Expert Haskell development skill. Covers type-driven design, GHC extensions, Cabal/Stack/Nix builds, performance optimization, testing, and the modern Haskell library ecosystem. Activate for any Haskell programming, debugging, or architecture tasks.

精通 Haskell 开发，涵盖类型驱动设计、GHC 扩展、Cabal/Stack/Nix 构建、性能优化、测试以及现代 Haskell 库生态。适用于任何 Haskell 编程、调试或架构任务。