Ruby Metaprogramming

greeting.rb

class Greeting
  def initialize text
    @text = text
  end
  
  def welcome
    @text
  end
end

my_object = Greeting.new "Hello"
my_object.class # => Greeting
my_object.class.instance_methods false # => [:welcome]
my_object.instance_variables # => [:@text]

orb.rb

class Entity
  attr_reader :table, :ident
  
  def initialize table, ident
    @table = table
    @ident = ident
    Database.sql "INSERT INTO #{table} (id) VALUES (#{ident})"
  end
  
  def set col, val
    Database.sql "UPDATE #{table} SET #{col}='#{val}' WHERE id = #{ident}"
  end
  
  def get col
    Database.sql("SELECT #{col} FROM #{table} WHERE id = #{ident}")[0][0]
  end
end

test.rb

def test
end