If the capacity is zero or absent, the channel is unbuffered and communication
succeeds only when both a sender and receiver are ready. Otherwise, the channel
is buffered and communication succeeds without blocking if the buffer
is not full (sends) or not empty (receives).
A <code>nil</code> channel is never ready for communication.
</p>

<p>
A channel may be closed with the built-in function

pkg syscall (netbsd-386), const PROT_EXEC ideal-int
pkg syscall (netbsd-386), const PROT_NONE = 0
pkg syscall (netbsd-386), const PROT_NONE ideal-int
pkg syscall (netbsd-386), const PROT_READ = 1
pkg syscall (netbsd-386), const PROT_READ ideal-int
pkg syscall (netbsd-386), const PROT_WRITE = 2
pkg syscall (netbsd-386), const PROT_WRITE ideal-int
pkg syscall (netbsd-386), func FcntlFlock(uintptr, int, *Flock_t) error