func copyTableToMap(L *lua.State, t reflect.Type, idx int, visited map[uintptr]interface{}) interface{} {
if t == nil {
t = tmap
}
te, tk := t.Elem(), t.Key()
m := reflect.MakeMap(t)
// See copyTableToSlice.
ptr := L.ToPointer(idx)
if !luaIsEmpty(L, idx) {
visited[ptr] = m.Interface()
}
L.PushNil()
if idx < 0 {
idx--
}
for L.Next(idx) != 0 {
// key at -2, value at -1
key := reflect.ValueOf(luaToGo(L, tk, -2, visited))
val := reflect.ValueOf(luaToGo(L, te, -1, visited))
if val.Interface() == nullv.Interface() {
val = reflect.Zero(te)
}
m.SetMapIndex(key, val)
L.Pop(1)
}
return m.Interface()
}
func copyTableToStruct(L *lua.State, t reflect.Type, idx int, visited map[uintptr]interface{}) interface{} {
if t == nil {
RaiseError(L, "type argument must be non-nill")
}
wasPtr := t.Kind() == reflect.Ptr
if wasPtr {
t = t.Elem()
}
s := reflect.New(t) // T -> *T
ref := s.Elem()
// See copyTableToSlice.
ptr := L.ToPointer(idx)
if !luaIsEmpty(L, idx) {
if wasPtr {
visited[ptr] = s.Interface()
} else {
visited[ptr] = s.Elem().Interface()
}
}
// Associate Lua keys with Go fields: tags have priority over matching field
// name.
fields := map[string]string{}
st := ref.Type()
for i := 0; i < ref.NumField(); i++ {
field := st.Field(i)
tag := field.Tag.Get("lua")
if tag != "" {
fields[tag] = field.Name
continue
}
fields[field.Name] = field.Name
}
L.PushNil()
if idx < 0 {
idx--
}
for L.Next(idx) != 0 {
key := L.ToString(-2)
f := ref.FieldByName(fields[key])
if f.CanSet() && f.IsValid() {
val := reflect.ValueOf(luaToGo(L, f.Type(), -1, visited))
f.Set(val)
}
L.Pop(1)
}
if wasPtr {
return s.Interface()
}
return s.Elem().Interface()
}
// Also for arrays.
func copyTableToSlice(L *lua.State, t reflect.Type, idx int, visited map[uintptr]interface{}) interface{} {
if t == nil {
t = tslice
}
ref := t
// There is probably no point at accepting more than one level of dreference.
if t.Kind() == reflect.Ptr {
t = t.Elem()
}
n := int(L.ObjLen(idx))
var slice reflect.Value
if t.Kind() == reflect.Array {
slice = reflect.New(t)
slice = slice.Elem()
} else {
slice = reflect.MakeSlice(t, n, n)
}
// Do not add empty slices to the list of visited elements.
// The empty Lua table is a single instance object and gets re-used across maps, slices and others.
if n > 0 {
ptr := L.ToPointer(idx)
if ref.Kind() == reflect.Ptr {
visited[ptr] = slice.Addr().Interface()
} else {
visited[ptr] = slice.Interface()
}
}
te := t.Elem()
for i := 1; i <= n; i++ {
L.RawGeti(idx, i)
val := reflect.ValueOf(luaToGo(L, te, -1, visited))
if val.Interface() == nullv.Interface() {
val = reflect.Zero(te)
}
slice.Index(i - 1).Set(val)
L.Pop(1)
}
if ref.Kind() == reflect.Ptr {
return slice.Addr().Interface()
}
return slice.Interface()
}
func luaToGo(L *lua.State, t reflect.Type, idx int, visited map[uintptr]interface{}) interface{} {
var value interface{}
var kind reflect.Kind
if t != nil {
if t.Kind() == reflect.Ptr {
kind = t.Elem().Kind()
} else if t.Kind() == reflect.Interface {
// Let the Lua type drive the conversion.
t = nil
} else {
kind = t.Kind()
}
}
switch L.Type(idx) {
case lua.LUA_TNIL:
if t == nil {
return nil
}
switch kind {
default:
value = reflect.Zero(t).Interface()
}
case lua.LUA_TBOOLEAN:
if t == nil {
kind = reflect.Bool
}
switch kind {
case reflect.Bool:
ptr := new(bool)
*ptr = L.ToBoolean(idx)
value = *ptr
default:
value = reflect.Zero(t).Interface()
}
case lua.LUA_TSTRING:
if t == nil {
kind = reflect.String
}
switch kind {
case reflect.String:
tos := L.ToString(idx)
ptr := new(string)
*ptr = tos
value = *ptr
default:
value = reflect.Zero(t).Interface()
}
case lua.LUA_TNUMBER:
if t == nil {
// Infering the type here (e.g. int if round value) would break backward
// compatibility and drift away from Lua's design: the numeric type is
// specified at compile time.
kind = reflect.Float64
}
switch kind {
case reflect.Float64:
ptr := new(float64)
*ptr = L.ToNumber(idx)
value = *ptr
case reflect.Float32:
ptr := new(float32)
*ptr = float32(L.ToNumber(idx))
value = *ptr
case reflect.Int:
ptr := new(int)
*ptr = int(L.ToNumber(idx))
value = *ptr
case reflect.Int8:
ptr := new(int8)
*ptr = int8(L.ToNumber(idx))
value = *ptr
case reflect.Int16:
ptr := new(int16)
*ptr = int16(L.ToNumber(idx))
value = *ptr
case reflect.Int32:
ptr := new(int32)
*ptr = int32(L.ToNumber(idx))
value = *ptr
case reflect.Int64:
ptr := new(int64)
*ptr = int64(L.ToNumber(idx))
value = *ptr
case reflect.Uint:
ptr := new(uint)
*ptr = uint(L.ToNumber(idx))
value = *ptr
case reflect.Uint8:
ptr := new(uint8)
*ptr = uint8(L.ToNumber(idx))
value = *ptr
case reflect.Uint16:
ptr := new(uint16)
*ptr = uint16(L.ToNumber(idx))
value = *ptr
case reflect.Uint32:
ptr := new(uint32)
*ptr = uint32(L.ToNumber(idx))
value = *ptr
case reflect.Uint64:
ptr := new(uint64)
*ptr = uint64(L.ToNumber(idx))
value = *ptr
default:
value = reflect.Zero(t).Interface()
}
case lua.LUA_TTABLE:
if t == nil {
kind = reflect.Interface
}
fallthrough
default:
istable := L.IsTable(idx)
// If we don't know the type and the Lua object is userdata,
// then it might be a proxy for a Go object. Otherwise wrap
// it up as a LuaObject.
if t == nil && !istable {
if isValueProxy(L, idx) {
v, _ := valueOfProxy(L, idx)
return v.Interface()
}
return NewLuaObject(L, idx)
}
switch kind {
case reflect.Array:
if istable {
ptr := L.ToPointer(idx)
if val, ok := visited[ptr]; ok {
return val
}
value = copyTableToSlice(L, t, idx, visited)
} else {
value = mustUnwrapProxy(L, idx)
}
case reflect.Slice:
// if we get a table, then copy its values to a new slice
if istable {
ptr := L.ToPointer(idx)
if val, ok := visited[ptr]; ok {
return val
}
value = copyTableToSlice(L, t, idx, visited)
} else {
value = mustUnwrapProxy(L, idx)
}
case reflect.Map:
if istable {
ptr := L.ToPointer(idx)
if val, ok := visited[ptr]; ok {
return val
}
value = copyTableToMap(L, t, idx, visited)
} else {
value = mustUnwrapProxy(L, idx)
}
case reflect.Struct:
if istable {
ptr := L.ToPointer(idx)
if val, ok := visited[ptr]; ok {
return val
}
value = copyTableToStruct(L, t, idx, visited)
} else {
value = mustUnwrapProxy(L, idx)
}
case reflect.Interface:
if istable {
ptr := L.ToPointer(idx)
if val, ok := visited[ptr]; ok {
return val
}
// We have to make an executive decision here: tables with non-zero
// length are assumed to be slices!
if L.ObjLen(idx) > 0 {
value = copyTableToSlice(L, nil, idx, visited)
} else {
value = copyTableToMap(L, nil, idx, visited)
}
} else if L.IsNumber(idx) {
value = L.ToNumber(idx)
} else if L.IsString(idx) {
value = L.ToString(idx)
} else if L.IsBoolean(idx) {
value = L.ToBoolean(idx)
} else if L.IsNil(idx) {
return nil
} else {
value = mustUnwrapProxy(L, idx)
}
default:
value = mustUnwrapProxy(L, idx)
}
}
return value
}
