Network­Ports­Cowan

Network Ports

Network ports are a mild abstraction of TCP sockets. They are a disjoint type.

This proposal depends on SettingsListsCowan. Settings lists passed to procedures in this proposal MUST NOT contain the path key, but MAY contain the keys host and port defined below.

Client Procedures

The procedures in this section take a specification for a TCP socket and return a input/output port connected to the socket.

(open-network-client settings-list)

Returns an input/output port connected to the host and port specified by settings-list.

Server Procedures

(make-network-listener settings-list)

Returns an opaque listener object (which may be of any type) that will accept connections to the port and host (which must be a local address) specified in settings-list. If the host is not specified, the listener will accept connections that are made to port on any local address.

(open-network-server listener)

Waits for a client to connect to listener, and returns an input/output port connected to that client. When the port is closed, this procedure may be invoked again on the same listener.

Settings-list Keys

Implementations MUST support the following keys:

host

Specifies the host as a string. It may be an IPv4 dotted-decimal address, an IPv6 colon-hexadecimal address if supported by the operating system, or a host name to be looked up according to whatever operating system conventions exist, if any. Appropriate strings may refer to broadcast or multicast addresses.

port

Specifies the port number as an exact integer or the port name as a string. The meaning of a string is implementation-dependent, but is intended to be a standardized service name.