Hydra Framework

An all-in-one framework for writing Haskell apps which use the following features out of the box:

• Multithreading
• Safe STM-powered concurrency
• KV DB functionality (Redis & RocksDB backends supported)
• SQL DB functionality (beam incorporated, SQLite supported, PG & MySQL possible)
• Logging
• Random data generation
• Many others

With the framework, you can create complex applications that have a good maintainability, testability, simplicity, that have a good structure and are easy to read and change. The key principles in the framework:

• Layered architecture
• Separation of Subsystem Interfaces, Business Logic, Runtime and Implementation
• Convenient and simple to use eDSLs for Business Logic
• Layered structure of business application: State, Domain, Business Logic

The Hydra Project

This project demonstrates the principles of Software Design and Architecture in pure Functional Programming. It provides a framework implemented with several different approaches for easy comparison:

• Final Tagless
• Free Monad
• Church Encoded Free Monad

The project is a showcase for my book Functional Design and Architecture

Additional materials describing these ideas:

• Hierarchical Free Monads and Software Design in Functional Programming (Talk, Eng) | Slides (Eng)
• Final Tagless vs Free Monad (Talk, Rus) | Slides (Eng)
• Automatic whitebox testing with Free Moands (Showcase, Article)