Ah, I'm not use event kind for that. Each newsfeed define by user's contact list (default) or their follow/interest sets (NIP51). Lume just show its all into a single screen, and save the state when user close app into the local database, maybe save it into relay too with NIP78.
Discussion
So, I am going to start defining some type of Custom Feed event type.
nostr:nprofile1qqsf03c2gsmx5ef4c9zmxvlew04gdh7u94afnknp33qvv3c94kvwxgspz3mhxue69uhhyetvv9ujuerpd46hxtnfduq35amnwvaz7tmjv4kxz7fwwajhxar9wfhxyarr9e3k7mgprdmhxue69uhksmmyd33x7epwvdhhyctrd3jjuar0dak8x6lmt90 has his version below, but I find it too complicated with the union/diff/intersection stuff.
This is complicated by definition, but it would be nice to have a feed defined in Lume showing up on Amethyst.
as good a time as any to learn how to implement set operations
in Go i do them with for/range iterations and maps (which require mutexes because of concurrency)...
to be honest, a lot of C++ and other OOP programmers (java, rust) overemphasise the use of map/reduce operations, which are essentially set operations, but in my experience i need maybe one or two in a whole application and often this allows very specific implementations