[英]Casting a string to a func type in GoLang
I have a string which is the name of a function in GoLang. 我有一个字符串,它是GoLang中函数的名称。 I want to treat them as function.
我想将它们视为功能。 How should I do this?
我应该怎么做? I tried to achieve it through reflect.* but I didn't find a valid path for my purpose.
我试图通过反射来实现它。*但我没有找到适合我目的的有效路径。
I get the name fo handlers in a JSON file, and I want to execute those handlers. 我在JSON文件中获得处理程序的名称,我想执行这些处理程序。 Something like this:
像这样:
{
"students/show" : "ShowStudents",
"students/add" : "AddStudents"
}
Then I want to execute ShowStudents()
, but don't know how to treat it like a variable of type func
然后我想执行
ShowStudents()
,但是不知道如何将其视为func
类型的变量
establish a mapping between the keys in the json file and the functions, then use that to call the functions as they appear in the json 在json文件中的键和函数之间建立映射,然后使用它们来调用出现在json中的函数
package main
import (
"encoding/json"
"fmt"
)
func AddStudents() {
fmt.Println("woo")
}
func ShowStudents() {
fmt.Println("lots of students")
}
func main() {
js := `{
"students/show" : "ShowStudents",
"students/add" : "AddStudents"
}`
lookup := make(map[string]string)
json.Unmarshal([]byte(js), &lookup)
dispatch := make(map[string]func())
dispatch["students/show"] = ShowStudents
dispatch["students/add"] = AddStudents
for v, _ := range lookup {
print(v)
dispatch[v]()
}
}
Your task can be broken down into two steps: 您的任务可以分为两个步骤:
For step 1, I would unmarshal the JSON into a map[string]string, something like this: 对于步骤1,我将将JSON解组为map [string] string,如下所示:
b, err := ioutil.ReadFile(fname)
mp := make(map[string]string)
json.Unmarshal(b, &mp)
Coming to Step 2. In Go, it's not possible to convert string
directly to a function call, but it is possible to enumerate the methods of an object using reflect
package. 转到步骤2。在Go中,不可能将
string
直接转换为函数调用,但是可以使用reflect
包枚举对象的方法。 This can be used as a workaround in this case. 在这种情况下,可以将其用作解决方法。 Instead of writing those functions directly, bind them to a dummy type, something like this:
与其直接编写这些函数,不如将它们绑定到一个虚拟类型,如下所示:
type T int
func (t T) ShowStudents() {
fmt.Println("Showing Students")
}
func (t T) AddStudents() {
fmt.Println("Adding Students")
}
func main() {
var t T
reflect.ValueOf(t).MethodByName("ShowStudents").Call(nil)
}
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