Ruby 3.3.0-preview2 Released

Posted by naruse on 14 Sep 2023

We are pleased to announce the release of Ruby 3.3.0-preview2. Ruby 3.3 adds a new pure-Ruby JIT compiler named RJIT, uses Lrama as a parser generator, and many performance improvements especially YJIT.

RJIT

  • Introduced a pure-Ruby JIT compiler RJIT and replaced MJIT.
    • RJIT supports only x86_64 architecture on Unix platforms.
    • Unlike MJIT, it doesn’t require a C compiler at runtime.
  • RJIT exists only for experimental purposes.
    • You should keep using YJIT in production.
  • If you are interested in developing JIT for Ruby, please check out k0kubun’s presentation on Day 3 of RubyKaigi.

Use Lrama instead of Bison

YJIT

  • Major performance improvements over 3.2
    • Support for splat and rest arguments has been improved.
    • Registers are allocated for stack operations of the virtual machine.
    • More calls with optional arguments are compiled.
    • Exception handlers are also compiled.
    • Instance variables no longer exit to the interpreter with megamorphic Object Shapes.
    • Unsupported call types no longer exit to the interpreter.
    • Integer#!=, String#!=, Kernel#block_given?, Kernel#is_a?, Kernel#instance_of?, Module#=== are specially optimized.
    • Now more than 3x faster than the interpreter on optcarrot!
  • Metadata for compiled code uses a lot less memory.
  • Generate more compact code on ARM64
  • Option to start YJIT in paused mode and then later enable it manually
    • --yjit-pause and RubyVM::YJIT.resume
    • This can be used to enable YJIT only once your application is done booting
  • ratio_in_yjit stat produced by --yjit-stats is now available in release builds, a special stats or dev build is no longer required.
  • Exit tracing option now supports sampling
    • --trace-exits-sample-rate=N
  • More thorough testing and multiple bug fixes

Other Notable New Features

Language

Performance improvements

  • defined?(@ivar) is optimized with Object Shapes.

Other notable changes since 3.2

IRB

IRB has received several enhancements, including but not limited to:

  • Advanced irb:rdbg integration that provides an equivalent debugging experience to pry-byebug (doc).
  • Pager support for commands like ls and show_cmds.
  • More accurate and helpful information provided by the ls and show_source commands.

In addition, IRB has also undergone extensive refactoring and received dozens of bug fixes to facilitate easier future enhancements.

Compatibility issues

Note: Excluding feature bug fixes.

Removed constants

The following deprecated constants are removed.

Removed methods

The following deprecated methods are removed.

Stdlib compatibility issues

ext/readline is retired

  • We have reline that is pure Ruby implementation compatible with ext/readline API. We rely on reline in the future. If you need to use ext/readline, you can install ext/readline via rubygems.org with gem install readline-ext.
  • We no longer need to install libraries like libreadline or libedit.

C API updates

Updated C APIs

The following APIs are updated.

Removed C APIs

The following deprecated APIs are removed.

Standard library updates

RubyGems and Bundler warn if users require gem that is scheduled to become the bundled gems in the future version of Ruby.

The following default gems are updated.

  • RubyGems 3.5.0.dev
  • bigdecimal 3.1.4
  • bundler 2.5.0.dev
  • csv 3.2.8
  • erb 4.0.3
  • fiddle 1.1.2
  • fileutils 1.7.1
  • irb 1.7.4
  • nkf 0.1.3
  • optparse 0.4.0.pre.1
  • psych 5.1.0
  • reline 0.3.8
  • stringio 3.0.9
  • strscan 3.0.7
  • syntax_suggest 1.1.0
  • time 0.2.2
  • timeout 0.4.0
  • uri 0.12.2
  • yarp 0.9.0

The following bundled gems are updated.

  • minitest 5.19.0
  • test-unit 3.6.1
  • rexml 3.2.6
  • rss 0.3.0
  • net-imap 0.3.7
  • rbs 3.2.1
  • typeprof 0.21.8
  • debug 1.8.0

The following default gem is now bundled.

  • racc 1.7.1

See GitHub releases like Logger or changelog for details of the default gems or bundled gems.

See NEWS or commit logs for more details.

With those changes, 4970 files changed, 239635 insertions(+), 165275 deletions(-) since Ruby 3.2.0!

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What is Ruby

Ruby was first developed by Matz (Yukihiro Matsumoto) in 1993, and is now developed as Open Source. It runs on multiple platforms and is used all over the world especially for web development.