Book Image

Rust Standard Library Cookbook

By : Jan Hohenheim, Daniel Durante
Book Image

Rust Standard Library Cookbook

By: Jan Hohenheim, Daniel Durante

Overview of this book

Mozilla’s Rust is gaining much attention with amazing features and a powerful library. This book will take you through varied recipes to teach you how to leverage the Standard library to implement efficient solutions. The book begins with a brief look at the basic modules of the Standard library and collections. From here, the recipes will cover packages that support file/directory handling and interaction through parsing. You will learn about packages related to advanced data structures, error handling, and networking. You will also learn to work with futures and experimental nightly features. The book also covers the most relevant external crates in Rust. By the end of the book, you will be proficient at using the Rust Standard library.
Table of Contents (12 chapters)

How to do it...

  1. Open the Cargo.toml file that has been generated earlier for you.

  2. In the bin folder, create a file called retain_string.rs.

  3. Add the following code, and run it with cargo run --bin retain_string:

1   #![feature(string_retain)]
2   
3   fn main() {
4     let mut some_text = "H_el_l__o_ ___Wo_r__l_d_".to_string();
5     println!("Original text: {}", some_text);
6     // retain() removes all chars that don't fulfill a
7     // predicate in place, making it very efficient
8     some_text.retain(|c| c != '_');
9     println!("Text without underscores: {}", some_text);
10    some_text.retain(char::is_lowercase);
11    println!("Text with only lowercase letters: {}", some_text);
12  
13    // Before retain, you had to filter the string as an iterator 
over chars 14 // This will however create a new String, generating overhead 15 let filtered: String = "H_el_l__o_ ___Wo_r__l_d_" 16 ...