1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
// 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;

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)).sum()
    }

    #[inline]
    fn width_cjk(&self) -> usize {
        self.chars().map(|c| cw::width(c, true).unwrap_or(0)).sum()
    }
}