src/Marshaler/DynamoDb/ItemMarshaler.php
public function encodeGeoPoint(GeoPoint $geoPoint, Field $field)
    {
        return [
            'M' => [
                'type'        => [self::TYPE_STRING => 'Point'],
                'coordinates' => [
                    'L' => [
                        [self::TYPE_NUMBER => (string)$geoPoint->getLongitude()],
                        [self::TYPE_NUMBER => (string)$geoPoint->getLatitude()],
                    ],
                ],
            ],
        ];
    }
public function encodeGeoPoint(GeoPoint $geoPoint, Field $field)
    {
        return [
            'M' => [
                'type'        => [self::TYPE_STRING => 'Point'],
                'coordinates' => [
                    'L' => [
                        [self::TYPE_NUMBER => (string)$geoPoint->getLongitude()],
                        [self::TYPE_NUMBER => (string)$geoPoint->getLatitude()],
                    ],
                ],
            ],
        ];
    }
@param GeoPoint $geoPoint
@param Field    $field

@return mixed