UNIC is a project to develop components for the Rust programming language to provide high-quality and easy-to-use crates for Unicode and Internationalization data and algorithms. In other words, it's like ICU for Rust, written completely in Rust, mostly in safe mode, but also benefiting from performance gains of unsafe mode when possible.

Programming language: Rust
License: GNU General Public License v3.0 or later
Latest version: v0.9.0

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UNIC: Unicode and Internationalization Crates for Rust


Travis Rust-1.45+ Unicode-10.0.0 Release Crates.io Documentation Gitter


UNIC is a project to develop components for the Rust programming language to provide high-quality and easy-to-use crates for Unicode and Internationalization data and algorithms. In other words, it's like ICU for Rust, written completely in Rust, mostly in safe mode, but also benefiting from performance gains of unsafe mode when possible.

See [UNIC Changelog](CHANGELOG.md) for latest release details.

Project Goal

The goal for UNIC is to provide access to all levels of Unicode and Internationalization functionalities, starting from Unicode character properties, to Unicode algorithms for processing text, and more advanced (locale-based) processes based on Unicode Common Locale Data Repository (CLDR).

Other standards and best practices, like IETF RFCs, are also implemented, as needed by Unicode/CLDR components, or common demand.

Project Status

At the moment UNIC is under heavy development: the API is updated frequently on master branch, and there will be API breakage between each 0.x release. Please see open issues for changes planed.

We expect to have the 1.0 version released in 2018 and maintain a stable API afterwards, with possibly one or two API updates per year for the first couple of years.

Design Goals

  1. Primary goal of UNIC is to provide reliable functionality by way of easy-to-use API. Therefore, new components are added may not be well-optimized for performance, but will have enough tests to show conformance to the standard, and examples to show users how they can be used to address common needs.

  2. Next major goal for UNIC components is performance and low binary and memory footprints. Specially, optimizing runtime for ASCII and other common cases will encourage adaptation without fear of slowing down regular development processes.

  3. Components are guaranteed, to the extend possible, to provide consistent data and algorithms. Cross-component tests are used to catch any inconsistency between implementations, without slowing down development processes.

Components and their Organization

UNIC Components have a hierarchical organization, starting from the [unic](unic/) root, containing the major components. Each major component, in turn, may host some minor components.

API of major components are designed for the end-users of the libraries, and are expected to be extensively documented and accompanies with code examples.

In contrast to major components, minor components act as providers of data and algorithms for the higher-level, and their API is expected to be more performing, and possibly providing multiple ways of accessing the data.

The UNIC Super-Crate

The unic super-crate is a collection of all UNIC (major) components, providing an easy way of access to all functionalities, when all or many are needed, instead of importing components one-by-one. This crate ensures all components imported are compatible in algorithms and consistent data-wise.

Main code examples and cross-component integration tests are implemented under this crate.

Major Components

  • [unic-char](unic/char/): Unicode Character Tools. Crates.io

  • [unic-ucd](unic/ucd/): Unicode Character Database (UAX#44). Crates.io

  • [unic-bidi](unic/bidi/): Unicode Bidirectional Algorithm (UAX#9). Crates.io

  • [unic-normal](unic/normal/): Unicode Normalization Forms (UAX#15). Crates.io

  • [unic-segment](unic/segment/): Unicode Text Segmentation Algorithms (UAX#29). Crates.io

  • [unic-idna](unic/idna/): Unicode IDNA Compatibility Processing (UTS#46). Crates.io

  • [unic-emoji](unic/emoji/): Unicode Emoji (UTS#51). Crates.io


  • [unic-cli](apps/cli): UNIC Command-Line Tools Crates.io

Code Organization: Combined Repository

Some of the reasons to have a combined repository these components are:

  • Faster development. Implementing new Unicode/i18n components very often depends on other (lower level) components, which in turn may need adjustments—expose new API, fix bugs, etc—that can be developed, tested and reviewed in less cycles and shorter times.

  • Implementation Integrity. Multiple dependencies on other components mean that the components need to, to some level, agree with each other. Many Unicode algorithms, composed from smaller ones, assume that all parts of the algorithm is using the same version of Unicode data. Violation of this assumption can cause inconsistencies and hard-to-catch bugs. In a combined repository, it's possible to reach a better integrity during development, as well as with cross-component (integration) tests.

  • Pay for what you need. Small components (basic crates), which cross-depend only on what they need, allow users to only bring in what they consume in their project.

  • Shared bootstrapping. Considerable amount of extending Unicode/i18n functionalities depends on converting source Unicode/locale data into structured formats for the destination programming language. In a combined repository, it's easier to maintain these bootstrapping tools, expand coverage, and use better data structures for more efficiency.


  • [Unicode and Rust](docs/Unicode_and_Rust.md)
  • [UNIC Versioning](docs/Versioning.md)
  • [UNIC Unicode API](docs/Unicode_API.md)
  • [UNIC API Guideline](docs/API_Guideline.md)
  • UNIC API Reference (autogenerated on docs.rs)

How to Use UNIC

In Cargo.toml:

unic = "0.9.0"  # This has Unicode 10.0.0 data and algorithms

And in main.rs:

extern crate unic;

use unic::ucd::common::is_alphanumeric;
use unic::bidi::BidiInfo;
use unic::normal::StrNormalForm;
use unic::segment::{GraphemeIndices, Graphemes, WordBoundIndices, WordBounds, Words};
use unic::ucd::normal::compose;
use unic::ucd::{is_cased, Age, BidiClass, CharAge, CharBidiClass, StrBidiClass, UnicodeVersion};

fn main() {

    // Age

    assert_eq!(Age::of('A').unwrap().actual(), UnicodeVersion { major: 1, minor: 1, micro: 0 });
    assert_eq!(Age::of('\u{A0000}'), None);
        UnicodeVersion { major: 2, minor: 0, micro: 0 }

    if let Some(age) = '🦊'.age() {
        assert_eq!(age.actual().major, 9);
        assert_eq!(age.actual().minor, 0);
        assert_eq!(age.actual().micro, 0);

    // Bidi

    let text = concat![


    assert_eq!(text.chars().nth(0).unwrap().bidi_class(), BidiClass::RightToLeft);

    assert_eq!(text.chars().nth(3).unwrap().bidi_class(), BidiClass::LeftToRight);

    let bidi_info = BidiInfo::new(text, None);
    assert_eq!(bidi_info.paragraphs.len(), 1);

    let para = &bidi_info.paragraphs[0];
    assert_eq!(para.level.number(), 1);
    assert_eq!(para.level.is_rtl(), true);

    let line = para.range.clone();
    let display = bidi_info.reorder_line(para, line);

    // Case

    assert_eq!(is_cased('A'), true);
    assert_eq!(is_cased('א'), false);

    // Normalization

    assert_eq!(compose('A', '\u{030A}'), Some('Å'));

    let s = "ÅΩ";
    let c = s.nfc().collect::<String>();
    assert_eq!(c, "ÅΩ");

    // Segmentation

        &["a\u{310}", "e\u{301}", "o\u{308}\u{332}"]

        &["a", "\r\n", "b", "🇺🇳", "🇮🇨"]

        GraphemeIndices::new("a̐éö̲\r\n").collect::<Vec<(usize, &str)>>(),
        &[(0, "a̐"), (3, "é"), (6, "ö̲"), (11, "\r\n")]

            "The quick (\"brown\") fox can't jump 32.3 feet, right?",
            |s: &&str| s.chars().any(is_alphanumeric),
        &["The", "quick", "brown", "fox", "can't", "jump", "32.3", "feet", "right"]

        WordBounds::new("The quick (\"brown\")  fox").collect::<Vec<&str>>(),
        &["The", " ", "quick", " ", "(", "\"", "brown", "\"", ")", " ", " ", "fox"]

        WordBoundIndices::new("Brr, it's 29.3°F!").collect::<Vec<(usize, &str)>>(),
            (0, "Brr"),
            (3, ","),
            (4, " "),
            (5, "it's"),
            (9, " "),
            (10, "29.3"),
            (14, "°"),
            (16, "F"),
            (17, "!")

You can find more examples under [examples](examples/) and [tests](tests/) directories. (And more to be added as UNIC expands...)


Licensed under either of

at your option.


Unless you explicitly state otherwise, any contribution intentionally submitted for inclusion in the work by you, as defined in the Apache-2.0 license, shall be dual licensed as above, without any additional terms or conditions.

Code of Conduct

UNIC project follows The Rust Code of Conduct. You can find a copy of it in [CODE_OF_CONDUCT.md](CODE_OF_CONDUCT.md) or online at https://www.rust-lang.org/conduct.html.

*Note that all licence references and agreements mentioned in the UNIC README section above are relevant to that project's source code only.