Third-party notices for charr
=============================

Scope of this file
------------------

Charr's original code and documentation are copyright (c) 2026 Travers Ching
and are distributed under the MIT License recorded in `DESCRIPTION` and
`LICENSE`. Material derived from stringr is also distributed under the MIT
License, with the upstream copyright notice reproduced below.

This file collects the copyright and license notices for material included in
charr from stringr and stringi. The complete ICU4C notice is supplied in the
separate `icu/LICENSE` file because it includes the Unicode License v3 and all
third-party component notices from the ICU distribution.

stringi
-------

Charr's optimized backends contain R and C++ code copied or adapted from
stringi. The package's original ICU4C vendoring layout and parts of its build
configuration were also adapted from stringi. Copied files that carried
upstream copyright and BSD notices retain them. This aggregate notice also
applies to stringi-derived code that charr has since reorganized or rewritten.

The pinned source is stringi 1.8.9 at commit
68fe9b91cee2ca959d72a75660add028531d6af1 (2026-07-30).

Copyright (c) 2013-2025, Marek Gagolewski <https://www.gagolewski.com/>
All rights reserved.

Redistribution and use in source and binary forms, with or without
modification, are permitted provided that the following conditions are met:

1. Redistributions of source code must retain the above copyright notice,
   this list of conditions and the following disclaimer.

2. Redistributions in binary form must reproduce the above copyright notice,
   this list of conditions and the following disclaimer in the documentation
   and/or other materials provided with the distribution.

3. Neither the name of the copyright holder nor the names of its contributors
   may be used to endorse or promote products derived from this software
   without specific prior written permission.

THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE FOR
ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
(INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON
ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
(INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.

ICU4C
-----

Charr bundles ICU4C 78.3 source code and data from Unicode, Inc. and others.
The primary notice is copyright (c) 2016-2025 Unicode, Inc. under the Unicode
License v3, SPDX identifier Unicode-3.0. ICU also contains components with
their own copyright holders and compatible terms.

The complete Unicode License v3 and every third-party notice supplied with
ICU4C 78.3 are included in `icu/LICENSE` in the installed package and
`src/icu78/LICENSE` in the repository and source package. Those files are
retained verbatim from ICU's distribution.

Charr carries twelve small source adjustments for compiler diagnostics and
portability. They do not alter ICU's license terms. The adjusted files and
changes are listed under "Source-package adjustments" in
`src/icu78/UPSTREAM.md` in the source package, which also records source
archive hashes and data provenance.

stringr
-------

Charr is a fork of stringr, and its R interface, documentation, and tests
contain material derived from it. Current stringr metadata identifies Hadley
Wickham and Posit Software, PBC as copyright holders.

Copyright (c) 2023 stringr authors

Permission is hereby granted, free of charge, to any person obtaining a copy
of this software and associated documentation files (the "Software"), to deal
in the Software without restriction, including without limitation the rights
to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
copies of the Software, and to permit persons to whom the Software is
furnished to do so, subject to the following conditions:

The above copyright notice and this permission notice shall be included in all
copies or substantial portions of the Software.

THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
SOFTWARE.

Tatoeba
-------

Charr's benchmark measures against sentences from the Tatoeba Project
(<https://tatoeba.org>), released under Creative Commons Attribution 2.0 France
with attribution to Tatoeba. Some sentences are additionally available under
CC0 1.0, and sentences from the Tanaka Corpus are in the public domain.

No Tatoeba data is included in this package or in its repository. The benchmark
reads a sentence export the maintainer supplies locally, and the corpus it
derives from that export is untracked.

External package dependencies
-----------------------------

Charr calls the installed stringi package for its reference backend and uses
the installed charport package for ALTREP interoperability. Those package
distributions are not bundled in charr and retain their own licenses. This
does not change the notices above for stringi-derived source that is included
directly in charr.
