I learned a lot about what is possible to do with range functions, and I'm really excited for what they will bring to the language!
K-way merge has been a great playground for this, the range function API suits the use case very well.
I'm looking forward to try it in other scenarios, my next step would be to see the impact of using this code in https://github.com/parquet-go/parquet-go to merge parquet files.