handle QUIT messages

Prior to this commit ExIrc did not know what to do with QUIT messages,
which would result in nicks remaining in the `Channels` data structure
when they should not. This commit implements handling of the QUIT
message and ensures that the new `Channels.user_quit` function is called
to flush the departing user from all known channels.

Close #40

1 files changed, 10 insertions, 0 deletions

diff --git a/lib/exirc/channels.ex b/lib/exirc/channels.ex
index b7a6d4c..b108de9 100644
--- a/lib/exirc/channels.ex
+++ b/lib/exirc/channels.ex
@@ -118,6 +118,16 @@ defmodule ExIrc.Channels do
     users_manip(channel_tree, channel_name, manipfn)
   end
 
+  def user_quit(channel_tree, nick) do
+    pnick = strip_rank([nick])
+    manipfn = fn(channel_nicks) -> :lists.usort(channel_nicks -- pnick) end
+    foldl = fn(channel_name, new_channel_tree) ->
+      name = downcase(channel_name)
+      users_manip(new_channel_tree, name, manipfn)
+    end
+    :lists.foldl(foldl, channel_tree, channels(channel_tree))
+  end
+
   @doc """
   Update the nick of a user in a tracked channel when they change their nick
   """