4 files changed, 35 insertions, 4 deletions
diff --git a/lib/optparse/ac.rb b/lib/optparse/ac.rb
index 0953725e46..23fc740d10 100644
--- a/lib/optparse/ac.rb
+++ b/lib/optparse/ac.rb
@@ -1,7 +1,11 @@
 # frozen_string_literal: false
 require_relative '../optparse'
 
+#
+# autoconf-like options.
+#
 class OptionParser::AC < OptionParser
+  # :stopdoc:
   private
 
   def _check_ac_args(name, block)
@@ -14,6 +18,7 @@ class OptionParser::AC < OptionParser
   end
 
   ARG_CONV = proc {|val| val.nil? ? true : val}
+  private_constant :ARG_CONV
 
   def _ac_arg_enable(prefix, name, help_string, block)
     _check_ac_args(name, block)
@@ -29,16 +34,27 @@ class OptionParser::AC < OptionParser
     enable
   end
 
+  # :startdoc:
+
   public
 
+  # Define <tt>--enable</tt> / <tt>--disable</tt> style option
+  #
+  # Appears as <tt>--enable-<i>name</i></tt> in help message.
   def ac_arg_enable(name, help_string, &block)
     _ac_arg_enable("enable", name, help_string, block)
   end
 
+  # Define <tt>--enable</tt> / <tt>--disable</tt> style option
+  #
+  # Appears as <tt>--disable-<i>name</i></tt> in help message.
   def ac_arg_disable(name, help_string, &block)
     _ac_arg_enable("disable", name, help_string, block)
   end
 
+  # Define <tt>--with</tt> / <tt>--without</tt> style option
+  #
+  # Appears as <tt>--with-<i>name</i></tt> in help message.
   def ac_arg_with(name, help_string, &block)
     _check_ac_args(name, block)
 
diff --git a/lib/optparse/kwargs.rb b/lib/optparse/kwargs.rb
index 992aca467e..59a2f61544 100644
--- a/lib/optparse/kwargs.rb
+++ b/lib/optparse/kwargs.rb
@@ -7,12 +7,17 @@ class OptionParser
   #
   # :include: ../../doc/optparse/creates_option.rdoc
   #
-  def define_by_keywords(options, meth, **opts)
-    meth.parameters.each do |type, name|
+  # Defines options which set in to _options_ for keyword parameters
+  # of _method_.
+  #
+  # Parameters for each keywords are given as elements of _params_.
+  #
+  def define_by_keywords(options, method, **params)
+    method.parameters.each do |type, name|
       case type
       when :key, :keyreq
         op, cl = *(type == :key ? %w"[ ]" : ["", ""])
-        define("--#{name}=#{op}#{name.upcase}#{cl}", *opts[name]) do |o|
+        define("--#{name}=#{op}#{name.upcase}#{cl}", *params[name]) do |o|
           options[name] = o
         end
       end
diff --git a/lib/optparse/optparse.gemspec b/lib/optparse/optparse.gemspec
index a4287ddeee..1aa54aa781 100644
--- a/lib/optparse/optparse.gemspec
+++ b/lib/optparse/optparse.gemspec
@@ -22,7 +22,8 @@ Gem::Specification.new do |spec|
   spec.metadata["homepage_uri"] = spec.homepage
   spec.metadata["source_code_uri"] = spec.homepage
 
-  spec.files         = Dir["{doc,lib,misc}/**/*"] + %w[README.md ChangeLog COPYING]
+  spec.files         = Dir["{doc,lib,misc}/**/{*,.document}"] +
+                       %w[README.md ChangeLog COPYING .document .rdoc_options]
   spec.rdoc_options  = ["--main=README.md", "--op=rdoc", "--page-dir=doc"]
   spec.bindir        = "exe"
   spec.executables   = []
diff --git a/lib/optparse/version.rb b/lib/optparse/version.rb
index b869d8fe51..b5ed695146 100644
--- a/lib/optparse/version.rb
+++ b/lib/optparse/version.rb
@@ -2,6 +2,11 @@
 # OptionParser internal utility
 
 class << OptionParser
+  #
+  # Shows version string in packages if Version is defined.
+  #
+  # +pkgs+:: package list
+  #
   def show_version(*pkgs)
     progname = ARGV.options.program_name
     result = false
@@ -47,6 +52,8 @@ class << OptionParser
     result
   end
 
+  # :stopdoc:
+
   def each_const(path, base = ::Object)
     path.split(/::|\//).inject(base) do |klass, name|
       raise NameError, path unless Module === klass
@@ -68,4 +75,6 @@ class << OptionParser
       end
     end
   end
+
+  # :startdoc:
 end