sys_locale/
lib.rs

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1//! A library to safely and easily obtain the current locale on the system or for an application.
2//!
3//! This library currently supports the following platforms:
4//! - Android
5//! - iOS (and derivatives such as watchOS, tvOS, and visionOS)
6//! - macOS
7//! - Linux, BSD, and other UNIX variations
8//! - WebAssembly on the web (via the `js` feature)
9//! - Windows
10#![cfg_attr(any(not(unix), target_vendor = "apple", target_os = "android"), no_std)]
11extern crate alloc;
12use alloc::string::String;
13
14#[cfg(target_os = "android")]
15mod android;
16#[cfg(target_os = "android")]
17use android as provider;
18
19#[cfg(target_vendor = "apple")]
20mod apple;
21#[cfg(target_vendor = "apple")]
22use apple as provider;
23
24#[cfg(all(unix, not(any(target_vendor = "apple", target_os = "android"))))]
25mod unix;
26#[cfg(all(unix, not(any(target_vendor = "apple", target_os = "android"))))]
27use unix as provider;
28
29#[cfg(all(target_family = "wasm", feature = "js", not(unix)))]
30mod wasm;
31#[cfg(all(target_family = "wasm", feature = "js", not(unix)))]
32use wasm as provider;
33
34#[cfg(windows)]
35mod windows;
36#[cfg(windows)]
37use windows as provider;
38
39#[cfg(not(any(unix, all(target_family = "wasm", feature = "js", not(unix)), windows)))]
40mod provider {
41    pub fn get() -> impl Iterator<Item = alloc::string::String> {
42        core::iter::empty()
43    }
44}
45
46/// Returns the most preferred locale for the system or application.
47///
48/// This is equivalent to `get_locales().next()` (the first entry).
49///
50/// # Returns
51///
52/// Returns [`Some(String)`] with a BCP 47 language tag inside.  
53/// If the locale couldn't be obtained, [`None`] is returned instead.
54///
55/// # Example
56///
57/// ```no_run
58/// use sys_locale::get_locale;
59///
60/// let current_locale = get_locale().unwrap_or_else(|| String::from("en-US"));
61///
62/// println!("The locale is {}", current_locale);
63/// ```
64pub fn get_locale() -> Option<String> {
65    get_locales().next()
66}
67
68/// Returns the preferred locales for the system or application, in descending order of preference.
69///
70/// # Returns
71///
72/// Returns an [`Iterator`] with any number of BCP 47 language tags inside.  
73/// If no locale preferences could be obtained, the iterator will be empty.
74///
75/// # Example
76///
77/// ```no_run
78/// use sys_locale::get_locales;
79///
80/// let mut  locales = get_locales();
81///
82/// println!("The most preferred locale is {}", locales.next().unwrap_or("en-US".to_string()));
83/// println!("The least preferred locale is {}", locales.last().unwrap_or("en-US".to_string()));
84/// ```
85pub fn get_locales() -> impl Iterator<Item = String> {
86    provider::get()
87}
88
89#[cfg(test)]
90mod tests {
91    use super::{get_locale, get_locales};
92    extern crate std;
93
94    #[cfg(all(target_family = "wasm", feature = "js", not(unix)))]
95    use wasm_bindgen_test::wasm_bindgen_test as test;
96    #[cfg(all(target_family = "wasm", feature = "js", not(unix)))]
97    wasm_bindgen_test::wasm_bindgen_test_configure!(run_in_browser);
98
99    #[test]
100    fn can_obtain_locale() {
101        assert!(get_locale().is_some(), "no locales were returned");
102        let locales = get_locales();
103        for (i, locale) in locales.enumerate() {
104            assert!(!locale.is_empty(), "locale string {} was empty", i);
105            assert!(
106                !locale.ends_with('\0'),
107                "locale {} contained trailing NUL",
108                i
109            );
110        }
111    }
112}
sys_locale/lib.rs

sys_locale/
lib.rs
