[Swift] - Minify Email

minifyEmail.swift

import Foundation

extension String {

    /// Return a mimified email from this string, like glau***@gmail.com, the mimified length is half as the email length
    var emailMinified : String? {
        get {
            var email = self
            if let atIndex = email.components(separatedBy: "@").first?.endIndex {
                let middleIndex = atIndex.encodedOffset/2
                let offset = atIndex.encodedOffset - middleIndex
                let start = email.index(email.startIndex, offsetBy: offset)
                let mimify = String(repeating: "*", count: atIndex.encodedOffset - start.encodedOffset)
                email.replaceSubrange(start..<atIndex, with: mimify)
                return email
            }
            return nil
        }
    }
}

let newEmail = "glauber@gmail.com"
print(newEmail.emailMinified ?? "can't be minified")