ruby_tco_flag.rb

def traverse(tail)
  head = list.shift
  puts "Element: #{head}, Stack Count: #{caller.count}" #=> new line
  return if tail.empty?
  traverse(tail)
end

# Normal ruby
traverse(large_array)
# Element: 1, 			Stack Count: 1
# Element: ..., 		Stack Count: ...
# Element: ..., 		Stack Count: ...
# Element: 10918, 	Stack Count: 10918
# => stack level too deep (SystemStackError)

# TCO-enabled
traverse(large_array)
# Element: 1, 			Stack Count: 1
# Element: ..., 		Stack Count: 1
# Element: ..., 		Stack Count: 1
# Element: 500000, 	Stack Count: 1