Merge pull request #4342 from jekyll/pr/remove-objectspace-and-use-inherited

Merge pull request 4342

lib/jekyll/generator.rb

@@ -1,4 +1,3 @@
 module Jekyll
-  class Generator < Plugin
+  Generator = Class.new(Plugin)
-  end
 end

lib/jekyll/plugin.rb

@@ -1,20 +1,39 @@
 module Jekyll
   class Plugin
-    PRIORITIES = { :lowest => -100,
+    PRIORITIES = {
       :low => -10,
+      :highest => 100,
+      :lowest => -100,
       :normal => 0,
-                   :high => 10,
+      :high => 10
-                   :highest => 100 }
+    }
 
-    # Fetch all the subclasses of this class and its subclasses' subclasses.
     #
-    # Returns an array of descendant classes.
+
-    def self.descendants
+    def self.inherited(const)
-      descendants = []
+      return catch_inheritance(const) do |const_|
-      ObjectSpace.each_object(singleton_class) do |k|
+        catch_inheritance(const_)
-        descendants.unshift k unless k == self
       end
-      descendants
+    end
+
+    #
+
+    def self.catch_inheritance(const)
+      const.define_singleton_method :inherited do |const_|
+        (@children ||= Set.new).add const_
+        if block_given?
+          yield const_
+        end
+      end
+    end
+
+    #
+
+    def self.descendants
+      @children ||= Set.new
+      out = @children.map(&:descendants)
+      out << self unless superclass == Plugin
+      Set.new(out).flatten
     end
 
     # Get or set the priority of this plugin. When called without an

lib/jekyll/site.rb

@@ -263,25 +263,21 @@ module Jekyll
     end
 
     # Get the implementation class for the given Converter.
-    #
-    # klass - The Class of the Converter to fetch.
-    #
     # Returns the Converter instance implementing the given Converter.
+    # klass - The Class of the Converter to fetch.
+
     def find_converter_instance(klass)
-      converters.find { |c| c.class == klass } || proc { raise "No converter for #{klass}" }.call
+      converters.find { |klass_| klass_.instance_of?(klass) } || \
+        raise("No Converters found for #{klass}")
     end
 
+    # klass - class or module containing the subclasses.
+    # Returns array of instances of subclasses of parameter.
     # Create array of instances of the subclasses of the class or module
     # passed in as argument.
-    #
+
-    # klass - class or module containing the subclasses which should be
-    #         instantiated
-    #
-    # Returns array of instances of subclasses of parameter
     def instantiate_subclasses(klass)
-      klass.descendants.select do |c|
+      klass.descendants.select { |c| !safe || c.safe }.sort.map do |c|
-        !safe || c.safe
-      end.sort.map do |c|
         c.new(config)
       end
     end