Code sample #4 from my Medium post "Namespacing Swift code with nested types"

Namespacing-Swift-code-with-nested-types-3.swift

struct Post {
    let id: Int
    let author: User
    let title: String
    let text: String

    // MARK: - TextFormatter

    class TextFormatter {
        private let options: Set<Option>

        init(options: Set<Option>) {
            self.options = options
        }

        func formatTitle(for post: Post) -> String {
            return post.title.formatted(withOptions: options)
        }

        func formatText(for post: Post) -> String {
            return post.text.formatted(withOptions: options)
        }

        // MARK: - Option

        enum Option {
            case highlightNames
            case highlightLinks
        }
    }
}