Exemplo n.º 1
0
func (e *Evaluator) unaryOperation(u *ast.UnaryOperationExpr) bool {
	defer func() {
		if er := recover(); er != nil {
			e.err = errors.Errorf("%v", er)
		}
	}()
	aDatum := u.V.GetDatum()
	if aDatum.IsNull() {
		u.SetNull()
		return true
	}
	switch op := u.Op; op {
	case opcode.Not:
		n, err := aDatum.ToBool()
		if err != nil {
			e.err = errors.Trace(err)
		} else if n == 0 {
			u.SetInt64(1)
		} else {
			u.SetInt64(0)
		}
	case opcode.BitNeg:
		// for bit operation, we will use int64 first, then return uint64
		n, err := aDatum.ToInt64()
		if err != nil {
			e.err = errors.Trace(err)
			return false
		}
		u.SetUint64(uint64(^n))
	case opcode.Plus:
		switch aDatum.Kind() {
		case types.KindInt64,
			types.KindUint64,
			types.KindFloat64,
			types.KindFloat32,
			types.KindMysqlDuration,
			types.KindMysqlTime,
			types.KindString,
			types.KindMysqlDecimal,
			types.KindBytes,
			types.KindMysqlHex,
			types.KindMysqlBit,
			types.KindMysqlEnum,
			types.KindMysqlSet:
			u.SetDatum(*aDatum)
		default:
			e.err = ErrInvalidOperation
			return false
		}
	case opcode.Minus:
		switch aDatum.Kind() {
		case types.KindInt64:
			u.SetInt64(-aDatum.GetInt64())
		case types.KindUint64:
			u.SetInt64(-int64(aDatum.GetUint64()))
		case types.KindFloat64:
			u.SetFloat64(-aDatum.GetFloat64())
		case types.KindFloat32:
			u.SetFloat32(-aDatum.GetFloat32())
		case types.KindMysqlDuration:
			var to = new(mysql.MyDecimal)
			var zero mysql.MyDecimal
			mysql.DecimalSub(&zero, aDatum.GetMysqlDuration().ToNumber(), to)
			u.SetMysqlDecimal(to)
		case types.KindMysqlTime:
			dec := aDatum.GetMysqlTime().ToNumber()
			var zero, to mysql.MyDecimal
			mysql.DecimalSub(&zero, dec, &to)
			u.SetMysqlDecimal(&to)
		case types.KindString, types.KindBytes:
			f, err := types.StrToFloat(aDatum.GetString())
			e.err = errors.Trace(err)
			u.SetFloat64(-f)
		case types.KindMysqlDecimal:
			dec := aDatum.GetMysqlDecimal()
			var zero, to mysql.MyDecimal
			mysql.DecimalSub(&zero, dec, &to)
			u.SetMysqlDecimal(&to)
		case types.KindMysqlHex:
			u.SetFloat64(-aDatum.GetMysqlHex().ToNumber())
		case types.KindMysqlBit:
			u.SetFloat64(-aDatum.GetMysqlBit().ToNumber())
		case types.KindMysqlEnum:
			u.SetFloat64(-aDatum.GetMysqlEnum().ToNumber())
		case types.KindMysqlSet:
			u.SetFloat64(-aDatum.GetMysqlSet().ToNumber())
		default:
			e.err = ErrInvalidOperation
			return false
		}
	default:
		e.err = ErrInvalidOperation
		return false
	}

	return true
}