rubyneverfails.rb

# Ruby syntax never fails to amaze me, casefile whatever.
# Yes, this could be accomplished more elegantly another way. But this is fun.

require 'ostruct'

def DStruct(*a)
  klass = Struct.new(*a)
  defs = Hash.new
  yield defs
  klass.send :define_method, :initialize do |*a|
    super
    for attrib, dval in defs
      self.send("#{attrib}=", dval) if self.send(attrib).nil?
    end
  end
  return klass
end

class Person <
  DStruct(:first, :last, :job) do |defaults|
    defaults[:first] = "Joe"
    defaults[:last]  = "Bloggs"
    defaults[:job]   = "Comic Gravedigger"
  end

  def describe
    "#{first} #{last}, the #{job}"
  end

end

dude = Person.new("Ann")
puts dude.describe   # ==> "Ann Bloggs, the Comic Gravedigger"
dude = Person.new(nil, nil, "Social Media Expert")
puts dude.describe   # ==> "Joe Bloggs, the Social Media Expert"