Swift "Configuration" Operator

ConfigurationOperator.swift

//
//  ConfigurationOperator.swift
//
//  Created by Matthew L. Judy on 2024/3/21.
//


/// Configuration Operator:
/// Provides an expressive way to instantiate, configure, and assign an object
/// in a single perceived step, reducing the boilerplate necessary to achieve
/// the same outcome using traditional closure-based assignment.
///
/// - Example: ``DateFormatter``
///     ```
///     // Configure DateFormatter using Configuration operator:
///     let iso8601A = ISO8601DateFormatter() <| { $0.formatOptions = [.withFullDate, .withDashSeparatorInDate] }
///
///     // Configure DateFormatter using traditional closure:
///     let iso8601B: ISO8601DateFormatter = {
///         let formatter = ISO8601DateFormatter()
///         formatter.formatOptions = [.withFullDate, .withDashSeparatorInDate]
///         return formatter
///     }()
///     ```

/// - Example: ``Calendar``
///     ```
///     // Configure Calendar using Configuration operator:
///     let calendarA = Calendar.current <| { $0.timeZone = TimeZone(identifier: "UTC")! }
///
///     // Configure Calendar using traditional closure:
///     let calendar: Calendar = {
///         let calendar = Calendar.current
///         calendar.timeZone = TimeZone(identifier: "UTC")!
///         return calendar
///     }()
///     ```
///
infix operator <| : AssignmentPrecedence
func <| <Subject: Any> (subject: Subject, modifier: ((inout Subject) -> Void)) -> Subject
{
    var subject = subject
    modifier(&subject)
    return subject
}