hash.rb

class Hash
  def values_classify
    inject({}) do |options, (key, value)|
      options[key] = value.class
      options
    end
  end

  def values_classify!
    replace(self.values_classify)
  end

  def values_classify_recursive
    inject({}) do |options, (key, value)|
      if value.instance_of?(Hash)
        options[key] = value.values_classify_recursive
      else
        options[key] = value.class
      end
      options
    end
  end

  def replace_by_path(path, replae_value)
    inject({}) do |options, (key, value)|
      if path.instance_of?(Array) and path.first == key
        path.shift
        if path.empty?
          options[key] = replae_value
        else
          options[key] = self[key].replace_by_path(path, replae_value)
        end
      else
        options[key] = value
      end
      options
    end
  end
end


hash = {:aa => 'aa', :hash => {:foo => 'iaa'}, :bar => 'bar'}
hash.replace_by_path([:hash, :foo], "replacemenet")
#=>  {:bar=>"bar", :hash=>{:foo=>"replacemenet"}, :aa=>"aa"}
hash.values_classify           #= > {:bar=>String, :hash=>Hash, :aa=>String}
hash.values_classify_recursive #= > {:bar=>String, :hash=>{:foo=>String}, :aa=>String}
hash.values_classify!
hash                           #= > {:bar=>String, :hash=>Hash, :aa=>String}