Brandon Lucas
cdc4f47272
- Fix string interpolation issues: escape curly braces with \{ and \}
since unescaped { triggers string interpolation
- Fix effectful function invocation: use "let _ = run main() with {}"
instead of bare "main()" calls
- Use inline record types instead of type aliases (structural typing)
- Fix flake.nix to show build progress instead of suppressing output
Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>
REST API Demo
A simple task management REST API demonstrating Lux's HTTP server effect and effect tracking.
Features Demonstrated
- HttpServer Effect: Built-in HTTP server with effect tracking
- Pattern Matching: Route handling via pattern matching
- JSON: Serialization and parsing
- ADTs:
ApiResponsetype with Success/Error variants - Effect Signatures: All side effects explicitly declared
Running
cargo run -- projects/rest-api/main.lux
API Endpoints
| Method | Endpoint | Description |
|---|---|---|
| GET | / | API info |
| GET | /tasks | List all tasks |
| GET | /tasks/:id | Get task by ID |
| POST | /tasks | Create new task |
| PUT | /tasks/:id | Update task |
| DELETE | /tasks/:id | Delete task |
Example Usage
# Get API info
curl http://localhost:8080/
# List tasks
curl http://localhost:8080/tasks
# Get specific task
curl http://localhost:8080/tasks/1
# Create task
curl -X POST -d '{"title":"New task","done":false}' http://localhost:8080/tasks
# Update task
curl -X PUT -d '{"done":true}' http://localhost:8080/tasks/1
# Delete task
curl -X DELETE http://localhost:8080/tasks/1
Code Structure
main.lux
├── Data Types (Task, ApiResponse)
├── JSON Serialization (taskToJson, tasksToJson)
├── Route Handlers (handleGetTasks, handleCreateTask, etc.)
├── Router (route function with pattern matching)
├── Request Handler (handleRequest)
├── Server Loop (serveRequests - recursive)
└── Main Entry Point
Effect Tracking
All functions declare their effects explicitly:
fn handleRequest(req: Request): Unit with {Console, HttpServer} = ...
fn serveRequests(count: Int, max: Int): Unit with {Console, HttpServer} = ...
fn main(): Unit with {Console, HttpServer} = ...
This ensures:
- Side effects are visible in function signatures
- Testing is easier (swap effects for mocks)
- Compiler verifies effect usage
Notes
- Server handles 10 requests then stops (for demo purposes)
- Uses in-memory "database" (hardcoded tasks)
- Simplified JSON parsing for demonstration