func (self *Lua) RegisterFunction(name string, fun interface{}) {
path := strings.Split(name, ".")
name = path[len(path)-1]
path = path[0 : len(path)-1]
if len(path) == 0 {
path = append(path, "_G")
}
// ensure namespaces
for i, namespace := range path {
cNamespace := cstr(namespace)
if i == 0 { // top namespace
what := C.lua_getglobal(self.State, cNamespace)
if what == C.LUA_TNIL { // not exists
C.lua_settop(self.State, -2)
C.lua_createtable(self.State, 0, 0)
C.lua_setglobal(self.State, cNamespace)
C.lua_getglobal(self.State, cNamespace)
}
if C.lua_type(self.State, -1) != C.LUA_TTABLE {
self.Panic("global %s is not a table", namespace)
}
} else { // sub namespace
C.lua_pushstring(self.State, cNamespace)
C.lua_rawget(self.State, -2)
if C.lua_type(self.State, -1) == C.LUA_TNIL {
C.lua_settop(self.State, -2)
C.lua_pushstring(self.State, cNamespace)
C.lua_createtable(self.State, 0, 0)
C.lua_rawset(self.State, -3)
C.lua_pushstring(self.State, cNamespace)
C.lua_rawget(self.State, -2)
}
if C.lua_type(self.State, -1) != C.LUA_TTABLE {
self.Panic("namespace %s is not a table", namespace)
}
}
}
// register function
funcType := reflect.TypeOf(fun)
if funcType.IsVariadic() {
self.Panic("cannot register variadic function: %v", fun)
}
argc := funcType.NumIn()
cName := cstr(name)
function := &Function{
fun: fun,
lua: self,
name: name,
funcType: funcType,
funcValue: reflect.ValueOf(fun),
argc: argc,
}
funcId := rand.Int63()
functionRegister.Set(funcId, function)
C.register_function(self.State, cName, (C.int64_t)(funcId))
self.Functions[name] = function
C.lua_settop(self.State, -2)
}
// Formats a string and pushes it into the stack. Provides all formatting
// verbs found in package fmt. Returns a pointer to the resultant
// formatted string.
func (s *State) Pushfstring(format string, v ...interface{}) *string {
str := fmt.Sprintf(format, v)
cs := C.CString(str)
defer C.free(unsafe.Pointer(cs))
C.lua_pushstring(s.l, cs)
return &str
}
func (lua *Lua) PushGoValue(value reflect.Value) {
switch t := value.Type(); t.Kind() {
case reflect.Bool:
if value.Bool() {
C.lua_pushboolean(lua.State, C.int(1))
} else {
C.lua_pushboolean(lua.State, C.int(0))
}
case reflect.String:
C.lua_pushstring(lua.State, C.CString(value.String()))
case reflect.Int, reflect.Int8, reflect.Int16, reflect.Int32, reflect.Int64:
C.lua_pushnumber(lua.State, C.lua_Number(C.longlong(value.Int())))
case reflect.Uint, reflect.Uint8, reflect.Uint16, reflect.Uint32, reflect.Uint64:
C.lua_pushnumber(lua.State, C.lua_Number(C.ulonglong(value.Uint())))
case reflect.Float32, reflect.Float64:
C.lua_pushnumber(lua.State, C.lua_Number(C.double(value.Float())))
case reflect.Slice:
length := value.Len()
C.lua_createtable(lua.State, C.int(length), 0)
for i := 0; i < length; i++ {
C.lua_pushnumber(lua.State, C.lua_Number(i+1))
lua.PushGoValue(value.Index(i))
C.lua_settable(lua.State, -3)
}
case reflect.Interface:
lua.PushGoValue(value.Elem())
case reflect.Ptr, reflect.UnsafePointer:
C.lua_pushlightuserdata(lua.State, unsafe.Pointer(value.Pointer()))
default:
lua.Panic("wrong return value %v %v", value, t.Kind())
}
}
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
}
// Peval evaluates a piece of lua code. no panic when error occur.
func (l *Lua) Peval(code string, envs ...interface{}) (returns []interface{}, err error) {
defer C.lua_settop(l.State, 0)
C.push_errfunc(l.State)
curTop := C.lua_gettop(l.State)
// parse
cCode := C.CString(code)
defer C.free(unsafe.Pointer(cCode))
if ret := C.luaL_loadstring(l.State, cCode); ret != 0 { // load error
return nil, fmt.Errorf("LOAD ERROR: %s", C.GoString(C.lua_tolstring(l.State, -1, nil)))
}
// env
if len(envs) > 0 {
if len(envs)%2 != 0 {
return nil, fmt.Errorf("number of arguments not match")
}
C.lua_createtable(l.State, 0, 0)
for i := 0; i < len(envs); i += 2 {
name, ok := envs[i].(string)
if !ok {
return nil, fmt.Errorf("name must be string, not %v", envs[i])
}
C.lua_pushstring(l.State, cstr(name))
err := l.pushGoValue(envs[i+1], name)
if err != nil {
return nil, err
}
C.lua_rawset(l.State, -3)
}
// set env
C.set_eval_env(l.State)
}
// call
l.err = nil
if ret := C.lua_pcall(l.State, 0, C.LUA_MULTRET, -2); ret != 0 {
// error occured
return nil, fmt.Errorf("CALL ERROR: %s", C.GoString(C.lua_tolstring(l.State, -1, nil)))
} else if l.err != nil { // error raise by invokeGoFunc
return nil, l.err
} else {
// return values
nReturn := C.lua_gettop(l.State) - curTop
returns = make([]interface{}, int(nReturn))
for i := C.int(0); i < nReturn; i++ {
value, err := l.toGoValue(-1-i, interfaceType)
if err != nil {
return nil, err
}
if value != nil {
returns[int(nReturn-1-i)] = value.Interface()
} else {
returns[int(nReturn-1-i)] = nil
}
}
}
return
}
// Pcall calls a lua function. no panic
func (l *Lua) Pcall(fullname string, args ...interface{}) (returns []interface{}, err error) {
C.push_errfunc(l.State)
curTop := C.lua_gettop(l.State)
// get function
path := strings.Split(fullname, ".")
for i, name := range path {
if i == 0 {
C.lua_getfield(l.State, C.LUA_GLOBALSINDEX, cstr(name))
} else {
if C.lua_type(l.State, -1) != C.LUA_TTABLE {
return nil, fmt.Errorf("%s is not a function", fullname)
}
C.lua_pushstring(l.State, cstr(name))
C.lua_gettable(l.State, -2)
C.lua_remove(l.State, -2) // remove table
}
}
if C.lua_type(l.State, -1) != C.LUA_TFUNCTION {
return nil, fmt.Errorf("%s is not a function", fullname)
}
// args
for _, arg := range args {
l.pushGoValue(arg, "")
}
// call
l.err = nil
if ret := C.lua_pcall(l.State, C.int(len(args)), C.LUA_MULTRET, C.int(-(len(args))-2)); ret != 0 {
// error occured
return nil, fmt.Errorf("CALL ERROR: %s", C.GoString(C.lua_tolstring(l.State, -1, nil)))
} else if l.err != nil { // error raise by invokeGoFunc
return nil, l.err
} else {
// return values
nReturn := C.lua_gettop(l.State) - curTop
returns = make([]interface{}, int(nReturn))
for i := C.int(0); i < nReturn; i++ {
value, err := l.toGoValue(-1-i, interfaceType)
if err != nil {
return nil, err
}
returns[int(nReturn-1-i)] = value.Interface()
}
}
return
}
// Pushes the string str onto the stack.
func (this *State) Pushstring(str string) {
cs := C.CString(str)
defer C.free(unsafe.Pointer(cs))
C.lua_pushstring(this.luastate, cs)
}
func (L *State) PushString(str string) {
C.lua_pushstring(L.s, C.CString(str))
}
func (L *State) PushString(str string) {
Cstr := C.CString(str)
defer C.free(unsafe.Pointer(Cstr))
C.lua_pushstring(L.s, Cstr)
}
func (l *Lua) pushGoValue(v interface{}, name string) error {
if v == nil {
C.lua_pushnil(l.State)
return nil
}
switch value := v.(type) {
case bool:
if value {
C.lua_pushboolean(l.State, C.int(1))
} else {
C.lua_pushboolean(l.State, C.int(0))
}
case string:
C.lua_pushstring(l.State, C.CString(value))
case int:
C.lua_pushnumber(l.State, C.lua_Number(C.longlong(value)))
case int8:
C.lua_pushnumber(l.State, C.lua_Number(C.longlong(value)))
case int16:
C.lua_pushnumber(l.State, C.lua_Number(C.longlong(value)))
case int32:
C.lua_pushnumber(l.State, C.lua_Number(C.longlong(value)))
case int64:
C.lua_pushnumber(l.State, C.lua_Number(C.longlong(value)))
case uint:
C.lua_pushnumber(l.State, C.lua_Number(C.ulonglong(value)))
case uint8:
C.lua_pushnumber(l.State, C.lua_Number(C.ulonglong(value)))
case uint16:
C.lua_pushnumber(l.State, C.lua_Number(C.ulonglong(value)))
case uint32:
C.lua_pushnumber(l.State, C.lua_Number(C.ulonglong(value)))
case uint64:
C.lua_pushnumber(l.State, C.lua_Number(C.ulonglong(value)))
case float32:
C.lua_pushnumber(l.State, C.lua_Number(C.double(value)))
case float64:
C.lua_pushnumber(l.State, C.lua_Number(C.double(value)))
case unsafe.Pointer:
C.lua_pushlightuserdata(l.State, value)
default:
// not basic types, use reflect
switch valueType := reflect.TypeOf(v); valueType.Kind() {
case reflect.Func:
// function
if valueType.IsVariadic() {
return fmt.Errorf("variadic function is not supported, %s", name)
}
function := &_Function{
name: name,
lua: l,
fun: v,
funcType: valueType,
funcValue: reflect.ValueOf(v),
argc: valueType.NumIn(),
}
funcsLock.Lock()
funcs = append(funcs, function)
id := len(funcs) - 1
funcsLock.Unlock()
C.push_go_func(l.State, C.int64_t(id))
case reflect.Slice:
value := reflect.ValueOf(v)
length := value.Len()
C.lua_createtable(l.State, C.int(length), 0)
for i := 0; i < length; i++ {
C.lua_pushnumber(l.State, C.lua_Number(i+1))
err := l.pushGoValue(value.Index(i).Interface(), "")
if err != nil {
return err
}
C.lua_settable(l.State, -3)
}
case reflect.Ptr:
C.lua_pushlightuserdata(l.State, unsafe.Pointer(reflect.ValueOf(v).Pointer()))
default:
// unknown type
return fmt.Errorf("unsupported type %v", v)
}
}
return nil
}
func (L *State) pushString(str string) {
cs := C.CString(str)
defer C.free(unsafe.Pointer(cs))
C.lua_pushstring(L.s, cs)
}