`std/network`

The network: name resolution, TCP - a listener that accepts connections and a stream whose two directions are a Source and a Sink of Bytes - and UDP, a socket that sends and receives datagrams. The IP addresses and socket addresses it connects to are the values of std/ip, re-exported here, so a file that only names an address can import them without claiming the network.

const server = TcpListener.listen(SocketAddress(IpAddress.loopback, 0))?
const client = TcpStream.connect(server.localAddress()).await()?

Everything that waits answers a Task and is cancellable; a timeout is within. Needs the network capability inside a sandboxed script. See docs/design/NETWORK.md for the IO core under it; TLS is std/tls.

Modules

std/network/dnsDNS lookups: the stub resolver that asks a recursive name server for the records of a name (docs/design/DNS.md section 7).
std/network/errorNetworkError: what every operation of std/network fails with, one wrapper type, so a new kind of failure is never a breaking change (see "Algebraic Data Types and Pattern Matching" in CONCEPT.md).
std/network/tcpTCP: TcpListener accepts connections, TcpStream is one, and resolve turns a name into addresses.
std/network/udpUDP: a UdpSocket sends and receives datagrams - each one whole, with the address it came from, or not at all (docs/design/NETWORK.md section 4, slice 5).

Everything

fn lookupThe records of recordType that name has, asked of the name servers the system is configured with: Resolver()'s [Resolver.lookup].
type NetworkErrorWhat went wrong on the network.
extend NetworkError with From<AddressError>An address read from text that is none.
extend NetworkError with From<DnsError>A name that is no domain name, where a lookup was asked for one: lookup(DomainName.tryFrom(text)?, ...).
fn randomQueryIdentifierA random identifier for a DNS query, from the system's randomness (RFC 5452 section 9.2): what every transport of DNS draws for each question it sends, so that a forged answer has to guess it.
fn resolveThe addresses host names: a literal address as it is, localhost as the two loopback addresses, and every other name through the system's resolver, in the order it answered.
type ResolverHow [lookup] asks: which name servers, how long an attempt waits, and how many rounds over the servers it makes.
fn systemNameServersThe name servers the system is configured with, in its order, on port 53: the servers of the network adapters that are up on Windows, the nameserver lines of /etc/resolv.conf elsewhere.
type TcpAcceptorWhat [TcpListener.acceptor] answers: the right to accept on a listening socket, as a value that moves between workers.
type TcpListenerA socket that listens for connections.
type TcpSinkThe writing direction of a [TcpStream]: a Sink<Bytes, NetworkError>.
type TcpSourceThe reading direction of a [TcpStream]: a Source<Bytes, NetworkError>.
type TcpStreamOne TCP connection: bytes in both directions, in order, until either side ends its half.
type UdpSocketA UDP socket: bound to a local address, and - once [UdpSocket.connect] named one - connected to one peer.