Brandon Lucas
7e76acab18
Website rebuilt from scratch based on analysis of 11 beloved language websites (Elm, Zig, Gleam, Swift, Kotlin, Haskell, OCaml, Crystal, Roc, Rust, Go). New website structure: - Homepage with hero, playground, three pillars, install guide - Language Tour with interactive lessons (hello world, types, effects) - Examples cookbook with categorized sidebar - API documentation index - Installation guide (Nix and source) - Sleek/noble design (black/gold, serif typography) Also includes: - New stdlib/json.lux module for JSON serialization - Enhanced stdlib/http.lux with middleware and routing - New string functions (charAt, indexOf, lastIndexOf, repeat) - LSP improvements (rename, signature help, formatting) - Package manager transitive dependency resolution - Updated documentation for effects and stdlib - New showcase example (task_manager.lux) Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>
108 lines
2.5 KiB
Markdown
108 lines
2.5 KiB
Markdown
# Task Manager Showcase
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This example demonstrates Lux's three killer features in a practical, real-world context.
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## Running the Example
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```bash
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lux run examples/showcase/task_manager.lux
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```
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## Features Demonstrated
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### 1. Algebraic Effects
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Every function signature shows exactly what side effects it can perform:
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```lux
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fn createTask(title: String, priority: String): Task@latest
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with {TaskStore, Random} = { ... }
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```
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- `TaskStore` - database operations
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- `Random` - random number generation
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- No hidden I/O or surprise calls
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### 2. Behavioral Types
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Compile-time guarantees about function behavior:
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```lux
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fn formatTask(task: Task@latest): String
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is pure // No side effects
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is deterministic // Same input = same output
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is total // Always terminates
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```
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```lux
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fn completeTask(id: String): Option<Task@latest>
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is idempotent // Safe to retry
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with {TaskStore}
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```
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### 3. Schema Evolution
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Versioned types with automatic migration:
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```lux
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type Task @v2 {
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id: String,
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title: String,
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done: Bool,
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priority: String, // New in v2
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from @v1 = { ...old, priority: "medium" }
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}
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```
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### 4. Handler Swapping (Testing)
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Test without mocks by swapping effect handlers:
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```lux
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// Production
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run processOrders() with {
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TaskStore = PostgresTaskStore,
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Logger = CloudLogger
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}
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// Testing
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run processOrders() with {
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TaskStore = InMemoryTaskStore,
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Logger = SilentLogger
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}
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```
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## Why This Matters
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| Traditional Languages | Lux |
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| Side effects are implicit | Effects in type signatures |
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| Runtime crashes | Compile-time verification |
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| Complex mocking frameworks | Simple handler swapping |
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| Manual migration code | Automatic schema evolution |
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| Hope for retry safety | Verified idempotency |
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## File Structure
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```
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showcase/
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├── README.md # This file
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└── task_manager.lux # Main example with all features
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```
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## Key Sections in the Code
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1. **Versioned Data Types** - `Task @v1`, `@v2`, `@v3` with migrations
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2. **Pure Functions** - `is pure`, `is total`, `is deterministic`, `is idempotent`
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3. **Effects** - `effect TaskStore` and `effect Logger`
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4. **Effect Handlers** - `InMemoryTaskStore`, `ConsoleLogger`
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5. **Testing** - `runTestScenario()` with swapped handlers
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6. **Migration Demo** - `demonstrateMigration()`
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## Next Steps
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- Read the [Behavioral Types Guide](../../docs/guide/12-behavioral-types.md)
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- Read the [Schema Evolution Guide](../../docs/guide/13-schema-evolution.md)
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- Explore [more examples](../)
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