How can I define a Lua function with gopher-lua that has a pre-defined table as param, where the Lua script can access the table within that function?

I know how to define a Go function and set it global (the Double example from the docs). But what, if the argument of this function should be a pre-defined table?

function calling_this_function_would_be_required(predefined_table)
  print(predefined_table["something"])
end

The IMAP server Dovecot does provide something like the above: https://doc.dovecot.org/configuration_manual/authentication/lua_based_authentication/#examples

And I would like to also provide pre-defined functions with a table (or even user data). But I really have no idea on how to achieve this.

Having a table set global is easy (L.SetGlobal(...)), but how do I add it to a expected function?

Adding some function in Go

func CallMe(L *lua.LState) {
    // How do I add a table as argument??
}

func Foo() {
    L := NewState()
    defer L.Close()

    t := L.NewTable()
    t.RawSetString("example", lua.LString("some_value"))

    // I do not want a global table. I would like an expected Lua function that has _this_ table as argument
    L.SetGlobal("predefined_table", t)

    // Not even sure with his...
    L.SetGlobal("calling_this_function_is_required", L.NewFunction©llMe)) 
}

If someone could enlight me a bit that would be great :-) Thanks in advance

Solution

Based on @koyaanisqatsi answer, I found out how to get things working in Go.

Go code example:

package main

import (
    "fmt"

    "github.com/yuin/gopher-lua"
)

type Person struct {
    Name       string
    GivenName  string
    Street     string
    PostalCode string
    City       string
}

func main() {
    p := &Person{
        Name:       "Mustermann",
        GivenName:  "Max",
        Street:     "Sackgasse 19",
        PostalCode: "36304",
        City:       "Alsfeld",
    }

    L := lua.NewState()
    defer L.Close()

    if err := L.DoFile("sample.lua"); err != nil {
        panic(err)
    }

    t := L.NewTable()
    t.RawSetString("name", lua.LString(p.Name))
    t.RawSetString("given_name", lua.LString(p.GivenName))
    t.RawSetString("street", lua.LString(p.Street))
    t.RawSetString("postal_code", lua.LString(p.PostalCode))
    t.RawSetString("city", lua.LString(p.City))

    if err := L.CallByParam(lua.P{
        Fn:      L.GetGlobal("call_me"),
        NRet:    1,
        Protect: true,
    }, t); err != nil {
        panic(err)
    }

    ret := L.Get(-1) // returned value
    L.Pop(1)         // remove received value

    fmt.Println("The result of the Lua function is:", ret)
}

sample.lua file:

function call_me(tbl)
    print(tbl.name)
    print(tbl.given_name)
    print(tbl.street)
    print(tbl.postal_code)
    print(tbl.city)

    return 0
end

Result:

Mustermann
Max
Sackgasse 19
36304
Alsfeld
The result of the Lua function is: 0