rnd-fp-practiceslisted

# Functional Programming Practices ## Overview Concrete rules for writing code in a functional style. These complement KISS practices — KISS prevents over-engineering, FP practices guide _how_ to structure the code that remains. **Core principle:** Separate what you compute from what you do. Pure logic in, effects out. ## How to Use **During Phase 0 (Discovery):** 1. Detect which languages/frameworks are present in the project (by file extensions, config files, or dependencies) 2. Read only the relevant language files (e.g., `${CLAUDE_SKILL_DIR}/elixir.md`, `${CLAUDE_SKILL_DIR}/javascript.md`) 3. Include the language-specific FP rules in the discovery context passed to the Planner **Language detection heuristics:** | Files present | Load | |---|---| | `*.sh`, `*.bash`, `Makefile` | `${CLAUDE_SKILL_DIR}/bash.md` | | `*.ex`, `*.exs`, `mix.exs` | `${CLAUDE_SKILL_DIR}/elixir.md` | | `*.js`, `*.ts`, `*.jsx`, `*.tsx`, `*.css`, `*.html` | `${CLAUDE_SKILL_DIR}/javascript.md` | | `*.py`, `pyproject.toml`, `requirements.txt` | `${CLAUDE_SKILL_DIR}/python.md` | | `*.lean`, `lakefile.lean` | `${CLAUDE_SKILL_DIR}/lean.md` | | `*.svelte`, `svelte.config.*` | `${CLAUDE_SKILL_DIR}/svelte.md` | | `*.kk`, `koka.json` | `${CLAUDE_SKILL_DIR}/koka.md` | | `mix.exs` with `:postgrex` or `:ecto`, or `*.sql` files | `${CLAUDE_SKILL_DIR}/postgresql.md` | | DuckDB usage, `*.duckdb` files, or analytical/data tasks | `${CLAUDE_SKILL_DIR}/duckdb.md` | **Overriding:** Projects can ship their own `r