pyramids.rb

trap('INT') do
  print("\n")
  exit
end

output = Enumerator.new do |yielder|
  chars = "▁▂▃▄▅▆█".split("")
  chars = chars + chars.reverse
  nums = (0..(chars.length - 1)).to_a
  loop do
    char = chars.fetch(nums.first)
    yielder << char
    nums.rotate!
  end
end

loop do
  print output.next
  sleep 0.1
end