how to make a callback based socket interface?

[Xavier Wang <weasley.wx@...>]

Hi dear list,

I'm thinking about net game programming in Lua, I have used luasocket
before, but it blocking in sending/receiving, I have a question, are
there callback based socket interface in Lua? e.g.

local s = socket.connect("www.google.com", 80)
s:send("GET /\r\n", function(e, chunk)
    print(e, chunk)
end)

that is to register a callback to interface, and when the send/receive
finished, the callback will called by interface.

Are there anyone have the same idea or some experience? Thank you :-)