Add multi-language support with --lang option
- Add --lang option accepting 'en' (default), 'es', or 'fr' - Update greeting() function to accept language parameter - Return Option<String> to handle unsupported languages gracefully - Print error message with supported languages for unknown languages - Exit with status 1 on error - Add comprehensive tests for all supported languages
2 files+59−80/2 viewed
| 1 | 1 | //! Greetings. | |
| 2 | 2 | ||
| 3 | − | /// The greeting for `name`. | |
| 4 | − | pub fn greeting(name: &str) -> String { | |
| 5 | − | format!("Hello, {name}!") | |
| 3 | + | /// The greeting for `name` in the given language. | |
| 4 | + | /// Supported languages: "en" (English), "es" (Spanish), "fr" (French). | |
| 5 | + | /// Returns None for unknown languages. | |
| 6 | + | pub fn greeting(name: &str, lang: &str) -> Option<String> { | |
| 7 | + | match lang { | |
| 8 | + | "en" => Some(format!("Hello, {name}!")), | |
| 9 | + | "es" => Some(format!("¡Hola, {name}!")), | |
| 10 | + | "fr" => Some(format!("Bonjour, {name} !")), | |
| 11 | + | _ => None, | |
| 12 | + | } | |
| 6 | 13 | } | |
| 7 | 14 | ||
| 8 | 15 | #[cfg(test)] | |
| 11 | 18 | ||
| 12 | 19 | #[test] | |
| 13 | 20 | fn greets_by_name() { | |
| 14 | − | assert_eq!(greeting("Ada"), "Hello, Ada!"); | |
| 21 | + | assert_eq!(greeting("Ada", "en"), Some("Hello, Ada!".to_string())); | |
| 22 | + | } | |
| 23 | + | ||
| 24 | + | #[test] | |
| 25 | + | fn greets_in_spanish() { | |
| 26 | + | assert_eq!(greeting("Ana", "es"), Some("¡Hola, Ana!".to_string())); | |
| 27 | + | } | |
| 28 | + | ||
| 29 | + | #[test] | |
| 30 | + | fn greets_in_french() { | |
| 31 | + | assert_eq!(greeting("Luc", "fr"), Some("Bonjour, Luc !".to_string())); | |
| 32 | + | } | |
| 33 | + | ||
| 34 | + | #[test] | |
| 35 | + | fn unknown_language_returns_none() { | |
| 36 | + | assert_eq!(greeting("Ada", "de"), None); | |
| 15 | 37 | } | |
| 16 | 38 | } |
| 1 | 1 | use std::env; | |
| 2 | + | use std::process; | |
| 2 | 3 | ||
| 3 | 4 | use hello::greeting; | |
| 4 | 5 | ||
| 5 | 6 | fn main() { | |
| 6 | − | // The name given, or whoever is signed in. | |
| 7 | − | let name = env::args() | |
| 8 | − | .nth(1) | |
| 7 | + | let mut args = env::args().skip(1); | |
| 8 | + | let mut lang = "en".to_string(); | |
| 9 | + | let mut name = None; | |
| 10 | + | ||
| 11 | + | // Parse arguments | |
| 12 | + | while let Some(arg) = args.next() { | |
| 13 | + | if arg == "--lang" { | |
| 14 | + | lang = match args.next() { | |
| 15 | + | Some(l) => l, | |
| 16 | + | None => { | |
| 17 | + | eprintln!("Error: --lang requires an argument"); | |
| 18 | + | process::exit(1); | |
| 19 | + | } | |
| 20 | + | }; | |
| 21 | + | } else { | |
| 22 | + | name = Some(arg); | |
| 23 | + | break; | |
| 24 | + | } | |
| 25 | + | } | |
| 26 | + | ||
| 27 | + | // Get the name, or fall back to USER env var, or "world" | |
| 28 | + | let name = name | |
| 9 | 29 | .or_else(|| env::var("USER").ok()) | |
| 10 | 30 | .unwrap_or_else(|| "world".to_owned()); | |
| 11 | − | println!("{}", greeting(&name)); | |
| 31 | + | ||
| 32 | + | // Get the greeting, or print error and exit | |
| 33 | + | match greeting(&name, &lang) { | |
| 34 | + | Some(msg) => println!("{}", msg), | |
| 35 | + | None => { | |
| 36 | + | eprintln!("Error: unknown language '{}'", lang); | |
| 37 | + | eprintln!("Supported languages: en, es, fr"); | |
| 38 | + | process::exit(1); | |
| 39 | + | } | |
| 40 | + | } | |
| 12 | 41 | } |