Apparently, there was no QP-trie implementation in Go. So, now there is: https://github.com/jedisct1/go-fpst … (a direct port of my FPST library, probably much slower than the C version, but we’ll see).
Using pointer tagging can be tricky, you need to manage your arena instead of using Go’s allocator. Not sure that prefetching is possible and would have any benefits either. I’m using a simple critbit for the time being; will work on a proper qptrie later.