Robotics Systems Types

When using RST, there is often the need for sending multiple Messages of the same type at the same time/close to another (see examples: LegList , ClassifiedRegions2D , ClassifiedRegions3D , States , and many others). This is often motivated by the fact that Message information is derived from a single certain cause (e.g. an image, a model, a previous message, etc..) and semantically/chronologically belongs together (e.g.: faces in an image, persons in a point cloud, etc.).

If one encounters this situation with a Message type X, there are two ways of dealing with this:

1. Create Messages of type X individually and add the same cause (i.e. an Event UUID) when sending it
2. Create a "container" RST Xs (just as the ones mentioned above) which only holds an array of the Message type X

Both of these have their advantages and downsides. It is not always clear, which is better and each can have a big impact on implementations and system design.

Therefore, I want to propose a straight forward feature for RST: Automatically generate "container" Message types for every RST which only holds an array of that type.

A short example:

• I create a new Message type Z and add it to the RST sandbox
• When building RST, an additional Message of type Zs is created which simply holds an array of Z RSTs
• In my software I create multiple Messages of type Z which I append to the generated Message of type Zs
• Once I am done for a certain set, I send the Message of type Zs
• Receiving parties can directly access the semantically/chronologically related information in Message Zs without the need to parse causes or investigate further on individual Z Messages