[ruby-core:122384] [Ruby Bug#21392] Data classes do not allow overriding #inspect
From:
"austin (Austin Ziegler) via ruby-core" <ruby-core@...>
Date:
2025-06-03 02:14:59 UTC
List:
ruby-core #122384
Issue #21392 has been updated by austin (Austin Ziegler).
nobu (Nobuyoshi Nakada) wrote in #note-5:
> austin (Austin Ziegler) wrote in #note-3:
> > You are correct (and I should have known better; I have unit tests proving this).
>
> What unit tests?
In my feature branch where I'm converting to Data classes.
>
> You can define `pretty_print` for IRB.
>
> ```ruby
> def pretty_print(q)
> q.text "CIELAB"
> q.breakable
> q.group 2, "[", "]" do
> q.text "%.4f%%" % l
> q.breakable
> q.text "%.4f" % a
> q.breakable
> q.text "%.4f" % b
> end
> end
> ```
This is the problem, of course, with having maintained something backwards compatible (Color is currently _nominally_ valid for 1.8) as long as I have. I wasn't aware that there was a new call for defining a pretty print, because IRB *used* to fall back to `inspect`. However, `Data` classes presumably define a pretty printer and overrides `#inspect` within IRB.
This is good to know, and I'll define a `pretty_print` method.
This can be closed.
----------------------------------------
Bug #21392: Data classes do not allow overriding #inspect
https://bugs.ruby-lang.org/issues/21392#change-113532
* Author: austin (Austin Ziegler)
* Status: Assigned
* Assignee: ima1zumi (Mari Imaizumi)
* ruby -v: 3.4.4
* Backport: 3.2: UNKNOWN, 3.3: UNKNOWN, 3.4: UNKNOWN
----------------------------------------
I'm preparing a new version of Color and I have decided to make all of the colour classes Data classes. However, it does not appear that `#inspect` can be overridden:
```ruby
module Color
CIELAB = Data.define(:l, :a, :b) do
def inspect
"CIELAB [%.4f%% %.4f %.4f]" % [l, a, b]
end
end
end
p Color::CIELAB[1,2,3]
# Expected => CIELAB[1.000% 2.000 3.000]
# Actual #<data Color::CIELAB l=10, a=-125.0, b=20.5>
```
This feels like it should be permitted.
--
https://bugs.ruby-lang.org/
______________________________________________
ruby-core mailing list -- ruby-core@ml.ruby-lang.org
To unsubscribe send an email to ruby-core-leave@ml.ruby-lang.org
ruby-core info -- https://ml.ruby-lang.org/mailman3/lists/ruby-core.ml.ruby-lang.org/