There is no runtime or reflect method or function that provides the functionality that you are looking for.
The closest thing I could find is:
package main
import (
"azul3d.org/lmath.v1"
"fmt"
"reflect"
)
type Empty struct{}
func main() {
fmt.Println(reflect.TypeOf(Empty{}).PkgPath())
fmt.Println(reflect.TypeOf(lmath.Vec3{0, 0, 0}).PkgPath())
}
This would output:
main
azul3d.org/lmath.v1
You could also read the first line of the file and remove the "package" substring.
(Not sure if it's the best idea)
package main
import (
"bufio"
"bytes"
"fmt"
"os"
)
func main() {
file, err := os.Open("so.go")
if err != nil {
panic(err)
}
r := bufio.NewReader(file)
line, _, err := r.ReadLine()
if err != nil {
panic(err)
}
packageName := bytes.TrimPrefix(line, []byte("package "))
fmt.Println(string(packageName))
}