def self.create(arg)
case arg
when IPv6
return arg
when String
address = ''
if Regex_8Hex =~ arg
arg.scan(/[0-9A-Fa-f]+/) {|hex| address << [hex.hex].pack('n')}
elsif Regex_CompressedHex =~ arg
prefix = $1
suffix = $2
a1 = ''
a2 = ''
prefix.scan(/[0-9A-Fa-f]+/) {|hex| a1 << [hex.hex].pack('n')}
suffix.scan(/[0-9A-Fa-f]+/) {|hex| a2 << [hex.hex].pack('n')}
omitlen = 16 - a1.length - a2.length
address << a1 << "\00"" * omitlen << a2
elsif Regex_6Hex4Dec =~ arg
prefix, a, b, c, d = $1, $2.to_i, $3.to_i, $4.to_i, $5.to_i
if (0..255) === a && (0..255) === b && (0..255) === c && (0..255) === d
prefix.scan(/[0-9A-Fa-f]+/) {|hex| address << [hex.hex].pack('n')}
address << [a, b, c, d].pack('CCCC')
else
raise ArgumentError.new("not numeric IPv6 address: " + arg)
end
elsif Regex_CompressedHex4Dec =~ arg
prefix, suffix, a, b, c, d = $1, $2, $3.to_i, $4.to_i, $5.to_i, $6.to_i
if (0..255) === a && (0..255) === b && (0..255) === c && (0..255) === d
a1 = ''
a2 = ''
prefix.scan(/[0-9A-Fa-f]+/) {|hex| a1 << [hex.hex].pack('n')}
suffix.scan(/[0-9A-Fa-f]+/) {|hex| a2 << [hex.hex].pack('n')}
omitlen = 12 - a1.length - a2.length
address << a1 << "\00"" * omitlen << a2 << [a, b, c, d].pack('CCCC')
else
raise ArgumentError.new("not numeric IPv6 address: " + arg)
end
else
raise ArgumentError.new("not numeric IPv6 address: " + arg)
end
return IPv6.new(address)
else
raise ArgumentError.new("cannot interpret as IPv6 address: #{arg.inspect}")
end
end