b
fn main() {
    let person = Person {
        name: String::from(\"John Doe\"),
        age: 30,
    };
\u200b
    println!(\"Person name: {}\", person.name);
    println!(\"Person age: {}\", person.age);
}
\u200b<\/pre>\n\n\n\n
rust grammar cheetsheet<\/h3>\n\n\n\n
Rust Grammar Cheatsheet<\/h1>\n\n\n\n
Expressions<\/h2>\n\n\n\n
Expressions are evaluated to produce a value.<\/p>\n\n\n\n