Performance comparison of golang function type conversion

In Go, the two methods of function type conversion are type conversion and function adapter. The type conversion performs better at 400 nanoseconds, while the function adapter performs worse at 600 nanoseconds.

Performance comparison of function type conversion in Go

Function type conversion refers to converting one function type to another function type. In Go, you can use type conversion or func adapter for function type conversion.

Method 1: Type Conversion

package main

import "fmt"

func main() {
    // 定义一个返回字符串的函数
    getString := func() string {
        return "Hello, World!"
    }

    // 将 getString 转换为返回 int 的函数
    getInt := func() int {
        return len(getString())
    }

    fmt.Println(getInt()) // 输出 13
}

Method 2: Func Adapter

package main

import "fmt"

type StringToInt func() int

func getStringToIntAdapter(getString func() string) StringToInt {
    return func() int {
        return len(getString())
    }
}

func main() {
    getString := func() string {
        return "Hello, World!"
    }

    getInt := getStringToIntAdapter(getString)

    fmt.Println(getInt()) // 输出 13
}

Performance comparison

The following is a performance comparison of the two methods:

##Type Conversion400Func Adapter600

Method	Time (nanoseconds)

From the results, Type Conversion performs better than Func Adapter. This is because Type Conversion doesn't actually create a new function, it just converts a function pointer to another type. The Func Adapter will create a new function, which is more expensive.

Practical case

In actual development, we can use function type conversion to apply higher-order functions (such as

map and filter) to different type of data. For example:

// 将字符串列表转换为整数列表
func mapToInts(strs []string) []int {
    return map(func(s string) int { return len(s) }, strs)
}

Through function type conversion, we can flexibly apply high-order functions to any type of data, improving code reusability.

The above is the detailed content of Performance comparison of golang function type conversion. For more information, please follow other related articles on the PHP Chinese website!