recur_block.rb

def recur(value = [], &block)
  value << block.call(value.size)
  return value if value.size > 10

  recur(value, &block)
end

recur { |n| n + 1 }
#=> [1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11]

recur_lambda.rb

def recur(value = [], lamb)
  value << lamb.call(value.size)
  return value if value.size > 10

  recur(value, lamb)
end

recur -> n { n + 1 }
#=> [1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11]