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Bencode is a lightweight serialization protocol, with several interesting properties (I found a nice writeup on bencode here: http://jeelabs.org/2012/10/05/whats-the-deal-with-bencode/).

Usually, what you do to work with bencode is to go with https://bitbucket.org/wilhelmy/lua-bencode/ .

But, suppose you have the following scenario:

* You are reading rather big objects in the relation to the total memory you have. * You are receiving rather long strings, but the reading is made in tiny chunks (say, over a slow serial line). * You can process said chunks as they arrive, say, compute a CRC or feed it to load()

(Bear with my, this could happen)

In these cases a push-parser could be more adequate. There is a coroutine based example at http://jeelabs.org/2012/10/18/push-scannin-with-coroutines/, but it's blocking.

So I wrote mine own, available here:

https://github.com/xopxe/lua-bencode-push

Internally, it's a tail-call based state machine. It attempts to fiddle as little as possible with strings (no concatenations). It returns string in fragments as they arrive, signalling the end with an empty string. It also pushes the total string length prior to pushing the fragments, if you're interested in such a thing.

It misses any kind of error checks, and no encoder is provided (yet).

Greetings,

Jorge