Remove embedded copy of Net::IMAP

This was actually causing problems to read IMAP data back.

2 files changed, 1 insertions, 3602 deletions

diff --git a/lib/feed2imap/imap.rb b/lib/feed2imap/imap.rb
index 4c54456..2e796f6 100644
--- a/lib/feed2imap/imap.rb
+++ b/lib/feed2imap/imap.rb
@@ -18,7 +18,7 @@ Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
 =end
 
 # Imap connection handling
-require 'feed2imap/rubyimap'
+require 'net/imap'
 begin
 require 'openssl'
 rescue LoadError
diff --git a/lib/feed2imap/rubyimap.rb b/lib/feed2imap/rubyimap.rb
deleted file mode 100644
index 43af035..0000000
--- a/lib/feed2imap/rubyimap.rb
+++ /dev/null
@@ -1,3601 +0,0 @@
-# File fetched from
-# http://svn.ruby-lang.org/cgi-bin/viewvc.cgi/trunk/lib/net/imap.rb?view=log
-# Current rev: 27336
-############################################################################
-#
-# = net/imap.rb
-#
-# Copyright (C) 2000  Shugo Maeda <shugo@ruby-lang.org>
-#
-# This library is distributed under the terms of the Ruby license.
-# You can freely distribute/modify this library.
-#
-# Documentation: Shugo Maeda, with RDoc conversion and overview by William
-# Webber.
-#
-# See Net::IMAP for documentation.
-#
-
-
-require "socket"
-require "monitor"
-require "digest/md5"
-require "strscan"
-begin
-  require "openssl"
-rescue LoadError
-end
-
-module Net
-
-  #
-  # Net::IMAP implements Internet Message Access Protocol (IMAP) client
-  # functionality.  The protocol is described in [IMAP].
-  #
-  # == IMAP Overview
-  #
-  # An IMAP client connects to a server, and then authenticates
-  # itself using either #authenticate() or #login().  Having
-  # authenticated itself, there is a range of commands
-  # available to it.  Most work with mailboxes, which may be
-  # arranged in an hierarchical namespace, and each of which
-  # contains zero or more messages.  How this is implemented on
-  # the server is implementation-dependent; on a UNIX server, it
-  # will frequently be implemented as a files in mailbox format
-  # within a hierarchy of directories.
-  #
-  # To work on the messages within a mailbox, the client must
-  # first select that mailbox, using either #select() or (for
-  # read-only access) #examine().  Once the client has successfully
-  # selected a mailbox, they enter _selected_ state, and that
-  # mailbox becomes the _current_ mailbox, on which mail-item
-  # related commands implicitly operate.
-  #
-  # Messages have two sorts of identifiers: message sequence
-  # numbers, and UIDs.
-  #
-  # Message sequence numbers number messages within a mail box
-  # from 1 up to the number of items in the mail box.  If new
-  # message arrives during a session, it receives a sequence
-  # number equal to the new size of the mail box.  If messages
-  # are expunged from the mailbox, remaining messages have their
-  # sequence numbers "shuffled down" to fill the gaps.
-  #
-  # UIDs, on the other hand, are permanently guaranteed not to
-  # identify another message within the same mailbox, even if
-  # the existing message is deleted.  UIDs are required to
-  # be assigned in ascending (but not necessarily sequential)
-  # order within a mailbox; this means that if a non-IMAP client
-  # rearranges the order of mailitems within a mailbox, the
-  # UIDs have to be reassigned.  An IMAP client cannot thus
-  # rearrange message orders.
-  #
-  # == Examples of Usage
-  #
-  # === List sender and subject of all recent messages in the default mailbox
-  #
-  #   imap = Net::IMAP.new('mail.example.com')
-  #   imap.authenticate('LOGIN', 'joe_user', 'joes_password')
-  #   imap.examine('INBOX')
-  #   imap.search(["RECENT"]).each do |message_id|
-  #     envelope = imap.fetch(message_id, "ENVELOPE")[0].attr["ENVELOPE"]
-  #     puts "#{envelope.from[0].name}: \t#{envelope.subject}"
-  #   end
-  #
-  # === Move all messages from April 2003 from "Mail/sent-mail" to "Mail/sent-apr03"
-  #
-  #   imap = Net::IMAP.new('mail.example.com')
-  #   imap.authenticate('LOGIN', 'joe_user', 'joes_password')
-  #   imap.select('Mail/sent-mail')
-  #   if not imap.list('Mail/', 'sent-apr03')
-  #     imap.create('Mail/sent-apr03')
-  #   end
-  #   imap.search(["BEFORE", "30-Apr-2003", "SINCE", "1-Apr-2003"]).each do |message_id|
-  #     imap.copy(message_id, "Mail/sent-apr03")
-  #     imap.store(message_id, "+FLAGS", [:Deleted])
-  #   end
-  #   imap.expunge
-  #
-  # == Thread Safety
-  #
-  # Net::IMAP supports concurrent threads. For example,
-  #
-  #   imap = Net::IMAP.new("imap.foo.net", "imap2")
-  #   imap.authenticate("cram-md5", "bar", "password")
-  #   imap.select("inbox")
-  #   fetch_thread = Thread.start { imap.fetch(1..-1, "UID") }
-  #   search_result = imap.search(["BODY", "hello"])
-  #   fetch_result = fetch_thread.value
-  #   imap.disconnect
-  #
-  # This script invokes the FETCH command and the SEARCH command concurrently.
-  #
-  # == Errors
-  #
-  # An IMAP server can send three different types of responses to indicate
-  # failure:
-  #
-  # NO:: the attempted command could not be successfully completed.  For
-  #      instance, the username/password used for logging in are incorrect;
-  #      the selected mailbox does not exists; etc.
-  #
-  # BAD:: the request from the client does not follow the server's
-  #       understanding of the IMAP protocol.  This includes attempting
-  #       commands from the wrong client state; for instance, attempting
-  #       to perform a SEARCH command without having SELECTed a current
-  #       mailbox.  It can also signal an internal server
-  #       failure (such as a disk crash) has occurred.
-  #
-  # BYE:: the server is saying goodbye.  This can be part of a normal
-  #       logout sequence, and can be used as part of a login sequence
-  #       to indicate that the server is (for some reason) unwilling
-  #       to accept our connection.  As a response to any other command,
-  #       it indicates either that the server is shutting down, or that
-  #       the server is timing out the client connection due to inactivity.
-  #
-  # These three error response are represented by the errors
-  # Net::IMAP::NoResponseError, Net::IMAP::BadResponseError, and
-  # Net::IMAP::ByeResponseError, all of which are subclasses of
-  # Net::IMAP::ResponseError.  Essentially, all methods that involve
-  # sending a request to the server can generate one of these errors.
-  # Only the most pertinent instances have been documented below.
-  #
-  # Because the IMAP class uses Sockets for communication, its methods
-  # are also susceptible to the various errors that can occur when
-  # working with sockets.  These are generally represented as
-  # Errno errors.  For instance, any method that involves sending a
-  # request to the server and/or receiving a response from it could
-  # raise an Errno::EPIPE error if the network connection unexpectedly
-  # goes down.  See the socket(7), ip(7), tcp(7), socket(2), connect(2),
-  # and associated man pages.
-  #
-  # Finally, a Net::IMAP::DataFormatError is thrown if low-level data
-  # is found to be in an incorrect format (for instance, when converting
-  # between UTF-8 and UTF-16), and Net::IMAP::ResponseParseError is
-  # thrown if a server response is non-parseable.
-  #
-  #
-  # == References
-  #
-  # [[IMAP]]
-  #    M. Crispin, "INTERNET MESSAGE ACCESS PROTOCOL - VERSION 4rev1",
-  #    RFC 2060, December 1996.  (Note: since obsoleted by RFC 3501)
-  #
-  # [[LANGUAGE-TAGS]]
-  #    Alvestrand, H., "Tags for the Identification of
-  #    Languages", RFC 1766, March 1995.
-  #
-  # [[MD5]]
-  #    Myers, J., and M. Rose, "The Content-MD5 Header Field", RFC
-  #    1864, October 1995.
-  #
-  # [[MIME-IMB]]
-  #    Freed, N., and N. Borenstein, "MIME (Multipurpose Internet
-  #    Mail Extensions) Part One: Format of Internet Message Bodies", RFC
-  #    2045, November 1996.
-  #
-  # [[RFC-822]]
-  #    Crocker, D., "Standard for the Format of ARPA Internet Text
-  #    Messages", STD 11, RFC 822, University of Delaware, August 1982.
-  #
-  # [[RFC-2087]]
-  #    Myers, J., "IMAP4 QUOTA extension", RFC 2087, January 1997.
-  #
-  # [[RFC-2086]]
-  #    Myers, J., "IMAP4 ACL extension", RFC 2086, January 1997.
-  #
-  # [[RFC-2195]]
-  #    Klensin, J., Catoe, R., and Krumviede, P., "IMAP/POP AUTHorize Extension
-  #    for Simple Challenge/Response", RFC 2195, September 1997.
-  #
-  # [[SORT-THREAD-EXT]]
-  #    Crispin, M., "INTERNET MESSAGE ACCESS PROTOCOL - SORT and THREAD
-  #    Extensions", draft-ietf-imapext-sort, May 2003.
-  #
-  # [[OSSL]]
-  #    http://www.openssl.org
-  #
-  # [[RSSL]]
-  #    http://savannah.gnu.org/projects/rubypki
-  #
-  # [[UTF7]]
-  #    Goldsmith, D. and Davis, M., "UTF-7: A Mail-Safe Transformation Format of
-  #    Unicode", RFC 2152, May 1997.
-  #
-  class IMAP
-    include MonitorMixin
-    if defined?(OpenSSL)
-      include OpenSSL
-      include SSL
-    end
-
-    #  Returns an initial greeting response from the server.
-    attr_reader :greeting
-
-    # Returns recorded untagged responses.  For example:
-    #
-    #   imap.select("inbox")
-    #   p imap.responses["EXISTS"][-1]
-    #   #=> 2
-    #   p imap.responses["UIDVALIDITY"][-1]
-    #   #=> 968263756
-    attr_reader :responses
-
-    # Returns all response handlers.
-    attr_reader :response_handlers
-
-    # The thread to receive exceptions.
-    attr_accessor :client_thread
-
-    # Flag indicating a message has been seen
-    SEEN = :Seen
-
-    # Flag indicating a message has been answered
-    ANSWERED = :Answered
-
-    # Flag indicating a message has been flagged for special or urgent
-    # attention
-    FLAGGED = :Flagged
-
-    # Flag indicating a message has been marked for deletion.  This
-    # will occur when the mailbox is closed or expunged.
-    DELETED = :Deleted
-
-    # Flag indicating a message is only a draft or work-in-progress version.
-    DRAFT = :Draft
-
-    # Flag indicating that the message is "recent", meaning that this
-    # session is the first session in which the client has been notified
-    # of this message.
-    RECENT = :Recent
-
-    # Flag indicating that a mailbox context name cannot contain
-    # children.
-    NOINFERIORS = :Noinferiors
-
-    # Flag indicating that a mailbox is not selected.
-    NOSELECT = :Noselect
-
-    # Flag indicating that a mailbox has been marked "interesting" by
-    # the server; this commonly indicates that the mailbox contains
-    # new messages.
-    MARKED = :Marked
-
-    # Flag indicating that the mailbox does not contains new messages.
-    UNMARKED = :Unmarked
-
-    # Returns the debug mode.
-    def self.debug
-      return @@debug
-    end
-
-    # Sets the debug mode.
-    def self.debug=(val)
-      return @@debug = val
-    end
-
-    # Returns the max number of flags interned to symbols.
-    def self.max_flag_count
-      return @@max_flag_count
-    end
-
-    # Sets the max number of flags interned to symbols.
-    def self.max_flag_count=(count)
-      @@max_flag_count = count
-    end
-
-    # Adds an authenticator for Net::IMAP#authenticate.  +auth_type+
-    # is the type of authentication this authenticator supports
-    # (for instance, "LOGIN").  The +authenticator+ is an object
-    # which defines a process() method to handle authentication with
-    # the server.  See Net::IMAP::LoginAuthenticator,
-    # Net::IMAP::CramMD5Authenticator, and Net::IMAP::DigestMD5Authenticator
-    # for examples.
-    #
-    #
-    # If +auth_type+ refers to an existing authenticator, it will be
-    # replaced by the new one.
-    def self.add_authenticator(auth_type, authenticator)
-      @@authenticators[auth_type] = authenticator
-    end
-
-    # Disconnects from the server.
-    def disconnect
-      begin
-        begin
-          # try to call SSL::SSLSocket#io.
-          @sock.io.shutdown
-        rescue NoMethodError
-          # @sock is not an SSL::SSLSocket.
-          @sock.shutdown
-        end
-      rescue Errno::ENOTCONN
-        # ignore `Errno::ENOTCONN: Socket is not connected' on some platforms.
-      end
-      @receiver_thread.join
-      @sock.close
-    end
-
-    # Returns true if disconnected from the server.
-    def disconnected?
-      return @sock.closed?
-    end
-
-    # Sends a CAPABILITY command, and returns an array of
-    # capabilities that the server supports.  Each capability
-    # is a string.  See [IMAP] for a list of possible
-    # capabilities.
-    #
-    # Note that the Net::IMAP class does not modify its
-    # behaviour according to the capabilities of the server;
-    # it is up to the user of the class to ensure that
-    # a certain capability is supported by a server before
-    # using it.
-    def capability
-      synchronize do
-        send_command("CAPABILITY")
-        return @responses.delete("CAPABILITY")[-1]
-      end
-    end
-
-    # Sends a NOOP command to the server. It does nothing.
-    def noop
-      send_command("NOOP")
-    end
-
-    # Sends a LOGOUT command to inform the server that the client is
-    # done with the connection.
-    def logout
-      send_command("LOGOUT")
-    end
-
-    # Sends a STARTTLS command to start TLS session.
-    def starttls(options = {}, verify = true)
-      send_command("STARTTLS") do |resp|
-        if resp.kind_of?(TaggedResponse) && resp.name == "OK"
-          begin
-            # for backward compatibility
-            certs = options.to_str
-            options = create_ssl_params(certs, verify)
-          rescue NoMethodError
-          end
-          start_tls_session(options)
-        end
-      end
-    end
-
-    # Sends an AUTHENTICATE command to authenticate the client.
-    # The +auth_type+ parameter is a string that represents
-    # the authentication mechanism to be used. Currently Net::IMAP
-    # supports authentication mechanisms:
-    #
-    #   LOGIN:: login using cleartext user and password.
-    #   CRAM-MD5:: login with cleartext user and encrypted password
-    #              (see [RFC-2195] for a full description).  This
-    #              mechanism requires that the server have the user's
-    #              password stored in clear-text password.
-    #
-    # For both these mechanisms, there should be two +args+: username
-    # and (cleartext) password.  A server may not support one or other
-    # of these mechanisms; check #capability() for a capability of
-    # the form "AUTH=LOGIN" or "AUTH=CRAM-MD5".
-    #
-    # Authentication is done using the appropriate authenticator object:
-    # see @@authenticators for more information on plugging in your own
-    # authenticator.
-    #
-    # For example:
-    #
-    #    imap.authenticate('LOGIN', user, password)
-    #
-    # A Net::IMAP::NoResponseError is raised if authentication fails.
-    def authenticate(auth_type, *args)
-      auth_type = auth_type.upcase
-      unless @@authenticators.has_key?(auth_type)
-        raise ArgumentError,
-          format('unknown auth type - "%s"', auth_type)
-      end
-      authenticator = @@authenticators[auth_type].new(*args)
-      send_command("AUTHENTICATE", auth_type) do |resp|
-        if resp.instance_of?(ContinuationRequest)
-          data = authenticator.process(resp.data.text.unpack("m")[0])
-          s = [data].pack("m").gsub(/\n/, "")
-          send_string_data(s)
-          put_string(CRLF)
-        end
-      end
-    end
-
-    # Sends a LOGIN command to identify the client and carries
-    # the plaintext +password+ authenticating this +user+.  Note
-    # that, unlike calling #authenticate() with an +auth_type+
-    # of "LOGIN", #login() does *not* use the login authenticator.
-    #
-    # A Net::IMAP::NoResponseError is raised if authentication fails.
-    def login(user, password)
-      send_command("LOGIN", user, password)
-    end
-
-    # Sends a SELECT command to select a +mailbox+ so that messages
-    # in the +mailbox+ can be accessed.
-    #
-    # After you have selected a mailbox, you may retrieve the
-    # number of items in that mailbox from @responses["EXISTS"][-1],
-    # and the number of recent messages from @responses["RECENT"][-1].
-    # Note that these values can change if new messages arrive
-    # during a session; see #add_response_handler() for a way of
-    # detecting this event.
-    #
-    # A Net::IMAP::NoResponseError is raised if the mailbox does not
-    # exist or is for some reason non-selectable.
-    def select(mailbox)
-      synchronize do
-        @responses.clear
-        send_command("SELECT", mailbox)
-      end
-    end
-
-    # Sends a EXAMINE command to select a +mailbox+ so that messages
-    # in the +mailbox+ can be accessed.  Behaves the same as #select(),
-    # except that the selected +mailbox+ is identified as read-only.
-    #
-    # A Net::IMAP::NoResponseError is raised if the mailbox does not
-    # exist or is for some reason non-examinable.
-    def examine(mailbox)
-      synchronize do
-        @responses.clear
-        send_command("EXAMINE", mailbox)
-      end
-    end
-
-    # Sends a CREATE command to create a new +mailbox+.
-    #
-    # A Net::IMAP::NoResponseError is raised if a mailbox with that name
-    # cannot be created.
-    def create(mailbox)
-      send_command("CREATE", mailbox)
-    end
-
-    # Sends a DELETE command to remove the +mailbox+.
-    #
-    # A Net::IMAP::NoResponseError is raised if a mailbox with that name
-    # cannot be deleted, either because it does not exist or because the
-    # client does not have permission to delete it.
-    def delete(mailbox)
-      send_command("DELETE", mailbox)
-    end
-
-    # Sends a RENAME command to change the name of the +mailbox+ to
-    # +newname+.
-    #
-    # A Net::IMAP::NoResponseError is raised if a mailbox with the
-    # name +mailbox+ cannot be renamed to +newname+ for whatever
-    # reason; for instance, because +mailbox+ does not exist, or
-    # because there is already a mailbox with the name +newname+.
-    def rename(mailbox, newname)
-      send_command("RENAME", mailbox, newname)
-    end
-
-    # Sends a SUBSCRIBE command to add the specified +mailbox+ name to
-    # the server's set of "active" or "subscribed" mailboxes as returned
-    # by #lsub().
-    #
-    # A Net::IMAP::NoResponseError is raised if +mailbox+ cannot be
-    # subscribed to, for instance because it does not exist.
-    def subscribe(mailbox)
-      send_command("SUBSCRIBE", mailbox)
-    end
-
-    # Sends a UNSUBSCRIBE command to remove the specified +mailbox+ name
-    # from the server's set of "active" or "subscribed" mailboxes.
-    #
-    # A Net::IMAP::NoResponseError is raised if +mailbox+ cannot be
-    # unsubscribed from, for instance because the client is not currently
-    # subscribed to it.
-    def unsubscribe(mailbox)
-      send_command("UNSUBSCRIBE", mailbox)
-    end
-
-    # Sends a LIST command, and returns a subset of names from
-    # the complete set of all names available to the client.
-    # +refname+ provides a context (for instance, a base directory
-    # in a directory-based mailbox hierarchy).  +mailbox+ specifies
-    # a mailbox or (via wildcards) mailboxes under that context.
-    # Two wildcards may be used in +mailbox+: '*', which matches
-    # all characters *including* the hierarchy delimiter (for instance,
-    # '/' on a UNIX-hosted directory-based mailbox hierarchy); and '%',
-    # which matches all characters *except* the hierarchy delimiter.
-    #
-    # If +refname+ is empty, +mailbox+ is used directly to determine
-    # which mailboxes to match.  If +mailbox+ is empty, the root
-    # name of +refname+ and the hierarchy delimiter are returned.
-    #
-    # The return value is an array of +Net::IMAP::MailboxList+. For example:
-    #
-    #   imap.create("foo/bar")
-    #   imap.create("foo/baz")
-    #   p imap.list("", "foo/%")
-    #   #=> [#<Net::IMAP::MailboxList attr=[:Noselect], delim="/", name="foo/">, \\
-    #        #<Net::IMAP::MailboxList attr=[:Noinferiors, :Marked], delim="/", name="foo/bar">, \\
-    #        #<Net::IMAP::MailboxList attr=[:Noinferiors], delim="/", name="foo/baz">]
-    def list(refname, mailbox)
-      synchronize do
-        send_command("LIST", refname, mailbox)
-        return @responses.delete("LIST")
-      end
-    end
-
-    # Sends the GETQUOTAROOT command along with specified +mailbox+.
-    # This command is generally available to both admin and user.
-    # If mailbox exists, returns an array containing objects of
-    # Net::IMAP::MailboxQuotaRoot and Net::IMAP::MailboxQuota.
-    def getquotaroot(mailbox)
-      synchronize do
-        send_command("GETQUOTAROOT", mailbox)
-        result = []
-        result.concat(@responses.delete("QUOTAROOT"))
-        result.concat(@responses.delete("QUOTA"))
-        return result
-      end
-    end
-
-    # Sends the GETQUOTA command along with specified +mailbox+.
-    # If this mailbox exists, then an array containing a
-    # Net::IMAP::MailboxQuota object is returned.  This
-    # command generally is only available to server admin.
-    def getquota(mailbox)
-      synchronize do
-        send_command("GETQUOTA", mailbox)
-        return @responses.delete("QUOTA")
-      end
-    end
-
-    # Sends a SETQUOTA command along with the specified +mailbox+ and
-    # +quota+.  If +quota+ is nil, then quota will be unset for that
-    # mailbox.  Typically one needs to be logged in as server admin
-    # for this to work.  The IMAP quota commands are described in
-    # [RFC-2087].
-    def setquota(mailbox, quota)
-      if quota.nil?
-        data = '()'
-      else
-        data = '(STORAGE ' + quota.to_s + ')'
-      end
-      send_command("SETQUOTA", mailbox, RawData.new(data))
-    end
-
-    # Sends the SETACL command along with +mailbox+, +user+ and the
-    # +rights+ that user is to have on that mailbox.  If +rights+ is nil,
-    # then that user will be stripped of any rights to that mailbox.
-    # The IMAP ACL commands are described in [RFC-2086].
-    def setacl(mailbox, user, rights)
-      if rights.nil?
-        send_command("SETACL", mailbox, user, "")
-      else
-        send_command("SETACL", mailbox, user, rights)
-      end
-    end
-
-    # Send the GETACL command along with specified +mailbox+.
-    # If this mailbox exists, an array containing objects of
-    # Net::IMAP::MailboxACLItem will be returned.
-    def getacl(mailbox)
-      synchronize do
-        send_command("GETACL", mailbox)
-        return @responses.delete("ACL")[-1]
-      end
-    end
-
-    # Sends a LSUB command, and returns a subset of names from the set
-    # of names that the user has declared as being "active" or
-    # "subscribed".  +refname+ and +mailbox+ are interpreted as
-    # for #list().
-    # The return value is an array of +Net::IMAP::MailboxList+.
-    def lsub(refname, mailbox)
-      synchronize do
-        send_command("LSUB", refname, mailbox)
-        return @responses.delete("LSUB")
-      end
-    end
-
-    # Sends a STATUS command, and returns the status of the indicated
-    # +mailbox+. +attr+ is a list of one or more attributes that
-    # we are request the status of.  Supported attributes include:
-    #
-    #   MESSAGES:: the number of messages in the mailbox.
-    #   RECENT:: the number of recent messages in the mailbox.
-    #   UNSEEN:: the number of unseen messages in the mailbox.
-    #
-    # The return value is a hash of attributes. For example:
-    #
-    #   p imap.status("inbox", ["MESSAGES", "RECENT"])
-    #   #=> {"RECENT"=>0, "MESSAGES"=>44}
-    #
-    # A Net::IMAP::NoResponseError is raised if status values
-    # for +mailbox+ cannot be returned, for instance because it
-    # does not exist.
-    def status(mailbox, attr)
-      synchronize do
-        send_command("STATUS", mailbox, attr)
-        return @responses.delete("STATUS")[-1].attr
-      end
-    end
-
-    # Sends a APPEND command to append the +message+ to the end of
-    # the +mailbox+. The optional +flags+ argument is an array of
-    # flags to initially passing to the new message.  The optional
-    # +date_time+ argument specifies the creation time to assign to the
-    # new message; it defaults to the current time.
-    # For example:
-    #
-    #   imap.append("inbox", <<EOF.gsub(/\n/, "\r\n"), [:Seen], Time.now)
-    #   Subject: hello
-    #   From: shugo@ruby-lang.org
-    #   To: shugo@ruby-lang.org
-    #
-    #   hello world
-    #   EOF
-    #
-    # A Net::IMAP::NoResponseError is raised if the mailbox does
-    # not exist (it is not created automatically), or if the flags,
-    # date_time, or message arguments contain errors.
-    def append(mailbox, message, flags = nil, date_time = nil)
-      args = []
-      if flags
-        args.push(flags)
-      end
-      args.push(date_time) if date_time
-      args.push(Literal.new(message))
-      send_command("APPEND", mailbox, *args)
-    end
-
-    # Sends a CHECK command to request a checkpoint of the currently
-    # selected mailbox.  This performs implementation-specific
-    # housekeeping, for instance, reconciling the mailbox's
-    # in-memory and on-disk state.
-    def check
-      send_command("CHECK")
-    end
-
-    # Sends a CLOSE command to close the currently selected mailbox.
-    # The CLOSE command permanently removes from the mailbox all
-    # messages that have the \Deleted flag set.
-    def close
-      send_command("CLOSE")
-    end
-
-    # Sends a EXPUNGE command to permanently remove from the currently
-    # selected mailbox all messages that have the \Deleted flag set.
-    def expunge
-      synchronize do
-        send_command("EXPUNGE")
-        return @responses.delete("EXPUNGE")
-      end
-    end
-
-    # Sends a SEARCH command to search the mailbox for messages that
-    # match the given searching criteria, and returns message sequence
-    # numbers.  +keys+ can either be a string holding the entire
-    # search string, or a single-dimension array of search keywords and
-    # arguments.  The following are some common search criteria;
-    # see [IMAP] section 6.4.4 for a full list.
-    #
-    # <message set>:: a set of message sequence numbers.  ',' indicates
-    #                 an interval, ':' indicates a range.  For instance,
-    #                 '2,10:12,15' means "2,10,11,12,15".
-    #
-    # BEFORE <date>:: messages with an internal date strictly before
-    #                 <date>.  The date argument has a format similar
-    #                 to 8-Aug-2002.
-    #
-    # BODY <string>:: messages that contain <string> within their body.
-    #
-    # CC <string>:: messages containing <string> in their CC field.
-    #
-    # FROM <string>:: messages that contain <string> in their FROM field.
-    #
-    # NEW:: messages with the \Recent, but not the \Seen, flag set.
-    #
-    # NOT <search-key>:: negate the following search key.
-    #
-    # OR <search-key> <search-key>:: "or" two search keys together.
-    #
-    # ON <date>:: messages with an internal date exactly equal to <date>,
-    #             which has a format similar to 8-Aug-2002.
-    #
-    # SINCE <date>:: messages with an internal date on or after <date>.
-    #
-    # SUBJECT <string>:: messages with <string> in their subject.
-    #
-    # TO <string>:: messages with <string> in their TO field.
-    #
-    # For example:
-    #
-    #   p imap.search(["SUBJECT", "hello", "NOT", "NEW"])
-    #   #=> [1, 6, 7, 8]
-    def search(keys, charset = nil)
-      return search_internal("SEARCH", keys, charset)
-    end
-
-    # As for #search(), but returns unique identifiers.
-    def uid_search(keys, charset = nil)
-      return search_internal("UID SEARCH", keys, charset)
-    end
-
-    # Sends a FETCH command to retrieve data associated with a message
-    # in the mailbox. The +set+ parameter is a number or an array of
-    # numbers or a Range object. The number is a message sequence
-    # number.  +attr+ is a list of attributes to fetch; see the
-    # documentation for Net::IMAP::FetchData for a list of valid
-    # attributes.
-    # The return value is an array of Net::IMAP::FetchData. For example:
-    #
-    #   p imap.fetch(6..8, "UID")
-    #   #=> [#<Net::IMAP::FetchData seqno=6, attr={"UID"=>98}>, \\
-    #        #<Net::IMAP::FetchData seqno=7, attr={"UID"=>99}>, \\
-    #        #<Net::IMAP::FetchData seqno=8, attr={"UID"=>100}>]
-    #   p imap.fetch(6, "BODY[HEADER.FIELDS (SUBJECT)]")
-    #   #=> [#<Net::IMAP::FetchData seqno=6, attr={"BODY[HEADER.FIELDS (SUBJECT)]"=>"Subject: test\r\n\r\n"}>]
-    #   data = imap.uid_fetch(98, ["RFC822.SIZE", "INTERNALDATE"])[0]
-    #   p data.seqno
-    #   #=> 6
-    #   p data.attr["RFC822.SIZE"]
-    #   #=> 611
-    #   p data.attr["INTERNALDATE"]
-    #   #=> "12-Oct-2000 22:40:59 +0900"
-    #   p data.attr["UID"]
-    #   #=> 98
-    def fetch(set, attr)
-      return fetch_internal("FETCH", set, attr)
-    end
-
-    # As for #fetch(), but +set+ contains unique identifiers.
-    def uid_fetch(set, attr)
-      return fetch_internal("UID FETCH", set, attr)
-    end
-
-    # Sends a STORE command to alter data associated with messages
-    # in the mailbox, in particular their flags. The +set+ parameter
-    # is a number or an array of numbers or a Range object. Each number
-    # is a message sequence number.  +attr+ is the name of a data item
-    # to store: 'FLAGS' means to replace the message's flag list
-    # with the provided one; '+FLAGS' means to add the provided flags;
-    # and '-FLAGS' means to remove them.  +flags+ is a list of flags.
-    #
-    # The return value is an array of Net::IMAP::FetchData. For example:
-    #
-    #   p imap.store(6..8, "+FLAGS", [:Deleted])
-    #   #=> [#<Net::IMAP::FetchData seqno=6, attr={"FLAGS"=>[:Seen, :Deleted]}>, \\
-    #        #<Net::IMAP::FetchData seqno=7, attr={"FLAGS"=>[:Seen, :Deleted]}>, \\
-    #        #<Net::IMAP::FetchData seqno=8, attr={"FLAGS"=>[:Seen, :Deleted]}>]
-    def store(set, attr, flags)
-      return store_internal("STORE", set, attr, flags)
-    end
-
-    # As for #store(), but +set+ contains unique identifiers.
-    def uid_store(set, attr, flags)
-      return store_internal("UID STORE", set, attr, flags)
-    end
-
-    # Sends a COPY command to copy the specified message(s) to the end
-    # of the specified destination +mailbox+. The +set+ parameter is
-    # a number or an array of numbers or a Range object. The number is
-    # a message sequence number.
-    def copy(set, mailbox)
-      copy_internal("COPY", set, mailbox)
-    end
-
-    # As for #copy(), but +set+ contains unique identifiers.
-    def uid_copy(set, mailbox)
-      copy_internal("UID COPY", set, mailbox)
-    end
-
-    # Sends a SORT command to sort messages in the mailbox.
-    # Returns an array of message sequence numbers. For example:
-    #
-    #   p imap.sort(["FROM"], ["ALL"], "US-ASCII")
-    #   #=> [1, 2, 3, 5, 6, 7, 8, 4, 9]
-    #   p imap.sort(["DATE"], ["SUBJECT", "hello"], "US-ASCII")
-    #   #=> [6, 7, 8, 1]
-    #
-    # See [SORT-THREAD-EXT] for more details.
-    def sort(sort_keys, search_keys, charset)
-      return sort_internal("SORT", sort_keys, search_keys, charset)
-    end
-
-    # As for #sort(), but returns an array of unique identifiers.
-    def uid_sort(sort_keys, search_keys, charset)
-      return sort_internal("UID SORT", sort_keys, search_keys, charset)
-    end
-
-    # Adds a response handler. For example, to detect when
-    # the server sends us a new EXISTS response (which normally
-    # indicates new messages being added to the mail box),
-    # you could add the following handler after selecting the
-    # mailbox.
-    #
-    #   imap.add_response_handler { |resp|
-    #     if resp.kind_of?(Net::IMAP::UntaggedResponse) and resp.name == "EXISTS"
-    #       puts "Mailbox now has #{resp.data} messages"
-    #     end
-    #   }
-    #
-    def add_response_handler(handler = Proc.new)
-      @response_handlers.push(handler)
-    end
-
-    # Removes the response handler.
-    def remove_response_handler(handler)
-      @response_handlers.delete(handler)
-    end
-
-    # As for #search(), but returns message sequence numbers in threaded
-    # format, as a Net::IMAP::ThreadMember tree.  The supported algorithms
-    # are:
-    #
-    # ORDEREDSUBJECT:: split into single-level threads according to subject,
-    #                  ordered by date.
-    # REFERENCES:: split into threads by parent/child relationships determined
-    #              by which message is a reply to which.
-    #
-    # Unlike #search(), +charset+ is a required argument.  US-ASCII
-    # and UTF-8 are sample values.
-    #
-    # See [SORT-THREAD-EXT] for more details.
-    def thread(algorithm, search_keys, charset)
-      return thread_internal("THREAD", algorithm, search_keys, charset)
-    end
-
-    # As for #thread(), but returns unique identifiers instead of
-    # message sequence numbers.
-    def uid_thread(algorithm, search_keys, charset)
-      return thread_internal("UID THREAD", algorithm, search_keys, charset)
-    end
-
-    # Sends an IDLE command that waits for notifications of new or expunged
-    # messages.  Yields responses from the server during the IDLE.
-    #
-    # Use #idle_done() to leave IDLE.
-    def idle(&response_handler)
-      raise LocalJumpError, "no block given" unless response_handler
-
-      response = nil
-
-      synchronize do
-        tag = Thread.current[:net_imap_tag] = generate_tag
-        put_string("#{tag} IDLE#{CRLF}")
-
-        begin
-          add_response_handler(response_handler)
-          @idle_done_cond = new_cond
-          @idle_done_cond.wait
-          @idle_done_cond = nil
-        ensure
-          remove_response_handler(response_handler)
-          put_string("DONE#{CRLF}")
-          response = get_tagged_response(tag, "IDLE")
-        end
-      end
-
-      return response
-    end
-
-    # Leaves IDLE.
-    def idle_done
-      synchronize do
-        if @idle_done_cond.nil?
-          raise Net::IMAP::Error, "not during IDLE"
-        end
-        @idle_done_cond.signal
-      end
-    end
-
-    # Decode a string from modified UTF-7 format to UTF-8.
-    #
-    # UTF-7 is a 7-bit encoding of Unicode [UTF7].  IMAP uses a
-    # slightly modified version of this to encode mailbox names
-    # containing non-ASCII characters; see [IMAP] section 5.1.3.
-    #
-    # Net::IMAP does _not_ automatically encode and decode
-    # mailbox names to and from utf7.
-    def self.decode_utf7(s)
-      return s.gsub(/&(.*?)-/n) {
-        if $1.empty?
-          "&"
-        else
-          base64 = $1.tr(",", "/")
-          x = base64.length % 4
-          if x > 0
-            base64.concat("=" * (4 - x))
-          end
-          base64.unpack("m")[0].unpack("n*").pack("U*")
-        end
-      }.force_encoding("UTF-8")
-    end
-
-    # Encode a string from UTF-8 format to modified UTF-7.
-    def self.encode_utf7(s)
-      return s.gsub(/(&)|([^\x20-\x7e]+)/u) {
-        if $1
-          "&-"
-        else
-          base64 = [$&.unpack("U*").pack("n*")].pack("m")
-          "&" + base64.delete("=\n").tr("/", ",") + "-"
-        end
-      }.force_encoding("ASCII-8BIT")
-    end
-
-    # Formats +time+ as an IMAP-style date.
-    def self.format_date(time)
-      return time.strftime('%d-%b-%Y')
-    end
-
-    # Formats +time+ as an IMAP-style date-time.
-    def self.format_datetime(time)
-      return time.strftime('%d-%b-%Y %H:%M %z')
-    end
-
-    private
-
-    CRLF = "\r\n"      # :nodoc:
-    PORT = 143         # :nodoc:
-    SSL_PORT = 993   # :nodoc:
-
-    @@debug = false
-    @@authenticators = {}
-    @@max_flag_count = 10000
-
-    # call-seq:
-    #    Net::IMAP.new(host, options = {})
-    #
-    # Creates a new Net::IMAP object and connects it to the specified
-    # +host+.
-    #
-    # +options+ is an option hash, each key of which is a symbol.
-    #
-    # The available options are:
-    #
-    # port::  port number (default value is 143 for imap, or 993 for imaps)
-    # ssl::   if options[:ssl] is true, then an attempt will be made
-    #         to use SSL (now TLS) to connect to the server.  For this to work
-    #         OpenSSL [OSSL] and the Ruby OpenSSL [RSSL] extensions need to
-    #         be installed.
-    #         if options[:ssl] is a hash, it's passed to
-    #         OpenSSL::SSL::SSLContext#set_params as parameters.
-    #
-    # The most common errors are:
-    #
-    # Errno::ECONNREFUSED:: connection refused by +host+ or an intervening
-    #                       firewall.
-    # Errno::ETIMEDOUT:: connection timed out (possibly due to packets
-    #                    being dropped by an intervening firewall).
-    # Errno::ENETUNREACH:: there is no route to that network.
-    # SocketError:: hostname not known or other socket error.
-    # Net::IMAP::ByeResponseError:: we connected to the host, but they
-    #                               immediately said goodbye to us.
-    def initialize(host, port_or_options = {},
-                   usessl = false, certs = nil, verify = true)
-      super()
-      @host = host
-      begin
-        options = port_or_options.to_hash
-      rescue NoMethodError
-        # for backward compatibility
-        options = {}
-        options[:port] = port_or_options
-        if usessl
-          options[:ssl] = create_ssl_params(certs, verify)
-        end
-      end
-      @port = options[:port] || (options[:ssl] ? SSL_PORT : PORT)
-      @tag_prefix = "RUBY"
-      @tagno = 0
-      @parser = ResponseParser.new
-      @sock = TCPSocket.open(@host, @port)
-      if options[:ssl]
-        start_tls_session(options[:ssl])
-        @usessl = true
-      else
-        @usessl = false
-      end
-      @responses = Hash.new([].freeze)
-      @tagged_responses = {}
-      @response_handlers = []
-      @tagged_response_arrival = new_cond
-      @continuation_request_arrival = new_cond
-      @idle_done_cond = nil
-      @logout_command_tag = nil
-      @debug_output_bol = true
-      @exception = nil
-
-      @greeting = get_response
-      if @greeting.name == "BYE"
-        @sock.close
-        raise ByeResponseError, @greeting
-      end
-
-      @client_thread = Thread.current
-      @receiver_thread = Thread.start {
-        receive_responses
-      }
-    end
-
-    def receive_responses
-      connection_closed = false
-      until connection_closed
-        synchronize do
-          @exception = nil
-        end
-        begin
-          resp = get_response
-        rescue Exception => e
-          synchronize do
-            @sock.close
-            @exception = e
-          end
-          break
-        end
-        unless resp
-          synchronize do
-            @exception = EOFError.new("end of file reached")
-          end
-          break
-        end
-        begin
-          synchronize do
-            case resp
-            when TaggedResponse
-              @tagged_responses[resp.tag] = resp
-              @tagged_response_arrival.broadcast
-              if resp.tag == @logout_command_tag
-                return
-              end
-            when UntaggedResponse
-              record_response(resp.name, resp.data)
-              if resp.data.instance_of?(ResponseText) &&
-                  (code = resp.data.code)
-                record_response(code.name, code.data)
-              end
-              if resp.name == "BYE" && @logout_command_tag.nil?
-                @sock.close
-                @exception = ByeResponseError.new(resp)
-                connection_closed = true
-              end
-            when ContinuationRequest
-              @continuation_request_arrival.signal
-            end
-            @response_handlers.each do |handler|
-              handler.call(resp)
-            end
-          end
-        rescue Exception => e
-          @exception = e
-          synchronize do
-            @tagged_response_arrival.broadcast
-            @continuation_request_arrival.broadcast
-          end
-        end
-      end
-      synchronize do
-        @tagged_response_arrival.broadcast
-        @continuation_request_arrival.broadcast
-      end
-    end
-
-    def get_tagged_response(tag, cmd)
-      until @tagged_responses.key?(tag)
-        raise @exception if @exception
-        @tagged_response_arrival.wait
-      end
-      resp = @tagged_responses.delete(tag)
-      case resp.name
-      when /\A(?:NO)\z/ni
-        raise NoResponseError, resp
-      when /\A(?:BAD)\z/ni
-        raise BadResponseError, resp
-      else
-        return resp
-      end
-    end
-
-    def get_response
-      buff = ""
-      while true
-        s = @sock.gets(CRLF)
-        break unless s
-        buff.concat(s)
-        if /\{(\d+)\}\r\n/n =~ s
-          s = @sock.read($1.to_i)
-          buff.concat(s)
-        else
-          break
-        end
-      end
-      return nil if buff.length == 0
-      if @@debug
-        $stderr.print(buff.gsub(/^/n, "S: "))
-      end
-      return @parser.parse(buff)
-    end
-
-    def record_response(name, data)
-      unless @responses.has_key?(name)
-        @responses[name] = []
-      end
-      @responses[name].push(data)
-    end
-
-    def send_command(cmd, *args, &block)
-      synchronize do
-        args.each do |i|
-          validate_data(i)
-        end
-        tag = generate_tag
-        put_string(tag + " " + cmd)
-        args.each do |i|
-          put_string(" ")
-          send_data(i)
-        end
-        put_string(CRLF)
-        if cmd == "LOGOUT"
-          @logout_command_tag = tag
-        end
-        if block
-          add_response_handler(block)
-        end
-        begin
-          return get_tagged_response(tag, cmd)
-        ensure
-          if block
-            remove_response_handler(block)
-          end
-        end
-      end
-    end
-
-    def generate_tag
-      @tagno += 1
-      return format("%s%04d", @tag_prefix, @tagno)
-    end
-
-    def put_string(str)
-      @sock.print(str)
-      if @@debug
-        if @debug_output_bol
-          $stderr.print("C: ")
-        end
-        $stderr.print(str.gsub(/\n(?!\z)/n, "\nC: "))
-        if /\r\n\z/n.match(str)
-          @debug_output_bol = true
-        else
-          @debug_output_bol = false
-        end
-      end
-    end
-
-    def validate_data(data)
-      case data
-      when nil
-      when String
-      when Integer
-        if data < 0 || data >= 4294967296
-          raise DataFormatError, num.to_s
-        end
-      when Array
-        data.each do |i|
-          validate_data(i)
-        end
-      when Time
-      when Symbol
-      else
-        data.validate
-      end
-    end
-
-    def send_data(data)
-      case data
-      when nil
-        put_string("NIL")
-      when String
-        send_string_data(data)
-      when Integer
-        send_number_data(data)
-      when Array
-        send_list_data(data)
-      when Time
-        send_time_data(data)
-      when Symbol
-        send_symbol_data(data)
-      else
-        data.send_data(self)
-      end
-    end
-
-    def send_string_data(str)
-      case str
-      when ""
-        put_string('""')
-      when /[\x80-\xff\r\n]/n
-        # literal
-        send_literal(str)
-      when /[(){ \x00-\x1f\x7f%*"\\]/n
-        # quoted string
-        send_quoted_string(str)
-      else
-        put_string(str)
-      end
-    end
-
-    def send_quoted_string(str)
-      put_string('"' + str.gsub(/["\\]/n, "\\\\\\&") + '"')
-    end
-
-    def send_literal(str)
-      put_string("{" + str.length.to_s + "}" + CRLF)
-      @continuation_request_arrival.wait
-      raise @exception if @exception
-      put_string(str)
-    end
-
-    def send_number_data(num)
-      put_string(num.to_s)
-    end
-
-    def send_list_data(list)
-      put_string("(")
-      first = true
-      list.each do |i|
-        if first
-          first = false
-        else
-          put_string(" ")
-        end
-        send_data(i)
-      end
-      put_string(")")
-    end
-
-    DATE_MONTH = %w(Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec)
-
-    def send_time_data(time)
-      t = time.dup.gmtime
-      s = format('"%2d-%3s-%4d %02d:%02d:%02d +0000"',
-                 t.day, DATE_MONTH[t.month - 1], t.year,
-                 t.hour, t.min, t.sec)
-      put_string(s)
-    end
-
-    def send_symbol_data(symbol)
-      put_string("\\" + symbol.to_s)
-    end
-
-    def search_internal(cmd, keys, charset)
-      if keys.instance_of?(String)
-        keys = [RawData.new(keys)]
-      else
-        normalize_searching_criteria(keys)
-      end
-      synchronize do
-        if charset
-          send_command(cmd, "CHARSET", charset, *keys)
-        else
-          send_command(cmd, *keys)
-        end
-        return @responses.delete("SEARCH")[-1]
-      end
-    end
-
-    def fetch_internal(cmd, set, attr)
-      if attr.instance_of?(String)
-        attr = RawData.new(attr)
-      end
-      synchronize do
-        @responses.delete("FETCH")
-        send_command(cmd, MessageSet.new(set), attr)
-        return @responses.delete("FETCH")
-      end
-    end
-
-    def store_internal(cmd, set, attr, flags)
-      if attr.instance_of?(String)
-        attr = RawData.new(attr)
-      end
-      synchronize do
-        @responses.delete("FETCH")
-        send_command(cmd, MessageSet.new(set), attr, flags)
-        return @responses.delete("FETCH")
-      end
-    end
-
-    def copy_internal(cmd, set, mailbox)
-      send_command(cmd, MessageSet.new(set), mailbox)
-    end
-
-    def sort_internal(cmd, sort_keys, search_keys, charset)
-      if search_keys.instance_of?(String)
-        search_keys = [RawData.new(search_keys)]
-      else
-        normalize_searching_criteria(search_keys)
-      end
-      normalize_searching_criteria(search_keys)
-      synchronize do
-        send_command(cmd, sort_keys, charset, *search_keys)
-        return @responses.delete("SORT")[-1]
-      end
-    end
-
-    def thread_internal(cmd, algorithm, search_keys, charset)
-      if search_keys.instance_of?(String)
-        search_keys = [RawData.new(search_keys)]
-      else
-        normalize_searching_criteria(search_keys)
-      end
-      normalize_searching_criteria(search_keys)
-      send_command(cmd, algorithm, charset, *search_keys)
-      return @responses.delete("THREAD")[-1]
-    end
-
-    def normalize_searching_criteria(keys)
-      keys.collect! do |i|
-        case i
-        when -1, Range, Array
-          MessageSet.new(i)
-        else
-          i
-        end
-      end
-    end
-
-    def create_ssl_params(certs = nil, verify = true)
-      params = {}
-      if certs
-        if File.file?(certs)
-          params[:ca_file] = certs
-        elsif File.directory?(certs)
-          params[:ca_path] = certs
-        end
-      end
-      if verify
-        params[:verify_mode] = VERIFY_PEER
-      else
-        params[:verify_mode] = VERIFY_NONE
-      end
-      return params
-    end
-
-    def start_tls_session(params = {})
-      unless defined?(OpenSSL)
-        raise "SSL extension not installed"
-      end
-      if @sock.kind_of?(OpenSSL::SSL::SSLSocket)
-        raise RuntimeError, "already using SSL"
-      end
-      begin
-        params = params.to_hash
-      rescue NoMethodError
-        params = {}
-      end
-      context = SSLContext.new
-      context.set_params(params)
-      if defined?(VerifyCallbackProc)
-        context.verify_callback = VerifyCallbackProc
-      end
-      @sock = SSLSocket.new(@sock, context)
-      @sock.sync_close = true
-      @sock.connect
-      if context.verify_mode != VERIFY_NONE
-        @sock.post_connection_check(@host)
-      end
-    end
-
-    class RawData # :nodoc:
-      def send_data(imap)
-        imap.send(:put_string, @data)
-      end
-
-      def validate
-      end
-
-      private
-
-      def initialize(data)
-        @data = data
-      end
-    end
-
-    class Atom # :nodoc:
-      def send_data(imap)
-        imap.send(:put_string, @data)
-      end
-
-      def validate
-      end
-
-      private
-
-      def initialize(data)
-        @data = data
-      end
-    end
-
-    class QuotedString # :nodoc:
-      def send_data(imap)
-        imap.send(:send_quoted_string, @data)
-      end
-
-      def validate
-      end
-
-      private
-
-      def initialize(data)
-        @data = data
-      end
-    end
-
-    class Literal # :nodoc:
-      def send_data(imap)
-        imap.send(:send_literal, @data)
-      end
-
-      def validate
-      end
-
-      private
-
-      def initialize(data)
-        @data = data
-      end
-    end
-
-    class MessageSet # :nodoc:
-      def send_data(imap)
-        imap.send(:put_string, format_internal(@data))
-      end
-
-      def validate
-        validate_internal(@data)
-      end
-
-      private
-
-      def initialize(data)
-        @data = data
-      end
-
-      def format_internal(data)
-        case data
-        when "*"
-          return data
-        when Integer
-          if data == -1
-            return "*"
-          else
-            return data.to_s
-          end
-        when Range
-          return format_internal(data.first) +
-            ":" + format_internal(data.last)
-        when Array
-          return data.collect {|i| format_internal(i)}.join(",")
-        when ThreadMember
-          return data.seqno.to_s +
-            ":" + data.children.collect {|i| format_internal(i).join(",")}
-        end
-      end
-
-      def validate_internal(data)
-        case data
-        when "*"
-        when Integer
-          ensure_nz_number(data)
-        when Range
-        when Array
-          data.each do |i|
-            validate_internal(i)
-          end
-        when ThreadMember
-          data.children.each do |i|
-            validate_internal(i)
-          end
-        else
-          raise DataFormatError, data.inspect
-        end
-      end
-
-      def ensure_nz_number(num)
-        if num < -1 || num == 0 || num >= 4294967296
-          msg = "nz_number must be non-zero unsigned 32-bit integer: " +
-                num.inspect
-          raise DataFormatError, msg
-        end
-      end
-    end
-
-    # Net::IMAP::ContinuationRequest represents command continuation requests.
-    #
-    # The command continuation request response is indicated by a "+" token
-    # instead of a tag.  This form of response indicates that the server is
-    # ready to accept the continuation of a command from the client.  The
-    # remainder of this response is a line of text.
-    #
-    #   continue_req    ::= "+" SPACE (resp_text / base64)
-    #
-    # ==== Fields:
-    #
-    # data:: Returns the data (Net::IMAP::ResponseText).
-    #
-    # raw_data:: Returns the raw data string.
-    ContinuationRequest = Struct.new(:data, :raw_data)
-
-    # Net::IMAP::UntaggedResponse represents untagged responses.
-    #
-    # Data transmitted by the server to the client and status responses
-    # that do not indicate command completion are prefixed with the token
-    # "*", and are called untagged responses.
-    #
-    #   response_data   ::= "*" SPACE (resp_cond_state / resp_cond_bye /
-    #                       mailbox_data / message_data / capability_data)
-    #
-    # ==== Fields:
-    #
-    # name:: Returns the name such as "FLAGS", "LIST", "FETCH"....
-    #
-    # data:: Returns the data such as an array of flag symbols,
-    #         a ((<Net::IMAP::MailboxList>)) object....
-    #
-    # raw_data:: Returns the raw data string.
-    UntaggedResponse = Struct.new(:name, :data, :raw_data)
-
-    # Net::IMAP::TaggedResponse represents tagged responses.
-    #
-    # The server completion result response indicates the success or
-    # failure of the operation.  It is tagged with the same tag as the
-    # client command which began the operation.
-    #
-    #   response_tagged ::= tag SPACE resp_cond_state CRLF
-    #
-    #   tag             ::= 1*<any ATOM_CHAR except "+">
-    #
-    #   resp_cond_state ::= ("OK" / "NO" / "BAD") SPACE resp_text
-    #
-    # ==== Fields:
-    #
-    # tag:: Returns the tag.
-    #
-    # name:: Returns the name. the name is one of "OK", "NO", "BAD".
-    #
-    # data:: Returns the data. See ((<Net::IMAP::ResponseText>)).
-    #
-    # raw_data:: Returns the raw data string.
-    #
-    TaggedResponse = Struct.new(:tag, :name, :data, :raw_data)
-
-    # Net::IMAP::ResponseText represents texts of responses.
-    # The text may be prefixed by the response code.
-    #
-    #   resp_text       ::= ["[" resp_text_code "]" SPACE] (text_mime2 / text)
-    #                       ;; text SHOULD NOT begin with "[" or "="
-    #
-    # ==== Fields:
-    #
-    # code:: Returns the response code. See ((<Net::IMAP::ResponseCode>)).
-    #
-    # text:: Returns the text.
-    #
-    ResponseText = Struct.new(:code, :text)
-
-    #
-    # Net::IMAP::ResponseCode represents response codes.
-    #
-    #   resp_text_code  ::= "ALERT" / "PARSE" /
-    #                       "PERMANENTFLAGS" SPACE "(" #(flag / "\*") ")" /
-    #                       "READ-ONLY" / "READ-WRITE" / "TRYCREATE" /
-    #                       "UIDVALIDITY" SPACE nz_number /
-    #                       "UNSEEN" SPACE nz_number /
-    #                       atom [SPACE 1*<any TEXT_CHAR except "]">]
-    #
-    # ==== Fields:
-    #
-    # name:: Returns the name such as "ALERT", "PERMANENTFLAGS", "UIDVALIDITY"....
-    #
-    # data:: Returns the data if it exists.
-    #
-    ResponseCode = Struct.new(:name, :data)
-
-    # Net::IMAP::MailboxList represents contents of the LIST response.
-    #
-    #   mailbox_list    ::= "(" #("\Marked" / "\Noinferiors" /
-    #                       "\Noselect" / "\Unmarked" / flag_extension) ")"
-    #                       SPACE (<"> QUOTED_CHAR <"> / nil) SPACE mailbox
-    #
-    # ==== Fields:
-    #
-    # attr:: Returns the name attributes. Each name attribute is a symbol
-    #        capitalized by String#capitalize, such as :Noselect (not :NoSelect).
-    #
-    # delim:: Returns the hierarchy delimiter
-    #
-    # name:: Returns the mailbox name.
-    #
-    MailboxList = Struct.new(:attr, :delim, :name)
-
-    # Net::IMAP::MailboxQuota represents contents of GETQUOTA response.
-    # This object can also be a response to GETQUOTAROOT.  In the syntax
-    # specification below, the delimiter used with the "#" construct is a
-    # single space (SPACE).
-    #
-    #    quota_list      ::= "(" #quota_resource ")"
-    #
-    #    quota_resource  ::= atom SPACE number SPACE number
-    #
-    #    quota_response  ::= "QUOTA" SPACE astring SPACE quota_list
-    #
-    # ==== Fields:
-    #
-    # mailbox:: The mailbox with the associated quota.
-    #
-    # usage:: Current storage usage of mailbox.
-    #
-    # quota:: Quota limit imposed on mailbox.
-    #
-    MailboxQuota = Struct.new(:mailbox, :usage, :quota)
-
-    # Net::IMAP::MailboxQuotaRoot represents part of the GETQUOTAROOT
-    # response. (GETQUOTAROOT can also return Net::IMAP::MailboxQuota.)
-    #
-    #    quotaroot_response ::= "QUOTAROOT" SPACE astring *(SPACE astring)
-    #
-    # ==== Fields:
-    #
-    # mailbox:: The mailbox with the associated quota.
-    #
-    # quotaroots:: Zero or more quotaroots that effect the quota on the
-    #              specified mailbox.
-    #
-    MailboxQuotaRoot = Struct.new(:mailbox, :quotaroots)
-
-    # Net::IMAP::MailboxACLItem represents response from GETACL.
-    #
-    #    acl_data        ::= "ACL" SPACE mailbox *(SPACE identifier SPACE rights)
-    #
-    #    identifier      ::= astring
-    #
-    #    rights          ::= astring
-    #
-    # ==== Fields:
-    #
-    # user:: Login name that has certain rights to the mailbox
-    #        that was specified with the getacl command.
-    #
-    # rights:: The access rights the indicated user has to the
-    #          mailbox.
-    #
-    MailboxACLItem = Struct.new(:user, :rights)
-
-    # Net::IMAP::StatusData represents contents of the STATUS response.
-    #
-    # ==== Fields:
-    #
-    # mailbox:: Returns the mailbox name.
-    #
-    # attr:: Returns a hash. Each key is one of "MESSAGES", "RECENT", "UIDNEXT",
-    #        "UIDVALIDITY", "UNSEEN". Each value is a number.
-    #
-    StatusData = Struct.new(:mailbox, :attr)
-
-    # Net::IMAP::FetchData represents contents of the FETCH response.
-    #
-    # ==== Fields:
-    #
-    # seqno:: Returns the message sequence number.
-    #         (Note: not the unique identifier, even for the UID command response.)
-    #
-    # attr:: Returns a hash. Each key is a data item name, and each value is
-    #        its value.
-    #
-    #        The current data items are:
-    #
-    #        [BODY]
-    #           A form of BODYSTRUCTURE without extension data.
-    #        [BODY[<section>]<<origin_octet>>]
-    #           A string expressing the body contents of the specified section.
-    #        [BODYSTRUCTURE]
-    #           An object that describes the [MIME-IMB] body structure of a message.
-    #           See Net::IMAP::BodyTypeBasic, Net::IMAP::BodyTypeText,
-    #           Net::IMAP::BodyTypeMessage, Net::IMAP::BodyTypeMultipart.
-    #        [ENVELOPE]
-    #           A Net::IMAP::Envelope object that describes the envelope
-    #           structure of a message.
-    #        [FLAGS]
-    #           A array of flag symbols that are set for this message. flag symbols
-    #           are capitalized by String#capitalize.
-    #        [INTERNALDATE]
-    #           A string representing the internal date of the message.
-    #        [RFC822]
-    #           Equivalent to BODY[].
-    #        [RFC822.HEADER]
-    #           Equivalent to BODY.PEEK[HEADER].
-    #        [RFC822.SIZE]
-    #           A number expressing the [RFC-822] size of the message.
-    #        [RFC822.TEXT]
-    #           Equivalent to BODY[TEXT].
-    #        [UID]
-    #           A number expressing the unique identifier of the message.
-    #
-    FetchData = Struct.new(:seqno, :attr)
-
-    # Net::IMAP::Envelope represents envelope structures of messages.
-    #
-    # ==== Fields:
-    #
-    # date:: Returns a string that represents the date.
-    #
-    # subject:: Returns a string that represents the subject.
-    #
-    # from:: Returns an array of Net::IMAP::Address that represents the from.
-    #
-    # sender:: Returns an array of Net::IMAP::Address that represents the sender.
-    #
-    # reply_to:: Returns an array of Net::IMAP::Address that represents the reply-to.
-    #
-    # to:: Returns an array of Net::IMAP::Address that represents the to.
-    #
-    # cc:: Returns an array of Net::IMAP::Address that represents the cc.
-    #
-    # bcc:: Returns an array of Net::IMAP::Address that represents the bcc.
-    #
-    # in_reply_to:: Returns a string that represents the in-reply-to.
-    #
-    # message_id:: Returns a string that represents the message-id.
-    #
-    Envelope = Struct.new(:date, :subject, :from, :sender, :reply_to,
-                          :to, :cc, :bcc, :in_reply_to, :message_id)
-
-    #
-    # Net::IMAP::Address represents electronic mail addresses.
-    #
-    # ==== Fields:
-    #
-    # name:: Returns the phrase from [RFC-822] mailbox.
-    #
-    # route:: Returns the route from [RFC-822] route-addr.
-    #
-    # mailbox:: nil indicates end of [RFC-822] group.
-    #           If non-nil and host is nil, returns [RFC-822] group name.
-    #           Otherwise, returns [RFC-822] local-part
-    #
-    # host:: nil indicates [RFC-822] group syntax.
-    #        Otherwise, returns [RFC-822] domain name.
-    #
-    Address = Struct.new(:name, :route, :mailbox, :host)
-
-    #
-    # Net::IMAP::ContentDisposition represents Content-Disposition fields.
-    #
-    # ==== Fields:
-    #
-    # dsp_type:: Returns the disposition type.
-    #
-    # param:: Returns a hash that represents parameters of the Content-Disposition
-    #         field.
-    #
-    ContentDisposition = Struct.new(:dsp_type, :param)
-
-    # Net::IMAP::ThreadMember represents a thread-node returned
-    # by Net::IMAP#thread
-    #
-    # ==== Fields:
-    #
-    # seqno:: The sequence number of this message.
-    #
-    # children:: an array of Net::IMAP::ThreadMember objects for mail
-    # items that are children of this in the thread.
-    #
-    ThreadMember = Struct.new(:seqno, :children)
-
-    # Net::IMAP::BodyTypeBasic represents basic body structures of messages.
-    #
-    # ==== Fields:
-    #
-    # media_type:: Returns the content media type name as defined in [MIME-IMB].
-    #
-    # subtype:: Returns the content subtype name as defined in [MIME-IMB].
-    #
-    # param:: Returns a hash that represents parameters as defined in [MIME-IMB].
-    #
-    # content_id:: Returns a string giving the content id as defined in [MIME-IMB].
-    #
-    # description:: Returns a string giving the content description as defined in
-    #               [MIME-IMB].
-    #
-    # encoding:: Returns a string giving the content transfer encoding as defined in
-    #            [MIME-IMB].
-    #
-    # size:: Returns a number giving the size of the body in octets.
-    #
-    # md5:: Returns a string giving the body MD5 value as defined in [MD5].
-    #
-    # disposition:: Returns a Net::IMAP::ContentDisposition object giving
-    #               the content disposition.
-    #
-    # language:: Returns a string or an array of strings giving the body
-    #            language value as defined in [LANGUAGE-TAGS].
-    #
-    # extension:: Returns extension data.
-    #
-    # multipart?:: Returns false.
-    #
-    class BodyTypeBasic < Struct.new(:media_type, :subtype,
-                                     :param, :content_id,
-                                     :description, :encoding, :size,
-                                     :md5, :disposition, :language,
-                                     :extension)
-      def multipart?
-        return false
-      end
-
-      # Obsolete: use +subtype+ instead.  Calling this will
-      # generate a warning message to +stderr+, then return
-      # the value of +subtype+.
-      def media_subtype
-        $stderr.printf("warning: media_subtype is obsolete.\n")
-        $stderr.printf("         use subtype instead.\n")
-        return subtype
-      end
-    end
-
-    # Net::IMAP::BodyTypeText represents TEXT body structures of messages.
-    #
-    # ==== Fields:
-    #
-    # lines:: Returns the size of the body in text lines.
-    #
-    # And Net::IMAP::BodyTypeText has all fields of Net::IMAP::BodyTypeBasic.
-    #
-    class BodyTypeText < Struct.new(:media_type, :subtype,
-                                    :param, :content_id,
-                                    :description, :encoding, :size,
-                                    :lines,
-                                    :md5, :disposition, :language,
-                                    :extension)
-      def multipart?
-        return false
-      end
-
-      # Obsolete: use +subtype+ instead.  Calling this will
-      # generate a warning message to +stderr+, then return
-      # the value of +subtype+.
-      def media_subtype
-        $stderr.printf("warning: media_subtype is obsolete.\n")
-        $stderr.printf("         use subtype instead.\n")
-        return subtype
-      end
-    end
-
-    # Net::IMAP::BodyTypeMessage represents MESSAGE/RFC822 body structures of messages.
-    #
-    # ==== Fields:
-    #
-    # envelope:: Returns a Net::IMAP::Envelope giving the envelope structure.
-    #
-    # body:: Returns an object giving the body structure.
-    #
-    # And Net::IMAP::BodyTypeMessage has all methods of Net::IMAP::BodyTypeText.
-    #
-    class BodyTypeMessage < Struct.new(:media_type, :subtype,
-                                       :param, :content_id,
-                                       :description, :encoding, :size,
-                                       :envelope, :body, :lines,
-                                       :md5, :disposition, :language,
-                                       :extension)
-      def multipart?
-        return false
-      end
-
-      # Obsolete: use +subtype+ instead.  Calling this will
-      # generate a warning message to +stderr+, then return
-      # the value of +subtype+.
-      def media_subtype
-        $stderr.printf("warning: media_subtype is obsolete.\n")
-        $stderr.printf("         use subtype instead.\n")
-        return subtype
-      end
-    end
-
-    # Net::IMAP::BodyTypeMultipart represents multipart body structures
-    # of messages.
-    #
-    # ==== Fields:
-    #
-    # media_type:: Returns the content media type name as defined in [MIME-IMB].
-    #
-    # subtype:: Returns the content subtype name as defined in [MIME-IMB].
-    #
-    # parts:: Returns multiple parts.
-    #
-    # param:: Returns a hash that represents parameters as defined in [MIME-IMB].
-    #
-    # disposition:: Returns a Net::IMAP::ContentDisposition object giving
-    #               the content disposition.
-    #
-    # language:: Returns a string or an array of strings giving the body
-    #            language value as defined in [LANGUAGE-TAGS].
-    #
-    # extension:: Returns extension data.
-    #
-    # multipart?:: Returns true.
-    #
-    class BodyTypeMultipart < Struct.new(:media_type, :subtype,
-                                         :parts,
-                                         :param, :disposition, :language,
-                                         :extension)
-      def multipart?
-        return true
-      end
-
-      # Obsolete: use +subtype+ instead.  Calling this will
-      # generate a warning message to +stderr+, then return
-      # the value of +subtype+.
-      def media_subtype
-        $stderr.printf("warning: media_subtype is obsolete.\n")
-        $stderr.printf("         use subtype instead.\n")
-        return subtype
-      end
-    end
-
-    class ResponseParser # :nodoc:
-      def initialize
-        @str = nil
-        @pos = nil
-        @lex_state = nil
-        @token = nil
-        @flag_symbols = {}
-      end
-
-      def parse(str)
-        @str = str
-        @pos = 0
-        @lex_state = EXPR_BEG
-        @token = nil
-        return response
-      end
-
-      private
-
-      EXPR_BEG          = :EXPR_BEG
-      EXPR_DATA         = :EXPR_DATA
-      EXPR_TEXT         = :EXPR_TEXT
-      EXPR_RTEXT        = :EXPR_RTEXT
-      EXPR_CTEXT        = :EXPR_CTEXT
-
-      T_SPACE   = :SPACE
-      T_NIL     = :NIL
-      T_NUMBER  = :NUMBER
-      T_ATOM    = :ATOM
-      T_QUOTED  = :QUOTED
-      T_LPAR    = :LPAR
-      T_RPAR    = :RPAR
-      T_BSLASH  = :BSLASH
-      T_STAR    = :STAR
-      T_LBRA    = :LBRA
-      T_RBRA    = :RBRA
-      T_LITERAL = :LITERAL
-      T_PLUS    = :PLUS
-      T_PERCENT = :PERCENT
-      T_CRLF    = :CRLF
-      T_EOF     = :EOF
-      T_TEXT    = :TEXT
-
-      BEG_REGEXP = /\G(?:\
-(?# 1:  SPACE   )( +)|\
-(?# 2:  NIL     )(NIL)(?=[\x80-\xff(){ \x00-\x1f\x7f%*"\\\[\]+])|\
-(?# 3:  NUMBER  )(\d+)(?=[\x80-\xff(){ \x00-\x1f\x7f%*"\\\[\]+])|\
-(?# 4:  ATOM    )([^\x80-\xff(){ \x00-\x1f\x7f%*"\\\[\]+]+)|\
-(?# 5:  QUOTED  )"((?:[^\x00\r\n"\\]|\\["\\])*)"|\
-(?# 6:  LPAR    )(\()|\
-(?# 7:  RPAR    )(\))|\
-(?# 8:  BSLASH  )(\\)|\
-(?# 9:  STAR    )(\*)|\
-(?# 10: LBRA    )(\[)|\
-(?# 11: RBRA    )(\])|\
-(?# 12: LITERAL )\{(\d+)\}\r\n|\
-(?# 13: PLUS    )(\+)|\
-(?# 14: PERCENT )(%)|\
-(?# 15: CRLF    )(\r\n)|\
-(?# 16: EOF     )(\z))/ni
-
-      DATA_REGEXP = /\G(?:\
-(?# 1:  SPACE   )( )|\
-(?# 2:  NIL     )(NIL)|\
-(?# 3:  NUMBER  )(\d+)|\
-(?# 4:  QUOTED  )"((?:[^\x00\r\n"\\]|\\["\\])*)"|\
-(?# 5:  LITERAL )\{(\d+)\}\r\n|\
-(?# 6:  LPAR    )(\()|\
-(?# 7:  RPAR    )(\)))/ni
-
-      TEXT_REGEXP = /\G(?:\
-(?# 1:  TEXT    )([^\x00\r\n]*))/ni
-
-      RTEXT_REGEXP = /\G(?:\
-(?# 1:  LBRA    )(\[)|\
-(?# 2:  TEXT    )([^\x00\r\n]*))/ni
-
-      CTEXT_REGEXP = /\G(?:\
-(?# 1:  TEXT    )([^\x00\r\n\]]*))/ni
-
-      Token = Struct.new(:symbol, :value)
-
-      def response
-        token = lookahead
-        case token.symbol
-        when T_PLUS
-          result = continue_req
-        when T_STAR
-          result = response_untagged
-        else
-          result = response_tagged
-        end
-        match(T_CRLF)
-        match(T_EOF)
-        return result
-      end
-
-      def continue_req
-        match(T_PLUS)
-        match(T_SPACE)
-        return ContinuationRequest.new(resp_text, @str)
-      end
-
-      def response_untagged
-        match(T_STAR)
-        match(T_SPACE)
-        token = lookahead
-        if token.symbol == T_NUMBER
-          return numeric_response
-        elsif token.symbol == T_ATOM
-          case token.value
-          when /\A(?:OK|NO|BAD|BYE|PREAUTH)\z/ni
-            return response_cond
-          when /\A(?:FLAGS)\z/ni
-            return flags_response
-          when /\A(?:LIST|LSUB)\z/ni
-            return list_response
-          when /\A(?:QUOTA)\z/ni
-            return getquota_response
-          when /\A(?:QUOTAROOT)\z/ni
-            return getquotaroot_response
-          when /\A(?:ACL)\z/ni
-            return getacl_response
-          when /\A(?:SEARCH|SORT)\z/ni
-            return search_response
-          when /\A(?:THREAD)\z/ni
-            return thread_response
-          when /\A(?:STATUS)\z/ni
-            return status_response
-          when /\A(?:CAPABILITY)\z/ni
-            return capability_response
-          else
-            return text_response
-          end
-        else
-          parse_error("unexpected token %s", token.symbol)
-        end
-      end
-
-      def response_tagged
-        tag = atom
-        match(T_SPACE)
-        token = match(T_ATOM)
-        name = token.value.upcase
-        match(T_SPACE)
-        return TaggedResponse.new(tag, name, resp_text, @str)
-      end
-
-      def response_cond
-        token = match(T_ATOM)
-        name = token.value.upcase
-        match(T_SPACE)
-        return UntaggedResponse.new(name, resp_text, @str)
-      end
-
-      def numeric_response
-        n = number
-        match(T_SPACE)
-        token = match(T_ATOM)
-        name = token.value.upcase
-        case name
-        when "EXISTS", "RECENT", "EXPUNGE"
-          return UntaggedResponse.new(name, n, @str)
-        when "FETCH"
-          shift_token
-          match(T_SPACE)
-          data = FetchData.new(n, msg_att)
-          return UntaggedResponse.new(name, data, @str)
-        end
-      end
-
-      def msg_att
-        match(T_LPAR)
-        attr = {}
-        while true
-          token = lookahead
-          case token.symbol
-          when T_RPAR
-            shift_token
-            break
-          when T_SPACE
-            shift_token
-            token = lookahead
-          end
-          case token.value
-          when /\A(?:ENVELOPE)\z/ni
-            name, val = envelope_data
-          when /\A(?:FLAGS)\z/ni
-            name, val = flags_data
-          when /\A(?:INTERNALDATE)\z/ni
-            name, val = internaldate_data
-          when /\A(?:RFC822(?:\.HEADER|\.TEXT)?)\z/ni
-            name, val = rfc822_text
-          when /\A(?:RFC822\.SIZE)\z/ni
-            name, val = rfc822_size
-          when /\A(?:BODY(?:STRUCTURE)?)\z/ni
-            name, val = body_data
-          when /\A(?:UID)\z/ni
-            name, val = uid_data
-          else
-            parse_error("unknown attribute `%s'", token.value)
-          end
-          attr[name] = val
-        end
-        return attr
-      end
-
-      def envelope_data
-        token = match(T_ATOM)
-        name = token.value.upcase
-        match(T_SPACE)
-        return name, envelope
-      end
-
-      def envelope
-        @lex_state = EXPR_DATA
-        token = lookahead
-        if token.symbol == T_NIL
-          shift_token
-          result = nil
-        else
-          match(T_LPAR)
-          date = nstring
-          match(T_SPACE)
-          subject = nstring
-          match(T_SPACE)
-          from = address_list
-          match(T_SPACE)
-          sender = address_list
-          match(T_SPACE)
-          reply_to = address_list
-          match(T_SPACE)
-          to = address_list
-          match(T_SPACE)
-          cc = address_list
-          match(T_SPACE)
-          bcc = address_list
-          match(T_SPACE)
-          in_reply_to = nstring
-          match(T_SPACE)
-          message_id = nstring
-          match(T_RPAR)
-          result = Envelope.new(date, subject, from, sender, reply_to,
-                                to, cc, bcc, in_reply_to, message_id)
-        end
-        @lex_state = EXPR_BEG
-        return result
-      end
-
-      def flags_data
-        token = match(T_ATOM)
-        name = token.value.upcase
-        match(T_SPACE)
-        return name, flag_list
-      end
-
-      def internaldate_data
-        token = match(T_ATOM)
-        name = token.value.upcase
-        match(T_SPACE)
-        token = match(T_QUOTED)
-        return name, token.value
-      end
-
-      def rfc822_text
-        token = match(T_ATOM)
-        name = token.value.upcase
-        match(T_SPACE)
-        return name, nstring
-      end
-
-      def rfc822_size
-        token = match(T_ATOM)
-        name = token.value.upcase
-        match(T_SPACE)
-        return name, number
-      end
-
-      def body_data
-        token = match(T_ATOM)
-        name = token.value.upcase
-        token = lookahead
-        if token.symbol == T_SPACE
-          shift_token
-          return name, body
-        end
-        name.concat(section)
-        token = lookahead
-        if token.symbol == T_ATOM
-          name.concat(token.value)
-          shift_token
-        end
-        match(T_SPACE)
-        data = nstring
-        return name, data
-      end
-
-      def body
-        @lex_state = EXPR_DATA
-        token = lookahead
-        if token.symbol == T_NIL
-          shift_token
-          result = nil
-        else
-          match(T_LPAR)
-          token = lookahead
-          if token.symbol == T_LPAR
-            result = body_type_mpart
-          else
-            result = body_type_1part
-          end
-          match(T_RPAR)
-        end
-        @lex_state = EXPR_BEG
-        return result
-      end
-
-      def body_type_1part
-        token = lookahead
-        case token.value
-        when /\A(?:TEXT)\z/ni
-          return body_type_text
-        when /\A(?:MESSAGE)\z/ni
-          return body_type_msg
-        else
-          return body_type_basic
-        end
-      end
-
-      def body_type_basic
-        mtype, msubtype = media_type
-        token = lookahead
-        if token.symbol == T_RPAR
-          return BodyTypeBasic.new(mtype, msubtype)
-        end
-        match(T_SPACE)
-        param, content_id, desc, enc, size = body_fields
-        md5, disposition, language, extension = body_ext_1part
-        return BodyTypeBasic.new(mtype, msubtype,
-                                 param, content_id,
-                                 desc, enc, size,
-                                 md5, disposition, language, extension)
-      end
-
-      def body_type_text
-        mtype, msubtype = media_type
-        match(T_SPACE)
-        param, content_id, desc, enc, size = body_fields
-        match(T_SPACE)
-        lines = number
-        md5, disposition, language, extension = body_ext_1part
-        return BodyTypeText.new(mtype, msubtype,
-                                param, content_id,
-                                desc, enc, size,
-                                lines,
-                                md5, disposition, language, extension)
-      end
-
-      def body_type_msg
-        mtype, msubtype = media_type
-        match(T_SPACE)
-        param, content_id, desc, enc, size = body_fields
-        match(T_SPACE)
-        env = envelope
-        match(T_SPACE)
-        b = body
-        match(T_SPACE)
-        lines = number
-        md5, disposition, language, extension = body_ext_1part
-        return BodyTypeMessage.new(mtype, msubtype,
-                                   param, content_id,
-                                   desc, enc, size,
-                                   env, b, lines,
-                                   md5, disposition, language, extension)
-      end
-
-      def body_type_mpart
-        parts = []
-        while true
-          token = lookahead
-          if token.symbol == T_SPACE
-            shift_token
-            break
-          end
-          parts.push(body)
-        end
-        mtype = "MULTIPART"
-        msubtype = case_insensitive_string
-        param, disposition, language, extension = body_ext_mpart
-        return BodyTypeMultipart.new(mtype, msubtype, parts,
-                                     param, disposition, language,
-                                     extension)
-      end
-
-      def media_type
-        mtype = case_insensitive_string
-        match(T_SPACE)
-        msubtype = case_insensitive_string
-        return mtype, msubtype
-      end
-
-      def body_fields
-        param = body_fld_param
-        match(T_SPACE)
-        content_id = nstring
-        match(T_SPACE)
-        desc = nstring
-        match(T_SPACE)
-        enc = case_insensitive_string
-        match(T_SPACE)
-        size = number
-        return param, content_id, desc, enc, size
-      end
-
-      def body_fld_param
-        token = lookahead
-        if token.symbol == T_NIL
-          shift_token
-          return nil
-        end
-        match(T_LPAR)
-        param = {}
-        while true
-          token = lookahead
-          case token.symbol
-          when T_RPAR
-            shift_token
-            break
-          when T_SPACE
-            shift_token
-          end
-          name = case_insensitive_string
-          match(T_SPACE)
-          val = string
-          param[name] = val
-        end
-        return param
-      end
-
-      def body_ext_1part
-        token = lookahead
-        if token.symbol == T_SPACE
-          shift_token
-        else
-          return nil
-        end
-        md5 = nstring
-
-        token = lookahead
-        if token.symbol == T_SPACE
-          shift_token
-        else
-          return md5
-        end
-        disposition = body_fld_dsp
-
-        token = lookahead
-        if token.symbol == T_SPACE
-          shift_token
-        else
-          return md5, disposition
-        end
-        language = body_fld_lang
-
-        token = lookahead
-        if token.symbol == T_SPACE
-          shift_token
-        else
-          return md5, disposition, language
-        end
-
-        extension = body_extensions
-        return md5, disposition, language, extension
-      end
-
-      def body_ext_mpart
-        token = lookahead
-        if token.symbol == T_SPACE
-          shift_token
-        else
-          return nil
-        end
-        param = body_fld_param
-
-        token = lookahead
-        if token.symbol == T_SPACE
-          shift_token
-        else
-          return param
-        end
-        disposition = body_fld_dsp
-        match(T_SPACE)
-        language = body_fld_lang
-
-        token = lookahead
-        if token.symbol == T_SPACE
-          shift_token
-        else
-          return param, disposition, language
-        end
-
-        extension = body_extensions
-        return param, disposition, language, extension
-      end
-
-      def body_fld_dsp
-        token = lookahead
-        if token.symbol == T_NIL
-          shift_token
-          return nil
-        end
-        match(T_LPAR)
-        dsp_type = case_insensitive_string
-        match(T_SPACE)
-        param = body_fld_param
-        match(T_RPAR)
-        return ContentDisposition.new(dsp_type, param)
-      end
-
-      def body_fld_lang
-        token = lookahead
-        if token.symbol == T_LPAR
-          shift_token
-          result = []
-          while true
-            token = lookahead
-            case token.symbol
-            when T_RPAR
-              shift_token
-              return result
-            when T_SPACE
-              shift_token
-            end
-            result.push(case_insensitive_string)
-          end
-        else
-          lang = nstring
-          if lang
-            return lang.upcase
-          else
-            return lang
-          end
-        end
-      end
-
-      def body_extensions
-        result = []
-        while true
-          token = lookahead
-          case token.symbol
-          when T_RPAR
-            return result
-          when T_SPACE
-            shift_token
-          end
-          result.push(body_extension)
-        end
-      end
-
-      def body_extension
-        token = lookahead
-        case token.symbol
-        when T_LPAR
-          shift_token
-          result = body_extensions
-          match(T_RPAR)
-          return result
-        when T_NUMBER
-          return number
-        else
-          return nstring
-        end
-      end
-
-      def section
-        str = ""
-        token = match(T_LBRA)
-        str.concat(token.value)
-        token = match(T_ATOM, T_NUMBER, T_RBRA)
-        if token.symbol == T_RBRA
-          str.concat(token.value)
-          return str
-        end
-        str.concat(token.value)
-        token = lookahead
-        if token.symbol == T_SPACE
-          shift_token
-          str.concat(token.value)
-          token = match(T_LPAR)
-          str.concat(token.value)
-          while true
-            token = lookahead
-            case token.symbol
-            when T_RPAR
-              str.concat(token.value)
-              shift_token
-              break
-            when T_SPACE
-              shift_token
-              str.concat(token.value)
-            end
-            str.concat(format_string(astring))
-          end
-        end
-        token = match(T_RBRA)
-        str.concat(token.value)
-        return str
-      end
-
-      def format_string(str)
-        case str
-        when ""
-          return '""'
-        when /[\x80-\xff\r\n]/n
-          # literal
-          return "{" + str.length.to_s + "}" + CRLF + str
-        when /[(){ \x00-\x1f\x7f%*"\\]/n
-          # quoted string
-          return '"' + str.gsub(/["\\]/n, "\\\\\\&") + '"'
-        else
-          # atom
-          return str
-        end
-      end
-
-      def uid_data
-        token = match(T_ATOM)
-        name = token.value.upcase
-        match(T_SPACE)
-        return name, number
-      end
-
-      def text_response
-        token = match(T_ATOM)
-        name = token.value.upcase
-        match(T_SPACE)
-        @lex_state = EXPR_TEXT
-        token = match(T_TEXT)
-        @lex_state = EXPR_BEG
-        return UntaggedResponse.new(name, token.value)
-      end
-
-      def flags_response
-        token = match(T_ATOM)
-        name = token.value.upcase
-        match(T_SPACE)
-        return UntaggedResponse.new(name, flag_list, @str)
-      end
-
-      def list_response
-        token = match(T_ATOM)
-        name = token.value.upcase
-        match(T_SPACE)
-        return UntaggedResponse.new(name, mailbox_list, @str)
-      end
-
-      def mailbox_list
-        attr = flag_list
-        match(T_SPACE)
-        token = match(T_QUOTED, T_NIL)
-        if token.symbol == T_NIL
-          delim = nil
-        else
-          delim = token.value
-        end
-        match(T_SPACE)
-        name = astring
-        return MailboxList.new(attr, delim, name)
-      end
-
-      def getquota_response
-        # If quota never established, get back
-        # `NO Quota root does not exist'.
-        # If quota removed, get `()' after the
-        # folder spec with no mention of `STORAGE'.
-        token = match(T_ATOM)
-        name = token.value.upcase
-        match(T_SPACE)
-        mailbox = astring
-        match(T_SPACE)
-        match(T_LPAR)
-        token = lookahead
-        case token.symbol
-        when T_RPAR
-          shift_token
-          data = MailboxQuota.new(mailbox, nil, nil)
-          return UntaggedResponse.new(name, data, @str)
-        when T_ATOM
-          shift_token
-          match(T_SPACE)
-          token = match(T_NUMBER)
-          usage = token.value
-          match(T_SPACE)
-          token = match(T_NUMBER)
-          quota = token.value
-          match(T_RPAR)
-          data = MailboxQuota.new(mailbox, usage, quota)
-          return UntaggedResponse.new(name, data, @str)
-        else
-          parse_error("unexpected token %s", token.symbol)
-        end
-      end
-
-      def getquotaroot_response
-        # Similar to getquota, but only admin can use getquota.
-        token = match(T_ATOM)
-        name = token.value.upcase
-        match(T_SPACE)
-        mailbox = astring
-        quotaroots = []
-        while true
-          token = lookahead
-          break unless token.symbol == T_SPACE
-          shift_token
-          quotaroots.push(astring)
-        end
-        data = MailboxQuotaRoot.new(mailbox, quotaroots)
-        return UntaggedResponse.new(name, data, @str)
-      end
-
-      def getacl_response
-        token = match(T_ATOM)
-        name = token.value.upcase
-        match(T_SPACE)
-        mailbox = astring
-        data = []
-        token = lookahead
-        if token.symbol == T_SPACE
-          shift_token
-          while true
-            token = lookahead
-            case token.symbol
-            when T_CRLF
-              break
-            when T_SPACE
-              shift_token
-            end
-            user = astring
-            match(T_SPACE)
-            rights = astring
-            ##XXX data.push([user, rights])
-            data.push(MailboxACLItem.new(user, rights))
-          end
-        end
-        return UntaggedResponse.new(name, data, @str)
-      end
-
-      def search_response
-        token = match(T_ATOM)
-        name = token.value.upcase
-        token = lookahead
-        if token.symbol == T_SPACE
-          shift_token
-          data = []
-          while true
-            token = lookahead
-            case token.symbol
-            when T_CRLF
-              break
-            when T_SPACE
-              shift_token
-            end
-            data.push(number)
-          end
-        else
-          data = []
-        end
-        return UntaggedResponse.new(name, data, @str)
-      end
-
-      def thread_response
-        token = match(T_ATOM)
-        name = token.value.upcase
-        token = lookahead
-
-        if token.symbol == T_SPACE
-          threads = []
-
-          while true
-            shift_token
-            token = lookahead
-
-            case token.symbol
-            when T_LPAR
-              threads << thread_branch(token)
-            when T_CRLF
-              break
-            end
-          end
-        else
-          # no member
-          threads = []
-        end
-
-        return UntaggedResponse.new(name, threads, @str)
-      end
-
-      def thread_branch(token)
-        rootmember = nil
-        lastmember = nil
-
-        while true
-          shift_token    # ignore first T_LPAR
-          token = lookahead
-
-          case token.symbol
-          when T_NUMBER
-            # new member
-            newmember = ThreadMember.new(number, [])
-            if rootmember.nil?
-              rootmember = newmember
-            else
-              lastmember.children << newmember
-            end
-            lastmember = newmember
-          when T_SPACE
-            # do nothing
-          when T_LPAR
-            if rootmember.nil?
-              # dummy member
-              lastmember = rootmember = ThreadMember.new(nil, [])
-            end
-
-            lastmember.children << thread_branch(token)
-          when T_RPAR
-            break
-          end
-        end
-
-        return rootmember
-      end
-
-      def status_response
-        token = match(T_ATOM)
-        name = token.value.upcase
-        match(T_SPACE)
-        mailbox = astring
-        match(T_SPACE)
-        match(T_LPAR)
-        attr = {}
-        while true
-          token = lookahead
-          case token.symbol
-          when T_RPAR
-            shift_token
-            break
-          when T_SPACE
-            shift_token
-          end
-          token = match(T_ATOM)
-          key = token.value.upcase
-          match(T_SPACE)
-          val = number
-          attr[key] = val
-        end
-        data = StatusData.new(mailbox, attr)
-        return UntaggedResponse.new(name, data, @str)
-      end
-
-      def capability_response
-        token = match(T_ATOM)
-        name = token.value.upcase
-        match(T_SPACE)
-        data = []
-        while true
-          token = lookahead
-          case token.symbol
-          when T_CRLF
-            break
-          when T_SPACE
-            shift_token
-          end
-          data.push(atom.upcase)
-        end
-        return UntaggedResponse.new(name, data, @str)
-      end
-
-      def resp_text
-        @lex_state = EXPR_RTEXT
-        token = lookahead
-        if token.symbol == T_LBRA
-          code = resp_text_code
-        else
-          code = nil
-        end
-        token = match(T_TEXT)
-        @lex_state = EXPR_BEG
-        return ResponseText.new(code, token.value)
-      end
-
-      def resp_text_code
-        @lex_state = EXPR_BEG
-        match(T_LBRA)
-        token = match(T_ATOM)
-        name = token.value.upcase
-        case name
-        when /\A(?:ALERT|PARSE|READ-ONLY|READ-WRITE|TRYCREATE|NOMODSEQ)\z/n
-          result = ResponseCode.new(name, nil)
-        when /\A(?:PERMANENTFLAGS)\z/n
-          match(T_SPACE)
-          result = ResponseCode.new(name, flag_list)
-        when /\A(?:UIDVALIDITY|UIDNEXT|UNSEEN)\z/n
-          match(T_SPACE)
-          result = ResponseCode.new(name, number)
-        else
-          token = lookahead
-          if token.symbol == T_SPACE
-            shift_token
-            @lex_state = EXPR_CTEXT
-            token = match(T_TEXT)
-            @lex_state = EXPR_BEG
-            result = ResponseCode.new(name, token.value)
-          else
-            result = ResponseCode.new(name, nil)
-          end
-        end
-        match(T_RBRA)
-        @lex_state = EXPR_RTEXT
-        return result
-      end
-
-      def address_list
-        token = lookahead
-        if token.symbol == T_NIL
-          shift_token
-          return nil
-        else
-          result = []
-          match(T_LPAR)
-          while true
-            token = lookahead
-            case token.symbol
-            when T_RPAR
-              shift_token
-              break
-            when T_SPACE
-              shift_token
-            end
-            result.push(address)
-          end
-          return result
-        end
-      end
-
-      ADDRESS_REGEXP = /\G\
-(?# 1: NAME     )(?:NIL|"((?:[^\x80-\xff\x00\r\n"\\]|\\["\\])*)") \
-(?# 2: ROUTE    )(?:NIL|"((?:[^\x80-\xff\x00\r\n"\\]|\\["\\])*)") \
-(?# 3: MAILBOX  )(?:NIL|"((?:[^\x80-\xff\x00\r\n"\\]|\\["\\])*)") \
-(?# 4: HOST     )(?:NIL|"((?:[^\x80-\xff\x00\r\n"\\]|\\["\\])*)")\
-\)/ni
-
-      def address
-        match(T_LPAR)
-        if @str.index(ADDRESS_REGEXP, @pos)
-          # address does not include literal.
-          @pos = $~.end(0)
-          name = $1
-          route = $2
-          mailbox = $3
-          host = $4
-          for s in [name, route, mailbox, host]
-            if s
-              s.gsub!(/\\(["\\])/n, "\\1")
-            end
-          end
-        else
-          name = nstring
-          match(T_SPACE)
-          route = nstring
-          match(T_SPACE)
-          mailbox = nstring
-          match(T_SPACE)
-          host = nstring
-          match(T_RPAR)
-        end
-        return Address.new(name, route, mailbox, host)
-      end
-
-#        def flag_list
-#       result = []
-#       match(T_LPAR)
-#       while true
-#         token = lookahead
-#         case token.symbol
-#         when T_RPAR
-#           shift_token
-#           break
-#         when T_SPACE
-#           shift_token
-#         end
-#         result.push(flag)
-#       end
-#       return result
-#        end
-
-#        def flag
-#       token = lookahead
-#       if token.symbol == T_BSLASH
-#         shift_token
-#         token = lookahead
-#         if token.symbol == T_STAR
-#           shift_token
-#           return token.value.intern
-#         else
-#           return atom.intern
-#         end
-#       else
-#         return atom
-#       end
-#        end
-
-      FLAG_REGEXP = /\
-(?# FLAG        )\\([^\x80-\xff(){ \x00-\x1f\x7f%"\\]+)|\
-(?# ATOM        )([^\x80-\xff(){ \x00-\x1f\x7f%*"\\]+)/n
-
-      def flag_list
-        if @str.index(/\(([^)]*)\)/ni, @pos)
-          @pos = $~.end(0)
-          return $1.scan(FLAG_REGEXP).collect { |flag, atom|
-            if atom
-              atom
-            else
-              symbol = flag.capitalize.untaint.intern
-              @flag_symbols[symbol] = true
-              if @flag_symbols.length > IMAP.max_flag_count
-                raise FlagCountError, "number of flag symbols exceeded"
-              end
-              symbol
-            end
-          }
-        else
-          parse_error("invalid flag list")
-        end
-      end
-
-      def nstring
-        token = lookahead
-        if token.symbol == T_NIL
-          shift_token
-          return nil
-        else
-          return string
-        end
-      end
-
-      def astring
-        token = lookahead
-        if string_token?(token)
-          return string
-        else
-          return atom
-        end
-      end
-
-      def string
-        token = lookahead
-        if token.symbol == T_NIL
-          shift_token
-          return nil
-        end
-        token = match(T_QUOTED, T_LITERAL)
-        return token.value
-      end
-
-      STRING_TOKENS = [T_QUOTED, T_LITERAL, T_NIL]
-
-      def string_token?(token)
-        return STRING_TOKENS.include?(token.symbol)
-      end
-
-      def case_insensitive_string
-        token = lookahead
-        if token.symbol == T_NIL
-          shift_token
-          return nil
-        end
-        token = match(T_QUOTED, T_LITERAL)
-        return token.value.upcase
-      end
-
-      def atom
-        result = ""
-        while true
-          token = lookahead
-          if atom_token?(token)
-            result.concat(token.value)
-            shift_token
-          else
-            if result.empty?
-              parse_error("unexpected token %s", token.symbol)
-            else
-              return result
-            end
-          end
-        end
-      end
-
-      ATOM_TOKENS = [
-        T_ATOM,
-        T_NUMBER,
-        T_NIL,
-        T_LBRA,
-        T_RBRA,
-        T_PLUS
-      ]
-
-      def atom_token?(token)
-        return ATOM_TOKENS.include?(token.symbol)
-      end
-
-      def number
-        token = lookahead
-        if token.symbol == T_NIL
-          shift_token
-          return nil
-        end
-        token = match(T_NUMBER)
-        return token.value.to_i
-      end
-
-      def nil_atom
-        match(T_NIL)
-        return nil
-      end
-
-      def match(*args)
-        token = lookahead
-        unless args.include?(token.symbol)
-          parse_error('unexpected token %s (expected %s)',
-                      token.symbol.id2name,
-                      args.collect {|i| i.id2name}.join(" or "))
-        end
-        shift_token
-        return token
-      end
-
-      def lookahead
-        unless @token
-          @token = next_token
-        end
-        return @token
-      end
-
-      def shift_token
-        @token = nil
-      end
-
-      def next_token
-        case @lex_state
-        when EXPR_BEG
-          if @str.index(BEG_REGEXP, @pos)
-            @pos = $~.end(0)
-            if $1
-              return Token.new(T_SPACE, $+)
-            elsif $2
-              return Token.new(T_NIL, $+)
-            elsif $3
-              return Token.new(T_NUMBER, $+)
-            elsif $4
-              return Token.new(T_ATOM, $+)
-            elsif $5
-              return Token.new(T_QUOTED,
-                               $+.gsub(/\\(["\\])/n, "\\1"))
-            elsif $6
-              return Token.new(T_LPAR, $+)
-            elsif $7
-              return Token.new(T_RPAR, $+)
-            elsif $8
-              return Token.new(T_BSLASH, $+)
-            elsif $9
-              return Token.new(T_STAR, $+)
-            elsif $10
-              return Token.new(T_LBRA, $+)
-            elsif $11
-              return Token.new(T_RBRA, $+)
-            elsif $12
-              len = $+.to_i
-              val = @str[@pos, len]
-              @pos += len
-              return Token.new(T_LITERAL, val)
-            elsif $13
-              return Token.new(T_PLUS, $+)
-            elsif $14
-              return Token.new(T_PERCENT, $+)
-            elsif $15
-              return Token.new(T_CRLF, $+)
-            elsif $16
-              return Token.new(T_EOF, $+)
-            else
-              parse_error("[Net::IMAP BUG] BEG_REGEXP is invalid")
-            end
-          else
-            @str.index(/\S*/n, @pos)
-            parse_error("unknown token - %s", $&.dump)
-          end
-        when EXPR_DATA
-          if @str.index(DATA_REGEXP, @pos)
-            @pos = $~.end(0)
-            if $1
-              return Token.new(T_SPACE, $+)
-            elsif $2
-              return Token.new(T_NIL, $+)
-            elsif $3
-              return Token.new(T_NUMBER, $+)
-            elsif $4
-              return Token.new(T_QUOTED,
-                               $+.gsub(/\\(["\\])/n, "\\1"))
-            elsif $5
-              len = $+.to_i
-              val = @str[@pos, len]
-              @pos += len
-              return Token.new(T_LITERAL, val)
-            elsif $6
-              return Token.new(T_LPAR, $+)
-            elsif $7
-              return Token.new(T_RPAR, $+)
-            else
-              parse_error("[Net::IMAP BUG] DATA_REGEXP is invalid")
-            end
-          else
-            @str.index(/\S*/n, @pos)
-            parse_error("unknown token - %s", $&.dump)
-          end
-        when EXPR_TEXT
-          if @str.index(TEXT_REGEXP, @pos)
-            @pos = $~.end(0)
-            if $1
-              return Token.new(T_TEXT, $+)
-            else
-              parse_error("[Net::IMAP BUG] TEXT_REGEXP is invalid")
-            end
-          else
-            @str.index(/\S*/n, @pos)
-            parse_error("unknown token - %s", $&.dump)
-          end
-        when EXPR_RTEXT
-          if @str.index(RTEXT_REGEXP, @pos)
-            @pos = $~.end(0)
-            if $1
-              return Token.new(T_LBRA, $+)
-            elsif $2
-              return Token.new(T_TEXT, $+)
-            else
-              parse_error("[Net::IMAP BUG] RTEXT_REGEXP is invalid")
-            end
-          else
-            @str.index(/\S*/n, @pos)
-            parse_error("unknown token - %s", $&.dump)
-          end
-        when EXPR_CTEXT
-          if @str.index(CTEXT_REGEXP, @pos)
-            @pos = $~.end(0)
-            if $1
-              return Token.new(T_TEXT, $+)
-            else
-              parse_error("[Net::IMAP BUG] CTEXT_REGEXP is invalid")
-            end
-          else
-            @str.index(/\S*/n, @pos) #/
-            parse_error("unknown token - %s", $&.dump)
-          end
-        else
-          parse_error("invalid @lex_state - %s", @lex_state.inspect)
-        end
-      end
-
-      def parse_error(fmt, *args)
-        if IMAP.debug
-          $stderr.printf("@str: %s\n", @str.dump)
-          $stderr.printf("@pos: %d\n", @pos)
-          $stderr.printf("@lex_state: %s\n", @lex_state)
-          if @token
-            $stderr.printf("@token.symbol: %s\n", @token.symbol)
-            $stderr.printf("@token.value: %s\n", @token.value.inspect)
-          end
-        end
-        raise ResponseParseError, format(fmt, *args)
-      end
-    end
-
-    # Authenticator for the "LOGIN" authentication type.  See
-    # #authenticate().
-    class LoginAuthenticator
-      def process(data)
-        case @state
-        when STATE_USER
-          @state = STATE_PASSWORD
-          return @user
-        when STATE_PASSWORD
-          return @password
-        end
-      end
-
-      private
-
-      STATE_USER = :USER
-      STATE_PASSWORD = :PASSWORD
-
-      def initialize(user, password)
-        @user = user
-        @password = password
-        @state = STATE_USER
-      end
-    end
-    add_authenticator "LOGIN", LoginAuthenticator
-
-    # Authenticator for the "PLAIN" authentication type.  See
-    # #authenticate().
-    class PlainAuthenticator
-      def process(data)
-        return "\0#{@user}\0#{@password}"
-      end
-
-      private
-
-      def initialize(user, password)
-        @user = user
-        @password = password
-      end
-    end
-    add_authenticator "PLAIN", PlainAuthenticator
-
-    # Authenticator for the "CRAM-MD5" authentication type.  See
-    # #authenticate().
-    class CramMD5Authenticator
-      def process(challenge)
-        digest = hmac_md5(challenge, @password)
-        return @user + " " + digest
-      end
-
-      private
-
-      def initialize(user, password)
-        @user = user
-        @password = password
-      end
-
-      def hmac_md5(text, key)
-        if key.length > 64
-          key = Digest::MD5.digest(key)
-        end
-
-        k_ipad = key + "\0" * (64 - key.length)
-        k_opad = key + "\0" * (64 - key.length)
-        for i in 0..63
-          k_ipad[i] = (k_ipad[i].ord ^ 0x36).chr
-          k_opad[i] = (k_opad[i].ord ^ 0x5c).chr
-        end
-
-        digest = Digest::MD5.digest(k_ipad + text)
-
-        return Digest::MD5.hexdigest(k_opad + digest)
-      end
-    end
-    add_authenticator "CRAM-MD5", CramMD5Authenticator
-
-    # Authenticator for the "DIGEST-MD5" authentication type.  See
-    # #authenticate().
-    class DigestMD5Authenticator
-      def process(challenge)
-	case @stage
-	when STAGE_ONE
-	  @stage = STAGE_TWO
-	  sparams = {}
-	  c = StringScanner.new(challenge)
-	  while c.scan(/(?:\s*,)?\s*(\w+)=("(?:[^\\"]+|\\.)*"|[^,]+)\s*/)
-	    k, v = c[1], c[2]
-	    if v =~ /^"(.*)"$/
-	      v = $1
-	      if v =~ /,/
-		v = v.split(',')
-	      end
-	    end
-	    sparams[k] = v
-	  end
-
-	  raise DataFormatError, "Bad Challenge: '#{challenge}'" unless c.rest.size == 0
-	  raise Error, "Server does not support auth (qop = #{sparams['qop'].join(',')})" unless sparams['qop'].include?("auth")
-
-	  response = {
-	    :nonce => sparams['nonce'],
-	    :username => @user,
-	    :realm => sparams['realm'],
-	    :cnonce => Digest::MD5.hexdigest("%.15f:%.15f:%d" % [Time.now.to_f, rand, Process.pid.to_s]),
-	    :'digest-uri' => 'imap/' + sparams['realm'],
-	    :qop => 'auth',
-	    :maxbuf => 65535,
-	    :nc => "%08d" % nc(sparams['nonce']),
-	    :charset => sparams['charset'],
-	  }
-
-	  response[:authzid] = @authname unless @authname.nil?
-
-	  # now, the real thing
-	  a0 = Digest::MD5.digest( [ response.values_at(:username, :realm), @password ].join(':') )
-
-	  a1 = [ a0, response.values_at(:nonce,:cnonce) ].join(':')
-	  a1 << ':' + response[:authzid] unless response[:authzid].nil?
-
-	  a2 = "AUTHENTICATE:" + response[:'digest-uri']
-	  a2 << ":00000000000000000000000000000000" if response[:qop] and response[:qop] =~ /^auth-(?:conf|int)$/
-
-	  response[:response] = Digest::MD5.hexdigest(
-	    [
-	     Digest::MD5.hexdigest(a1),
-	     response.values_at(:nonce, :nc, :cnonce, :qop),
-	     Digest::MD5.hexdigest(a2)
-	    ].join(':')
-	  )
-
-	  return response.keys.map {|key| qdval(key.to_s, response[key]) }.join(',')
-	when STAGE_TWO
-	  @stage = nil
-	  # if at the second stage, return an empty string
-	  if challenge =~ /rspauth=/
-	    return ''
-	  else
-	    raise ResponseParseError, challenge
-	  end
-	else
-	  raise ResponseParseError, challenge
-	end
-      end
-
-      def initialize(user, password, authname = nil)
-	@user, @password, @authname = user, password, authname
-	@nc, @stage = {}, STAGE_ONE
-      end
-
-      private
-
-      STAGE_ONE = :stage_one
-      STAGE_TWO = :stage_two
-
-      def nc(nonce)
-	if @nc.has_key? nonce
-	  @nc[nonce] = @nc[nonce] + 1
-	else
-	  @nc[nonce] = 1
-	end
-	return @nc[nonce]
-      end
-
-      # some responses need quoting
-      def qdval(k, v)
-	return if k.nil? or v.nil?
-	if %w"username authzid realm nonce cnonce digest-uri qop".include? k
-	  v.gsub!(/([\\"])/, "\\\1")
-	  return '%s="%s"' % [k, v]
-	else
-	  return '%s=%s' % [k, v]
-	end
-      end
-    end
-    add_authenticator "DIGEST-MD5", DigestMD5Authenticator
-
-    # Superclass of IMAP errors.
-    class Error < StandardError
-    end
-
-    # Error raised when data is in the incorrect format.
-    class DataFormatError < Error
-    end
-
-    # Error raised when a response from the server is non-parseable.
-    class ResponseParseError < Error
-    end
-
-    # Superclass of all errors used to encapsulate "fail" responses
-    # from the server.
-    class ResponseError < Error
-
-      # The response that caused this error
-      attr_accessor :response
-
-      def initialize(response)
-        @response = response
-
-        super @response.data.text
-      end
-
-    end
-
-    # Error raised upon a "NO" response from the server, indicating
-    # that the client command could not be completed successfully.
-    class NoResponseError < ResponseError
-    end
-
-    # Error raised upon a "BAD" response from the server, indicating
-    # that the client command violated the IMAP protocol, or an internal
-    # server failure has occurred.
-    class BadResponseError < ResponseError
-    end
-
-    # Error raised upon a "BYE" response from the server, indicating
-    # that the client is not being allowed to login, or has been timed
-    # out due to inactivity.
-    class ByeResponseError < ResponseError
-    end
-
-    # Error raised when too many flags are interned to symbols.
-    class FlagCountError < Error
-    end
-  end
-end
-
-if __FILE__ == $0
-  # :enddoc:
-  require "getoptlong"
-
-  $stdout.sync = true
-  $port = nil
-  $user = ENV["USER"] || ENV["LOGNAME"]
-  $auth = "login"
-  $ssl = false
-
-  def usage
-    $stderr.print <<EOF
-usage: #{$0} [options] <host>
-
-  --help                        print this message
-  --port=PORT                   specifies port
-  --user=USER                   specifies user
-  --auth=AUTH                   specifies auth type
-  --ssl                         use ssl
-EOF
-  end
-
-  def get_password
-    print "password: "
-    system("stty", "-echo")
-    begin
-      return gets.chop
-    ensure
-      system("stty", "echo")
-      print "\n"
-    end
-  end
-
-  def get_command
-    printf("%s@%s> ", $user, $host)
-    if line = gets
-      return line.strip.split(/\s+/)
-    else
-      return nil
-    end
-  end
-
-  parser = GetoptLong.new
-  parser.set_options(['--debug', GetoptLong::NO_ARGUMENT],
-                     ['--help', GetoptLong::NO_ARGUMENT],
-                     ['--port', GetoptLong::REQUIRED_ARGUMENT],
-                     ['--user', GetoptLong::REQUIRED_ARGUMENT],
-                     ['--auth', GetoptLong::REQUIRED_ARGUMENT],
-                     ['--ssl', GetoptLong::NO_ARGUMENT])
-  begin
-    parser.each_option do |name, arg|
-      case name
-      when "--port"
-        $port = arg
-      when "--user"
-        $user = arg
-      when "--auth"
-        $auth = arg
-      when "--ssl"
-        $ssl = true
-      when "--debug"
-        Net::IMAP.debug = true
-      when "--help"
-        usage
-        exit(1)
-      end
-    end
-  rescue
-    usage
-    exit(1)
-  end
-
-  $host = ARGV.shift
-  unless $host
-    usage
-    exit(1)
-  end
-
-  imap = Net::IMAP.new($host, :port => $port, :ssl => $ssl)
-  begin
-    password = get_password
-    imap.authenticate($auth, $user, password)
-    while true
-      cmd, *args = get_command
-      break unless cmd
-      begin
-        case cmd
-        when "list"
-          for mbox in imap.list("", args[0] || "*")
-            if mbox.attr.include?(Net::IMAP::NOSELECT)
-              prefix = "!"
-            elsif mbox.attr.include?(Net::IMAP::MARKED)
-              prefix = "*"
-            else
-              prefix = " "
-            end
-            print prefix, mbox.name, "\n"
-          end
-        when "select"
-          imap.select(args[0] || "inbox")
-          print "ok\n"
-        when "close"
-          imap.close
-          print "ok\n"
-        when "summary"
-          unless messages = imap.responses["EXISTS"][-1]
-            puts "not selected"
-            next
-          end
-          if messages > 0
-            for data in imap.fetch(1..-1, ["ENVELOPE"])
-              print data.seqno, ": ", data.attr["ENVELOPE"].subject, "\n"
-            end
-          else
-            puts "no message"
-          end
-        when "fetch"
-          if args[0]
-            data = imap.fetch(args[0].to_i, ["RFC822.HEADER", "RFC822.TEXT"])[0]
-            puts data.attr["RFC822.HEADER"]
-            puts data.attr["RFC822.TEXT"]
-          else
-            puts "missing argument"
-          end
-        when "logout", "exit", "quit"
-          break
-        when "help", "?"
-          print <<EOF
-list [pattern]                  list mailboxes
-select [mailbox]                select mailbox
-close                           close mailbox
-summary                         display summary
-fetch [msgno]                   display message
-logout                          logout
-help, ?                         display help message
-EOF
-        else
-          print "unknown command: ", cmd, "\n"
-        end
-      rescue Net::IMAP::Error
-        puts $!
-      end
-    end
-  ensure
-    imap.logout
-    imap.disconnect
-  end
-end
-