Go 无论接收者类型如何，都在 interface{} 上动态调用方法

多亏了@Jeremy Wall，我相信我能够解决我的问题.基本问题是在interface{}上调用动态命名的方法.共4例.

1. interface{}底层数据为值，接收方为值
2. interface{}基础数据是指针，接收器是值
3. interface{}基础数据是值，接收器是指针
4. interface{}底层数据为指针，接收方为指针

使用反射，我们可以确定接口的下层值.然后，使用进一步的反射，我们可以生成当前类型的替代数据类型.如果传入的数据是一个值，我们需要生成指向它的指针

value := reflect.ValueOf(data)
if value.Type().Kind() == reflect.Ptr {
    ptr = value
    value = ptr.Elem() // acquire value referenced by pointer
} else {
    ptr = reflect.New(reflect.TypeOf(i)) // create new pointer
    temp := ptr.Elem() // create variable to value of pointer
    temp.Set(value) // set value of variable to our passed in value
}

现在我们有了这两种数据类型，我们可以简单地使用每种数据类型来判断现有方法

var finalMethod reflect.Value
method := value.MethodByName(methodName)
if method.IsValid() {
    finalMethod = method
}
// check for method on pointer
method = ptr.MethodByName(methodName)
if method.IsValid() {
    finalMethod = method
}

if (finalMethod.IsValid()) {
    return finalMethod.Call([]reflect.Value{})[0].String()
}

因此，考虑到这一点，我们可以有效地动态调用任何方法，无论声明为*receiver还是receiver.

完整概念证明:http://play.golang.org/p/AU-Km5VjZs

package main

import (
    "fmt"
    "reflect"
)

type Test struct {
    Start string
}

// value receiver
func (t Test) Finish() string {
    return t.Start + "finish"
}

// pointer receiver
func (t *Test) Another() string {
    return t.Start + "another"
}

func CallMethod(i interface{}, methodName string) interface{} {
    var ptr reflect.Value
    var value reflect.Value
    var finalMethod reflect.Value

    value = reflect.ValueOf(i)

    // if we start with a pointer, we need to get value pointed to
    // if we start with a value, we need to get a pointer to that value
    if value.Type().Kind() == reflect.Ptr {
        ptr = value
        value = ptr.Elem()
    } else {
        ptr = reflect.New(reflect.TypeOf(i))
        temp := ptr.Elem()
        temp.Set(value)
    }

    // check for method on value
    method := value.MethodByName(methodName)
    if method.IsValid() {
        finalMethod = method
    }
    // check for method on pointer
    method = ptr.MethodByName(methodName)
    if method.IsValid() {
        finalMethod = method
    }

    if (finalMethod.IsValid()) {
        return finalMethod.Call([]reflect.Value{})[0].Interface()
    }

    // return or panic, method not found of either type
    return ""
}

func main() {
    i := Test{Start: "start"}
    j := Test{Start: "start2"}

    fmt.Println(CallMethod(i, "Finish"))
    fmt.Println(CallMethod(&i, "Finish"))
    fmt.Println(CallMethod(i, "Another"))
    fmt.Println(CallMethod(&i, "Another"))
    fmt.Println(CallMethod(j, "Finish"))
    fmt.Println(CallMethod(&j, "Finish"))
    fmt.Println(CallMethod(j, "Another"))
    fmt.Println(CallMethod(&j, "Another"))
}