模块 Gem::VersionOption

# File lib/rubygems/version_option.rb, line 18
def add_platform_option(task = command, *wrap)
  Gem::OptionParser.accept Gem::Platform do |value|
    if value == Gem::Platform::RUBY
      value
    else
      Gem::Platform.new value
    end
  end

  add_option("--platform PLATFORM", Gem::Platform,
             "Specify the platform of gem to #{task}", *wrap) do |value, options|
    unless options[:added_platform]
      Gem.platforms = [Gem::Platform::RUBY]
      options[:added_platform] = true
    end

    Gem.platforms << value unless Gem.platforms.include? value
  end
end

# File lib/rubygems/version_option.rb, line 41
def add_prerelease_option(*wrap)
  add_option("--[no-]prerelease",
             "Allow prerelease versions of a gem", *wrap) do |value, options|
    options[:prerelease] = value
    options[:explicit_prerelease] = true
  end
end

# File lib/rubygems/version_option.rb, line 52
def add_version_option(task = command, *wrap)
  Gem::OptionParser.accept Gem::Requirement do |value|
    Gem::Requirement.new(*value.split(/\s*,\s*/))
  end

  add_option("-v", "--version VERSION", Gem::Requirement,
             "Specify version of gem to #{task}", *wrap) do |value, options|
    # Allow handling for multiple --version operators
    if options[:version] && !options[:version].none?
      options[:version].concat([value])
    else
      options[:version] = value
    end

    explicit_prerelease_set = !options[:explicit_prerelease].nil?
    options[:explicit_prerelease] = false unless explicit_prerelease_set

    options[:prerelease] = value.prerelease? unless
      options[:explicit_prerelease]
  end
end

# File lib/rubygems/version_option.rb, line 77
def get_platform_from_requirements(requirements)
  Gem.platforms[1].to_s if requirements.key? :added_platform
end