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Ipv6Address final

final class Ipv6Address extends IpAddress

A 128-bit IPv6 address stored as 16 bytes in network (big-endian) order.

Textual form follows RFC 5952 compressed notation (e.g. "::1", "2001:db8::1"). Mixed IPv4/IPv6 strings (e.g. "::ffff:192.0.2.1") are also accepted by fromString.

Inheritance

Object → Ordered<A>HostIpAddressIpv6Address

Properties

asHost no setter inherited

Host get asHost

Returns this as a Host (identity).

Inherited from Host.

Implementation
dart
Host get asHost => this;

asIpAddress no setter inherited

IpAddress get asIpAddress

Returns this as an IpAddress (identity).

Inherited from IpAddress.

Implementation
dart
IpAddress get asIpAddress => this;

bitSize no setter inherited

int get bitSize

The number of bits in this address (32 for IPv4, 128 for IPv6).

Inherited from IpAddress.

Implementation
dart
int get bitSize => fold((_) => 32, (_) => 128);

hashCode no setter inherited

int get hashCode

The hash code for this object.

A hash code is a single integer which represents the state of the object that affects operator == comparisons.

All objects have hash codes. The default hash code implemented by Object represents only the identity of the object, the same way as the default operator == implementation only considers objects equal if they are identical (see identityHashCode).

If operator == is overridden to use the object state instead, the hash code must also be changed to represent that state, otherwise the object cannot be used in hash based data structures like the default Set and Map implementations.

Hash codes must be the same for objects that are equal to each other according to operator ==. The hash code of an object should only change if the object changes in a way that affects equality. There are no further requirements for the hash codes. They need not be consistent between executions of the same program and there are no distribution guarantees.

Objects that are not equal are allowed to have the same hash code. It is even technically allowed that all instances have the same hash code, but if clashes happen too often, it may reduce the efficiency of hash-based data structures like HashSet or HashMap.

If a subclass overrides hashCode, it should override the operator == operator as well to maintain consistency.

Inherited from IpAddress.

Implementation
dart
@override
int get hashCode => Object.hashAll(_bytes);

isMappedV4 no setter inherited

bool get isMappedV4

Returns true if this is an IPv6 address in the ::ffff:0:0/96 (IPv4-mapped) block.

Inherited from IpAddress.

Implementation
dart
bool get isMappedV4 => fold((_) => false, Ipv6Address.MappedV4Block.contains);

isMulticast no setter override

bool get isMulticast

Returns true if this address is in the multicast range.

Implementation
dart
@override
bool get isMulticast => MulticastRangeStart <= this && this <= MulticastRangeEnd;

isSourceSpecificMulticast no setter override

bool get isSourceSpecificMulticast

Returns true if this address is in the source-specific multicast (SSM) range.

Implementation
dart
@override
bool get isSourceSpecificMulticast =>
    SourceSpecificMulticastRangeStart <= this && this <= SourceSpecificMulticastRangeEnd;

runtimeType no setter inherited

Type get runtimeType

A representation of the runtime type of the object.

Inherited from Object.

Implementation
dart
external Type get runtimeType;

version no setter inherited

IpVersion get version

The IP version of this address.

Inherited from IpAddress.

Implementation
dart
IpVersion get version => fold((_) => IpVersion.v4, (_) => IpVersion.v6);

Methods

asIpv4() inherited

Returns Some(v4) if this address is (or collapses to) an Ipv4Address, otherwise None.

Inherited from IpAddress.

Implementation
dart
Option<Ipv4Address> asIpv4() => collapseMappedV4().fold((v4) => Some(v4), (_) => none());

asIpv6() inherited

Returns Some(v6) if this is an Ipv6Address, otherwise None.

Inherited from IpAddress.

Implementation
dart
Option<Ipv6Address> asIpv6() => fold((_) => none(), (v6) => Some(v6));

asMulticast() override

Option<Multicast<Ipv6Address>> asMulticast()

Returns a Multicast wrapper if this address is a multicast address, otherwise None.

Implementation
dart
@override
Option<Multicast<Ipv6Address>> asMulticast() => Multicast.fromIpAddress(this);

asSourceSpecificMulticast() override

Option<SourceSpecificMulticastStrict<Ipv6Address>> asSourceSpecificMulticast()

Returns a strict SourceSpecificMulticastStrict wrapper if this address is in the SSM range, otherwise None.

Implementation
dart
@override
Option<SourceSpecificMulticastStrict<Ipv6Address>> asSourceSpecificMulticast() =>
    SourceSpecificMulticast.fromIpAddress(this);

asSourceSpecificMulticastLenient() override

Option<SourceSpecificMulticast<Ipv6Address>> asSourceSpecificMulticastLenient()

Returns a lenient SourceSpecificMulticast wrapper if this address is any multicast address, otherwise None.

Implementation
dart
@override
Option<SourceSpecificMulticast<Ipv6Address>> asSourceSpecificMulticastLenient() =>
    SourceSpecificMulticast.fromIpAddressLenient(this);

collapseMappedV4() inherited

IpAddress collapseMappedV4()

If this is an IPv6 address that is a mapped IPv4 address (i.e. ::ffff:a.b.c.d), returns the corresponding Ipv4Address. Otherwise returns this address unchanged.

Inherited from IpAddress.

Implementation
dart
IpAddress collapseMappedV4() => fold(identity, (v6) {
  if (v6.isMappedV4) {
    return IpAddress.fromBytes(
      v6.toBytes().toIList().takeRight(4).toList(),
    ).getOrElse(() => throw Exception('IpAddress.collapseMappedV4 failure: $v6'));
  } else {
    return v6;
  }
});

compareTo() inherited

int compareTo(Host that)

Compares this object to another object.

Returns a value like a Comparator when comparing this to other. That is, it returns a negative integer if this is ordered before other, a positive integer if this is ordered after other, and zero if this and other are ordered together.

The other argument must be a value that is comparable to this object.

Inherited from Host.

Implementation
dart
@override
int compareTo(Host that) {
  return switch (this) {
    final Ipv4Address x => switch (that) {
      final Ipv4Address y => IpAddress.compareBytes(x, y),
      final Ipv6Address y => IpAddress.compareBytes(x.toCompatV6(), y),
      _ => -1,
    },
    final Ipv6Address x => switch (that) {
      final Ipv4Address y => IpAddress.compareBytes(x, y.toCompatV6()),
      final Ipv6Address y => IpAddress.compareBytes(x, y),
      _ => -1,
    },
    final Hostname x => switch (that) {
      final Ipv4Address _ => 1,
      final Ipv6Address _ => 1,
      final Hostname y => x.toString().compareTo(y.toString()),
      final IDN y => x.toString().compareTo(y.hostname.toString()),
    },
    final IDN x => switch (that) {
      final Ipv4Address _ => 1,
      final Ipv6Address _ => 1,
      final Hostname y => x.hostname.toString().compareTo(y.toString()),
      final IDN y => x.hostname.toString().compareTo(y.hostname.toString()),
    },
  };
}

fold() override

A fold<A>(A Function(Ipv4Address) v4, A Function(Ipv6Address) v6)

Dispatches to v4 or v6 depending on the address family.

Implementation
dart
@override
A fold<A>(
  Function1<Ipv4Address, A> v4,
  Function1<Ipv6Address, A> v6,
) => v6(this);

masked()

Returns this address ANDed with mask (bitwise AND).

Implementation
dart
Ipv6Address masked(Ipv6Address mask) => Ipv6Address.fromBigInt(toBigInt() & mask.toBigInt());

maskedLast()

Ipv6Address maskedLast(Ipv6Address mask)

Returns the last address in the subnet defined by mask (bitwise OR of network prefix with the inverted mask).

Implementation
dart
Ipv6Address maskedLast(Ipv6Address mask) =>
    Ipv6Address.fromBigInt(toBigInt() & mask.toBigInt() | ~mask.toBigInt());

next()

Returns the address that follows this one (wraps around on overflow).

Implementation
dart
Ipv6Address next() => Ipv6Address.fromBigInt(toBigInt() + BigInt.one);

noSuchMethod() inherited

dynamic noSuchMethod(Invocation invocation)

Invoked when a nonexistent method or property is accessed.

A dynamic member invocation can attempt to call a member which doesn't exist on the receiving object. Example:

dart
dynamic object = 1;
object.add(42); // Statically allowed, run-time error

This invalid code will invoke the noSuchMethod method of the integer 1 with an Invocation representing the .add(42) call and arguments (which then throws).

Classes can override noSuchMethod to provide custom behavior for such invalid dynamic invocations.

A class with a non-default noSuchMethod invocation can also omit implementations for members of its interface. Example:

dart
class MockList<T> implements List<T> {
  noSuchMethod(Invocation invocation) {
    log(invocation);
    super.noSuchMethod(invocation); // Will throw.
  }
}
void main() {
  MockList().add(42);
}

This code has no compile-time warnings or errors even though the MockList class has no concrete implementation of any of the List interface methods. Calls to List methods are forwarded to noSuchMethod, so this code will log an invocation similar to Invocation.method(#add, [42]) and then throw.

If a value is returned from noSuchMethod, it becomes the result of the original invocation. If the value is not of a type that can be returned by the original invocation, a type error occurs at the invocation.

The default behavior is to throw a NoSuchMethodError.

Inherited from Object.

Implementation
dart
@pragma("vm:entry-point")
@pragma("wasm:entry-point")
external dynamic noSuchMethod(Invocation invocation);

prefixBits() inherited

int prefixBits()

Counts the number of leading one-bits in the address, treating the bytes as a network mask. Used to derive the prefix length from a mask address.

Inherited from IpAddress.

Implementation
dart
int prefixBits() {
  int zerosIn(int value, int bits) {
    int res = 0;
    int x = value;

    while ((x & (1 << (bits - 1))) == 0 && res < bits) {
      x = x << 1;
      res++;
    }

    return res;
  }

  int zeros(Uint8List l) {
    int n = 0;

    for (final i in l) {
      n += zerosIn(~i, 8);

      if (n == 0 || n % 8 != 0) {
        return n;
      }
    }

    return n;
  }

  return zeros(_bytes);
}

previous()

Ipv6Address previous()

Returns the address that precedes this one (wraps around on underflow).

Implementation
dart
Ipv6Address previous() => Ipv6Address.fromBigInt(toBigInt() - BigInt.one);

resolve() inherited

IO<IList<IpAddress>> resolve()

Resolves this host to a list of IpAddress values.

If this is already an IpAddress, returns it immediately. For Hostname and IDN values, performs a DNS lookup via Dns.resolve.

Inherited from Host.

Implementation
dart
IO<IList<IpAddress>> resolve() => switch (this) {
  final IpAddress ip => IO.pure(ilist([ip])),
  final Hostname hostname => Dns.resolve(hostname),
  final IDN idn => Dns.resolve(idn.hostname),
};

reverse() inherited

IO<Hostname> reverse()

Performs a reverse DNS lookup, returning the Hostname associated with this address. Fails the IO if no PTR record is found.

Inherited from IpAddress.

Implementation
dart
IO<Hostname> reverse() => Dns.reverse(this);

reverseOption() inherited

IO<Option<Hostname>> reverseOption()

Performs a reverse DNS lookup, returning Some hostname if a PTR record exists or None otherwise.

Inherited from IpAddress.

Implementation
dart
IO<Option<Hostname>> reverseOption() => Dns.reverseOption(this);

toBigInt()

BigInt toBigInt()

Returns the address as a 128-bit BigInt.

Implementation
dart
BigInt toBigInt() {
  var result = BigInt.zero;
  Iterable<int>.generate(_bytes.length).forEach((i) {
    result = (result << 8) | BigInt.from(0x0ff & _bytes[i]);
  });

  return result;
}

toBytes() inherited

Uint8List toBytes()

Returns a copy of the underlying bytes as a new Uint8List.

Inherited from IpAddress.

Implementation
dart
Uint8List toBytes() => Uint8List.fromList(_bytes.toList());

toMixedString()

String toMixedString()

Returns the mixed IPv4/IPv6 string form where the last 4 bytes are expressed as a dotted-decimal IPv4 address (e.g. "::ffff:192.0.2.1").

Implementation
dart
String toMixedString() {
  final bytes = toBytes();
  final v4 = Ipv4Address.fromByteList(
    bytes.getRange(12, 16),
  ).getOrElse(() => throw Exception('IPv6 toMixedString failure for: $this'));

  bytes.setRange(12, 16, [0, 1, 0, 1]);

  final s = _unsafeFromBytes(bytes).toString();
  final prefix = s.substring(0, s.length - 3);

  return prefix + v4.toString();
}

toString() override

String toString()

Returns the RFC 5952 compressed string, e.g. "2001:db8::1". The longest run of consecutive all-zero groups is condensed to "::"; ties are resolved by the leftmost run.

Implementation
dart
@override
String toString() {
  final fields = List.filled(8, 0);
  var condensing = false;
  var condensedStart = -1;
  var maxCondensedStart = -1;
  var condensedLength = 0;
  var maxCondensedLength = 0;
  var idx = 0;

  while (idx < 8) {
    final j = 2 * idx;
    final field = ((0x0ff & _bytes[j]) << 8) | (0x0ff & _bytes[j + 1]);
    fields[idx] = field;

    if (field == 0) {
      if (!condensing) {
        condensing = true;
        condensedStart = idx;
        condensedLength = 0;
      }
      condensedLength += 1;
    } else {
      condensing = false;
    }
    if (condensedLength > maxCondensedLength) {
      maxCondensedLength = condensedLength;
      maxCondensedStart = condensedStart;
    }
    idx += 1;
  }

  if (maxCondensedLength == 1) {
    maxCondensedStart = -1;
  }

  final str = StringBuffer();
  idx = 0;

  while (idx < 8) {
    if (idx == maxCondensedStart) {
      str.write('::');
      idx += maxCondensedLength;
    } else {
      final hextet = fields[idx].toRadixString(16);
      str.write(hextet);
      idx += 1;
      if (idx < 8 && idx != maxCondensedStart) {
        str.write(':');
      }
    }
  }

  return str.toString();
}

toUncondensedString()

String toUncondensedString()

Returns the full uncondensed 32-hex-digit form, e.g. "0000:0000:0000:0000:0000:0000:0000:0001" for loopback.

Implementation
dart
String toUncondensedString() {
  final str = StringBuffer();
  final bytes = toBytes();

  var idx = 0;

  while (idx < 16) {
    final field = ((bytes[idx] & 0xff) << 8) | (bytes[idx + 1] & 0xff);
    final hextet = field.toRadixString(16).padLeft(4, '0');
    str.write(hextet);
    idx += 2;
    if (idx < 15) {
      str.write(':');
    }
  }

  return str.toString();
}

Operators

operator /() override

Cidr<Ipv6Address> operator /(int prefixBits)

Creates a Cidr block from this address and prefixBits.

Implementation
dart
@override
Cidr<Ipv6Address> operator &#47;(int prefixBits) => Cidr.of(this, prefixBits);

operator <() inherited

bool operator <(Host that)

Returns true if this value is less than that.

Inherited from Ordered.

Implementation
dart
bool operator <(A that) => compareTo(that) < 0;

operator <=() inherited

bool operator <=(Host that)

Returns true if this value is less than or equal to that.

Inherited from Ordered.

Implementation
dart
bool operator <=(A that) => compareTo(that) <= 0;

operator ==() inherited

bool operator ==(Object other)

The equality operator.

The default behavior for all Objects is to return true if and only if this object and other are the same object.

Override this method to specify a different equality relation on a class. The overriding method must still be an equivalence relation. That is, it must be:

  • Total: It must return a boolean for all arguments. It should never throw.

  • Reflexive: For all objects o, o == o must be true.

  • Symmetric: For all objects o1 and o2, o1 == o2 and o2 == o1 must either both be true, or both be false.

  • Transitive: For all objects o1, o2, and o3, if o1 == o2 and o2 == o3 are true, then o1 == o3 must be true.

The method should also be consistent over time, so whether two objects are equal should only change if at least one of the objects was modified.

If a subclass overrides the equality operator, it should override the hashCode method as well to maintain consistency.

Inherited from IpAddress.

Implementation
dart
@override
bool operator ==(Object other) => switch (other) {
  final IpAddress that =>
    version == that.version && ilist(_bytes).zip(ilist(that._bytes)).forall((t) => t.$1 == t.$2),
  _ => false,
};

operator >() inherited

bool operator >(Host that)

Returns true if this value is greater than that.

Inherited from Ordered.

Implementation
dart
bool operator >(A that) => compareTo(that) > 0;

operator >=() inherited

bool operator >=(Host that)

Returns true if this value is greater than or equal to that.

Inherited from Ordered.

Implementation
dart
bool operator >=(A that) => compareTo(that) >= 0;

Static Properties

MappedV4Block read / write

Cidr<Ipv6Address> MappedV4Block

getter:

The IPv4-mapped address block ::ffff:0:0/96. Used by IpAddress.isMappedV4 and IpAddress.collapseMappedV4.

setter:

The IPv4-mapped address block ::ffff:0:0/96. Used by IpAddress.isMappedV4 and IpAddress.collapseMappedV4.

Implementation
dart
static Cidr<Ipv6Address> MappedV4Block = Cidr.of(
  Ipv6Address.fromBytes(0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 255, 255, 0, 0, 0, 0),
  96,
);

MulticastRangeEnd final

final Ipv6Address MulticastRangeEnd

Last IP address in the IPv6 multicast range (ffff:ffff:ffff:ffff:ffff:ffff:ffff:ffff).

Implementation
dart
static final MulticastRangeEnd = fromBytes(
  255,
  255,
  255,
  255,
  255,
  255,
  255,
  255,
  255,
  255,
  255,
  255,
  255,
  255,
  255,
  255,
);

MulticastRangeStart final

final Ipv6Address MulticastRangeStart

First IP address in the IPv6 multicast range (ff00:😃.

Implementation
dart
static final MulticastRangeStart = fromBytes(255, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0);

SourceSpecificMulticastRangeEnd final

final Ipv6Address SourceSpecificMulticastRangeEnd

Last IP address in the IPv6 source specific multicast range (ff3f:ffff:ffff:ffff:ffff:ffff:ffff:ffff).

Implementation
dart
static final SourceSpecificMulticastRangeEnd = fromBytes(
  255,
  63,
  255,
  255,
  255,
  255,
  255,
  255,
  255,
  255,
  255,
  255,
  255,
  255,
  255,
  255,
);

SourceSpecificMulticastRangeStart final

final Ipv6Address SourceSpecificMulticastRangeStart

First IP address in the IPv6 source specific multicast range (ff30:😃.

Implementation
dart
static final SourceSpecificMulticastRangeStart = fromBytes(
  255,
  48,
  0,
  0,
  0,
  0,
  0,
  0,
  0,
  0,
  0,
  0,
  0,
  0,
  0,
  0,
);

Static Methods

fromBigInt()

Ipv6Address fromBigInt(BigInt value)

Creates an Ipv6Address from a 128-bit BigInt value in network byte order.

Implementation
dart
static Ipv6Address fromBigInt(BigInt value) {
  final bytes = Uint8List(16);

  var rem = value;
  Range.inclusive(15, 0, -1).foreach((i) {
    bytes[i] = (rem & BigInt.from(0x0ff)).toInt();
    rem = rem >> 8;
  });

  return _unsafeFromBytes(bytes);
}

fromByteList()

Option<Ipv6Address> fromByteList(Iterable<int> bytes)

Returns an Ipv6Address from an iterable of exactly 16 bytes, or None otherwise.

Implementation
dart
static Option<Ipv6Address> fromByteList(Iterable<int> bytes) =>
    Option.when(() => bytes.length == 16, () => _unsafeFromBytes(bytes));

fromBytes() override

Ipv6Address fromBytes(
  int b0,
  int b1,
  int b2,
  int b3,
  int b4,
  int b5,
  int b6,
  int b7,
  int b8,
  int b9,
  int b10,
  int b11,
  int b12,
  int b13,
  int b14,
  int b15,
)

Creates an Ipv6Address from 16 individual byte values. Each byte is masked to 8 bits.

Implementation
dart
static Ipv6Address fromBytes(
  int b0,
  int b1,
  int b2,
  int b3,
  int b4,
  int b5,
  int b6,
  int b7,
  int b8,
  int b9,
  int b10,
  int b11,
  int b12,
  int b13,
  int b14,
  int b15,
) => _unsafeFromBytes(
  Uint8List.fromList(
    [
      b0,
      b1,
      b2,
      b3,
      b4,
      b5,
      b6,
      b7,
      b8,
      b9,
      b10,
      b11,
      b12,
      b13,
      b14,
      b15,
    ].map((b) => b & 0xff).toList(),
  ),
);

fromString() override

Option<Ipv6Address> fromString(String value)

Parses an IPv6 address string in standard or mixed notation, returning None if parsing fails.

Implementation
dart
static Option<Ipv6Address> fromString(String value) =>
    _fromNonMixedString(value).orElse(() => _fromMixedString(value));

loopback() override

IO<IList<IpAddress>> loopback()

Returns the IPv6 loopback addresses for the current host.

Implementation
dart
static IO<IList<IpAddress>> loopback() =>
    IpAddress.loopback().map((ifaces) => ifaces.filter((iface) => iface.version == IpVersion.v6));

mask()

Ipv6Address mask(int bits)

Returns the subnet mask address for the given bits prefix length (0–128, clamped).

Implementation
dart
static Ipv6Address mask(int bits) {
  final b = bits.clamp(0, 128);

  if (b == 0) {
    return Ipv6Address.fromBigInt(BigInt.zero);
  } else {
    final mask = (BigInt.one << 128) - (BigInt.one << (128 - b));
    return Ipv6Address.fromBigInt(mask);
  }
}