class ReeMapper::Integer

def cast(value, role: nil)
  if value.is_a?(Integer)
    value
  elsif value.is_a?(String)
    begin
      Integer(value)
    rescue ArgumentError => e
      raise ReeMapper::CoercionError, "is invalid integer"
    end
  else
    raise ReeMapper::TypeError, "should be an integer"
  end
end

def db_dump(value, role: nil)
  serialize(value, role: role)
end

def db_load(value, role: nil)
  cast(value, role: role)
end

def serialize(value, role: nil)
  if value.is_a? Integer
    value
  else
    raise ReeMapper::TypeError, 'should be an integer'
  end
end