A custom identifier to convert an IPv6 address to an integer and vice versa.

/*
{

  $longipv6() by jaytea

  This custom identifier is similar in usage to mIRC's own $longip(), but
  handles IPv6 addresses instead of IPv4 ones.

  Syntax: $longipv6(<IP/N>)

  Takes in either a valid IPv6 address or a 128-bit unsigned integer and 
  performs a conversion between the two. Keep in mind that mIRC doesn't
  normally handle numbers with 128 bits of precision, so this alias is
  more limited in potential uses than its native $longip() counterpart.

  Examples:

  $longipv6(1) = ::1
  $longipv6(12345678901234567890) = ::ab54:a98c:eb1f:ad2
  $longipv6(::ab54:a98c:eb1f:ad2) = 12345678901234567890
  $longipv6(ffff::) = 340277174624079928635746076935438991360
  $longipv6(abc) = $null

  Since 'abc' is neither a valid IPv6 address or a non-negative integer,
  the result is $null. In general, if you are using an older version of
  mIRC without $iptype(), if ($longipv6(%IP) isnum) is true and only true
  when %IP is a valid IPv6 address. 

}
*/

alias longipv6 {
  if ($1-. isnum) {
    if ($1 >= 0) {
      var %num = $1, %i = 8, %out = :

      while (%i) {
        bunset &quot
        bset &quot 50 0

        while ($left(%num, 15) > 65535) {
          var %div = $int($calc($v1 / 65536)), %rem = $v1 % 65536
          bset -t &quot $calc(51 - $mid(%num, 16, 0) - $len(%div)) %div
          %num = %rem $+ $mid(%num, 16)
        }

        %out = $+(:, $base(0 $+ $v1, 10, 16), %out)
        !breplace &quot 0 48
        %num = $regsubex($bvar(&quot, 1-).text, /^0*/, )
        dec %i
      }

      if ($version > 6.35) return $lower($iptype($mid(%out, 2, -1)).compress) 
      return $lower($regsubex(%out, /.$|((?:(:)0)++)(:$|(?(?!\1).)+(?=.$))|(((^)))./g, \2\3))
    }
  }
  else {
    if ($version > 6.35) {
      if ($iptype($1-) != ipv6) return
    }
    elseif (!$regex($1-, /^(?(?=.*::)(?!(?>.*?:(?=:)){2})(::|(?>(?<=^|::)|:)[a-f\d]{1,4}+){1,8}+|(?1){8})$/)) return

    ; the above regular expression matches all valid IPv6 addresses

    var %n, %i = 8, %out, $&
      %3 = 281474976710656, $&
      %4 = 18446744073709551616, $&
      %5 = 1208925819614629174706176, $&
      %6 = 79228162514264337593543950336, $&
      %7 = 5192296858534827628530496329220096

    if ($version > 6.35) %n = $iptype($1).expand
    else %n = $replace($1, ::, $str(:0:, $calc(8 - $numtok($1, 58))))

    while (%i) {
      var %num = $base($gettok(%n, %i, 58), 16, 10), %pow = 8 - %i
      if (%pow < 3) {
        inc %out $calc(%num * 65536 ^ %pow)
      }
      elseif (%num) {
        var %pow = $eval(% $+ %pow, 2), %carry, %result

        while ($right(%pow, 10)) {
          var %mul = $v1 * %num, %result = $base($calc($right(%mul, 10) + %carry), 10, 10, 10) $&
            $+ %result, %carry = $left(%mul, -10), %pow = $left(%pow, -10)
        }

        var %result = %carry $+ %result, %carry, %num

        while (%out $+ %result) {
          var %add = $calc($right(%result, 15) + $right(%out, 15)), $&
            %num = $base($calc($right(%add, 15) + %carry), 10, 10, 15) $+ %num, $&
            %carry = $left(%add, -15), %out = $left(%out, -15), %result = $left(%result, -15)
        }

        %out = %carry $+ %num
      }
      dec %i
    }

    return $regsubex(%out, /^0*+\B/, )
  }
}