https://www.ruby-lang.org/en/news/2017/10/10/ruby-2-5-0-preview1-released/
Ruby 2.5.0-preview1 is the first preview release toward Ruby 2.5.0. It introduces some new features and performance improvements, for example:
New Features
- Print backtrace and error message in reverse order if STDERR is unchanged and a tty. [Feature #8661] [experimental]
- Top-level constant look-up is removed. [Feature #11547]
- rescue/else/ensure are allowed inside do/end blocks. [Feature #12906]
- yield_self [Feature #6721]
Other notable changes since 2.4
- Merge Onigmo to 6.1.1. It adds absent operator Note that Ruby 2.4.1 also includes this change.
- Merge bundler to standard libraries.
- Merge rubygems-2.6.13.
- Merge rdoc-6.0.0.beta2. Change lexer IRB based one to Ripper. It much improves the speed of generating document. https://github.com/ruby/rdoc/pull/512 This also includes
- Fix so many bugs in the last dozen years or so
- Support new Ruby syntaxes in the last several years
- Update supported Unicode version to 10.0.0.
See NEWS or commit logs for details.
With those changes, 6162 files changed, 28537 insertions(+), 339582 deletions(-) since Ruby 2.4.0!
Enjoy Ruby 2.5.0-preview1!
I wish there is more ...><