From: tenderlove@ruby-lang.org
To: ruby-core@ruby-lang.org
Subject: [ruby-core:100458] [Ruby master Misc#17199] id outputed by inspect and to_s output does not allow to find actual object_id and vice-versa
Date: Tue, 20 Oct 2020 21:32:16 +0000 (UTC) [thread overview]
Message-ID: <redmine.journal-88077.20201020213215.44605@ruby-lang.org> (raw)
In-Reply-To: redmine.issue-17199.20200928114039.44605@ruby-lang.org
Issue #17199 has been updated by tenderlovemaking (Aaron Patterson).
File 0001-Use-the-object-id-in-the-default-implementation-of-i.patch added
I think adding the object id to `inspect` is a good idea, though I think it should just have the object id, not `object_id >> 1` (or any other permutation). I don't think adding the object id to heap dumps is a good idea though since we would have to generate an object id for every object in the heap.
I've attached a patch with the object id in `inspect`
----------------------------------------
Misc #17199: id outputed by inspect and to_s output does not allow to find actual object_id and vice-versa
https://bugs.ruby-lang.org/issues/17199#change-88077
* Author: Annih (Baptiste Courtois)
* Status: Open
* Priority: Normal
----------------------------------------
Hello, here is my first ruby issue sorry in advance if it is incorrectly filled.
# Issue
The value returned by `#object_id` is not aligned anymore with displayed info in `#inspect` and `#to_s` methods.
## with ruby < 2.7
``` ruby
Object.new.tap { |o| p "#to_s=#{o.to_s}, #inspect=#{o.inspect}, #__id__=#{o.__id__}, shifted_id=#{(o.__id__ << 1).to_s(16)}" }
"#to_s=#<Object:0x0000000000d202a8>, #inspect=#<Object:0x0000000000d202a8>, #__id__=6881620, shifted_id=d202a8"
```
## with ruby >= 2.7
``` ruby
Object.new.tap { |o| p "#to_s=#{o.to_s}, #inspect=#{o.inspect}, #__id__=#{o.__id__}, shifted_id=#{(o.__id__ << 1).to
s(16)}" }
"#to_s=#<Object:0x0000555dc8640b88>, #inspect=#<Object:0x0000555dc8640b88>, #__id__=220, shifted_id=1b8"
```
# Consequences
It makes harder:
- to implement a clean override of the `#inspect` method. i.e. How to keep the same output without ability to compute to the same "object_id" value.
- to debug the object using the inspect output. i.e. `ObjectSpace._id2ref(id_from_inspect >> 1)` used to work, now it doesn't (`RangeError: <xXx> is not id value`).
# Suggestion
IMHO either:
- the `#to_s` and `#inspect` documentation are obsolete `The default [...] [shows|prints] [...] an encoding of the object id` and the change could have been a bit more advertised
- they should use the result of `#object_id` instead of displaying the object pointer address
Another solution could be to provide a method to get access to the address, but I'm not sure you want that.
P.S. While debugging my problem I found [this ruby-forum thread](https://www.ruby-forum.com/t/understanding-object-id-in-ruby-2-7/260268/4) where people dived a bit more than me into ruby's code.
---Files--------------------------------
0001-Use-the-object-id-in-the-default-implementation-of-i.patch (1.16 KB)
--
https://bugs.ruby-lang.org/
next prev parent reply other threads:[~2020-10-20 21:32 UTC|newest]
Thread overview: 7+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-09-28 11:40 [ruby-core:100200] [Ruby master Misc#17199] id outputed by inspect and to_s output does not allow to find actual object_id and vice-versa baptiste.courtois
2020-10-20 15:55 ` [ruby-core:100446] " chris
2020-10-20 18:31 ` [ruby-core:100448] " johnson.joel.b
2020-10-20 20:06 ` [ruby-core:100450] " eregontp
2020-10-20 20:15 ` [ruby-core:100451] " nate.berkopec
2020-10-20 21:32 ` tenderlove [this message]
2020-10-20 21:35 ` [ruby-core:100459] " tenderlove
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