不能用方法遍历struct吗？

My problem is, I have the specified app:

myapp
     |- app/main.go
     |- data/a.go
     |- data/b.go

In a.go I have struct with methods

package data 

type A struct {
    Field_a string
    Field_b string
}

func (a A) SomeMethod() string {
    return "somemethod A"
}

In b.go similar:

package data

type B struct {
    Field_a string
    Field_b string
}

func (b B) SomeMethod() string {
    return "somemethod B"
}

Now I'm refering in main.go in such manner:

package main

import (
    "fmt"
    "myapp/data"
)

func main() {
    a := data.A{"x","y"} // it works
    b := data.B{"x","y"} // works as well
    c := data.A{"x","y"}.SomeMethod() // works
    d := data.B{"x","y"}.SomeMethod() // works too
    fmt.Printf("a: %T
",a)
    fmt.Printf("b: %T
",b)
    fmt.Printf("c: %T
",c)
    fmt.Printf("d: %T
",d)
}

But the problem which I have is that I want to iterate over these structs from package data and I've tried the following approach:

structPool := []struct{
   fielda string
   fieldb string
}{
   data.A{"x","y"}, // data.A{"x","y"}.SometMethod() is valid at this point
   data.B{"x","y"}, // data.B{"x","y"}.SometMethod() is valid at this point
}

for _, structObj := range structPool {
    // can't use here structObj.SomeMethod() - why?
} 

And I also tried to inititialize this slice structPool like this: []interface{} or []struct{} etc but still compiler does not see methods from these packages inside for loop. :(

I will be highly appreciated for any clues. Thank in advance

First of all, what you have done has created a new array with field fielda and fieldb. Its has nothing to do with your structure A and B. So basically you can't call method someMethod().

structPool = []struct {
    fielda string
    fieldb string
}{}

You need to implement interface to operate on these struct.

Define a interface like

type Common interface {
    someMethod() string
}

And your structure A and B both has implemented this interface.

Now make array of this interface with your data of A and B.

structPool := []Common{
        A{"x", "y"},
        B{"x", "y"},
}

Iterate over this array structObj.someMethod()

Hope this will help.

See in action if necessary: playground

Another example: https://gobyexample.com/interfaces

Other reference: http://www.golangbootcamp.com/book/interfaces