Declarative means to define object properties by passing a hash to the constructor, which will set the corresponding ivars.
require 'constructor' class Horse constructor :name, :breed, :weight end Horse.new :name => 'Ed', :breed => 'Mustang', :weight => 342
By default the ivars do not get accessors defined. But you can get them auto-made if you want:
class Horse constructor :name, :breed, :weight, :accessors => true end ... puts my_horse.weight
Arguments specified are required by default. You can disable strict argument checking with :strict option. This means that the constructor will not raise an error if you pass more or fewer arguments than declared.
class Donkey constructor :age, :odor, :strict => false end
… this allows you to pass either an age or odor key (or neither) to the Donkey constructor.
sudo gem install constructor
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