unic_char_basics/
private_use.rs

1// Copyright 2018 The UNIC Project Developers.
2//
3// See the COPYRIGHT file at the top-level directory of this distribution.
4//
5// Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or
6// http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
7// <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your
8// option. This file may not be copied, modified, or distributed
9// except according to those terms.
10
11//! Unicode Private-Use Characters
12//!
13//! *Unicode Private-Use Characters* are the Unicode code-poitns whose interpretation is not
14//! specified by a character encoding standard and whose use and interpretation may be determined by
15//! private agreement among cooperating users.
16//!
17//! Since Unicode 2.0.0, the list of Unicode Private-Use characters is *stabilized* by the Unicode
18//! Standard and will never change.
19//!
20//! References:
21//! - https://www.unicode.org/faq/private_use.html#private_use
22//! - https://www.unicode.org/policies/stability_policy.html#Property_Value
23
24/// Check if the Unicode code-point provided is a *Unicode Private-Use Character*.
25///
26/// - https://www.unicode.org/faq/private_use.html#private_use
27pub fn is_private_use(codepoint: char) -> bool {
28    match codepoint {
29        '\u{e000}'..='\u{f8ff}' // 6,400 Plane 0 (BMP) chars
30        | '\u{f_0000}'..='\u{f_fffd}' // 65,534 Plane 15 chars
31        | '\u{10_0000}'..='\u{10_fffd}' // 65,534 Plane 16 chars
32        => {
33            true
34        }
35        _ => false,
36    }
37}
38
39#[cfg(test)]
40mod tests {
41    use super::is_private_use;
42
43    #[test]
44    fn test_sample_codepoints() {
45        // Plane 0 (BMP)
46        assert_eq!(is_private_use('\u{0}'), false);
47        assert_eq!(is_private_use('\u{20}'), false);
48        assert_eq!(is_private_use('\u{41}'), false);
49        assert_eq!(is_private_use('\u{80}'), false);
50        assert_eq!(is_private_use('\u{200c}'), false);
51        assert_eq!(is_private_use('\u{d7ff}'), false);
52
53        assert_eq!(is_private_use('\u{e000}'), true);
54        assert_eq!(is_private_use('\u{e001}'), true);
55        assert_eq!(is_private_use('\u{f8fe}'), true);
56        assert_eq!(is_private_use('\u{f8ff}'), true);
57        assert_eq!(is_private_use('\u{f900}'), false);
58
59        assert_eq!(is_private_use('\u{fdcf}'), false);
60        assert_eq!(is_private_use('\u{fdd0}'), false);
61        assert_eq!(is_private_use('\u{fdd1}'), false);
62        assert_eq!(is_private_use('\u{fdee}'), false);
63        assert_eq!(is_private_use('\u{fdef}'), false);
64        assert_eq!(is_private_use('\u{fdf0}'), false);
65
66        assert_eq!(is_private_use('\u{fff0}'), false);
67        assert_eq!(is_private_use('\u{fffc}'), false);
68        assert_eq!(is_private_use('\u{fffd}'), false);
69        assert_eq!(is_private_use('\u{fffe}'), false);
70        assert_eq!(is_private_use('\u{ffff}'), false);
71
72        // Plane 1 (SMP)
73        assert_eq!(is_private_use('\u{1_0000}'), false);
74        assert_eq!(is_private_use('\u{1_0001}'), false);
75        assert_eq!(is_private_use('\u{1_fffd}'), false);
76        assert_eq!(is_private_use('\u{1_fffe}'), false);
77        assert_eq!(is_private_use('\u{1_ffff}'), false);
78
79        // Plane 14 (SSP)
80        assert_eq!(is_private_use('\u{e_0000}'), false);
81        assert_eq!(is_private_use('\u{e_0001}'), false);
82        assert_eq!(is_private_use('\u{e_fffd}'), false);
83        assert_eq!(is_private_use('\u{e_fffe}'), false);
84        assert_eq!(is_private_use('\u{e_ffff}'), false);
85
86        // Plane 15 (PUA-A)
87        assert_eq!(is_private_use('\u{f_0000}'), true);
88        assert_eq!(is_private_use('\u{f_0001}'), true);
89        assert_eq!(is_private_use('\u{f_fffd}'), true);
90        assert_eq!(is_private_use('\u{f_fffe}'), false);
91        assert_eq!(is_private_use('\u{f_ffff}'), false);
92
93        // Plane 16 (PUA-B)
94        assert_eq!(is_private_use('\u{10_0000}'), true);
95        assert_eq!(is_private_use('\u{10_0001}'), true);
96        assert_eq!(is_private_use('\u{10_fffd}'), true);
97        assert_eq!(is_private_use('\u{10_fffe}'), false);
98        assert_eq!(is_private_use('\u{10_ffff}'), false);
99    }
100}
unic_char_basics/private_use.rs

unic_char_basics/
private_use.rs
