In comments, start @ autocomplete sooner

[cellio]

meta:293672

When pinging a user in a comment, we start suggesting completions after three characters have been typed. The meta request is to start after 1 character.

I don't know the performance implications. If they're bad, we should decline this. With a single character there would be a lot more possible completions, except that it appears that we only consider users who've interacted with the post. I just typed @art in a comment where ArtOfCode had not participated, and I didn't get a suggested completion. If that is so, then it seems like offering suggestions after 1 character wouldn't be bad in most reasonable cases because the pool of candidates is still small. I haven't yet tested what we do today if AAA1, AAA2, AAA3... AAA20 have all participated in a thread. If we handle that, then I assume we could handle A1, A2...A20 the same way.

[Oaphi]

Given that our minimum length for usernames is 3 characters in the first place, it makes sense to trigger autocomplete sooner. Both performance and server load don't seem to be a concern here: we request the list of pingable users only once per thread, and all the processing is done client-side - it's not sophisticated either. Don't see any reason not to grant the request