Jamii I've seen your ocaml implementations, your code has been very instructive - thanks!

How do you manage in erlang without mutable arrays? It must be expensive to build it out of tuples.

atm I'm not doing live streaming so I can store & reload these from disk. I'm likely to end up using hipe_bifs:bitarray* or https://github.com/ferd/bitarray where those are not available, if needed. See http://erlang.org/pipermail/erlang-questions/2009-May/043485... for an example.