gistfile1.rb

class SignalVariable
  attr_reader :value
 
  def add(val)
    #we switch from a raw string to an array if this is the second time we've added
    if @value
      #add the new value to the array 
      #it looks strange but it doesn't matter how many times you have added an item
      #it's easier then an if x then y else z concept to me
      @value = [@value, val].flatten
    else
      @value = val
    end
  end
end

class Signal
  def initialize()
    #setup the hash and have it create the variable object for every new item
    @variables = Hash.new{ |h,k| h[k] = SignalVariable.new }
  end

  def add_variable(name, value)
    @variables[name].add(value)
  end
 
  def method_missing(name, *args)
    #this will allow a call to Signal.xxx to return xxx automatically 
    #no need to define every variable
    return @variables[name].value if @variables.key?(name)
    super
  end
end