[ruby-core:75311] [Ruby trunk Feature#12334] Final/Readonly Support for Fields / Instance Variables

Issue #12334 has been updated by Tsuyoshi Sawada.


I think what you want is a constant that belongs to an instance and can be defined in a method body (and further raises an error instead of warning when redefinition is attempted). But that does not make sense to me. It means that you can only call that method once. And it would bring many other impractical restrictions.

----------------------------------------
Feature #12334: Final/Readonly Support for Fields / Instance Variables
https://bugs.ruby-lang.org/issues/12334#change-58438

* Author: Brady Wied
* Status: Open
* Priority: Normal
* Assignee: 
----------------------------------------
This sort of relates to https://bugs.ruby-lang.org/issues/11911

C# through 'readonly' and Java through 'final' variables/fields allow me to only allow assigning a field in the initializer. It might be nice to embrace some controlled mutation by having this feature in Ruby. Sometimes its tempting in other methods to reassign a field but you really want to control that from the initializer.

Freezing targets a different problem by controlling what I can mutate within that field's object. The two can compliment each other but I see them as each solving a different problem. I know it's possible to freeze an entire instance of a class and not allow reassigning the field that way, but then I'm in an all or none situation where I can't have controlled mutation.



-- 
https://bugs.ruby-lang.org/

Unsubscribe: <mailto:[e-mail]?subject=unsubscribe>
<http://lists.ruby-lang.org/cgi-bin/mailman/options/ruby-core>