在Golang中如何在其他包文件中使用struct？

I am new in Golang and need some help.

As you can see in the code below I am tring to create REST API in Golang. I use mux (Gorilla Mux) and pq (PostgreSQL driver) as third party libraries. Don't want to use ORM.

Inside application.go file I have InitializeRoutes function with a list of all aviable routes. GetFactors function process one of these routes. I am tring to define GetFactors function logic in other file called factors.go. Inside factors.go file I want to use Application struct which was defined in application.go. How to make it correctly? Right now as you can see they are in different packages. For thats why factors.go file don't see Application struct.

Project structure:

main.go
application.go
controllers
    factors.go

main.go:

package main

func main()  {
    application := Application{}
    application.Initialization()
    application.Run("localhost:8000")
}

application.go:

package main

import (
    "database/sql"
    "github.com/gorilla/mux"
    "log"
    "net/http"
    "rest-api/configurations"
)

type Application struct {
    Router *mux.Router
    Database *sql.DB
}

func (application *Application) Initialization() {
    var err error
    application.Database, err = configurations.DatabaseConnection()
    if err != nil {
        log.Fatal(err)
    }

    application.Router = mux.NewRouter()
    application.Router.StrictSlash(true)

    application.InitializeRoutes()
}

func (application *Application) Run(address string) {
    log.Fatal(http.ListenAndServe(address, application.Router))
}

func (application *Application) InitializeRoutes() {
    application.Router.HandleFunc("/api/factors", application.GetFactors).Methods("GET")
    // other code
}

controllers/factors.go:

package controllers

import (
    "net/http"
)

func (application *Application) GetFactors(rw http.ResponseWriter, request *http.Request) {
    // code
}

Well, finally I decided to redesign the project structure.

main.go
routes
    routes.go
controllers
    factors.go
models
    factors.go

main.go:

import (
    "your_project_name/routes"
)

func main()  {
    // code
    router := mux.NewRouter()
    routes.Use(router)
    // code
}

routes/routes.go:

package routes

import (
    "github.com/gorilla/mux"
    "your_application_name/controllers"
)

func Use(router *mux.Router) {
    router.HandleFunc("/api/factors", controllers.GetFactors).Methods("GET")
}

controllers/factors.go:

package controllers

var GetFactors = func(res http.ResponseWriter, req *http.Request) {
    // code
}