elixir

name	elixir
description	Elixir language skill covering OTP, Phoenix, Ecto, pipe operator, pattern matching, and Mix. Use when building Elixir applications.
trigger	elixir, phoenix, ecto, otp, genserver, supervisor, elixir pipe, elixir pattern matching, mix, liveview

elixir

Core Concepts

• OTP: GenServer for stateful server processes, Supervisor for fault tolerance trees, Application for system startup
• Pattern Matching: = operator is match not assignment, pin operator (^) matches existing value, case/function clause destructuring
• Pipe Operator: |> chains function calls, first argument flows as next function's first parameter, improves readability
• Immutability: all data is immutable, rebinding name to new value, persistent data structures for efficiency

Phoenix & Ecto

• Phoenix: HTTP + WebSocket framework, router (pipeline/browser/api scopes), controllers, LiveView for real-time UI
• LiveView: server-rendered reactive UI, stateful processes, OTA updates via WebSocket, no JS required
• Ecto: database wrapper and query generator, schemas map to DB tables, changesets for validation, Repo for queries
• Contexts: bounded module groups for domain logic, explicit public interfaces, prevent leaky dependencies

Tooling

• Mix: project generator, dependency management, custom tasks, test runner with ExUnit
• IEx: interactive shell with recompilation, debugger, process inspection
• Hex: package registry, publishes libraries, dependency resolution

Common Patterns

• Supervised process tree (Application -> Supervisor -> Children)
• Enum.map/Enum.filter with pipe for data transformation
• with/else for complex pipeline error handling
• Phoenix PubSub for real-time messaging across nodes