native_natural_sort

Locale-aware, numeric-aware natural string sorting for Flutter using each platform's native collation engine.

Features

• x Cross-platform: Android, iOS, macOS, Linux, Windows
• x Locale-aware sorting via each platform's native collation engine
• x Numeric-aware natural sort (e.g. file2 < file10)
• x Sort-time locale and direction overrides
• x Dual Windows backends: Pigeon (CompareStringEx) or FFI (ICU)
• x Direct FFI access via IcuCollation for advanced use cases

Getting started

Add dependency with flutter pub add command

flutter pub add native_natural_sort

Or add below line to pubspec.yaml

dependencies:
  ...
  native_natural_sort: any  # or specific version

Then run flutter pub get.

Usage

import 'package:native_natural_sort/native_natural_sort.dart';

final sort = NativeSort();
await sort.config(SortOptions());
final sorted = await sort.sort([
  SortItem(id: 'a', value: 'file10.txt'),
  SortItem(id: 'b', value: 'file2.txt'),
  SortItem(id: 'c', value: 'file1.txt'),
]);
// sorted: [c, b, a]  (file1 < file2 < file10)

Platform-specific options

await sort.config(SortOptions(
  android: SortOptionsAndroid(
    locale: Locale('zh'),
    direction: SortDirection.descending,
  ),
  windows: SortOptionsWindows(
    locale: Locale('en'),
    sort: WindowsSort.ffi(),  // or WindowsSort.pigeon()
  ),
));

Sort-time overrides

final sorted = await sort.sort(
  items,
  locale: Locale('fr'),
  direction: SortDirection.descending,
);

Windows backend selection

Backend	Technology	Notes
WindowsSort.ffi()	OS-bundled ICU DLL	Default
WindowsSort.pigeon()	CompareStringEx (Win32)

Direct FFI access

import 'package:native_natural_sort/native_natural_sort.dart';

final loader = MyCollationLibraryLoader(); // see Linux/Windows FFI loaders
await loader.init();
final collator = loader.collator('en');
final sorted = collator.sort(
  items: ['file10.txt', 'file2.txt', 'file1.txt'],
  idOf: (s) => s,
  valueOf: (s) => s,
);

For more examples, see the integration tests.

Architecture

NativeSortService (unified Dart API)
├── Android   → Pigeon → android.icu.text.Collator
├── iOS       → Pigeon → localizedStandardCompare
├── macOS     → Pigeon → localizedStandardCompare
├── Linux     → Dart FFI → system libicui18n
└── Windows   → Pigeon (CompareStringEx) or FFI (ICU)

Development

# Regenerate platform channel code
make gen

# Run analysis
make analyze

# Run tests
make test

Donate

License

This project is licensed under the Apache License, Version 2.0. See LICENSE for the full license text.

Copyright 2026 Fries_I23

Licensed under the Apache License, Version 2.0 (the "License");
you may not use this file except in compliance with the License.
You may obtain a copy of the License at

    http://www.apache.org/licenses/LICENSE-2.0

Unless required by applicable law or agreed to in writing, software
distributed under the License is distributed on an "AS IS" BASIS,
WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
See the License for the specific language governing permissions and
limitations under the License.