Scala has a similar data structure https://www.scala-lang.org/api/2.13.6/scala/collection/immut.... Something was in the air in 2013.
I have always thought Hickeys main contribution was making it default in a coherent way, and proved it could be done. Before clojure most peoplle still thought immutable data structures were too I practical.
He took what was a research topic and made it standard. There were no other 5bit partitioned tries in (wide) use. I think he did that in a way that signals a fantastic sense of taste, and if you are implementing a programming language you need taste.
Scala got introduced in 2004, with the first Programming in Scala book, in 2008.
HN had plenty of PureScript and Elm.
FP finally was going to get their spotlight, and then mainstream languages got enough FP features to keep being the go to tooling.
I still don’t understand why they’re referred to as persistent vectors rather than immutable vectors, but I digress.
I believe that immutable just means, well, immutable, but persistent means that updates are achieved via structural sharing, so they’re efficient.
if you think immutable updates are O(n) in 2026, you're so far behind the curve it's laughable
it's crazy how many ppl i interview just stop thinking and insist you can't do better than O(n)
You wanted 2+1 to yield 3, but instead you get a runtime exception telling you that 2 can't be changed.
haskell too had them (IntMap honestly works fine in that use case)