Documentation cleanup.

Includes patches by Hugh Sasse:
* ping.rb
* weakref.rb
* mailread.rb


git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@10668 b2dd03c8-39d4-4d8f-98ff-823fe69b080e

lib/tsort.rb

@@ -8,10 +8,11 @@
 # TSort implements topological sorting using Tarjan's algorithm for
 # strongly connected components.
 #
-# TSort is designed to be able to be used with any object which can be interpreted
-# as a directed graph.
-# TSort requires two methods to interpret an object as a graph:
-# tsort_each_node and tsort_each_child:
+# TSort is designed to be able to be used with any object which can be
+# interpreted as a directed graph.
+#
+# TSort requires two methods to interpret an object as a graph,
+# tsort_each_node and tsort_each_child.
 #
 # * tsort_each_node is used to iterate for all nodes over a graph.
 # * tsort_each_child is used to iterate for child nodes of a given node.
@@ -30,82 +31,82 @@
 # method, which fetches the array of child nodes and then iterates over that
 # array using the user-supplied block.
 #
-#  require 'tsort'
-#
-#  class Hash
-#    include TSort
-#    alias tsort_each_node each_key
-#    def tsort_each_child(node, &block)
-#      fetch(node).each(&block)
-#    end
-#  end
-#
-#  {1=>[2, 3], 2=>[3], 3=>[], 4=>[]}.tsort
-#  #=> [3, 2, 1, 4]
-#
-#  {1=>[2], 2=>[3, 4], 3=>[2], 4=>[]}.strongly_connected_components
-#  #=> [[4], [2, 3], [1]]
+#   require 'tsort'
+#   
+#   class Hash
+#     include TSort
+#     alias tsort_each_node each_key
+#     def tsort_each_child(node, &block)
+#       fetch(node).each(&block)
+#     end
+#   end
+#   
+#   {1=>[2, 3], 2=>[3], 3=>[], 4=>[]}.tsort
+#   #=> [3, 2, 1, 4]
+#   
+#   {1=>[2], 2=>[3, 4], 3=>[2], 4=>[]}.strongly_connected_components
+#   #=> [[4], [2, 3], [1]]
 #
 # == A More Realistic Example
 #
 # A very simple `make' like tool can be implemented as follows:
 #
-#  require 'tsort'
-#
-#  class Make
-#    def initialize
-#      @dep = {}
-#      @dep.default = []
-#    end
-#
-#    def rule(outputs, inputs=[], &block)
-#      triple = [outputs, inputs, block]
-#      outputs.each {|f| @dep[f] = [triple]}
-#      @dep[triple] = inputs
-#    end
-#
-#    def build(target)
-#      each_strongly_connected_component_from(target) {|ns|
-#        if ns.length != 1
-#          fs = ns.delete_if {|n| Array === n}
-#          raise TSort::Cyclic.new("cyclic dependencies: #{fs.join ', '}")
-#        end
-#        n = ns.first
-#        if Array === n
-#          outputs, inputs, block = n
-#          inputs_time = inputs.map {|f| File.mtime f}.max
-#          begin
-#            outputs_time = outputs.map {|f| File.mtime f}.min
-#          rescue Errno::ENOENT
-#            outputs_time = nil
-#          end
-#          if outputs_time == nil ||
-#             inputs_time != nil && outputs_time <= inputs_time
-#            sleep 1 if inputs_time != nil && inputs_time.to_i == Time.now.to_i
-#            block.call
-#          end
-#        end
-#      }
-#    end
-#
-#    def tsort_each_child(node, &block)
-#      @dep[node].each(&block)
-#    end
-#    include TSort
-#  end
-#
-#  def command(arg)
-#    print arg, "\n"
-#    system arg
-#  end
-#
-#  m = Make.new
-#  m.rule(%w[t1]) { command 'date > t1' }
-#  m.rule(%w[t2]) { command 'date > t2' }
-#  m.rule(%w[t3]) { command 'date > t3' }
-#  m.rule(%w[t4], %w[t1 t3]) { command 'cat t1 t3 > t4' }
-#  m.rule(%w[t5], %w[t4 t2]) { command 'cat t4 t2 > t5' }
-#  m.build('t5')
+#   require 'tsort'
+#   
+#   class Make
+#     def initialize
+#       @dep = {}
+#       @dep.default = []
+#     end
+#     
+#     def rule(outputs, inputs=[], &block)
+#       triple = [outputs, inputs, block]
+#       outputs.each {|f| @dep[f] = [triple]}
+#       @dep[triple] = inputs
+#     end
+#     
+#     def build(target)
+#       each_strongly_connected_component_from(target) {|ns|
+#         if ns.length != 1
+#           fs = ns.delete_if {|n| Array === n}
+#           raise TSort::Cyclic.new("cyclic dependencies: #{fs.join ', '}")
+#         end
+#         n = ns.first
+#         if Array === n
+#           outputs, inputs, block = n
+#           inputs_time = inputs.map {|f| File.mtime f}.max
+#           begin
+#             outputs_time = outputs.map {|f| File.mtime f}.min
+#           rescue Errno::ENOENT
+#             outputs_time = nil
+#           end
+#           if outputs_time == nil ||
+#              inputs_time != nil && outputs_time <= inputs_time
+#             sleep 1 if inputs_time != nil && inputs_time.to_i == Time.now.to_i
+#             block.call
+#           end
+#         end
+#       }
+#     end
+#     
+#     def tsort_each_child(node, &block)
+#       @dep[node].each(&block)
+#     end
+#     include TSort
+#   end
+#   
+#   def command(arg)
+#     print arg, "\n"
+#     system arg
+#   end
+#   
+#   m = Make.new
+#   m.rule(%w[t1]) { command 'date > t1' }
+#   m.rule(%w[t2]) { command 'date > t2' }
+#   m.rule(%w[t3]) { command 'date > t3' }
+#   m.rule(%w[t4], %w[t1 t3]) { command 'cat t1 t3 > t4' }
+#   m.rule(%w[t5], %w[t4 t2]) { command 'cat t4 t2 > t5' }
+#   m.build('t5')
 #
 # == Bugs
 #