Namespace std::channel

This contains standard names for commonly used asynchronous channels. A channel has two ends: the sender and receiver. In the wire-level handshake protocol, the end that initiates the communication is referred to an the active end of the channel; the other end is passive. If the sender initiates the communication, then the channel is referred to as a push-type channel; if the receiver initiates the communication, the channel is referred to as a pull-type channel.

In the standard channel definitions, the channels are push-type unless otherwise specified.

template<pint N>
defchan e1of <: chan(enum<N>) (std::data::d1of?!<N> d; bool!? e);

The e1of<N> channel sends a one-of-N encoded data value using the .d field, and the receiver responds with an enable (inverted acknowledge) using the .e field. This uses a four-phase handshake protocol. The channel resets to an initial state without any data on its output.

template<pint N>
defchan er1of <: chan(enum<N>) (std::data::d1of?!<N> d; bool!? e);

SImilar to e1of<N>, except the channel resets with the data value 0 on its output.

template<pint N>
defchan ev1of <: chan(enum<N>) (std::data::d1of?!<N> d; bool?! v;  bool!? e);

This channel is similar to the e1of<N> channel, except that the .v (for data valid) field is also included in the interface. This is used to avoid replicating validity checks at the sender and receiver.