Code sample #6 from my Medium post "Namespacing Swift code with nested types"

Namespacing-Swift-code-with-nested-types-5.swift

struct Post {
    typealias TextFormatter = PostTextFormatter

    let id: Int
    let author: User
    let title: String
    let text: String
}

class PostTextFormatter {
    typealias Option = PostTextFormatterOption

    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)
    }
}

enum PostTextFormatterOption {
    case highlightNames
    case highlightLinks
}