Function objectArith

vm.go:2301–2344

(L *LState, opcode int, lhs, rhs LValue)

}

func objectArith(L *LState, opcode int, lhs, rhs LValue) LValue {
	event := ""
	switch opcode {
	case OP_ADD:
		event = "__add"
	case OP_SUB:
		event = "__sub"
	case OP_MUL:
		event = "__mul"
	case OP_DIV:
		event = "__div"
	case OP_MOD:
		event = "__mod"
	case OP_POW:
		event = "__pow"
	}
	op := L.metaOp2(lhs, rhs, event)
	if _, ok := op.(*LFunction); ok {
		L.reg.Push(op)
		L.reg.Push(lhs)
		L.reg.Push(rhs)
		L.Call(2, 1)
		return L.reg.Pop()
	}
	if str, ok := lhs.(LString); ok {
		if lnum, err := parseNumber(string(str)); err == nil {
			lhs = lnum
		}
	}
	if str, ok := rhs.(LString); ok {
		if rnum, err := parseNumber(string(str)); err == nil {
			rhs = rnum
		}
	}
	if v1, ok1 := lhs.(LNumber); ok1 {
		if v2, ok2 := rhs.(LNumber); ok2 {
			return numberArith(L, opcode, LNumber(v1), LNumber(v2))
		}
	}
	L.RaiseError(fmt.Sprintf("cannot perform %v operation between %v and %v",
		strings.TrimLeft(event, "_"), lhs.Type().String(), rhs.Type().String()))

	return LNil
}

func stringConcat(L *LState, total, last int) LValue {
	rhs := L.reg.Get(last)