4 files changed, 54 insertions, 3 deletions
diff --git a/mrbgems/mruby-object-ext/mrbgem.rake b/mrbgems/mruby-object-ext/mrbgem.rake
index 6d14b4a51..1aea2c8cd 100644
--- a/mrbgems/mruby-object-ext/mrbgem.rake
+++ b/mrbgems/mruby-object-ext/mrbgem.rake
@@ -1,5 +1,5 @@
 MRuby::Gem::Specification.new('mruby-object-ext') do |spec|
   spec.license = 'MIT'
   spec.author  = 'mruby developers'
-  spec.summary = 'Object class extension'
+  spec.summary = 'extensional methods shared by all objects'
 end
diff --git a/mrbgems/mruby-object-ext/mrblib/object.rb b/mrbgems/mruby-object-ext/mrblib/object.rb
index 581156cb0..f014df469 100644
--- a/mrbgems/mruby-object-ext/mrblib/object.rb
+++ b/mrbgems/mruby-object-ext/mrblib/object.rb
@@ -1,4 +1,18 @@
-class Object
+module Kernel
+  # call-seq:
+  #   obj.yield_self {|_obj|...} -> an_object
+  #   obj.then {|_obj|...}       -> an_object
+  #
+  # Yields <i>obj</i> and returns the result.
+  #
+  #   'my string'.yield_self {|s|s.upcase} #=> "MY STRING"
+  #
+  def yield_self(&block)
+    return to_enum :yield_self unless block
+    block.call(self)
+  end
+  alias then yield_self
+
   ##
   #  call-seq:
   #     obj.tap{|x|...}    -> obj
diff --git a/mrbgems/mruby-object-ext/src/object.c b/mrbgems/mruby-object-ext/src/object.c
index b076b3ec0..0aedc9a73 100644
--- a/mrbgems/mruby-object-ext/src/object.c
+++ b/mrbgems/mruby-object-ext/src/object.c
@@ -1,6 +1,7 @@
 #include <mruby.h>
 #include <mruby/array.h>
 #include <mruby/class.h>
+#include <mruby/hash.h>
 #include <mruby/proc.h>
 
 /*
@@ -33,6 +34,19 @@ nil_to_f(mrb_state *mrb, mrb_value obj)
 
 /*
  *  call-seq:
+ *     nil.to_h    -> {}
+ *
+ *  Always returns an empty hash.
+ */
+
+static mrb_value
+nil_to_h(mrb_state *mrb, mrb_value obj)
+{
+  return mrb_hash_new(mrb);
+}
+
+/*
+ *  call-seq:
  *     nil.to_i    -> 0
  *
  *  Always returns zero.
@@ -46,6 +60,22 @@ nil_to_i(mrb_state *mrb, mrb_value obj)
 
 /*
  *  call-seq:
+ *     obj.itself -> an_object
+ *
+ *  Returns <i>obj</i>.
+ *
+ *      string = 'my string' #=> "my string"
+ *      string.itself.object_id == string.object_id #=> true
+ *
+ */
+static mrb_value
+mrb_f_itself(mrb_state *mrb, mrb_value self)
+{
+  return self;
+}
+
+/*
+ *  call-seq:
  *     obj.instance_exec(arg...) {|var...| block }                       -> obj
  *
  *  Executes the given block within the context of the receiver
@@ -101,9 +131,12 @@ mrb_mruby_object_ext_gem_init(mrb_state* mrb)
 #ifndef MRB_WITHOUT_FLOAT
   mrb_define_method(mrb, n, "to_f", nil_to_f,       MRB_ARGS_NONE());
 #endif
+  mrb_define_method(mrb, n, "to_h", nil_to_h,       MRB_ARGS_NONE());
   mrb_define_method(mrb, n, "to_i", nil_to_i,       MRB_ARGS_NONE());
 
-  mrb_define_method(mrb, mrb->kernel_module, "instance_exec", mrb_obj_instance_exec, MRB_ARGS_ANY() | MRB_ARGS_BLOCK());
+  mrb_define_method(mrb, mrb->kernel_module, "itself", mrb_f_itself, MRB_ARGS_NONE());
+
+  mrb_define_method(mrb, mrb_class_get(mrb, "BasicObject"), "instance_exec", mrb_obj_instance_exec, MRB_ARGS_ANY() | MRB_ARGS_BLOCK());
 }
 
 void
diff --git a/mrbgems/mruby-object-ext/test/nil.rb b/mrbgems/mruby-object-ext/test/nil.rb
index fbff20629..9975e785a 100644
--- a/mrbgems/mruby-object-ext/test/nil.rb
+++ b/mrbgems/mruby-object-ext/test/nil.rb
@@ -7,6 +7,10 @@ assert('NilClass#to_f') do
   assert_equal 0.0, nil.to_f
 end
 
+assert('NilClass#to_h') do
+  assert_equal Hash.new, nil.to_h
+end
+
 assert('NilClass#to_i') do
   assert_equal 0, nil.to_i
 end