libmuslim

Dart FFI bindings for libmuslim, a collection of stb-style single-header C libraries for Muslim applications.

Currently bound: prayertimes.h — prayer times for a date and location across 21 calculation methods.

Usage

import 'package:libmuslim/prayertimes.dart';

final times = PrayerTimes.today(
  latitude: -6.2851291,    // negative = South
  longitude: 106.9814968,  // positive = East
  utcOffset: const Duration(hours: 7),
  parameters: const CalculationParameters.of(CalculationMethod.kemenag),
);

print(times.fajr);          // a UTC instant
print(times.next());        // Prayer.dhuhr, say
print(times.timeUntilNext());

Every time is a UTC instant carrying whole minutes, rounded up to match the C library's convention. Bad coordinates raise ArgumentError; a latitude where the sun never reaches the required angle raises PrayerTimesUnavailable.

The FFI bindings underneath are not exported. They live in lib/src/ because their names, structs and failure modes come from C and change when the vendored header changes.

Project structure

Each module is one vendored header, one translation unit that instantiates it, one ffigen config, and one public entry point.

• src/ — the vendored single-header libraries and the .c files that define their *_IMPLEMENTATION macro, plus abi_probe.c, which exports the header's own sizeof and constants so the tests can verify the Dart structs against the compiled C.

• ffigen/ — one config per module. Paths inside are relative to this directory, and every config pins the same asset-id so all generated files resolve against the single shared library.

• lib/<module>.dart — the public entry point per module. lib/src/<module>/ holds its generated bindings, which are never hand-edited.

• hook/build.dart — compiles every listed .c into one shared library.

Regenerating the bindings

dart run tool/regen.dart

This runs every config in ffigen/. Do not invoke ffigen directly unless CPATH already points at clang's resource include directory — libclang does not always find it, and the failure surfaces as a missing stddef.h.

Testing

dart test              # ABI verification and a published golden
cd example && flutter test

Platforms

Android, iOS, Linux, macOS and Windows. The C library is compiled from source by hook/build.dart, so there is no web support.

License

MIT. The vendored src/prayertimes.h is MIT as well, copyright 2025-2026 muslimtify-org. See LICENSE.