Import RDoc 3.1

git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@30413 b2dd03c8-39d4-4d8f-98ff-823fe69b080e

lib/rdoc/options.rb

@@ -240,6 +240,32 @@ class RDoc::Options
     @title ||= string
   end
 
+  ##
+  # Returns a properly-space list of generators and their descriptions.
+
+  def generator_descriptions
+    lengths = []
+
+    generators = RDoc::RDoc::GENERATORS.map do |name, generator|
+      lengths << name.length
+
+      description = generator::DESCRIPTION if
+        generator.const_defined? :DESCRIPTION
+
+      [name, description]
+    end
+
+    longest = lengths.max
+
+    generators.sort.map do |name, description|
+      if description then
+        "  %-*s - %s" % [longest, name, description]
+      else
+        "  #{name}"
+      end
+    end.join "\n"
+  end
+
   ##
   # Parse command line options.
 
@@ -274,8 +300,9 @@ Usage: #{opt.program_name} [options] [names...]
   will make rdoc show hashes in method links by default.  Command-line options
   always will override those in RDOCOPT.
 
-  - Darkfish creates frameless HTML output by Michael Granger.
-  - ri creates ri data files
+  Available formatters:
+
+#{generator_descriptions}
 
   RDoc understands the following file formats: