132 lines
4.3 KiB
Rust
132 lines
4.3 KiB
Rust
// Copyright 2012-2015 The Rust Project Developers. See the COPYRIGHT
|
||
// file at the top-level directory of this distribution and at
|
||
// http://rust-lang.org/COPYRIGHT.
|
||
//
|
||
// Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or
|
||
// http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
|
||
// <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.
|
||
|
||
//! Determine displayed width of `char` and `str` types according to
|
||
//! [Unicode Standard Annex #11](http://www.unicode.org/reports/tr11/)
|
||
//! rules.
|
||
//!
|
||
//! ```rust
|
||
//! extern crate unicode_width;
|
||
//!
|
||
//! use unicode_width::UnicodeWidthStr;
|
||
//!
|
||
//! fn main() {
|
||
//! let teststr = "Ｈｅｌｌｏ, ｗｏｒｌｄ!";
|
||
//! let width = UnicodeWidthStr::width(teststr);
|
||
//! println!("{}", teststr);
|
||
//! println!("The above string is {} columns wide.", width);
|
||
//! let width = teststr.width_cjk();
|
||
//! println!("The above string is {} columns wide (CJK).", width);
|
||
//! }
|
||
//! ```
|
||
//!
|
||
//! # features
|
||
//!
|
||
//! unicode-width supports a `no_std` feature. This eliminates dependence
|
||
//! on std, and instead uses equivalent functions from core.
|
||
//!
|
||
//! # crates.io
|
||
//!
|
||
//! You can use this package in your project by adding the following
|
||
//! to your `Cargo.toml`:
|
||
//!
|
||
//! ```toml
|
||
//! [dependencies]
|
||
//! unicode-width = "0.1.5"
|
||
//! ```
|
||
|
||
#![deny(missing_docs, unsafe_code)]
|
||
#![doc(html_logo_url = "https://unicode-rs.github.io/unicode-rs_sm.png",
|
||
html_favicon_url = "https://unicode-rs.github.io/unicode-rs_sm.png")]
|
||
|
||
#![cfg_attr(feature = "bench", feature(test))]
|
||
#![no_std]
|
||
|
||
#[cfg(test)]
|
||
#[macro_use]
|
||
extern crate std;
|
||
|
||
#[cfg(feature = "bench")]
|
||
extern crate test;
|
||
|
||
use tables::charwidth as cw;
|
||
pub use tables::UNICODE_VERSION;
|
||
|
||
use core::ops::Add;
|
||
|
||
mod tables;
|
||
|
||
#[cfg(test)]
|
||
mod tests;
|
||
|
||
/// Methods for determining displayed width of Unicode characters.
|
||
pub trait UnicodeWidthChar {
|
||
/// Returns the character's displayed width in columns, or `None` if the
|
||
/// character is a control character other than `'\x00'`.
|
||
///
|
||
/// This function treats characters in the Ambiguous category according
|
||
/// to [Unicode Standard Annex #11](http://www.unicode.org/reports/tr11/)
|
||
/// as 1 column wide. This is consistent with the recommendations for non-CJK
|
||
/// contexts, or when the context cannot be reliably determined.
|
||
fn width(self) -> Option<usize>;
|
||
|
||
/// Returns the character's displayed width in columns, or `None` if the
|
||
/// character is a control character other than `'\x00'`.
|
||
///
|
||
/// This function treats characters in the Ambiguous category according
|
||
/// to [Unicode Standard Annex #11](http://www.unicode.org/reports/tr11/)
|
||
/// as 2 columns wide. This is consistent with the recommendations for
|
||
/// CJK contexts.
|
||
fn width_cjk(self) -> Option<usize>;
|
||
}
|
||
|
||
impl UnicodeWidthChar for char {
|
||
#[inline]
|
||
fn width(self) -> Option<usize> { cw::width(self, false) }
|
||
|
||
#[inline]
|
||
fn width_cjk(self) -> Option<usize> { cw::width(self, true) }
|
||
}
|
||
|
||
/// Methods for determining displayed width of Unicode strings.
|
||
pub trait UnicodeWidthStr {
|
||
/// Returns the string's displayed width in columns.
|
||
///
|
||
/// Control characters are treated as having zero width.
|
||
///
|
||
/// This function treats characters in the Ambiguous category according
|
||
/// to [Unicode Standard Annex #11](http://www.unicode.org/reports/tr11/)
|
||
/// as 1 column wide. This is consistent with the recommendations for
|
||
/// non-CJK contexts, or when the context cannot be reliably determined.
|
||
fn width<'a>(&'a self) -> usize;
|
||
|
||
/// Returns the string's displayed width in columns.
|
||
///
|
||
/// Control characters are treated as having zero width.
|
||
///
|
||
/// This function treats characters in the Ambiguous category according
|
||
/// to [Unicode Standard Annex #11](http://www.unicode.org/reports/tr11/)
|
||
/// as 2 column wide. This is consistent with the recommendations for
|
||
/// CJK contexts.
|
||
fn width_cjk<'a>(&'a self) -> usize;
|
||
}
|
||
|
||
impl UnicodeWidthStr for str {
|
||
#[inline]
|
||
fn width(&self) -> usize {
|
||
self.chars().map(|c| cw::width(c, false).unwrap_or(0)).fold(0, Add::add)
|
||
}
|
||
|
||
#[inline]
|
||
fn width_cjk(&self) -> usize {
|
||
self.chars().map(|c| cw::width(c, true).unwrap_or(0)).fold(0, Add::add)
|
||
}
|
||
}
|