first working version

src/lib.rs

@@ -1,3 +1,147 @@
-#[test]
-fn it_works() {
+// 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);
+//! }
+//! ```
+//!
+//! # crates.io
+//!
+//! You can use this package in your project by adding the following
+//! to your `Cargo.toml`:
+//!
+//! ```toml
+//! [dependencies]
+//! unicode_width = "0.0.1"
+//! ```
+
+#![deny(missing_docs, unsafe_code)]
+#![feature(no_std, core)]
+#![no_std]
+
+extern crate core;
+
+#[cfg(test)]
+#[macro_use]
+extern crate std;
+
+use core::prelude::*;
+
+use tables::charwidth as cw;
+pub use tables::UNICODE_VERSION;
+
+mod tables;
+
+/// Methods for determining displayed width of Unicode characters.
+#[allow(missing_docs)]
+pub trait UnicodeWidthChar {
+    fn width(self) -> Option<usize>;
+    fn width_cjk(self) -> Option<usize>;
+}
+
+impl UnicodeWidthChar for char {
+    /// 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> { cw::width(self, false) }
+
+    /// 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> { cw::width(self, true) }
+}
+
+/// Methods for determining displayed width of Unicode strings.
+#[allow(missing_docs)]
+pub trait UnicodeWidthStr {
+    fn width<'a>(&'a self) -> usize;
+    fn width_cjk<'a>(&'a self) -> usize;
+}
+
+impl UnicodeWidthStr for str {
+    /// 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(&self) -> usize {
+        self.chars().map(|c| cw::width(c, false).unwrap_or(0)).sum()
+    }
+
+    /// 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(&self) -> usize {
+        self.chars().map(|c| cw::width(c, true).unwrap_or(0)).sum()
+    }
+}
+
+#[cfg(test)]
+mod tests {
+    #[test]
+    fn test_str() {
+        use super::UnicodeWidthStr;
+
+        assert_eq!(UnicodeWidthStr::width("ｈｅｌｌｏ"), 10);
+        assert_eq!("ｈｅｌｌｏ".width_cjk(), 10);
+        assert_eq!(UnicodeWidthStr::width("\0\0\0\x01\x01"), 0);
+        assert_eq!("\0\0\0\x01\x01".width_cjk(), 0);
+        assert_eq!(UnicodeWidthStr::width(""), 0);
+        assert_eq!("".width_cjk(), 0);
+        assert_eq!(UnicodeWidthStr::width("\u{2081}\u{2082}\u{2083}\u{2084}"), 4);
+        assert_eq!("\u{2081}\u{2082}\u{2083}\u{2084}".width_cjk(), 8);
+    }
+
+    #[test]
+    fn test_char() {
+        use super::UnicodeWidthChar;
+        use core::option::Option::{Some, None};
+
+        assert_eq!(UnicodeWidthChar::width('ｈ'), Some(2));
+        assert_eq!('ｈ'.width_cjk(), Some(2));
+        assert_eq!(UnicodeWidthChar::width('\x00'), Some(0));
+        assert_eq!('\x00'.width_cjk(), Some(0));
+        assert_eq!(UnicodeWidthChar::width('\x01'), None);
+        assert_eq!('\x01'.width_cjk(), None);
+        assert_eq!(UnicodeWidthChar::width('\u{2081}'), Some(1));
+        assert_eq!('\u{2081}'.width_cjk(), Some(2));
+    }
 }