From: John Higgins <wishdev@...>
Date: 2011-07-14T03:37:56+09:00
Subject: [ruby-core:38059] [Ruby 1.9 - Feature #4893] Literal Instantiation breaks Object Model


Issue #4893 has been updated by John Higgins.


Lazaridis Ilias wrote:
> Although the latest version (v4) works fine, I dislike to use the callbacks to set/clear the flag.
> 
> I have "fuzzily" the perfect implementation in mind, but it will take a few days until it becomes clear. Until then, I would be "glad" if someone detects a problem with the existent solution.

You are hijacking the callbacks - if anyone implemented any of the callbacks your implementation fails because your callbacks won't fire anymore
----------------------------------------
Feature #4893: Literal Instantiation breaks Object Model
http://redmine.ruby-lang.org/issues/4893

Author: Lazaridis Ilias
Status: Assigned
Priority: Low
Assignee: Yukihiro Matsumoto
Category: 
Target version: 


#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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