module ActiveRecord::AttributeAssignment

def _assign_attributes(attributes) 

def _assign_attributes(attributes)
  multi_parameter_attributes = nested_parameter_attributes = nil
  attributes.each do |k, v|
    key = k.to_s
    if key.include?("(")
      (multi_parameter_attributes ||= {})[key] = v
    elsif v.is_a?(Hash)
      (nested_parameter_attributes ||= {})[key] = v
    else
      _assign_attribute(key, v)
    end
  end
  assign_nested_parameter_attributes(nested_parameter_attributes) if nested_parameter_attributes
  assign_multiparameter_attributes(multi_parameter_attributes) if multi_parameter_attributes
end

def assign_multiparameter_attributes(pairs)

f for Float. If all the values for a given attribute are empty, the attribute will be set to +nil+.
parentheses to have the parameters typecasted before they're used in the constructor. Use i for Integer and
written_on (a date type) with Date.new("2004", "6", "24"). You can also specify a typecast character in the
So having the pairs written_on(1) = "2004", written_on(2) = "6", written_on(3) = "24", will instantiate
by calling new on the column type or aggregation type (through composed_of) object with these parameters.
Instantiates objects for all attribute classes that needs more than one constructor parameter. This is done 
def assign_multiparameter_attributes(pairs)
  execute_callstack_for_multiparameter_attributes(
    extract_callstack_for_multiparameter_attributes(pairs)
  )
end

def assign_nested_parameter_attributes(pairs)

Assign any deferred nested attributes after the base attributes have been set. 
def assign_nested_parameter_attributes(pairs)
  pairs.each { |k, v| _assign_attribute(k, v) }
end

def execute_callstack_for_multiparameter_attributes(callstack) 

def execute_callstack_for_multiparameter_attributes(callstack)
  errors = []
  callstack.each do |name, values_with_empty_parameters|
    if values_with_empty_parameters.each_value.all?(NilClass)
      values = nil
    else
      values = values_with_empty_parameters
    end
    send("#{name}=", values)
  rescue => ex
    errors << AttributeAssignmentError.new("error on assignment #{values_with_empty_parameters.values.inspect} to #{name} (#{ex.message})", ex, name)
  end
  unless errors.empty?
    error_descriptions = errors.map(&:message).join(",")
    raise MultiparameterAssignmentErrors.new(errors), "#{errors.size} error(s) on assignment of multiparameter attributes [#{error_descriptions}]"
  end
end

def extract_callstack_for_multiparameter_attributes(pairs) 

def extract_callstack_for_multiparameter_attributes(pairs)
  attributes = {}
  pairs.each do |(multiparameter_name, value)|
    attribute_name = multiparameter_name.split("(").first
    attributes[attribute_name] ||= {}
    parameter_value = value.empty? ? nil : type_cast_attribute_value(multiparameter_name, value)
    attributes[attribute_name][find_parameter_position(multiparameter_name)] ||= parameter_value
  end
  attributes
end

def find_parameter_position(multiparameter_name) 

def find_parameter_position(multiparameter_name)
  multiparameter_name.scan(/\(([0-9]*).*\)/).first.first.to_i
end

def type_cast_attribute_value(multiparameter_name, value) 

def type_cast_attribute_value(multiparameter_name, value)
  multiparameter_name =~ /\([0-9]*([if])\)/ ? value.send("to_" + $1) : value
end