Swift 中的宏? [英] Macros in Swift?

问题描述

Swift 目前是否支持宏，或者是否有未来计划增加支持?目前我正在分散:

Does Swift currently support macros, or are there future plans to add support? Currently I'm scattering:

Log.trace(nil, function: __FUNCTION__, file: __FILE__, line: __LINE__)

在我的代码中的各个地方.

In various places throughout my code.

推荐答案

在这种情况下，您应该为宏"参数添加一个默认值.

In this case you should add a default value for the "macro" parameters.

Swift 2.2 及更高版本

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 及更低版本

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")

这就是 fatalError 和 assert 函数的作用.

This is what fatalError and assert functions do.

除了另一个答案中已经提到的条件编译之外，没有其他宏.

There are no other macros except the conditional compilation already mentioned in another answer.

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