Question: What was the reason this was never upstreamed?

[edahlseng]

I saw in the README that there was a JIRA issue for this concept in Clojure core many years ago until it was declined in 2016. Nevertheless, there don't appear to be any comments about why the issue was declined; is anyone able to share more context on that decision? I'm simply curious to know if there are any learnings that can come from that decision (e.g. other ways of approaching the problem).

[Engelberg]

Rich Hickey didn't feel the benefits warranted inclusion in the language.

The best alternative approach I've seen is described in this twitter thread: https://twitter.com/cgrand/status/1281529221651795969