Ruby 3.3.0-preview1 Released

Posted by naruse on 12 May 2023

We are pleased to announce the release of Ruby 3.3.0-preview1. 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

  • Significant performance improvements over 3.2
    • Splat and rest arguments support has been improved.
    • Registers are allocated for stack operations of the virtual machine.
    • More calls with optional arguments are compiled.
    • Integer#!=, String#!=, Kernel#block_given?, Kernel#is_a?, Kernel#instance_of?, Module#=== are specially optimized.
    • Instance variables no longer exit to the interpreter with megamorphic Object Shapes.
  • Metadata for compiled code uses a lot less memory.
  • Improved code generation 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
  • Exit tracing option now supports sampling
    • --trace-exits-sample-rate=N
  • Multiple bug fixes

Other Notable New Features

Language

Performance improvements

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

Other notable changes since 3.2

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

The following default gems are updated.

  • RubyGems 3.5.0.dev
  • bigdecimal 3.1.4
  • bundler 2.5.0.dev
  • csv 3.2.7
  • fiddle 1.1.2
  • fileutils 1.7.1
  • irb 1.6.4
  • optparse 0.4.0.pre.1
  • psych 5.1.0
  • reline 0.3.3
  • stringio 3.0.7
  • strscan 3.0.7
  • syntax_suggest 1.0.4
  • time 0.2.2
  • timeout 0.3.2
  • uri 0.12.1

The following bundled gems are updated.

  • minitest 5.18.0
  • rbs 3.1.0
  • typeprof 0.21.7
  • debug 1.8.0

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, 1922 files changed, 75283 insertions(+), 44896 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.