Rust:
Using regular expressions
How to:
Rust’s regex library is a go-to for working with regular expressions. To use it, you’ll first need to add it to your Cargo.toml:
[dependencies]
regex = "1"Then, you can start implementing regex functionalities in your Rust code. Here’s how to perform some common operations:
Matching a Pattern in a String
use regex::Regex;
fn main() {
let re = Regex::new(r"^\d{4}-\d{2}-\d{2}$").unwrap();
let date = "2023-04-15";
println!("Does the text match the date pattern? {}", re.is_match(date));
// Output: Does the text match the date pattern? true
}Finding and Accessing Matches
use regex::Regex;
fn main() {
let text = "Rust 2023, C++ 2022, Python 2021";
let re = Regex::new(r"\b(\w+)\s(\d{4})").unwrap();
for cap in re.captures_iter(text) {
println!("Language: {}, Year: {}", &cap[1], &cap[2]);
}
// Output:
// Language: Rust, Year: 2023
// Language: C++, Year: 2022
// Language: Python, Year: 2021
}Replacing Text
use regex::Regex;
fn main() {
let re = Regex::new(r"\b(\w+)\s(\d{4})").unwrap();
let text = "Rust 2023, C++ 2022, Python 2021";
let replaced = re.replace_all(text, "$1 was updated in $2");
println!("Updated text: {}", replaced);
// Output: Updated text: Rust was updated in 2023, C++ was updated in 2022, Python was updated in 2021
}Splitting Text Using a Regex
use regex::Regex;
fn main() {
let re = Regex::new(r"\W+").unwrap(); // split at any non-word character
let text = "Rust-C++-Python-Go";
let fields: Vec<&str> = re.split(text).collect();
for field in fields {
println!("Language: {}", field);
}
// Output:
// Language: Rust
// Language: C++
// Language: Python
// Language: Go
}These examples provide a basic guide to getting started with regular expressions in Rust. As your needs become more sophisticated, the regex crate offers a wealth of functionality for complex pattern matching and text manipulation tasks.