I have a custom message with the following form that I would like to publish from the command line:

string type
float64[] trajectory
float64[] formation

When I publish other messages from the command line using rostopic pub, I can usually hit Tab after typing in the topic name, and the terminal will autocomplete the message type and give me a blank template message I can fill in. For example, when publishing a geometry_msgs/Twist command on the topic example_topic, I hit tab and this text is given to me by autocomplete:

$ rostopic pub -l /example_topic geometry_msgs/Twist "linear:
 x: 0.0
 y: 0.0
 z: 0.0
angular:
 x: 0.0
 y: 0.0
 z: 0.0" 

I can then go back and change the "0.0" values to what I want.

However, when I try this autocomplete message with my custom message above, autocomplete gives me this:

$ rostopic pub -l /example_custom_topic my_package/custom_message "type: ''
trajectory:
- 0
formation:
- 0"

To me, this is an ambiguous layout for the array fields. When I try to fill in the type field with 'circular' and the "0" fields with arrays such as [1.0, 2.0, ...], I get the error [WARN] [1556817030.775878]: Inbound TCP/IP connection failed: <class 'struct.error'>: 'required argument is not a float' when writing 'circular'.

How can I change the autocomplete output for my custom message to a different format that is clearer and works? For example, the format in this answer worked perfectly fine for me and is less ambiguous. It would be very nice to have autocomplete give me this different format.

$ rostopic pub -r 10 /example_topic my_package/custom_message "type: 'some_string'
   trajectory: [1.0, 2.0, 3.0]
   formation: [1.0, 2.0, 3.0]"

$ rostopic pub -r 10 /leader_cmd rcomv_r1/MSRPA "type: 'circle'
   trajectory: 
   [1.0, 2.0, 3.0]
   formation: 
   [1.0, 2.0, 3.0]"