rails/actionpack/lib/action_view/paths.rb

module ActionView #:nodoc:
  class PathSet < Array #:nodoc:
    def self.type_cast(obj)
      obj.is_a?(String) ? Path.new(obj) : obj
    end

    class Path #:nodoc:
      attr_reader :path, :paths
      delegate :to_s, :to_str, :inspect, :to => :path

      def initialize(path)
        @path = path.freeze
        reload!
      end

      def ==(path)
        to_str == path.to_str
      end

      def [](path)
        @paths[path]
      end

      # Rebuild load path directory cache
      def reload!
        @paths = {}

        templates_in_path do |template|
          @paths[template.path] = template
          @paths[template.path_without_extension] ||= template
        end

        @paths.freeze
      end

      private
        def templates_in_path
          (Dir.glob("#{@path}/**/*/**") | Dir.glob("#{@path}/**")).each do |file|
            unless File.directory?(file)
              template = Template.new(file.split("#{self}/").last, self)
              # Eager load memoized methods and freeze cached template
              template.freeze if Base.cache_template_loading
              yield template
            end
          end
        end
    end

    def initialize(*args)
      super(*args).map! { |obj| self.class.type_cast(obj) }
    end

    def reload!
      each { |path| path.reload! }
    end

    def <<(obj)
      super(self.class.type_cast(obj))
    end

    def push(*objs)
      delete_paths!(objs)
      super(*objs.map { |obj| self.class.type_cast(obj) })
    end

    def unshift(*objs)
      delete_paths!(objs)
      super(*objs.map { |obj| self.class.type_cast(obj) })
    end

    def [](template_path)
      each do |path|
        if template = path[template_path]
          return template
        end
      end
      nil
    end

    private
      def delete_paths!(paths)
        paths.each { |p1| delete_if { |p2| p1.to_s == p2.to_s } }
      end
  end
end