This repository is the core implementation of the Kotlin programming language, serving as the reference compiler and tooling suite. It encompasses the full compilation pipeline (frontend, IR, backends for JVM, JS, Native, Wasm), the standard library, and build tool integrations (Gradle, Maven). The architecture is modular, separating concerns into compiler logic, analysis APIs for IDEs, and platform-specific backends. Key entry points include the CLI compiler, the Gradle plugin, and the Analysis API used by IDEs like IntelliJ IDEA. The primary data flow involves parsing source code into PSI/FIR, transforming it into IR, and generating target-specific bytecode or executables. It relies on external dependencies such as the Java JDK, LLVM (for Native), and Gradle.
Chucker is a production-grade Android library for inspecting HTTP(S) traffic in-app. It acts as an OkHttp interceptor, capturing full request/response details (headers, bodies, timing, errors) and persisting them to a local Room database. The library provides a built-in Material Design UI for browsing, searching, filtering, and exporting transactions (HAR 1.2, plain text, curl commands). It is designed as a debug-only tool via a no-op variant for release builds. The architecture follows a clean separation: public API (ChuckerInterceptor, ChuckerCollector, BodyDecoder), internal data layer (Room entities, DAO, repository), support utilities (okio stream manipulation, JSON formatting, background services), and a full set of UI fragments/adapters. The codebase is well-tested (unit tests for interceptors, DAO, repository, utilities, ViewModels) and follows modern Android development practices (Kotlin, Coroutines, LiveData/Flow, ViewBinding, Compose sample). It handles edge cases like compressed bodies, large payloads, binary formats (protobuf), GraphQL, and SSL/TLS information. The project also includes CI/CD pipelines, automated dependency updates via Renovate, and migration guides for previous versions. While primarily an application library, it has a strong data storage component (Room database) and export functionality (HAR generation), making it useful for debugging network issues in any Android app.
xmlutil is a Kotlin Multiplatform XML library that provides three layers: a streaming pull-parser/writer abstraction (XmlReader/XmlWriter with a pure-Kotlin KtXmlReader and platform StAX/Android backends), a portable DOM Level 2 implementation with JVM/JS/Native/Wasm wrappers, and an XML serialization format for kotlinx.serialization (the XML.v1 codec with annotations such as @XmlSerialName, @XmlValue, @XmlPolyChildren and policy-based configuration). It is a library, not an application: there are no servers or CLIs, only published Maven artifacts (core, serialization, xmlschema, serialutil, testutil) plus examples, benchmarks, and a Gradle plugin used for building/publishing the library itself. It targets JVM, Android (deprecated module), JS, Native, and Wasm. The architecture is strictly modular: core/base holds platform-independent streaming, DOM, namespaces, and entity handling; core/jdk and core/android are platform backends; serialization implements the kotlinx.serialization format including type/descriptor caching, polymorphic parent handling, and compact-fragment support; xmlschema is a near-complete XML Schema 1.0/1.1 parser/resolver with a custom XPath expression engine and a purpose-built regex engine for XSD pattern facets; serialization-io and core/kxio bridge kotlinx-io sinks/sources; testutil ships cross-platform XML assertion helpers. The dominant data flow is: XML text -> streaming events (XmlReader) -> DOM or direct object deserialization, and the reverse for output, with XmlSerializationPolicy controlling naming, lists, maps, namespaces, and encoding/decoding behavior. The engineering depth is genuinely high: a hand-written XSD regex engine with Unicode decomposition and surrogate set classes, flat-array namespace stacks with O(1) depth operations, DTD/entity expansion logic, an LRU format cache with recursion detection, and binary-compatibility validation (API and klib .api files) on every build. Test coverage is extensive, including regression tests for dozens of numbered GitHub issues, a W3C XML Schema test-suite harness, and JVM benchmarks. The main weaknesses are an intentionally large experimental API surface (@ExperimentalXmlUtilApi), some boilerplate near-duplication in schema facet classes, and platform-source-set sprawl that multiplies maintenance cost. Maintenance is active: recent commits (Aug 2026), GitHub Actions CI (runTests, publish-snapshot, upload_release), zero Dependabot alerts, and modern tooling (Gradle version catalog, BOM, Gradle wrapper validation). Some legacy artifacts remain (stale .travis.yml, deprecated core-android and xmlserializable modules), but they are explicitly marked deprecated rather than silently rotting. Technical drift is low; the codebase deliberately tracks fast-moving kotlinx.serialization APIs and documents Kotlin compiler workarounds, indicating a maintained rather than abandoned project.
Camposer is a Kotlin Multiplatform camera library that provides a unified Compose Multiplatform API for camera functionality on Android (via CameraX) and iOS (via AVFoundation). It offers camera preview, photo capture, video recording, flash/torch control, zoom, tap-to-focus, exposure compensation, mirror mode, multi-lens selection, video stabilization, and image analysis (including barcode/QR scanning via the optional code-scanner module). The library is published on Maven Central and includes sample apps demonstrating both Android-only and cross-platform usage. The architecture follows a clean separation of concerns with an internal engine/applier layer: `CameraState` holds reactive state flows for all configurable properties, and platform-specific appliers (`PreviewApplier`, `VideoApplier`, etc.) write changes to the underlying hardware when the state changes. The public API exposes `CameraPreview` composable, `CameraSession` for state/info access, and `CameraController` for capture commands. The codebase is well-structured with expect/actual pattern, version catalogs, ABI validation, and extensive test infrastructure (unit tests, device tests, iOS tests). It is a well-crafted, actively maintained library with high reusability potential.
SwiftPoet is a Kotlin/Java library for programmatically generating Swift source code. It provides a fluent builder API to construct Swift files with classes, structs, enums, protocols, extensions, functions, properties, type aliases, imports, attributes, documentation, and more. The library handles type name resolution, import management, keyword escaping, and proper formatting including indentation and line wrapping. It is inspired by JavaPoet and designed for use in annotation processing, metadata-driven code generation, and similar scenarios. The architecture is a pure library with no runtime dependencies beyond Kotlin stdlib, making it lightweight and embeddable. The codebase demonstrates strong software craftsmanship with clean abstractions, extensive test coverage, and reusable utility components.
ImagePickerKMP is a Kotlin Multiplatform library (not a standalone application) that delivers production-grade media picking and barcode scanning capabilities for Android, iOS, JVM desktop, and web/JS/Wasm targets. The photo module (imagepickerkmp-photo) provides camera capture, gallery selection, image cropping, EXIF extraction with GPS redaction, configurable compression (LOW/MEDIUM/HIGH), and permission-request UI, all driven through a Compose Multiplatform API centered on rememberImagePickerKMP(). The scanner module (imagepickerkmp-scanner) provides continuous barcode/QR scanning with auto-zoom, distance warnings, batch mode, phantom-code suppression, and enterprise inactivity overlays, using ML Kit on Android and AVFoundation/Vision on iOS. A shared imagepicker-core module abstracts permissions, filesystem access, URI handling, language detection, and logging across platforms via the Kotlin expect/actual mechanism. The library is distributed as versioned Maven artifacts with a published JS bundle for web integration. Architecturally, the codebase is a modular multi-artifact Gradle project: imagepicker-core (infrastructure), imagepickerkmp-photo, and imagepickerkmp-scanner, with each module enforcing dependency boundaries (the scanner module explicitly prohibits depending on the photo module). Its design leans on config-driven API design (large nested data classes such as ImagePickerKMPConfig and ScannerBehaviorConfig with runtime validation), observable state holders (sealed Idle/Loading/Success/Dismissed/Error states backed by Compose mutableStateOf), and event-driven scanner orchestration. Platform-specific behavior is cleanly isolated through expect/actual: Android uses CameraX, ActivityResultContracts, and ExifInterface; iOS uses UIImagePickerController, PHPicker, PhotosUI, and CoreGraphics; desktop/web use file choosers or documented no-op stubs where camera hardware is unavailable. Localization spans 14 languages via YAML translation files and the i18nkonfig plugin, and CI (GitHub Actions) runs detekt static analysis, Kover coverage verification with a 90% line minimum, unit tests across commonTest/androidUnitTest/iosTest, and publishes coverage to Codecov. Maintenance is active: a recent commit history on the develop branch, one open issue, zero Dependabot alerts, and continuously updated Kotlin 2.x / Compose Multiplatform versions indicate steady upkeep. Known rough edges include intentionally blank PlatformPrewarm files, crop implementation stubs on JS/WASM, a handful of placeholder tests asserting true, duplicated permission-handling logic across photo/scanner modules, and a potentially stale build-and-bundle.sh referencing an old JS build path. Overall, this is a well-crafted, professionally engineered KMP library with genuinely reusable cross-platform abstractions and strong test discipline; it is a solid reference for Kotlin Multiplatform architecture and Compose-based camera/scanning UX.
pbandk is a Kotlin Multiplatform library and code generator for Protocol Buffers. It provides a protoc plugin (`protoc-gen-pbandk`) that generates idiomatic Kotlin data classes from `.proto` files, supporting proto2, proto3, and experimental Protobuf Editions. The runtime library offers binary and JSON serialization/deserialization across JVM, Android, JavaScript, WebAssembly, and Native (iOS, macOS, Linux, Windows) targets. The architecture is a classic protobuf toolchain: `.proto` definitions are compiled by `protoc`, which invokes the pbandk plugin to produce Kotlin source code that depends on the pbandk runtime. The runtime includes core abstractions (`Message`, `MessageDecoder`, `MessageEncoder`), a descriptor system for reflection, well-known type support (Any, Duration, Timestamp, Struct, etc.), and configurable JSON encoding. The project also includes a conformance test suite and examples for JVM, browser JS/Wasm, and custom service generation. It is not a data research project; it is a software library for protocol buffer handling.
A Kotlin library for Jetpack Compose that provides customizable fling/scroll physics, ported from Android's OverScroller. It offers configurable deceleration, friction, gravity, spline curves, and presets, with snap, adaptive, and pager behaviors. The library is structured as a single artifact with a clean configuration builder pattern, and includes a sample app for demonstration. Physics calculations are isolated in well-tested modules (FlingCalculator, AndroidFlingSpline), and documentation diagrams are regenerable from a self-contained Python script that ports the same math. The codebase demonstrates strong engineering practices with unit tests, migration guides, and consistent Kotlin/Compose idioms.
Napier is a Kotlin Multiplatform logging library that provides a clean, structured API inspired by Timber. The core library (napier module) defines an abstract `Antilog` class for custom log backends, a `DebugAntilog` implementation for each target (Android Logcat, JUL, Darwin print, JS console, Wasm console), and a thread-safe singleton `Napier` object with methods for all log levels. It supports Android, Darwin (iOS, macOS, watchOS, tvOS), JVM, JavaScript, and WasmJs. The repository also contains sample applications (Android, iOS, macOS, watchOS, JVM, JS) demonstrating integration, including Crashlytics and coroutines. The architecture is a simple library with a clear separation of concerns: a common API, platform-specific implementations via expect/actual, and atomic reference utilities for thread safety. This is not a data research repository; it is a pure application/library for logging.