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Object#instance_exec produces fewer garbage methods.

git-svn-id: http://svn-commit.rubyonrails.org/rails/trunk@7621 5ecf4fe2-1ee6-0310-87b1-e25e094e27de
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1 parent eca3b79 commit 8e78a4542e80a2d8d593547ecf8021b0e2902a0d @jeremy jeremy committed
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2 activesupport/CHANGELOG
@@ -1,5 +1,7 @@
*SVN*
+* Object#instance_exec produces fewer garbage methods. [Mauricio Fernandez]
+
* Decode json strings as Dates/Times if they're using a YAML-compatible format. Closes #9614 [Rick]
* Fixed cache_page to use the request url instead of the routing options when picking a save path #8614 [josh]
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27 activesupport/lib/active_support/core_ext/object/extending.rb
@@ -42,10 +42,31 @@ def instance_values #:nodoc:
values
end
end
-
+
unless defined? instance_exec # 1.9
- def instance_exec(*arguments, &block) #:nodoc:
- block.bind(self)[*arguments]
+ module InstanceExecMethods #:nodoc:
+ end
+ include InstanceExecMethods
+
+ # Evaluate the block with the given arguments within the context of
+ # this object, so self is set to the method receiver.
+ #
+ # From Mauricio's http://eigenclass.org/hiki/bounded+space+instance_exec
+ def instance_exec(*args, &block)
+ begin
+ old_critical, Thread.critical = Thread.critical, true
+ n = 0
+ n += 1 while respond_to?(method_name = "__instance_exec#{n}")
+ InstanceExecMethods.module_eval { define_method(method_name, &block) }
+ ensure
+ Thread.critical = old_critical
+ end
+
+ begin
+ send(method_name, *args)
+ ensure
+ InstanceExecMethods.module_eval { remove_method(method_name) } rescue nil
+ end
end
end
end
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11 activesupport/test/core_ext/object_and_class_ext_test.rb
@@ -216,8 +216,15 @@ def test_instance_values
end
def test_instance_exec_passes_arguments_to_block
- block = Proc.new { |value| [self, value] }
- assert_equal %w(hello goodbye), 'hello'.instance_exec('goodbye', &block)
+ assert_equal %w(hello goodbye), 'hello'.instance_exec('goodbye') { |v| [self, v] }
end
+ def test_instance_exec_with_frozen_obj
+ assert_equal %w(olleh goodbye), 'hello'.freeze.instance_exec('goodbye') { |v| [reverse, v] }
+ end
+
+ def test_instance_exec_nested
+ assert_equal %w(goodbye olleh bar), 'hello'.instance_exec('goodbye') { |arg|
+ [arg] + instance_exec('bar') { |v| [reverse, v] } }
+ end
end

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