golang global struct initialization

I want to declare a global struct variable which belongs to a certain package and initialize it.

I have a following directory structure:

main
├── symbol
|   ├── symbol.go
|   └── Comma.go
├── main.go
└── go.mod

symbol.go:

package symbol

type Symbol struct{
	Name string
	Format string
}

Comma.go:

package symbol

var Comma = Symbol{}

Comma.Name = "Comma"
Comma.Format = ","

main.go:

package main
import "fmt"
import "github.com/.../symbol"

func main() {
	s := symbol.Comma
	fmt.Println(s.Name)
}

When I run this, it says: <br>
syntax error: non-declaration statement outside function body

How can I fix this ?

Declaration statements are the only statement type allowed at package-level. The statements

Comma.Name = "Comma"
Comma.Format = ","

are assignment statements. Assigments are not declarations.

There are two ways to fix the problem. The first and preferred way is to initialize the value in the variable declaration using a composite literal.

 var Comma = Symbol{Name: "Comma", Format: ","}

The second way is to move the assignment statements to an init function:

func init() {
	Comma.Name = "Comma"
	Comma.Format = ","
}

init functions are automatically executed when the package is initialized.

Use a composite literal:

var Comma = Symbol{Name: "Comma", Format: ","}

The Go Programming Language Specification: Composite literals