re-anon-class-in-ruby-no-variable-struct.rb

# re: http://twitter.com/kazuho/status/684889103796600832

def run_each(obj)
  obj.each {|v| p v }
  obj.close
end

def test
  o = Struct.new(:is_open) do
    def each(&block)
      block.yield "hello\n"
    end

    def close
      self.is_open = false
    end
  end.new

  run_each(o)

  if o.is_open
    raise "close is not called!"
  end
end

test

re-anon-class-in-ruby-no-variable.rb

# re: http://twitter.com/kazuho/status/684889103796600832

def run_each(obj)
  obj.each {|v| p v }
  obj.close
end

def test
  o = Class.new do
    def initialize
      @is_open = false
    end

    attr_reader :is_open

    def each(&block)
      block.yield "hello\n"
    end

    def close
      @is_open = false
    end
  end.new

  run_each(o)

  if o.is_open
    raise "close is not called!"
  end
end

test

re-anon-class-in-ruby.rb

# re: http://twitter.com/kazuho/status/684889103796600832

def run_each(obj)
  obj.each {|v| p v }
  obj.close
end

def test
  is_open = true

  c = Class.new do
    define_method(:each) {|&block| block.yield "hello\n" }
    define_method(:close) { is_open = false }
  end
  run_each(c.new)

  if is_open
    raise "close is not called!"
  end
end

test