class MMHash < Hash
  def method_missing name, *args, &block
    self[name]
  end

  def [] index
    if index.is_a? String
      self[index.to_sym]
    else
      super
    end
  end
end



##### usage

CONF = {
  :group1 => {
    :a => 'a',
    :b => 'b',
    :c => 'c'
  },

  :group2 => {
    :aa => 1,
    :bb => 'bb'
  }
}


class MMHash < Hash
  def method_missing name, *args, &block
    self[name]
  end

  def [] index
    if index.is_a? String
      self[index.to_sym]
    else
      super
    end
  end
end

conf = MMHash.new

CONF.keys.each do |group|
  conf[group] = MMHash.new
  CONF[group].keys.each do |prop|
    conf[group][prop] = CONF[group][prop]
  end
end

p conf              # => {:group1=>{:a=>"a", :b=>"b", :c=>"c"}, :group2=>{:aa=>1, :bb=>"bb"}}
p conf[:group1]     # => {:a=>"a", :b=>"b", :c=>"c"}
p conf[:group1][:a] # => "a"
p conf[:group1][:t] # => nil
p conf.group10      # => nil
p conf.group1       # => {:a=>"a", :b=>"b", :c=>"c"}
p conf.group1.aa    # => nil
p conf['group10']   # => nil
p conf['group1']    # => {:a=>"a", :b=>"b", :c=>"c"}
p conf['group1'].aa # => nil
p conf['group1'].a  # => "a"

p conf.group10.aaa      # => Ideally this would be `nil`, but it seems impossible