module CardsLib module IsSet class << self def verify(cards, rules = [:unique, :paired], specs = {}) max = specs.fetch(:max) {Float::INFINITY} min = specs.fetch(:min) { 3 } rules.all? {|r| send(r, cards) } && (min..max).include?(cards.count) end private def unique(cards) cards.combination(2).all? {|a,b| a != b } end using Refinements::InjectWhile def paired(cards) cards.inject_while?(:paired?) end def suited(cards) cards.inject_while?(:suited?) end def ordered(cards) cards.sort.inject_while?(:ordered?) end end end end