I'm using the cl-irc library to connect to Slack, via the IRC gateway Slack provides.
However I'm getting the following error when I try to start the message loop with read-message-loop:
error while parsing arguments to DESTRUCTURING-BIND:
invalid number of elements in
("duncan_bayne" "Welcome" "to" "Slack" "IRC" "Gateway"
"server" "[email protected]")
to satisfy lambda list
(CL-IRC:NICKNAME CL-IRC::WELCOME-MESSAGE):
exactly 2 expected, but 8 found
[Condition of type SB-KERNEL::ARG-COUNT-ERROR]
...
Backtrace:
0: ((:METHOD CL-IRC::DEFAULT-HOOK (CL-IRC:IRC-RPL_WELCOME-MESSAGE)) #<CL-IRC:IRC-RPL_WELCOME-MESSAGE irc.tinyspeck.com RPL_WELCOME {1007FC6293}>) [fast-method]
1: ((:METHOD CL-IRC::APPLY-TO-HOOKS (T)) #<CL-IRC:IRC-RPL_WELCOME-MESSAGE irc.tinyspeck.com RPL_WELCOME {1007FC6293}>) [fast-method]
2: ((:METHOD CL-IRC:IRC-MESSAGE-EVENT (T CL-IRC:IRC-MESSAGE)) #<unavailable argument> #<CL-IRC:IRC-RPL_WELCOME-MESSAGE irc.tinyspeck.com RPL_WELCOME {1007FC6293}>) [fast-method]
3: ((:METHOD CL-IRC:READ-MESSAGE (CL-IRC:CONNECTION)) #<CL-IRC:CONNECTION myob.irc.slack.com {10068E8ED3}>) [fast-method]
4: ((:METHOD CL-IRC:READ-MESSAGE-LOOP (T)) #<CL-IRC:CONNECTION myob.irc.slack.com {10068E8ED3}>) [fast-method]
5: (SB-INT:SIMPLE-EVAL-IN-LEXENV (CL-IRC:READ-MESSAGE-LOOP *CONN*) #<NULL-LEXENV>)
6: (EVAL (CL-IRC:READ-MESSAGE-LOOP *CONN*))
While in the REPL I see:
UNHANDLED-EVENT:3672562852: RPL_MYINFO: irc.tinyspeck.com duncan_bayne "IRC-SLACK gateway"
I'm not sure what I'm doing wrong here; I'm fairly sure it's not my hooks, because the problem persists even if I disable them all.
Also, I can use the connection as expected - say, joining a channel and sending messages - provided I don't try to start the message loop.
At a guess, I'd say Slack is responding to connection with an unexpected message?
The fix as suggested by @jkilski is to modify cl-irc to accept the slightly unusual (but probably standards-compilant?) responses from Slack:
(in-package #:cl-irc)
(defmethod default-hook ((message irc-rpl_welcome-message))
(with-slots
(connection host user arguments)
message
(destructuring-bind
(nickname &rest welcome-message)
arguments
(setf (user connection)
(make-user connection
:nickname nickname
:hostname host
:username user)))))
(in-package #:irc)
(defmethod default-hook ((message irc-rpl_namreply-message))
(let* ((connection (connection message)))
(destructuring-bind
(nick chan-visibility channel &optional names)
(arguments message)
(declare (ignore nick))
(let ((channel (find-channel connection channel)))
(setf (visibility channel)
(or (second (assoc chan-visibility
'(("=" :public) ("*" :private) ("@" :secret))
:test #'string=))
:unknown))
(unless (has-mode-p channel 'namreply-in-progress)
(add-mode channel 'namreply-in-progress
(make-instance 'list-value-mode :value-type :user)))
(dolist (nickname (tokenize-string names))
(let ((user (find-or-make-user connection
(canonicalize-nickname connection
nickname))))
(unless (equal user (user connection))
(add-user connection user)
(add-user channel user))
(set-mode channel 'namreply-in-progress user)
(let* ((mode-char (getf (nick-prefixes connection)
(elt nickname 0)))
(mode-name (when mode-char
(mode-name-from-char connection
channel mode-char))))
(when mode-name
(if (has-mode-p channel mode-name)
(set-mode channel mode-name user)
(set-mode-value (add-mode channel mode-name
(make-mode connection
channel mode-name))
user))))))))))
I've applied to join the dev mailing list and will be submitting a patch shortly.