Defines the `Editor` trait with actions, motions, selection management, cursor blink, and input method support. Provides a reusable abstraction for any text input widget, decoupled from rendering. Demonstrates non-obvious skill in handling complex text editing state (undo/redo, selection caching, IME integration).

Implements the state machine for a tiling window manager widget (PaneGrid). Handles split, resize, swap, maximize, close, and drag-and-drop operations with a binary-split tree structure. The state management is intricate and self-contained, making it a reusable pattern for complex interactive layouts.

Provides a `Cache` with grouping for efficient redrawing of 2D geometry. Allows batching of cache entries and selective invalidation. This pattern is reusable for any incremental rendering system (e.g., canvas, charts) and demonstrates non-obvious optimization for frame-to-frame coherence.

Implements a custom allocator for packing textures into a GPU atlas. Uses a shelf-based algorithm to minimize fragmentation and support dynamic allocation/deallocation. This is a non-trivial data structure that can be extracted for any GPU texture batching system.

Manages the lifecycle of subscriptions in the Iced runtime. Tracks active subscriptions by unique IDs, handles addition/removal, and ensures proper cleanup. This pattern is reusable for any event-driven system that needs to manage dynamic subscriptions (e.g., WebSocket connections, sensor streams).