Is there a Swift alternative for NSLog(@"%s", __PRETTY_FUNCTION__)

Question

In Objective C you can log the method that is being called using:

NSLog(@"%s", __PRETTY_FUNCTION__)

Usually this is used from a logging macro.

Although Swift does not support macro's (I think) I still would like to use a generic log statement that includes the name of the function that was called. Is that possible in Swift?

Update: I now use this global function for logging which can be found here: https://github.com/evermeer/Stuff#print And which you can install using:

pod 'Stuff/Print'

Here is the code:

public class Stuff {

    public enum logLevel: Int {
        case info = 1
        case debug = 2
        case warn = 3
        case error = 4
        case fatal = 5
        case none = 6

        public func description() -> String {
            switch self {
            case .info:
                return "❓"
            case .debug:
                return "✳️"
            case .warn:
                return "⚠️"
            case .error:
                return "🚫"
            case .fatal:
                return "🆘"
            case .none:
                return ""
            }
        }
    }

    public static var minimumLogLevel: logLevel = .info

    public static func print<T>(_ object: T, _ level: logLevel = .debug, filename: String = #file, line: Int = #line, funcname: String = #function) {
        if level.rawValue >= Stuff.minimumLogLevel.rawValue {
            let dateFormatter = DateFormatter()
            dateFormatter.dateFormat = "MM/dd/yyyy HH:mm:ss:SSS"
            let process = ProcessInfo.processInfo
            let threadId = "?"
            let file = URL(string: filename)?.lastPathComponent ?? ""
            Swift.print("\n\(level.description()) .\(level) ⏱ \(dateFormatter.string(from: Foundation.Date())) 📱 \(process.processName) [\(process.processIdentifier):\(threadId)] 📂 \(file)(\(line)) ⚙️ \(funcname) ➡️\r\t\(object)")
        }
    }
}

Which you can use like this:

Stuff.print("Just as the standard print but now with detailed information")
Stuff.print("Now it's a warning", .warn)
Stuff.print("Or even an error", .error)

Stuff.minimumLogLevel = .error
Stuff.print("Now you won't see normal log output")
Stuff.print("Only errors are shown", .error)

Stuff.minimumLogLevel = .none
Stuff.print("Or if it's disabled you won't see any log", .error)    

Which will result in:

✳️ .debug ⏱ 02/13/2017 09:52:51:852 📱 xctest [18960:?] 📂 PrintStuffTests.swift(15) ⚙️ testExample() ➡️
    Just as the standard print but now with detailed information

⚠️ .warn ⏱ 02/13/2017 09:52:51:855 📱 xctest [18960:?] 📂 PrintStuffTests.swift(16) ⚙️ testExample() ➡️
    Now it's a warning

🚫 .error ⏱ 02/13/2017 09:52:51:855 📱 xctest [18960:?] 📂 PrintStuffTests.swift(17) ⚙️ testExample() ➡️
    Or even an error

🚫 .error ⏱ 02/13/2017 09:52:51:855 📱 xctest [18960:?] 📂 PrintStuffTests.swift(21) ⚙️ testExample() ➡️
    Only errors are shown

Answer 1

Swift has #file, #function, #line and #column. From Swift Programming Language:

#file - String - The name of the file in which it appears.

#line - Int - The line number on which it appears.

#column - Int - The column number in which it begins.

#function - String - The name of the declaration in which it appears.