go函數(shù)用匿名函數(shù)好，還是寫非匿名的好？

寫go的時候，函數(shù)是像下面的哪種方式好，哪種性能更優(yōu)？
方式一：

package main

import (
    "time"
    "fmt"
)

func main(){
    var getCurrentTime = func() string{
        return time.Now().Format("2006-01-06 15:04:05")
    }
    fmt.Println(getCurrentTime())
}

方式二：

package main

import (
    "time"
    "fmt"
)

func main(){
    fmt.Println(getCurrentTime())
}

func getCurrentTime() string {
    return time.Now().Format("2006-01-06 15:04:05")
}

回答

編輯回答

失魂人

Rob Pike's 5 Rules of Programming
Rule 1: You can't tell where a program is going to spend its time. Bottlenecks occur in surprising places, so don't try to second guess and put in a speed hack until you've proven that's where the bottleneck is.

自己做一下benchmark

func NamedFunc() string {                                
    return getCurrentTime()                              
}                                                        
                                                         
func AnonymousFunc() string {                            
    var f = func() string {                              
        return time.Now().Format("2006-01-06 15:04:05")  
    }                                                    
    return f()                                           
}                                                        
                                                         
func getCurrentTime() string {                           
    return time.Now().Format("2006-01-06 15:04:05")      
}                                                        


var str = ""                                  
                                              
func BenchmarkNamedFunc(b *testing.B) {       
    for i := 0; i < b.N; i++ {                
        str = NamedFunc()                     
    }                                         
}                                             
                                              
func BenchmarkAnonymousdFunc(b *testing.B) {  
    for i := 0; i < b.N; i++ {                
        str = AnonymousFunc()                 
    }                                         
}

我做的結果:

goos: linux
goarch: amd64
BenchmarkNamedFunc-8             5000000           248 ns/op
BenchmarkAnonymousdFunc-8        5000000           248 ns/op
PASS
ok      _/home/singlethread/test/src/definedfunc    3.020s

2017年10月29日 18:03

編輯回答