Independently of anything else: Yes, you should learn Haskell :) If Go is more your speed, here's an implementation in Go: https://git.lukeshu.com/btrfs-progs-

Independently of anything else: Yes, you should learn Haskell :) If Go is more your speed, here's an implementation in Go: https://git.lukeshu.com/btrfs-progs-ng/tree/cmd/btrfs-rec/inspect/rebuildmappings/kmp.go https://git.lukeshu.com/btrfs-progs-ng/tree/cmd/btrfs-rec/in... (though it is slightly complicated by the fact that it allows 'substr' to include fixed-length wildcards).