nicer cacth-log-error syntax for swift

logAndCatch.swift

/*

   Many times one does a catch and just wants to log the error, 
   perhaps with an utility that in the log message includes the function name and the source code line.
   With catchAndLog one can do the same but with a nicer and shorter syntax.
   Example, before:

    do {
      ... code ...
    } catch {
        functionToLogError("\(error)")
    }
  
   After:

    catchAndLog {
      ... code ...
    }

   Note well: using "return" inside the catchAndLog block would not have the intended effect!
*/

var DEBUG = true

public func catchAndLog(message: String = "", file: String = #file, function: String = #function, line: Int = #line, closure: () throws -> Void) {

    do {

        try closure()

    } catch {

        logError(message + " \(error)", file: file, function: function, line: line)

    }

}

public func log(_ message: String, file: String = #file, function: String = #function, line: Int = #line ) {

    logFunc("INFO", message: message, file: file, function: function, line: line)

}

public func logError(_ message: String, file: String = #file, function: String = #function, line: Int = #line ) {

    logFunc("ERROR", message: message, file: file, function: function, line: line)

}

public func logDebug(_ message: String, file: String = #file, function: String = #function, line: Int = #line ) {

    DispatchQueue.main.async { // read in the main thread the DEBUG variable (and also set it the main thread)

        if DEBUG {

            logFunc("DEBUG", message: message, file: file, function: function, line: line)

        }

    }

}

public func logFunc(_ tag: String, message: String, file: String = #file, function: String = #function, line: Int = #line ) {

    let message = "\(tag): \(debugCoordinates(file: file, function: function, line: line)) \(message)"

    NSLog(message)
    
}

public func debugCoordinates(file: String = #file, function: String = #function, line: Int = #line) -> String {

    let smallFunction: String
    if let idx = function.firstIndex(of: "(") {
        smallFunction = String(function[..<idx])
    } else {
        smallFunction = function
    }

    let smallFile: String
    if let idx = file.lastIndex(of: "/") {

        smallFile = String(file[file.index(after: idx)...])

    } else {

        smallFile = file

    }

    return "\(smallFile):\(smallFunction):\(line)"
}