Feature #15743

Updated by Eregon (Benoit Daloze) about 2 months ago

My understanding is that `RubyVM` is supposed to only exist on MRI/CRuby, and not on any other Ruby implementation.
In fact, almost all features under `RubyVM` are not realistically implementable on other major Ruby implementations (JRuby, TruffleRuby, Rubinius).

Unfortunately, the name doesn't reflect that it is specific to CRuby, e.g., JRuby/TruffleRuby/Rubinius are also "Ruby VMs".
And as a result it is not clear for many Ruby users that RubyVM is CRuby-specific.

The documentation is also unclear:
The RubyVM module provides some access to Ruby internals. This module is
for very limited purposes, such as debugging, prototyping, and research.
Normal users must not use it.

So I propose to rename RubyVM to CRuby.
That way, it is clear for everyone that this module is CRuby-specific.
It's also consistent with the JRuby module, the TruffleRuby module and the Rubinius module.

Proposed migration path:

* Introduce CRuby as an alias of RubyVM on `trunk`, and deprecate the RubyVM constant on `trunk` (for 2.7). the MRI 2.7 release).
* Remove `RubyVM` in Ruby 3.0.

What do you think?

cc @ko1 @k0kubun @headius