A few clarifications for JRuby:
- JRuby mimicked MRI’s non-GCable Symbols in earlier versions, but JRuby 9000 – which will ship with Ruby 2.2 support – makes Symbols GCable just like MRI.
- In JRuby, we do not use Symbols for IDs like method and constant names, so they will not cause an “immortal symbol” to be created.