// 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
}
