Rustで数当てコンソールアプリ
Dockerで開発環境
Dockerfile
FROM rust:1.32
RUN cargo install wasm-pack && cargo install cargo-generate
run
docker run -it --rm -p 8080:8080 -e USER=$USER -v "$PWD":/usr/src/ -w /usr/src eg-rust /bin/bash
パッケージ生成
cargo new guessing_game
cd guessing_game
こんな感じのファイルが生成されます。

ソース書き換え
main.rs
use std::io;
use std::cmp::Ordering;
use rand::Rng;
fn main() {
println!("Guess the number!");
let secret_number = rand::thread_rng().gen_range(1, 101);
println!("The secret number is: {}", secret_number);
loop {
println!("Please input your guess.");
let mut guess = String::new();
io::stdin().read_line(&mut guess)
.expect("Failed to read line");
let guess: u32 = match guess.trim().parse() {
Ok(num) => num,
Err(_) => continue,
};
println!("You guessed: {}", guess);
match guess.cmp(&secret_number) {
Ordering::Less => println!("Too small!"),
Ordering::Greater => println!("Too big!"),
Ordering::Equal => {
println!("You win!");
break;
}
}
}
}
Cargo.toml
dependenciesにrandを追加
....省略
[dependencies]
rand = "0.3.14"
動作確認
cargo run
こんな感じで、数当て
Guess the number!
The secret number is: 72
Please input your guess.
12
You guessed: 12
Too small!
Please input your guess.
34
You guessed: 34
Too small!
Please input your guess.
72
You guessed: 72
You win!