=head1 Protocol::WebSocket

A WebSocket message parser/constructor. It is not a server and is not meant to
be one. It can be used in any server, event loop etc.

=head2 Server handshake

    my $h = Protocol::WebSocket::Handshake::Server->new;

    # Parse client request
    $h->parse(<<"EOF");
    GET /demo HTTP/1.1
    Upgrade: WebSocket
    Connection: Upgrade
    Host: example.com
    Origin: http://example.com
    Sec-WebSocket-Key1: 18x 6]8vM;54 *(5:  {   U1]8  z [  8
    Sec-WebSocket-Key2: 1_ tx7X d  <  nw  334J702) 7]o}` 0

    Tm[K T2u
    EOF

    $h->error;   # Check if there were any errors
    $h->is_done; # Returns 1

    # Create response
    $h->to_string; # HTTP/1.1 101 WebSocket Protocol Handshake
                   # Upgrade: WebSocket
                   # Connection: Upgrade
                   # Sec-WebSocket-Origin: http://example.com
                   # Sec-WebSocket-Location: ws://example.com/demo
                   #
                   # fQJ,fN/4F4!~K~MH

=head2 Client handshake

    my $h = Protocol::WebSocket::Handshake::Client->new;

    # Create request
    $h->to_string; # GET /demo HTTP/1.1
                   # Upgrade: WebSocket
                   # Connection: Upgrade
                   # Host: example.com
                   # Origin: http://example.com
                   # Sec-WebSocket-Key1: 18x 6]8vM;54 *(5:  {   U1]8  z [  8
                   # Sec-WebSocket-Key2: 1_ tx7X d  <  nw  334J702) 7]o}` 0
                   #
                   # Tm[K T2u

    # Parse server response
    $h->parse(<<"EOF");
    HTTP/1.1 101 WebSocket Protocol Handshake
    Upgrade: WebSocket
    Connection: Upgrade
    Sec-WebSocket-Origin: http://example.com
    Sec-WebSocket-Location: ws://example.com/demo

    fQJ,fN/4F4!~K~MH
    EOF

    $h->error;   # Check if there were any errors
    $h->is_done; # Returns 1

=head2 Parsing and constructing frames

    # Create frame
    my $frame = Protocol::WebSocket::Frame->new('123');
    $frame->to_string; # \x00123\xff

    # Parse frames
    my $frame = Protocol::WebSocket::Frame->new;
    $frame->append("123\x00foo\xff56\x00bar\xff789");
    $f->next; # foo
    $f->next; # bar

=head2 Other features

=over 4

=item Cookie parsing

=item URL parsing

=back