elixir

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