class Ransack::Predicate

def initialize(opts = {})
  @name = opts[:name]
  @arel_predicate = opts[:arel_predicate]
  @type = opts[:type]
  @formatter = opts[:formatter]
  @validator = opts[:validator] ||
    lambda { |v| v.respond_to?(:empty?) ? !v.empty? : !v.nil? }
  @compound = opts[:compound]
  @wants_array = opts.fetch(:wants_array,
    @compound || Constants::IN_NOT_IN.include?(@arel_predicate))
end