NAME

       Mail::IMAPClient::MessageSet - ranges of message sequence numbers

SYNOPSIS

        my @msgs = $imap->search("SUBJECT","Virus"); # returns 1,3,4,5,6,9,10
        my $msgset = Mail::IMAPClient::MessageSet->new(@msgs);
        print $msgset;  # prints "1,3:6,9:10"

        # add message 14 to the set:
        $msgset += 14;
        print $msgset;  # prints "1,3:6,9:10,14"

        # add messages 16,17,18,19, and 20 to the set:
        $msgset .= "16,17,18:20";
        print $msgset;  # prints "1,3:6,9:10,14,16:20"

        # Hey, I didn't really want message 17 in there; let's take it out:
        $msgset -= 17;
        print $msgset;  # prints "1,3:6,9:10,14,16,18:20"

        # Now let's iterate over each message:
        for my $msg (@$msgset)
        {  print "$msg\n";  # Prints: "1\n3\n4\n5\n6..16\n18\n19\n20\n"
        }
        print join("\n", @$msgset)."\n";     # same simpler
        local $" = "\n"; print "@$msgset\n"; # even more simple

DESCRIPTION

       The Mail::IMAPClient::MessageSet module is designed to make life easier for programmers
       who need to manipulate potentially large sets of IMAP message UID's or sequence numbers.

       This module presents an object-oriented interface into handling your message sets. The
       object reference returned by the new method is an overloaded reference to a scalar
       variable that contains the message set's compact RFC2060 representation. The object is
       overloaded so that using it like a string returns this compact message set representation.
       You can also add messages to the set (using either a '.=' operator or a '+=' operator) or
       remove messages (with the '-=' operator). And if you use it as an array reference, it will
       humor you and act like one by calling unfold for you.

       RFC2060 specifies that multiple messages can be provided to certain IMAP commands by
       separating them with commas. For example, "1,2,3,4,5" would specify messages 1, 2, 3, 4,
       and (you guessed it!) 5. However, if you are performing an operation on lots of messages,
       this string can get quite long.  So long that it may slow down your transaction, and
       perhaps even cause the server to reject it. So RFC2060 also permits you to specify a range
       of messages, so that messages 1, 2, 3, 4 and 5 can also be specified as "1:5".

       This is where Mail::IMAPClient::MessageSet comes in. It will convert your message set into
       the shortest correct syntax. This could potentially save you tons of network I/O, as in
       the case where you want to fetch the flags for all messages in a 10000 message folder,
       where the messages are all numbered sequentially. Delimited as commas, and making the
       best-case assumption that the first message is message "1", it would take 48893 bytes to
       specify the whole message set using the comma-delimited method. To specify it as a range,
       it takes just seven bytes (1:10000).

       Note that the Mail::IMAPClient Range method can be used as a short-cut to specifying
       "Mail::IMAPClient::MessageSet->new(@etc)".)

CLASS METHODS

       The only class method you need to worry about is new. And if you create your
       Mail::IMAPClient::MessageSet objects via Mail::IMAPClient's Range method then you don't
       even need to worry about new.

   new
       Example:

        my $msgset = Mail::IMAPClient::MessageSet->new(@msgs);

       The new method requires at least one argument. That argument can be either a message, a
       comma-separated list of messages, a colon-separated range of messages, or a combination of
       comma-separated messages and colon-separated ranges. It can also be a reference to an
       array of messages, comma-separated message lists, and colon separated ranges.

       If more then one argument is supplied to new, then those arguments should be more message
       numbers, lists, and ranges (or references to arrays of them) just as in the first
       argument.

       The message numbers passed to new can really be any kind of number at all but to be useful
       in a Mail::IMAPClient session they should be either message UID's (if your Uid parameter
       is true) or message sequence numbers.

       The new method will return a reference to a Mail::IMAPClient::MessageSet object. That
       object, when double quoted, will act just like a string whose value is the message set
       expressed in the shortest possible way, with the message numbers sorted in ascending order
       and with duplicates removed.

OBJECT METHODS

       The only object method currently available to a Mail::IMAPClient::MessageSet object is the
       unfold method.

   unfold
       Example:

           my $msgset = $imap->Range( $imap->messages ) ;
           my @all_messages = $msgset->unfold;

       The unfold method returns an array of messages that belong to the message set. If called
       in a scalar context it returns a reference to the array instead.

OVERRIDDEN OPERATIONS

       Mail::IMAPClient::MessageSet overrides a number of operators in order to make manipulating
       your message sets easier. The overridden operations are:

   stringify
       Attempts to stringify a Mail::IMAPClient::MessageSet object will result in the compact
       message specification being returned, which is almost certainly what you will want.

   Auto-increment
       Attempts to autoincrement a Mail::IMAPClient::MessageSet object will result in a message
       (or messages) being added to the object's message set.

       Example:

           $msgset += 34;
           # Message #34 is now in the message set

   Concatenate
       Attempts to concatenate to a Mail::IMAPClient::MessageSet object will result in a message
       (or messages) being added to the object's message set.

       Example:

           $msgset .= "34,35,36,40:45";
           # Messages 34,35,36,40,41,42,43,44,and 45 are now in the message set

       The ".=" operator and the "+=" operator can be used interchangeably, but as you can see by
       looking at the examples there are times when use of one has an aesthetic advantage over
       use of the other.

   Autodecrement
       Attempts to autodecrement a Mail::IMAPClient::MessageSet object will result in a message
       being removed from the object's message set.

       Examples:

           $msgset -= 34;
           # Message #34 is no longer in the message set
           $msgset -= "1:10";
           # Messages 1 through 10 are no longer in the message set

       If you attempt to remove a message that was not in the original message set then your
       resulting message set will be the same as the original, only more expensive. However, if
       you attempt to remove several messages from the message set and some of those messages
       were in the message set and some were not, the additional overhead of checking for the
       messages that were not there is negligible. In either case you get back the message set
       you want regardless of whether it was already like that or not.

AUTHOR

        David J. Kernen
        The Kernen Consulting Group, Inc

COPYRIGHT

        Copyright 1999, 2000, 2001, 2002 The Kernen Group, Inc.
        All rights reserved.

       This program is free software; you can redistribute it and/or modify it under the terms of
       either:

       a) the "Artistic License" which comes with this Kit, or
       b) the GNU General Public License as published by the Free Software Foundation; either
       version 1, or (at your option) any later version.

       This program is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY;
       without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
       See either the GNU General Public License or the Artistic License for more details. All
       your base are belong to us.