Go OR-Done-Channel Pattern

Internal

• Go Channels

Overview

Reading from a channel until the channel is closed can be done by ranging over a channel:

for v := range c {
  // do something with the channel value, we exit the loop automatically when the channel is closed
  ...
}

The for/range syntax is simple and intuitive, but it cannot be used anymore if we want to make the loop preemptable by using a done channel. In that case we need to replace it with a for/select syntax and case for the state of the done channel (see an example here).

The equivalent syntax is:

for v := range orDone(done, c) {
  // do something with the channel value, we exit the loop automatically when the 'c' channel is closed
  // or when the 'done' channel is messaged (written onto or closed)
  ...
}

orDone()

The orDone(...) function: