* range.c (rb_range_beg_len): should return Qfalse for non-range

  object.

* pack.c (EXTEND16): [ruby-dev:27383]

* eval.c (set_trace_func): add rb_secure(4) to prevent adding
  tracing function.

* lib/delegate.rb: document update from James Edward Gray II
  <james@grayproductions.net>.  [ruby-core:05942]

* process.c (proc_daemon): should restrict execution on levels
  higher than $SAFE=2.  suggested by URABE Shyouhei
  <shyouhei@ice.uec.ac.jp>.

* lib/forwardable.rb: replaced by new implementation from
  <Daniel.Berger@qwest.com>.  [ruby-core:05899]

* file.c (path_check_0): disallow sticky world writable directory
  in PATH (and $LOAD_PATH).  [ruby-dev:27226]

* numeric.c (fix_idiv): 1.div(1.0) should return integer value.
  [ruby-dev:27235]

* lib/yaml.rb: require 'yaml/constants'.  [ruby-core:5776]

* lib/xmlrpc/client.rb (XMLRPC::Client::do_rpc): add charset
  information to content-type header.[ruby-core:5127]

* lib/xmlrpc/server.rb (CGIServer::serve): ditto.

* lib/xmlrpc/server.rb (ModRubyServer::serve): ditto.

* lib/xmlrpc/server.rb (WEBrickServlet::service): ditto.

* test/dbm/test_dbm.rb (TestDBM::test_s_open_error): remove
  test_s_open_error test to detect duplicate open.
  [ruby-dev:27202]

* eval.c (splat_value): use to_a to splat non Array object.

* object.c (nil_to_a): remove nil.to_a.  [experimental]


git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@9349 b2dd03c8-39d4-4d8f-98ff-823fe69b080e

1 files changed, 174 insertions, 21 deletions

diff --git a/lib/delegate.rb b/lib/delegate.rb
index 83aaf292a5..b54b57d7b7 100644
--- a/lib/delegate.rb
+++ b/lib/delegate.rb
@@ -1,21 +1,119 @@
-#  Delegation class that delegates even methods defined in super class,
-# which can not be covered with normal method_missing hack.
-#  
-#  Delegator is the abstract delegation class. Need to redefine
-# `__getobj__' method in the subclass.  SimpleDelegator is the 
-# concrete subclass for simple delegation.
+# = delegate -- Support for the Delegation Pattern
 #
-# Usage:
-#   foo = Object.new
-#   foo2 = SimpleDelegator.new(foo)
-#   foo.hash == foo2.hash # => false
+# Documentation by James Edward Gray II and Gavin Sinclair
 #
-#   Foo = DelegateClass(Array)
+# == Introduction
 #
-#  class ExtArray<DelegateClass(Array)
-#    ...
-#  end
+# This library provides three different ways to delegate method calls to an
+# object.  The easiest to use is SimpleDelegator.  Pass an object to the
+# constructor and all methods supported by the object will be delegated.  This
+# object can be changed later.
+#
+# Going a step further, the top level DelegateClass method allows you to easily
+# setup delegation through class inheritance.  This is considerably more
+# flexible and thus probably the most common use for this library.
+#
+# Finally, if you need full control over the delegation scheme, you can inherit
+# from the abstract class Delegator and customize as needed.  (If you find
+# yourself needing this control, have a look at _forwardable_, also in the
+# standard library.  It may suit your needs better.)
+#
+# == Notes
+#
+# Be advised, RDoc will not detect delegated methods.
+#
+# <b>delegate.rb provides full-class delegation via the
+# DelegateClass() method.  For single-method delegation via
+# def_delegator(), see forwardable.rb.</b>
+#
+# == Examples
+#
+# === SimpleDelegator
+#
+# Here's a simple example that takes advantage of the fact that
+# SimpleDelegator's delegation object can be changed at any time.
+#
+#   class Stats
+#     def initialize
+#       @source = SimpleDelegator.new([])
+#     end
+#     
+#     def stats( records )
+#       @source.__setobj__(records)
+#       	
+#       "Elements:  #{@source.size}\n" +
+#       " Non-Nil:  #{@source.compact.size}\n" +
+#       "  Unique:  #{@source.uniq.size}\n"
+#     end
+#   end
+#   
+#   s = Stats.new
+#   puts s.stats(%w{James Edward Gray II})
+#   puts
+#   puts s.stats([1, 2, 3, nil, 4, 5, 1, 2])
+#
+# <i>Prints:</i>
+#
+#   Elements:  4
+#    Non-Nil:  4
+#     Unique:  4
+# 
+#   Elements:  8
+#    Non-Nil:  7
+#     Unique:  6
+#
+# === DelegateClass()
+#
+# Here's a sample of use from <i>tempfile.rb</i>.
+#
+# A _Tempfile_ object is really just a _File_ object with a few special rules
+# about storage location and/or when the File should be deleted.  That makes for
+# an almost textbook perfect example of how to use delegation.
+#
+#   class Tempfile < DelegateClass(File)
+#     # constant and class member data initialization...
+#   
+#     def initialize(basename, tmpdir=Dir::tmpdir)
+#       # build up file path/name in var tmpname...
+#     
+#       @tmpfile = File.open(tmpname, File::RDWR|File::CREAT|File::EXCL, 0600)
+#     
+#       # ...
+#     
+#       super(@tmpfile)
+#     
+#       # below this point, all methods of File are supported...
+#     end
+#   
+#     # ...
+#   end
+#
+# === Delegator
+#
+# SimpleDelegator's implementation serves as a nice example here.
+#
+#    class SimpleDelegator < Delegator
+#      def initialize(obj)
+#        super             # pass obj to Delegator constructor, required
+#        @_sd_obj = obj    # store obj for future use
+#      end
+# 
+#      def __getobj__
+#        @_sd_obj          # return object we are delegating to, required
+#      end
+# 
+#      def __setobj__(obj)
+#        @_sd_obj = obj    # change delegation object, a feature we're providing
+#      end
+# 
+#      # ...
+#    end
 
+#
+# Delegator is an abstract class used to build delegator pattern objects from
+# subclasses.  Subclasses should redefine \_\_getobj\_\_.  For a concrete
+# implementation, see SimpleDelegator.
+#
 class Delegator
   preserved = ["__id__", "object_id", "__send__", "respond_to?"]
   instance_methods.each do |m|
@@ -23,10 +121,15 @@ class Delegator
     undef_method m
   end
 
+  #
+  # Pass in the _obj_ to delegate method calls to.  All methods supported by
+  # _obj_ will be delegated to.
+  #
   def initialize(obj)
     __setobj__(obj)
   end
 
+  # Handles the magic of delegation through \_\_getobj\_\_.
   def method_missing(m, *args)
     begin
       target = self.__getobj__
@@ -40,42 +143,79 @@ class Delegator
     end
   end
 
+  # 
+  # Checks for a method provided by this the delegate object by fowarding the 
+  # call through \_\_getobj\_\_.
+  # 
   def respond_to?(m)
     return true if super
     return self.__getobj__.respond_to?(m)
   end
 
+  #
+  # This method must be overridden by subclasses and should return the object
+  # method calls are being delegated to.
+  #
   def __getobj__
     raise NotImplementedError, "need to define `__getobj__'"
   end
 
+  #
+  # This method must be overridden by subclasses and change the object delegate
+  # to _obj_.
+  #
   def __setobj__(obj)
     raise NotImplementedError, "need to define `__setobj__'"
   end
 
+  # Serialization support for the object returned by \_\_getobj\_\_.
   def marshal_dump
     __getobj__
   end
+  # Reinitializes delegation from a serialized object.
   def marshal_load(obj)
     __setobj__(obj)
   end
 end
 
+#
+# A concrete implementation of Delegator, this class provides the means to
+# delegate all supported method calls to the object passed into the constructor
+# and even to change the object being delegated to at a later time with
+# \_\_setobj\_\_ .
+#
 class SimpleDelegator<Delegator
+  # Returns the current object method calls are being delegated to.
   def __getobj__
     @_sd_obj
   end
 
+  #
+  # Changes the delegate object to _obj_.
+  #
+  # It's important to note that this does *not* cause SimpleDelegator's methods
+  # to change.  Because of this, you probably only want to change delegation
+  # to objects of the same type as the original delegate.
+  #
+  # Here's an example of changing the delegation object.
+  #
+  #   names = SimpleDelegator.new(%w{James Edward Gray II})
+  #   puts names[1]    # => Edward
+  #   names.__setobj__(%w{Gavin Sinclair})
+  #   puts names[1]    # => Sinclair
+  #
   def __setobj__(obj)
     raise ArgumentError, "cannot delegate to self" if self.equal?(obj)
     @_sd_obj = obj
   end
 
+  # Clone support for the object returned by \_\_getobj\_\_.
   def clone
     copy = super
     copy.__setobj__(__getobj__.clone)
     copy
   end
+  # Duplication support for the object returned by \_\_getobj\_\_.
   def dup
     copy = super
     copy.__setobj__(__getobj__.dup)
@@ -83,11 +223,22 @@ class SimpleDelegator<Delegator
   end
 end
 
+# :stopdoc:
 # backward compatibility ^_^;;;
 Delegater = Delegator
 SimpleDelegater = SimpleDelegator
+# :startdoc:
 
 #
+# The primary interface to this library.  Use to setup delegation when defining
+# your class.
+#
+#   class MyClass < DelegateClass( ClassToDelegateTo )    # Step 1
+#     def initiaize
+#       super(obj_of_ClassToDelegateTo)                   # Step 2
+#     end
+#   end
+#
 def DelegateClass(superclass)
   klass = Class.new
   methods = superclass.public_instance_methods(true)
@@ -97,31 +248,31 @@ def DelegateClass(superclass)
     "clone", "dup", "marshal_dump", "marshal_load",
   ]
   klass.module_eval {
-    def initialize(obj)
+    def initialize(obj)  # :nodoc:
       @_dc_obj = obj
     end
-    def method_missing(m, *args)
+    def method_missing(m, *args)  # :nodoc:
       unless @_dc_obj.respond_to?(m)
         super(m, *args)
       end
       @_dc_obj.__send__(m, *args)
     end
-    def respond_to?(m)
+    def respond_to?(m)  # :nodoc:
       return true if super
       return @_dc_obj.respond_to?(m)
     end
-    def __getobj__
+    def __getobj__  # :nodoc:
       @_dc_obj
     end
-    def __setobj__(obj)
+    def __setobj__(obj)  # :nodoc:
       raise ArgumentError, "cannot delegate to self" if self.equal?(obj)
       @_dc_obj = obj
     end
-    def clone
+    def clone  # :nodoc:
       super
       __setobj__(__getobj__.clone)
     end
-    def dup
+    def dup  # :nodoc:
       super
       __setobj__(__getobj__.dup)
     end
@@ -145,6 +296,8 @@ def DelegateClass(superclass)
   return klass
 end
 
+# :enddoc:
+
 if __FILE__ == $0
   class ExtArray<DelegateClass(Array)
     def initialize()