Issue #21826 has been updated by Eregon (Benoit Daloze). Note that any usage of `RubyVM::AbstractSyntaxTree` in a gem is, by the documentation of that class and `RubyVM`, invalid (not debugging, prototyping, and research). That doesn't mean we should break them carelessly, but I think that does mean we don't need to ask before deprecating (we don't even do that for public stable API methods). I agree it would be nicer if there is a replacement in the same release it's deprecated, so #21795 would help there.
So, deprecation and removal needs careful synchronization with them, at least.
What do you suggest concretely? ---------------------------------------- Feature #21826: Deprecating RubyVM::AbstractSyntaxTree https://bugs.ruby-lang.org/issues/21826#change-116017 * Author: Eregon (Benoit Daloze) * Status: Open ---------------------------------------- I think it is time to deprecate `RubyVM::AbstractSyntaxTree`. [Matz has agreed that going forward the official parser API for Ruby will be the Prism API](https://railsatscale.com/2024-04-16-prism-in-2024/) so it's clear the official Ruby parsing API is the Prism API. `RubyVM::AbstractSyntaxTree` is CRuby-specific and does not work on any other Ruby implementation, the API is unstable, inconvenient, etc:
This module is experimental and its API is not stable, therefore it might change without notice. As examples, the order of children nodes is not guaranteed, the number of children nodes might change, there is no way to access children nodes by name, etc.
Because it's under `RubyVM`, it also has the following documented caveats:
This module is for very limited purposes, such as debugging, prototyping, and research. Normal users must not use it. This module is not portable between Ruby implementations.
Given these caveats I think it could possibly be fair enough to remove it without deprecation, however I see no urgency to remove it straight away so I think having it deprecated for one release is nicer for the few gems using it. The advantages of deprecating it are: * Make it clear that this API should not be used in new code * Encourage the few usages to migrate to the Prism API, which is stable, officially supported, designed with many people to be usable and convenient for every parsing/tooling usage, etc. * Improve portability of Ruby code between Ruby implementations So, let's deprecate `RubyVM::AbstractSyntaxTree` in 4.1, and remove it in 4.2? -- https://bugs.ruby-lang.org/