Displaying Human-Friendly Content

At a glance

Project structure

Source bundle/
└── Shared/
    ├── FormattersApp.swift
    ├── Dates/
    │   ├── DateFormatterView.swift
    │   ├── DateIntervalFormatterView.swift
    │   ├── RelativeDateTimeFormatterView.swift
    │   ├── DateComponentsFormatterView.swift
    │   └── DatesView.swift
    ├── MeasurementsView.swift
    ├── NumbersView.swift
    ├── ContentView.swift
    ├── Names/
    │   ├── NamesView.swift
    │   └── Monogram.swift
    └── FormatterList.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 6 project/configuration file(s) and 18 source declaration(s).

Overall architecture

flowchart LR
    N1["FormattersApp"]
    N2["ContentView"]
    N3["SwiftUI / AppKit APIs"]
    N1 --> N2
    N2 --> N3

Reference code

Shared/FormattersApp.swift:10 — architecture anchor

@main
struct FormattersApp: App {
    var body: some Scene {
        WindowGroup {
            ContentView()
        }
    }
}

Interpretation

The arrows summarize the source-visible entry, role-named types or folders, and framework direction; when nodes come from structural folders, the sequence is a high-level interpretation rather than proof that every adjacent node calls the next. Ownership is claimed only where the next section cites a stored property or assignment. The diagram is intentionally limited to the dominant path into Foundation.

Ownership and state

classDiagram
    DateFormatterView *-- ISO8601DateFormatter : sampleDate
    DateFormatterView *-- FormatterState : formatterState
    TemplateField *-- Int : id
    TemplateField o-- LocalizedStringKey : title

Ownership evidence

Shared/Dates/DateFormatterView.swift:11 — stored dependency or nearest verified ownership anchor

let sampleDate = ISO8601DateFormatter().date(from: "2020-06-22T09:41:00-07:00")!

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.

Concurrency, scheduling, and thread safety

Evidence limit: actor isolation, async/await, or Task creation does not by itself prove background-thread execution; Sendable conformance alone does not prove thread-safe mutation.

No source-visible execution, scheduling, or synchronization boundary was found in the indexed source.

@MainActor/MainActor.run, DispatchQueue.main, and RunLoop.main are reported as distinct isolation, queue, and event-loop mechanisms. A plain Task is kept separate from Task.detached; neither is labeled as a background thread.

State propagation, frameworks, and dependencies

Evidence limit: an import proves a source-level compilation dependency at the cited line; it does not prove runtime use, architectural adoption, or whether a Swift package is a direct application dependency.

receive(on:) describes downstream delivery scheduling, while subscribe(on:) describes upstream subscription/request/cancel scheduling. An import Combine alone establishes neither behavior nor a Store, reducer, Redux, or other application architecture.

Class and protocol design

Shared/FormattersApp.swift:11 — representative type boundary

@main
struct FormattersApp: App {
    // ...
            ContentView()
    // ...
}

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

Access control

Reference code

Shared/Dates/DateComponentsFormatterView.swift:11 — representative boundary

struct DateComponentsFormatterView: View {
    private let sampleDateComponents = DateComponents(hour: 2, minute: 15)
    // ...
}

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: FormattersApp; View: ContentView, DateComponentsFormatterView, DateFormatterView, DateIntervalFormatterView, DatesView.
• Protocols: no local protocol declaration in the scanned source.
• Methods: lengthIndicator, string, updateFormatter.
• Files: Shared/FormattersApp.swift, Shared/Dates/DateFormatterView.swift, Shared/Dates/DateIntervalFormatterView.swift, Shared/Dates/RelativeDateTimeFormatterView.swift, Shared/MeasurementsView.swift, Shared/NumbersView.swift.

Architecture takeaways

• FormattersApp is the main source-visible entry or composition anchor for this sample.
• Framework work reaches SwiftUI, AppKit, UIKit 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