ActiveSupport::OrderedOptions

Usually key value pairs are handled something like this:

h = {}
h[:boy] = 'John'
h[:girl] = 'Mary'
h[:boy]  # => 'John'
h[:girl] # => 'Mary'
h[:dog]  # => nil

Using OrderedOptions, the above code could be reduced to:

h = ActiveSupport::OrderedOptions.new
h.boy = 'John'
h.girl = 'Mary'
h.boy  # => 'John'
h.girl # => 'Mary'
h.dog  # => nil

To raise an exception when the value is blank, append a bang to the key name, like:

h.dog! # => raises KeyError: :dog is blank