func main() {
L := C.luaL_newstate()
defer C.lua_close(L)
C.luaL_openlibs(L) /* Load Lua libraries */
C.luaopen_cmsgpack(L)
sumS := C.CString(sum)
defer C.free(unsafe.Pointer(sumS))
C.luaL_loadstring(L, sumS)
msg, _ := msgpack.Marshal([]int{1, 2, 3, 4, 5, 6})
C.lua_pushstring(L, cptr(msg))
dstr := C.CString("mpdata")
defer C.free(unsafe.Pointer(dstr))
C.luaSetglobal(L, dstr)
C.luaExecute(L)
sum := C.lua_tonumber(L, -1)
fmt.Println(sum) // Output: 21
}
func packLuaNumber(out io.Writer, state State, object int) (n int, err error) {
value := float64(C.lua_tonumber(state.L, C.int(object)))
i := int64(value)
if float64(i) == value {
return P.PackVarint(out, i)
}
return P.PackFloat64(out, value)
}
// lua_tonumber
func (L *State) ToNumber(index int) float64 {
return float64(C.lua_tonumber(L.s, C.int(index)))
}
// Converts the Lua value at the given valid index to a float64. The
// Lua value must be a number or a string convertible to a number; otherwise,
// Tonumber returns 0.
func (this *State) Tonumber(index int) float64 {
return float64(C.lua_tonumber(this.luastate, C.int(index)))
}
//export golua_interface_newindex_callback
func golua_interface_newindex_callback(Li interface{}, iid uint, field_name_cstr *C.char) int {
L := Li.(*State)
iface := L.registry[iid]
ifacevalue := reflect.ValueOf(iface).Elem()
field_name := C.GoString(field_name_cstr)
fval := ifacevalue.FieldByName(field_name)
if fval.Kind() == reflect.Ptr {
fval = fval.Elem()
}
luatype := LuaValType(C.lua_type(L.s, 3))
switch fval.Kind() {
case reflect.Bool:
if luatype == LUA_TBOOLEAN {
fval.SetBool(int(C.lua_toboolean(L.s, 3)) != 0)
return 1
} else {
L.PushString("Wrong assignment to field " + field_name)
return -1
}
case reflect.Int:
fallthrough
case reflect.Int8:
fallthrough
case reflect.Int16:
fallthrough
case reflect.Int32:
fallthrough
case reflect.Int64:
if luatype == LUA_TNUMBER {
fval.SetInt(int64(C.lua_tointeger(L.s, 3)))
return 1
} else {
L.PushString("Wrong assignment to field " + field_name)
return -1
}
case reflect.Uint:
fallthrough
case reflect.Uint8:
fallthrough
case reflect.Uint16:
fallthrough
case reflect.Uint32:
fallthrough
case reflect.Uint64:
if luatype == LUA_TNUMBER {
fval.SetUint(uint64(C.lua_tointeger(L.s, 3)))
return 1
} else {
L.PushString("Wrong assignment to field " + field_name)
return -1
}
case reflect.String:
if luatype == LUA_TSTRING {
fval.SetString(C.GoString(C.lua_tolstring(L.s, 3, nil)))
return 1
} else {
L.PushString("Wrong assignment to field " + field_name)
return -1
}
case reflect.Float32:
fallthrough
case reflect.Float64:
if luatype == LUA_TNUMBER {
fval.SetFloat(float64(C.lua_tonumber(L.s, 3)))
return 1
} else {
L.PushString("Wrong assignment to field " + field_name)
return -1
}
}
L.PushString("Unsupported type of field " + field_name + ": " + fval.Type().String())
return -1
}
// Converts the Lua value at the given valid index to a float64. The
// Lua value must be a number or a string convertible to a number; otherwise,
// Tonumber returns 0.
func (s *State) Tonumber(index int) float64 {
return float64(C.lua_tonumber(s.l, C.int(index)))
}
func (l *Lua) toGoValue(i C.int, paramType reflect.Type) (ret *reflect.Value, err error) {
luaType := C.lua_type(l.State, i)
paramKind := paramType.Kind()
switch paramKind {
case reflect.Bool:
if luaType != C.LUA_TBOOLEAN {
err = fmt.Errorf("not a boolean")
return
}
v := reflect.ValueOf(C.lua_toboolean(l.State, i) == C.int(1))
ret = &v
case reflect.Int, reflect.Int8, reflect.Int16, reflect.Int32, reflect.Int64:
if luaType != C.LUA_TNUMBER {
err = fmt.Errorf("not an integer")
return
}
v := reflect.New(paramType).Elem()
v.SetInt(int64(C.lua_tointeger(l.State, i)))
ret = &v
case reflect.Uint, reflect.Uint8, reflect.Uint16, reflect.Uint32, reflect.Uint64:
if luaType != C.LUA_TNUMBER {
err = fmt.Errorf("not a unsigned")
return
}
v := reflect.New(paramType).Elem()
v.SetUint(uint64(C.lua_tointeger(l.State, i)))
ret = &v
case reflect.Float32, reflect.Float64:
if luaType != C.LUA_TNUMBER {
err = fmt.Errorf("not a float")
return
}
v := reflect.New(paramType).Elem()
v.SetFloat(float64(C.lua_tonumber(l.State, i)))
ret = &v
case reflect.Interface:
switch paramType {
case interfaceType:
switch luaType {
case C.LUA_TNUMBER:
v := reflect.New(floatType).Elem() // always return float64 for interface{}
v.SetFloat(float64(C.lua_tonumber(l.State, i)))
ret = &v
case C.LUA_TSTRING:
v := reflect.New(stringType).Elem()
v.SetString(C.GoString(C.lua_tolstring(l.State, i, nil)))
ret = &v
case C.LUA_TLIGHTUSERDATA, C.LUA_TUSERDATA:
v := reflect.ValueOf(C.lua_touserdata(l.State, i))
ret = &v
case C.LUA_TBOOLEAN:
v := reflect.New(boolType).Elem()
v.SetBool(C.lua_toboolean(l.State, i) == C.int(1))
ret = &v
case C.LUA_TNIL:
ret = nil
default:
err = fmt.Errorf("unsupported type %s for interface{}", luaTypeName(luaType))
return
}
default:
err = fmt.Errorf("only interface{} is supported, no %v", paramType)
return
}
case reflect.String:
if luaType != C.LUA_TSTRING {
err = fmt.Errorf("not a string")
return
}
v := reflect.New(paramType).Elem()
v.SetString(C.GoString(C.lua_tolstring(l.State, i, nil)))
ret = &v
case reflect.Slice:
switch luaType {
case C.LUA_TSTRING:
v := reflect.New(paramType).Elem()
cstr := C.lua_tolstring(l.State, i, nil)
v.SetBytes(C.GoBytes(unsafe.Pointer(cstr), C.int(C.strlen(cstr))))
ret = &v
case C.LUA_TTABLE:
v := reflect.MakeSlice(paramType, 0, 0)
C.lua_pushnil(l.State)
elemType := paramType.Elem()
for C.lua_next(l.State, i) != 0 {
elemValue, e := l.toGoValue(-1, elemType)
if e != nil {
err = e
return
}
// there is no nil value in lua table so elemValue will never be nil
v = reflect.Append(v, *elemValue)
C.lua_settop(l.State, -2)
ret = &v
}
default:
err = fmt.Errorf("wrong slice argument")
return
}
case reflect.Ptr:
if luaType != C.LUA_TLIGHTUSERDATA {
err = fmt.Errorf("not a pointer")
return
}
p := C.lua_topointer(l.State, i)
v := reflect.NewAt(paramType, unsafe.Pointer(&p)).Elem()
ret = &v
case reflect.Map:
if luaType != C.LUA_TTABLE {
err = fmt.Errorf("not a map")
return
}
v := reflect.MakeMap(paramType)
C.lua_pushnil(l.State)
keyType := paramType.Key()
elemType := paramType.Elem()
for C.lua_next(l.State, i) != 0 {
keyValue, e := l.toGoValue(-2, keyType)
if e != nil {
err = e
return
}
// table has no nil key so keyValue will not be nil
elemValue, e := l.toGoValue(-1, elemType)
if e != nil {
err = e
return
}
// table has no nil value so elemValue will not be nil
v.SetMapIndex(*keyValue, *elemValue)
C.lua_settop(l.State, -2)
}
ret = &v
case reflect.UnsafePointer:
v := reflect.ValueOf(C.lua_topointer(l.State, i))
ret = &v
default:
err = fmt.Errorf("unsupported toGoValue type %v", paramType)
return
}
return
}
func (state State) luaToGoValue(_lvalue int, outType *reflect.Type) (reflect.Value, error) {
L := state.L
lvalue := C.int(_lvalue)
ltype := C.lua_type(L, lvalue)
gkind := reflect.Invalid
if outType != nil {
gkind = (*outType).Kind()
}
switch ltype {
case C.LUA_TNONE, C.LUA_TNIL:
switch gkind {
case reflect.Invalid, reflect.Func, reflect.Ptr, reflect.Interface:
return reflect.ValueOf(nil), nil
}
case C.LUA_TBOOLEAN:
switch gkind {
case reflect.Invalid, reflect.Bool, reflect.Interface:
cv := C.lua_toboolean(L, lvalue)
var v bool
if cv == 0 {
v = false
} else {
v = true
}
return reflect.ValueOf(v), nil
}
//case C.LUA_TLIGHTUSERDATA:
//case C.LUA_TTHREAD:
case C.LUA_TNUMBER:
switch gkind {
case reflect.Int:
v := int(C.lua_tointeger(L, lvalue))
return reflect.ValueOf(v), nil
case reflect.Int8:
v := int8(C.lua_tointeger(L, lvalue))
return reflect.ValueOf(v), nil
case reflect.Int16:
v := int16(C.lua_tointeger(L, lvalue))
return reflect.ValueOf(v), nil
case reflect.Int32:
v := int32(C.lua_tointeger(L, lvalue))
return reflect.ValueOf(v), nil
case reflect.Int64:
v := int64(C.lua_tointeger(L, lvalue))
return reflect.ValueOf(v), nil
case reflect.Uint:
v := uint(C.lua_tointeger(L, lvalue))
return reflect.ValueOf(v), nil
case reflect.Uint8:
v := uint8(C.lua_tointeger(L, lvalue))
return reflect.ValueOf(v), nil
case reflect.Uint16:
v := uint16(C.lua_tointeger(L, lvalue))
return reflect.ValueOf(v), nil
case reflect.Uint32:
v := uint32(C.lua_tointeger(L, lvalue))
return reflect.ValueOf(v), nil
case reflect.Uint64:
v := uint64(C.lua_tointeger(L, lvalue))
return reflect.ValueOf(v), nil
case reflect.Float32:
v := float32(C.lua_tonumber(L, lvalue))
return reflect.ValueOf(v), nil
case reflect.Invalid, reflect.Interface, reflect.Float64:
v := float64(C.lua_tonumber(L, lvalue))
return reflect.ValueOf(v), nil
}
case C.LUA_TSTRING:
switch gkind {
case reflect.Invalid, reflect.String, reflect.Interface:
v := stringFromLua(L, lvalue)
return reflect.ValueOf(v), nil
}
case C.LUA_TTABLE:
if gkind == reflect.Slice && (*outType).Elem() == typeOfKeyValue {
return state.luaTableToKeyValues(int(_lvalue))
}
if gkind == reflect.Invalid || gkind == reflect.Interface || (outType != nil && *outType == reflect.TypeOf(theNullTable)) {
tbl := state.NewLuaTable(int(lvalue))
return reflect.ValueOf(tbl), nil
}
case C.LUA_TFUNCTION:
if gkind == reflect.Invalid || gkind == reflect.Interface || (outType != nil && *outType == reflect.TypeOf(theNullFunction)) {
fn := state.NewLuaFunction(int(lvalue))
return reflect.ValueOf(fn), nil
}
case C.LUA_TUSERDATA:
ref := C.clua_getGoRef(L, lvalue)
if ref != nil {
obj := (*refGo)(ref).obj
objType := reflect.TypeOf(obj)
objValue := reflect.ValueOf(obj)
if gkind == reflect.Invalid || gkind == reflect.Interface {
return objValue, nil
}
if outType != nil {
if objType == *outType {
return objValue, nil
}
if objType.Kind() == reflect.Ptr {
if objType.Elem() == *outType {
return objValue.Elem(), nil
}
}
}
}
}
return reflect.ValueOf(nil),
fmt.Errorf("cannot convert from lua-type `%v' to go-type `%v'",
luaTypeName(ltype), gkind)
}
func (L *State) getNumber(i int) (ret float64) {
return float64(C.lua_tonumber(L.s, C.int(i+1)))
}
func Tonumber(s *State, index int) float64 {
return float64(
C.lua_tonumber((*C.lua_State)(s),
C.int(index)))
}