XState is a production-grade TypeScript library for creating, interpreting, and executing finite state machines and statecharts, based on the SCXML standard and the actor model. The repository is a monorepo (pnpm workspaces) containing the core `xstate` package, the lighter `@xstate/store` for event-sourced state management, and framework-specific bindings for React, Vue, Svelte, Solid, Preact, and Angular. It also includes `xstate-inspect` for debugging, `xstate-immer` for Immer integration, a graph analysis module for model-based testing, and many example applications and templates. The core engine provides `createMachine`, `createActor`, `setup()` for type-safe machine definitions, built-in actions (assign, sendTo, raise, etc.), guard combinators, and actor logic factories (`fromPromise`, `fromCallback`, `fromObservable`). The store sub-package offers atoms, source atoms, and composable extensions like persist and undo/redo. The codebase demonstrates high craftsmanship with extensive TypeScript type inference, well-encapsulated modules, and comprehensive test coverage. It is actively maintained with continuous CI/CD and version management via changesets.
Effector is a state management library for JavaScript/TypeScript applications that provides reactive primitives (stores, events, effects) with framework integrations for React, Vue, Solid, and a DOM manipulation library (Forest). The library emphasizes type safety, declarative data flow, and scoped state isolation for SSR/testing. Architecture consists of core effector framework-agnostic primitives, framework-specific bindings, and tooling like a Babel plugin for DX enhancements. Key entry points include src/effector/index.ts (core API), packages/effector-react/index.ts (React bindings), and packages/forest/index.ts (Forest UI engine). Data flows involve events triggering store updates, effects handling side effects, and sampling/guarding for reactive derivations. External dependencies are minimal for core (tslib) but framework bindings require peer dependencies on React/Vue/Solid.
This repository is a curated, comprehensive geographic database of countries, states, cities, and postcodes, with a strong emphasis on ISO 3166 compliance and data quality. It is primarily a data_research project, though it includes supporting application code (export pipelines, validation tools, CI/CD) that enables multi-format distribution (JSON, CSV, SQL, Parquet, etc.). The raw data lives in the `contributions/` directory as JSON files, which are the source of truth. A rich ecosystem of Python, PHP, and Node.js scripts handles ingestion from community and official sources, idempotent correction, enrichment (timezones, translations), and export to 12+ formats. The repository is actively maintained by a community of contributors and automated bots, with rigorous PR validation (schema, coordinates, duplicates, cross-references) and extensive fix documentation. It answers questions like 'What are the administrative divisions of a country?' and 'What postcodes exist for a given locality?' and is used as a reference data source for applications worldwide.