// look up a Lua value by its full name. If idx is 0, then this name
// is assumed to start in the global table, e.g. "string.gsub".
// With non-zero idx, can be used to look up subfields of a table
func Lookup(L *lua.State, path string, idx int) {
parts := strings.Split(path, ".")
if idx != 0 {
L.PushValue(idx)
} else {
L.GetGlobal("_G")
}
for _, field := range parts {
L.GetField(-1, field)
L.Remove(-2) // remove table
}
}
func pushValue(state *lua.State, value interface{}) error {
switch v := value.(type) {
default:
return fmt.Errorf("An item of unknown type was included in the environment or arguments of a Lua call (skipping it): %v",
value)
case nil:
log.Println("Pushing nil onto lua stack")
state.PushNil()
case string:
log.Println("Pushing string onto lua stack")
state.PushString(v)
case int:
log.Println("Pushing int onto lua stack")
state.PushInteger(int64(v))
case int64:
log.Println("Pushing int64 onto lua stack")
state.PushInteger(v)
case float64:
log.Println("Pushing float64 onto lua stack")
state.PushNumber(v)
case bool:
log.Println("Pushing bool onto lua stack")
state.PushBoolean(v)
case map[string]interface{}:
log.Println("Pushing map[string]interface{} onto lua stack")
state.CreateTable(0, len(v))
for name, value := range v {
err := pushValue(state, value)
if err != nil {
// error means nothing was added to stack. So pop our new table so *we* leave nothing added to the stack.
state.Pop(1)
return err
}
state.SetField(-2, name)
}
// then leave the table on the stack
case ThingType:
// These are singleton sentinel values, so load them from Lua-land.
state.GetGlobal("world")
state.GetField(-1, strings.Title(v.String()))
state.Remove(-2)
case *Thing:
log.Println("Pushing *Thing onto lua stack")
return pushValue(state, v.Id)
case ThingId:
log.Println("Pushing ThingId onto lua stack")
// We're pushing a ThingId, so make a new userdata for it, with the Thing metatable.
userdata := state.NewUserdata(uintptr(unsafe.Sizeof(int64(0))))
thingPtr := (*int64)(userdata)
*thingPtr = int64(v)
if !state.IsUserdata(-1) {
log.Println("!!! HOGAD JUST PUSHED NEW USERDATA BUT IT ISN'T OMG !!!")
}
log.Println("Pushed ThingId", *thingPtr, "onto lua stack")
// Now make it act like a Thing.
state.LGetMetaTable(ThingMetaTableName) // ( udata -- udata mtbl )
state.SetMetaTable(-2) // ( udata mtbl -- udata )
// Let's just check that it's that, for sures.
if !state.IsUserdata(-1) {
log.Println("!!! WOOP WOOP DID NOT SET METATABLE RIGHT :( !!!")
}
}
return nil
}