proposal: net: export isDomainName

[chet]

I'd like to essentially re-open #2880 for consideration.

The motivating factor here is I have yet to find a good canonical piece of code which callers can leverage to validate an input name against RFC 1035. Searching around for such code yields a whole world of regexes people have come up with that don't fully implement the spec. net.isDomainName may not be perfect either (see: #17659), but it would do a better job that what I'm finding out there otherwise (and be faster).

The original issue got kicked around a lot and eventually closed, so I'm hoping for some feedback one way or the other this time around.

Thanks!

[bradfitz]

We definitely don't want to do this while all the questions from #17659 remain unanswered. Otherwise how would we document this function?

[chet]

@bradfitz Definitely. My main hope is a decision to this proposal can be made, one way or another. If a decision is made in favor of the proposal, I agree this needs to remain open until #17659 is resolved, and then go from there.

[rsc]

Putting this proposal on hold until at least #17659 is resolved.