Closes the channel. The method prevents any new value from being sent to the channel.

If the channel has buffered values, then subsequent calls to #receive will succeed and consume the buffer until it is empty.

All fibers blocked in #send or #receive will be awakened with Channel::ClosedError. All subsequent calls to #send will consider the channel closed. Subsequent calls to #receive will consider the channel closed if the buffer is empty.

Calling #close on a closed channel does not have any effect.

It returns true when the channel was successfully closed, or false if it was already closed.

Appends a String representation of this object which includes its class name, its object address and the values of all instance variables.

class Person
  def initialize(@name : String, @age : Int32)
  end
end

Person.new("John", 32).inspect # => #<Person:0x10fd31f20 @name="John", @age=32>

Receives a value from the channel. If there is a value waiting, then it is returned immediately. Otherwise, this method blocks until a value is sent to the channel.

Raises ClosedError if the channel is closed or closes while waiting for receive.

channel = Channel(Int32).new
spawn do
  channel.send(1)
end
channel.receive # => 1

Receives a value from the channel. If there is a value waiting, it is returned immediately. Otherwise, this method blocks until a value is sent to the channel.

Returns nil if the channel is closed or closes while waiting for receive.

Sends a value to the channel. If the channel has spare capacity, then the method returns immediately. Otherwise, this method blocks the calling fiber until another fiber calls #receive on the channel.

Raises ClosedError if the channel is closed or closes while waiting on a full channel.