Struct Inheritance

Here is a quick post to remember the days in Ruby that we used to use the struct inheritance pattern when we didn’t want to define classes with loads of attribute methods. As a quick shortcut to building a full object we can build a class that just inherits the methods from a struct. This is because everything in Ruby is an object. You can also define methods inside your struct class if you use this pattern.

class Stat < Struct.new(:time, :detail)
  def fullstat
    details.to_s + time.days.ago.to_s
  end
end

The normal way to use a struct is:

Stat = Struct.new(:time, :detail)

You would use this struct class like this, which is exactly the same as a normal class:

Stat.new(Time.now, :warn_log).fullstat

Your not supposed to inherit from this class and it’s meant to be lightweight. If you wan’t something with more flexibility then you can use OpenStruct by requiring ‘ostruct’ which will return an instantiated object.

Normal instantiated structs can be compared and also get enumerable methods on them.