Line-by-line transliteration of ICU4X decimal internationalization APIs, delivering locale-aware formatting with upstream feature parity and provable provenance via per-file port-lint Rust source headers.
This is a Kotlin Multiplatform line-by-line transliteration port of unicode-org/icu4x.
Original Project: This port is based on unicode-org/icu4x. All design credit and project intent belong to the upstream authors; this repository is a faithful port to Kotlin Multiplatform with no behavioural changes intended.
This is an in-progress port. The goal is feature parity with the upstream Rust crate while providing a native Kotlin Multiplatform API. Every Kotlin file carries a // port-lint: source <path> header naming its upstream Rust counterpart so the AST-distance tool can track provenance.
unicode-org/icu4xThe text below is reproduced and lightly edited from
https://github.com/unicode-org/icu4x. It is the upstream project's own description and remains under the upstream authors' authorship; links have been rewritten to absolute upstream URLs so they continue to resolve from this repository.
ICU4X provides components enabling wide range of software internationalization. It draws deeply from the experience of ICU4C/J, ECMA-402 and relies on data from the CLDR project.
ICU4X is fully implemented in the Rust programming language.
The design goals of ICU4X are:
Stay informed! Join our public, low-traffic mailing list: icu4x-announce@unicode.org. Note: After subscribing, check your spam folder for a confirmation.
For more information, please visit our website.
An example ICU4X powered application in Rust may look like this:
Cargo.toml:
[dependencies]
icu = "2.0.0"
src/main.rs:
use icu::calendar::Date;
icu::datetime::{DateTimeFormatter, fieldsets::YMD};
icu::locale::locale;
= DateTimeFormatter::(
locale!().(),
YMD::()
)
.();
= Date::(, , ).();
= dtf.format(&date).();
(
formatted_date,
);
ICU4X is developed by the ICU4X Technical Committee (ICU4X-TC) in the Unicode Consortium. The ICU4X-TC leads strategy and development of internationalization solutions for modern platforms and ecosystems, including client-side and resource-constrained environments. See unicode.org for more information on our governance.
ICU4X-TC convenes approximately once per quarter in advance of ICU4X releases. Most work in the interim takes place in the ICU4X Working Group (ICU4X WG), which makes technical recommendations, lands them in the repository, and records them in CHANGELOG.md. The recommendations of ICU4X WG are subject to approval by the ICU4X-TC.
Please subscribe to this repository to participate in discussions. If you want to contribute, see our contributing.md.
For the full charter, including answers to frequently asked questions, see charter.md.
ICU4X is a new project whose objective is to solve the needs of clients who wish to provide client-side internationalization for their products in resource-constrained environments.
ICU4X, or "ICU for X", will be built from the start with several key design constraints:
ICU4X will provide an ECMA-402-compatible API surface in the target client-side platforms, including the web platform, iOS, Android, WearOS, WatchOS, Flutter, and Fuchsia, supported in programming languages including Rust, JavaScript, Objective-C, Java, Dart, and C++.
Copyright © 2020-2024 Unicode, Inc. Unicode and the Unicode Logo are registered trademarks of Unicode, Inc. in the United States and other countries.
The project is released under LICENSE, the free and open-source Unicode License, which is based on the well-known MIT license, with the primary difference being that the Unicode License expressly covers data and data files, as well as code. For further information please see The Unicode Consortium Intellectual Property, Licensing, and Technical Contribution Policies.
A CLA is required to contribute to this project - please refer to the CONTRIBUTING.md file (or start a Pull Request) for more information.
The contents of this repository are governed by the Unicode Terms of Use.
dependencies {
implementation("io.github.kotlinmania:icu-decimal-kotlin:0.1.2")
}
./gradlew --no-daemon build
./gradlew --no-daemon test
See AGENTS.md and CLAUDE.md for translator discipline, port-lint header convention, and Rust → Kotlin idiom mapping.
This Kotlin port is distributed under the same Unicode-3.0 license as the upstream unicode-org/icu4x. See LICENSE (and any sibling LICENSE-* / NOTICE files mirrored from upstream) for the full text.
Original work copyrighted by the icu4x authors.
Kotlin port: Copyright (c) 2026 Sydney Renee and The Solace Project.
Thanks to the unicode-org/icu4x maintainers and contributors for the original Rust implementation. This port reproduces their work in Kotlin Multiplatform; bug reports about upstream design or behavior should go to the upstream repository.
Surfaced from shared tags and platforms — no rankings paid for.