firefox-main/third_party/rust/harfbuzz/src/language.rs

Source code

Revision control

Copy as Markdown

Other Tools

// Copyright 2018 The Servo Project Developers. See the COPYRIGHT
// file at the top-level directory of this distribution.
//
// Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or
// <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your
// option. This file may not be copied, modified, or distributed
// except according to those terms.
use crate::sys;
/// A language tag.
///
/// This corresponds to a [BCP 47] language tag.
///
/// This is a wrapper around the [`hb_language_t`] type from the
/// [`harfbuzz-sys`](crate::sys) crate.
///
/// [`hb_language_t`]: crate::sys::hb_language_t
#[derive(Copy, Clone, PartialEq, PartialOrd)]
pub struct Language {
/// The underlying `hb_language_t` from the `harfbuzz-sys` crate.
///
/// This isn't commonly needed unless interfacing directly with
/// functions from the `harfbuzz-sys` crate that haven't been
/// safely exposed.
raw: sys::hb_language_t,
}
impl Language {
/// Construct a `Language` from a string.
///
/// The string should be a [BCP 47] language tag.
///
/// Example:
///
/// ```
/// let lang = harfbuzz::Language::from_string("en-US");
/// assert!(lang.is_valid());
/// let lang = harfbuzz::Language::from_string("ja");
/// assert!(lang.is_valid());
/// let lang = harfbuzz::Language::from_string("zh-Hant");
/// assert!(lang.is_valid());
/// let lang = harfbuzz::Language::from_string("sr-Latn-RS");
/// assert!(lang.is_valid());
/// let lang = harfbuzz::Language::from_string("");
/// assert!(!lang.is_valid());
/// ```
///
pub fn from_string(lang: &str) -> Self {
Language {
raw: unsafe {
sys::hb_language_from_string(
lang.as_ptr() as *const core::ffi::c_char,
lang.len() as core::ffi::c_int,
)
},
}
}
/// Converts the language to a string.
///
/// Example:
/// ```
/// let lang = harfbuzz::Language::from_string("en-US");
/// assert_eq!(lang.to_string(), "en-us");
/// ```
pub fn to_string(&self) -> &str {
unsafe { core::ffi::CStr::from_ptr(sys::hb_language_to_string(self.raw)) }
.to_str()
.unwrap()
}
/// Construct a `Language` from a raw pointer.
///
/// # Safety
///
/// The pointer must be a valid pointer.
pub unsafe fn from_raw(raw: sys::hb_language_t) -> Self {
Language { raw }
}
/// Convert the `Language` to a raw pointer.
///
/// This is useful for interfacing with functions from the
/// [`harfbuzz-sys`](crate::sys) crate that haven't been safely exposed.
pub fn as_raw(self) -> sys::hb_language_t {
self.raw
}
/// Returns the default language for the process locale.
///
/// See [`hb_language_get_default()`] for more information.
///
/// Example:
///
/// ```
/// let lang = harfbuzz::Language::get_process_default();
/// assert!(lang.is_valid());
/// ```
///
pub fn get_process_default() -> Self {
Language {
raw: unsafe { sys::hb_language_get_default() },
}
}
/// Returns whether or not the language is valid.
///
/// TODO: This should go away and the constructor should
/// return an `Option<Language>`.
pub fn is_valid(self) -> bool {
!self.raw.is_null()
}
}
impl core::fmt::Debug for Language {
fn fmt(&self, fmt: &mut core::fmt::Formatter) -> core::fmt::Result {
fmt.write_str(self.to_string())
}
}
#[cfg(test)]
mod tests {
use super::Language;
#[test]
fn test_lookup() {
let en = Language::from_string("en_US");
assert!(en.is_valid());
}
}