POSTするとき nyan.nyan1=nyan&nyan.nyan2=nyan って書きたかった

hash_fold.rb

class Hash
  def fold!(separator = '.')
    folder = {}

    each do |key, value|
      next unless key.is_a? String

      dir = key.split separator, -1

      next if dir.length == 1

      dir_last = dir.pop
      cd = folder

      dir.each do |d|
        cd[d] = {} unless cd[d].is_a? Hash
        cd = cd[d]
      end

      cd[dir_last] = value
      delete key
    end

    merge! folder
    self
  end
end

hash_fold_example.rb

nyan = {
  'nyan.nyan' => 'nyan.nyan',
  'nyan.nyan1' => 'nyan.nyan1',
  'nyan.nyan2' => 'nyan.nyan2',
  'nyan.nyan.nyan4' => 'nyan.nyan.nyan4',
  'nyan.nyan.nyan5' => 'nyan.nyan.nyan5'
}

p nyan.fold!

# {
#   "nyan" => {
#     "nyan" => {
#       "nyan4" => "nyan.nyan.nyan4",
#       "nyan5" => "nyan.nyan.nyan5"
#     },
#     "nyan1" => "nyan.nyan1",
#     "nyan2" => "nyan.nyan2"
#   }
# }