Order / Limit an Array, like in SQL: array.order('score DESC, name').limit(3)

ruby array order.rb

class Array
  DESC_RX = /\s*desc$/i
  ASC_DESC_RX = /\s*(?:asc|desc)$/i

  def order(by)
    by = by.split(',').map(&:strip)

    sort do |a, b|
      by_is_desc = by.map { |col| col =~ DESC_RX }
      by_cols = by.map { |col| col.sub(ASC_DESC_RX, "") }

      by_values_a = by_cols.map { |col| a.send(col) }
      by_values_b = by_cols.map { |col| b.send(col) }

      by_is_desc.each.with_index do |is_desc, i|
        next unless is_desc
        by_values_a[i], by_values_b[i] = by_values_b[i], by_values_a[i]
      end

      by_values_a <=> by_values_b
    end
  end
  
  def limit(*args)
    if args.length > 1
      slice(args[0], args[1])
    else
      first(args[0])
    end
  end
end