Macros in Swift?
Solution 1:
In this case you should add a default value for the "macro" parameters.
Swift 2.2 and higher
func log(message: String,
function: String = #function,
file: String = #file,
line: Int = #line) {
print("Message \"\(message)\" (File: \(file), Function: \(function), Line: \(line))")
}
log("Some message")
Swift 2.1 and lower
func log(message: String,
function: String = __FUNCTION__,
file: String = __FILE__,
line: Int = __LINE__) {
print("Message \"\(message)\" (File: \(file.lastPathComponent), Function: \(function), Line: \(line))")
}
log("Some message")
This is what fatalError
and assert
functions do.
There are no other macros except the conditional compilation already mentioned in another answer.
Solution 2:
The Apple docs state that:
Declare simple macros as global constants, and translate complex macros into functions.
You can still use #if/#else/#endif - but my feeling is that they will not introduce macro functions, the language simply doesn't need it.
Solution 3:
Since XCode 7.3, the __FILE__
__FUNCTION__
and __LINE__
compile-time constants have become the nicer-looking #file
#function
and #line
respectively.
Solution 4:
Here is an updated Swift 2 answer.
func LogW(msg:String, function: String = #function, file: String = #file, line: Int = #line){
print("[WARNING]\(makeTag(function, file: file, line: line)) : \(msg)")
}
private func makeTag(function: String, file: String, line: Int) -> String{
let url = NSURL(fileURLWithPath: file)
let className = url.lastPathComponent ?? file
return "\(className) \(function)[\(line)]"
}
Example of use:
LogW("Socket connection error: \(error)")
Solution 5:
lastPathComponent
needs an NSURL
, so I changed the above code to this:
func log(message: String,
function: String = __FUNCTION__,
file: String = __FILE__,
line: Int = __LINE__) {
let url = NSURL(fileURLWithPath: file)
print("Message \"\(message)\" (File: \(url.lastPathComponent ?? "?"), Function: \(function), Line: \(line))")
}
log("some message")