Functional While look in ruby

while.rb

class While
  def initialize(&src_fn)
		@src_fn = src_fn
	end

	def do
		x = @src_fn.call
		while(x)
			yield(x)
			x = @src_fn.call
		end
	end
end

# While.new{@a = 1 + (@a || 0); @a <= 100 ? @a : nil}.do{|x| puts x}
# counts up to 100