Golang anonymous function use

One preface

        Recent research NSQ middleware , In the process of studying this middleware , I found some things I didn't use in my usual development work Golang characteristic ; Decided to record some knowledge learned in the process ; What to write in this article , It's about Golang The use of anonymous functions

Two Anonymous functions

        Anonymous function has no function name, only function body , It can be assigned as a type to a variable of function type , Anonymous functions are also often passed as variables .
       Go The language supports defining anonymous functions in code at any time . Anonymous functions , It consists of a function declaration and body without a function name . In short , Anonymous functions can be used as ordinary variables ： It can be passed or assigned to variables in functions .

3、 ... and Use Demo

        stay NSQ in , The code for using anonymous functions is as follows ：

exitCh := make(chan error)
	var once sync.Once
	exitFunc := func