unsafe-haskell-intro-fp-matsuri-2026

Read Haskell package documentation (Haddock HTML) and source code for the dependencies of a cabal nix-style project, preferring locally-built/cached files over the network. Use when: (1) looking up the API or docs of a dependency, (2) reading the source of a dependency, (3) understanding how a library function is implemented, (4) inspecting the types/instances a package exposes. Prefers the local cabal store and repo-cache; falls back to Hackage only for packages outside the project's dependency set. Trigger: "/haddock <package> [module]".

Format Haskell package descriptions and project files with cabal-gild — `*.cabal`, `cabal.project`, `cabal.project.local`, `cabal.project.freeze`. Normalises layout, sorts `build-depends`, and expands `-- cabal-gild: discover` module lists. Use when: (1) formatting or tidying a `.cabal` or `cabal.project` file, (2) after editing dependencies or stanzas, (3) refreshing auto-discovered module lists after adding/removing a module, (4) checking whether cabal files are already formatted. Trigger: "/haskell-cabal-gild", "cabal-gild", "format cabal".

Format Haskell source files — `*.hs`, `*.lhs`, `*.hsig` — with the project's configured formatter (fourmolu, ormolu, or stylish-haskell). Use when: (1) formatting Haskell source before compiling, (2) tidying code after edits, (3) applying a project's fourmolu/stylish style. Picks the formatter from project config, falling back to the first available. Trigger: "/haskell-format", "format Haskell", "fourmolu", "ormolu", "stylish-haskell".

Super-skill for developing Haskell projects with cabal nix-style builds. Orchestrates the Haskell Language Server, Haddock, and Hoogle tools into one workflow instead of duplicating them. Use when: (1) writing/editing/refactoring Haskell (.hs/.lhs/.hsig/.cabal/package.yaml) code, (2) building or typechecking a cabal project, (3) fixing compiler or type errors, (4) renaming or looking up symbols, (5) adding or changing dependencies. Treats cabal.project as the source of truth, prefers the LSP before full builds, and local docs over remote. Trigger: "/haskell" or any Haskell development task.