How should overlapping subjects be handled?

[FragLegs]

When a Receiver adds a subject to a stream, it means that events that match that subject should get delivered on the stream. For most SimpleSubjects, this is an unambiguous mapping. But for Aliases and ComplexSubjects, things are a little less clear. What should happen if the values in the Aliases simple subject or in the ComplexSubject overlap? Here are some examples:

example 1 - overlapping Aliases

1. Receiver adds:

   {
   "format": "aliases",
   "identifiers": {
   {
     "format": "email",
     "email": "user@example.com"
   },
   {
     "format": "phone_number",
     "phone_number": "+12065550100"
   }
   }

2. Receiver adds

   {
   "format": "aliases",
   "identifiers": {
   {
     "format": "email",
     "email": "user@example.com"
   },
   {
     "format": "opaque",
     "id": "12345"
   }
   }

   When the Transmitter wants to broadcast an event whose subject is

   {
   "format": "email",
   "email": "user@example.com"
   }

   should it be sent to the Receiver twice?

example 2 - overlapping ComplexSubjects

1. Receiver adds:

   {
   "user": {
     "format": "email",
     "email": "user@example.com"
   },
   "device": {
     "format": "opaque",
     "id": "12345"
   }
   }

2. Receiver adds

   {
   "user": {
     "format": "email",
     "email": "user@example.com"
   },
   }

   When the Transmitter wants to broadcast an event whose subject is

   {
   "format": "email",
   "email": "user@example.com"
   }

   should it be sent to the Receiver twice?

[tulshi]

I remember discussing this issue, but I don't remember the outcome. I can't find anything in the notes either. @FragLegs can you please update the issue if you remember any previous discussion?

[FragLegs]

We talked about the issue of incomplete Complex Subjects, which has been addressed in PR #57 . I don't think we've talked about the issue of overlapping subjects yet though.

[tulshi]

I'm closing this issue based on your comment. If you think it still needs work, please reopen.