1 // Copyright 2012-2015 The Rust Project Developers. See the COPYRIGHT
2 // file at the top-level directory of this distribution and at
3 // http://rust-lang.org/COPYRIGHT.
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 //! Determine if a `char` is a valid identifier for a parser and/or lexer according to
12 //! [Unicode Standard Annex #31](http://www.unicode.org/reports/tr31/) rules.
13 //!
14 //! ```rust
15 //! extern crate unicode_xid;
16 //!
17 //! use unicode_xid::UnicodeXID;
18 //!
19 //! fn main() {
20 //!     let ch = 'a';
21 //!     println!("Is {} a valid start of an identifier? {}", ch, UnicodeXID::is_xid_start(ch));
22 //! }
23 //! ```
24 //!
25 //! # features
26 //!
27 //! unicode-xid supports a `no_std` feature. This eliminates dependence
28 //! on std, and instead uses equivalent functions from core.
29 //!
30 
31 #![forbid(unsafe_code)]
32 #![deny(missing_docs)]
33 #![doc(
34     html_logo_url = "https://unicode-rs.github.io/unicode-rs_sm.png",
35     html_favicon_url = "https://unicode-rs.github.io/unicode-rs_sm.png"
36 )]
37 #![no_std]
38 #![cfg_attr(feature = "bench", feature(test, unicode_internals))]
39 
40 // #[cfg(test)]
41 // ANDROID: Unconditionally use std to allow building as a dylib.
42 // #[macro_use]
43 extern crate std;
44 
45 #[cfg(feature = "bench")]
46 extern crate test;
47 
48 use tables::derived_property;
49 pub use tables::UNICODE_VERSION;
50 
51 mod tables;
52 
53 #[cfg(test)]
54 mod tests;
55 
56 /// Methods for determining if a character is a valid identifier character.
57 pub trait UnicodeXID {
58     /// Returns whether the specified character satisfies the 'XID_Start'
59     /// Unicode property.
60     ///
61     /// 'XID_Start' is a Unicode Derived Property specified in
62     /// [UAX #31](http://unicode.org/reports/tr31/#NFKC_Modifications),
63     /// mostly similar to ID_Start but modified for closure under NFKx.
is_xid_start(self) -> bool64     fn is_xid_start(self) -> bool;
65 
66     /// Returns whether the specified `char` satisfies the 'XID_Continue'
67     /// Unicode property.
68     ///
69     /// 'XID_Continue' is a Unicode Derived Property specified in
70     /// [UAX #31](http://unicode.org/reports/tr31/#NFKC_Modifications),
71     /// mostly similar to 'ID_Continue' but modified for closure under NFKx.
is_xid_continue(self) -> bool72     fn is_xid_continue(self) -> bool;
73 }
74 
75 impl UnicodeXID for char {
76     #[inline]
is_xid_start(self) -> bool77     fn is_xid_start(self) -> bool {
78         derived_property::XID_Start(self)
79     }
80 
81     #[inline]
is_xid_continue(self) -> bool82     fn is_xid_continue(self) -> bool {
83         derived_property::XID_Continue(self)
84     }
85 }
86