IRC library

[Fingercomp 37]

There was no IRC library for OpenComputers, so I've made one. Here's a demo bot that uses it:

local com = require("component")
local event = require("event")
local thread = require("thread")

local gpu = com.gpu

local irc = require("irc")
local events = irc.events

local env = setmetatable({
  irc = irc,
  events = events,
}, {__index = _G})

local client = irc.builder()
  :connection {
    host = "irc.esper.net:6667",
    throttling = {
      maxDelay = 2,
      maxThroughput = 5,
    },
  }
  :auth {
    nickname = "oc-finger-irc",
    username = "fingercomp",
    realname = "OpenComputers IRC client library",
  }
  :bot {
    channels = {"#oc-finger-irc"},
    tracking = {
      users = true,
      modes = true,
      account = true,
      userInfo = true,
    },
  }
  :execution {
    threaded = true,
    reconnect = true,
    catchErrors = true,
  }
  :subscribe(events.irc.command, events.priority.high, function(self, client, evt)
    gpu.setForeground(0x00ff00)
    print("→ " .. evt.rawLine)
    gpu.setForeground(0xffffff)
  end)
  :subscribe(events.irc.write, events.priority.normal, function(self, client, evt)
    gpu.setForeground(0x00dbff)
    print("← " .. evt.line:gsub("[\r\n]*$", ""))
    gpu.setForeground(0xffffff)
  end)
  :subscribe(events.irc.message, irc.events.priority.normal, function(self, client, evt)
    if evt.source.nickname == "fingercomp" then
      if evt.message == "::quit" then
        evt:reply("Quitting.")
        evt.client:stop(("%s told me to quit."):format(evt.source.nickname))
      elseif evt.message == "::spam" then
        evt:reply("1")
        evt:reply("2")
        evt:reply("3")
        evt:reply("4")
        evt:reply("5")
      elseif evt.message == "::longmsg" then
        local msg = {}
        for i = 1, 256 do
          if i == 128 then
            table.insert(msg, tostring(i) .. " ")
          else
            table.insert(msg, tostring(i))
          end
        end
        evt:reply(table.concat(msg))
      elseif evt.message == "::error" then
        (nil).test()
      elseif evt.message:sub(1, #"::exec ") == "::exec " then
        local code = evt.message:sub(#"::exec " + 1)

        local chunk, reason = load("return " .. code, "=irc", "t", env)

        if not chunk then
          chunk, reason = load(code, "=irc", "t", env)
        end

        if not chunk then
          evt:reply(("\x0304Error:\x0f %s"):format(reason))
        else
          local result = table.pack(xpcall(chunk, debug.traceback))
          local success = table.remove(result, 1)
          result.n = result.n - 1

          for i = 1, result.n, 1 do
            if type(result) ~= "string" and type(result) ~= "number" and
                type(result) ~= "boolean" and type(result) ~= "nil" then
              result[i] = tostring(result[i])
            else
              result[i] = ("%q"):format(result[i]):gsub("\\\n", "\n")
            end
          end

          if not success then
            evt:reply(("\x0304Error:\x0f %s"):format(result[1]:match("^[^\n]*")))

            io.stderr:write(("%s\r\n"):format(result[1]))
          elseif result.n > 0 then
            evt:reply(table.concat(result, "  ", i, result.n))
          else
            evt:reply("\x0309Success")
          end
        end
      end
    end
  end)
  :subscribe(events.irc.ctcpRequest, irc.events.priority.normal, function(self, client, evt)
    if evt.ctcpCommand == "TIME" then
      evt:reply(os.date("%F %T"))
    end
  end)
  :subscribe(events.client.error, irc.events.priority.top, function(self, client, evt)
    print("Caught: " .. evt.traceback)
    evt:cancel()
  end)
  :build()

local t = thread.create(function()
  repeat
    local evt = event.pull("interrupted")
  until evt
end)

env.client = client
client:run()

thread.waitForAny({t, client.thread})
client:stop("Quitting.")

os.exit()

I don't want to brag about it too much, but I think the code is pretty.

Features

• Threaded execution.
• A nice API.
• IRCv3.2 capability negotiation.
• Throttling to prevent the bot from triggering anti-flood mechanisms.
• Tracks channel members, modes, nick changes, account names, etc.
• Automatically reconnects if it's disconnected from the IRC server.
• Splits long messages over multiple lines.
• The event bus can use coroutines as message handlers.

Links

• The GitLab repository: https://gitlab.com/cc-ru/irc-oc
• Documentation: https://gitlab.com/cc-ru/irc-oc/-/wikis/home
• Demo programs: https://gitlab.com/cc-ru/irc-oc/snippets