From: Lazaridis Ilias <ilias@...>
Date: 2011-06-26T11:01:03+09:00
Subject: [ruby-core:37358] [Ruby 1.9 - Bug #4893] Literal Instantiation breaks Object Model


Issue #4893 has been updated by Lazaridis Ilias.

File String_call_initialize.diff added

Yukihiro Matsumoto wrote:
> Your request has been too vague for me.  Your definition of terms such as "object model" seems different from others.  Probably the code will tell what you want.  I will reopen this issue when a patch is posted

Find attached a draft version of the modification (against branches/ruby_1_9_2) for review. The code should be self-explaining. I've tested on windows 7 with a small test-program (functionality) and with "nmake test" (compatibility when unused).

As you can see, the speed overhead (default, String.call_initialize = false) is near zero (one "if" call against "int").

If a user wants to have his alternate "initialize" method called, he just sets "String.call_initialize = true". The initialize method is called, passing the allocated and semi-initialized string object as a parameter. The user can now process the object as needed, thus it becomes full-initialized and identical to string objects instantiated by String#new().

I can invest some time refined the patch further, if needed. Please just let me know your requirements.
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Bug #4893: Literal Instantiation breaks Object Model
http://redmine.ruby-lang.org/issues/4893

Author: Lazaridis Ilias
Status: Rejected
Priority: Normal
Assignee: 
Category: 
Target version: 
ruby -v: 1.9.2


#String2.rb 
class String 
  def initialize(val) 
    self.replace(val) 
    puts object_id 
  end 
  def my_method_test 
    'has method <my_method_test>' 
  end 
end 

# command line 
$ irb 
irb(main):001:0> original = String.new("original") 
=> "original" 
irb(main):002:0> load "String2.rb" 
=> true 
irb(main):003:0> altered = String.new("altered") 
21878604 
=> "altered" 
irb(main):004:0> altered.my_method_test 
=> "has method <my_method_test>" 
irb(main):005:0> literal = "literal" 
=> "literal" 
irb(main):006:0> literal.my_method_test 
=> "has method <my_method_test>" 
irb(main):007:0> 

- 

The initialize method is an integral part of the class String. 
From the moment that "String2.rb" is loaded, the initialize method of 
class String has been validly redefined. 

(The behaviour of the String class within the "irb session" is 
altered) 

The altered initialize method is now an integral part of the class 
String. 

The altered String object behaves as expected (responds to 
"my_method_test, initialized via redefined initialize method). 

The String(Literal) object responds to "my_method_test", but it is was 
not initialized with the redefined initialize method. 

- 

The "Literal Instantiation" calls the original (core-C-level) String 
initialize method instead of the redefined one (user-language-level). 
This *breaks* the object model. 





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