brew/Library/Homebrew/options.rb

require 'set'

class Option
  attr_reader :name, :description, :flag

  def initialize(name, description="")
    @name = name
    @flag = "--#{name}"
    @description = description
  end

  def to_s
    flag
  end

  def <=>(other)
    return unless Option === other
    name <=> other.name
  end

  def ==(other)
    instance_of?(other.class) && name == other.name
  end
  alias_method :eql?, :==

  def hash
    name.hash
  end

  def inspect
    "#<#{self.class.name}: #{flag.inspect}>"
  end
end

class Options
  include Enumerable

  def self.create(array)
    new array.map { |e| Option.new(e[/^--(.+)$/, 1] || e) }
  end

  def initialize(*args)
    @options = Set.new(*args)
  end

  def each(*args, &block)
    @options.each(*args, &block)
  end

  def <<(o)
    @options << o
    self
  end

  def +(o)
    self.class.new(@options + o)
  end

  def -(o)
    self.class.new(@options - o)
  end

  def &(o)
    self.class.new(@options & o)
  end

  def |(o)
    self.class.new(@options | o)
  end

  def *(arg)
    @options.to_a * arg
  end

  def empty?
    @options.empty?
  end

  def as_flags
    map(&:flag)
  end

  def include?(o)
    any? { |opt| opt == o || opt.name == o || opt.flag == o }
  end

  alias_method :to_ary, :to_a

  def inspect
    "#<#{self.class.name}: #{to_a.inspect}>"
  end
end