Book Tracker: Using Evaluations to evaluate an intelligent feature

At a glance

Project structure

Source bundle/
├── DatasetExtractor/
│   └── main.swift
├── BookTracker/
│   ├── BookTrackerApp.swift
│   ├── Services/
│   │   ├── BookSearchTools.swift
│   │   └── BookTaggingService.swift
│   ├── Views/
│   │   ├── BookDetailView.swift
│   │   ├── LibraryView.swift
│   │   ├── SearchView.swift
│   │   └── AddBookView.swift
│   └── ContentView.swift
├── BookSampleGenerator/
│   └── main.swift
├── HillClimbingEvaluations/
│   └── ModelJudgeAlignmentEvaluation.swift
└── BookTrackerEvaluations/
    └── SearchBooks.swift

Structure observations

• Architecturally prominent files are ranked from entry points and role-named declarations; resource-only paths are omitted.
• Primary languages: Swift.
• The verified tree contains 3 project/configuration file(s) and 47 source declaration(s).

Overall architecture

flowchart LR
    Bundle["Sample bundle"]
    V1["BookTracker"]
    V2["DatasetExtractor"]
    Boundary["Evaluations APIs"]
    Bundle --> V1
    V1 --> Boundary
    Bundle --> V2
    V2 --> Boundary

Reference code

DatasetExtractor/main.swift:165 — architecture anchor

// @main cannot be used in main.swift — Swift's implicit top-level entry point and
// @main are mutually exclusive. Calling .main() explicitly is the equivalent.
DatasetExtractorCommand.main()

Interpretation

The branches represent separate entry-bearing project variants in the downloaded bundle, not runtime calls between those variants. Each branch is intentionally collapsed at the documented framework boundary; the detailed target-local flow remains in the cited files. Ownership is claimed only where the next section cites a stored property or assignment.

Ownership and state

classDiagram
    BookTrackerApp o-- ModelContainer : container
    BookSearchCollector *-- Array : orderedIDs
    BookSearchCollector *-- Set : seen
    BookSnapshot *-- String : id

Ownership evidence

BookTracker/BookTrackerApp.swift:14 — stored dependency or nearest verified ownership anchor

    let container: ModelContainer = {
        // ...
    }()

Composition arrows indicate a source-visible construction expression or locally owned value state; aggregation means the owner stores or receives a dependency without proving exclusive lifetime ownership.

Class and protocol design

BookTracker/BookTrackerApp.swift:13 — representative type boundary

struct BookTrackerApp: App {
    // ...
}

No local protocol conformance is claimed as protocol-oriented design; external framework conformances are listed only as dependencies.

Access control

Reference code

BookTracker/BookTrackerApp.swift:34 — representative boundary

private func addSampleBooks(in context: ModelContext) {
    // ...
}

Swift declarations without a modifier are internal; explicit private, fileprivate, private(set), public, or open entries above are interpreted by language semantics. Objective-C/C samples instead rely on header and implementation boundaries, which are not equivalent to Swift lexical privacy.

Logic ownership and placement

Design patterns

Naming conventions

• Types: App: BookTrackerApp; Command: DatasetExtractorCommand; Service: BookTaggingService; View: AddBookView, BookDetailView, BookTagsView, ContentView, LibraryView.
• Protocols: no local protocol declaration in the scanned source.
• Methods: run, extractPairs, extractPrompt, resolvedOutputURL, defaultOutputURL, addSampleBooks, add, call.
• Files: BookTracker/BookTrackerApp.swift, BookTracker/Views/BookDetailView.swift, BookTracker/Services/BookTaggingService.swift, BookTracker/ContentView.swift, BookTracker/Views/LibraryView.swift, BookTracker/Views/SearchView.swift.

Architecture takeaways

• main is the main source-visible entry or composition anchor for this sample.
• Framework work reaches SwiftUI, FoundationModels, SwiftData, Evaluations through a deliberately small high-level chain; the detailed API graph remains inside the cited implementation files.
• Stored-property evidence identifies lifecycle collaboration; it does not by itself prove exclusive object ownership.
• Access-control conclusions separate verified language visibility from the likely design rationale.
• The source does not justify labeling the design protocol-oriented.

Source map

• Official Apple documentation