NEWS for Ruby 2.7.0

This document is a list of user visible feature changes made between releases except for bug fixes.

Note that each entry is kept so brief that no reason behind or reference information is supplied with. For a full list of changes with all sufficient information, see the ChangeLog file or Redmine (e.g. https://bugs.ruby-lang.org/issues/$FEATURE_OR_BUG_NUMBER)

Changes since the 2.6.0 release

Language changes

Core classes updates (outstanding ones only)

Complex
New method
  • Added Complex#<=>. So 0 <=> 0i will not raise NoMethodError.

    Bug #15857
Encoding
  • Added new encoding CESU-8 [Feature #15931]

Enumerable
New method
Enumerator
New method
  • Added Enumerator::Yielder#to_proc so that a Yielder object can be directly passed to another method as a block argument. [Feature #15618]

FrozenError
New method
GC
New method
  • Added GC.compact method for compacting the heap. This function compacts live objects in the heap so that fewer pages may be used, and the heap may be more CoW friendly. [Feature #15626]

    Details on the algorithm and caveats can be found here: bugs.ruby-lang.org/issues/15626

IO
New method
Integer
Modified method
  • Integer#[] now supports range operation. [Feature #8842]

    0b01001101[2, 4]  #=> 0b0011
    0b01001100[2..5]  #=> 0b0011
    0b01001100[2...6] #=> 0b0011
        ^^^^
Module
New method
Modified method
Regexp / String
  • Update Unicode version and Emoji version from 11.0.0 to 12.0.0. [Feature #15321]

  • Update Unicode version to 12.1.0, adding support for U+32FF SQUARE ERA NAME REIWA. [Feature #15195]

Time

Stdlib updates (outstanding ones only)

Bundler
CGI
  • CGI.escapeHTML becomes 2~5x faster when there's at least one escaped character.

CSV
Date
Delegator
  • Object#DelegateClass accepts a block and module_evals it in the context of the returned class, similar to Class.new and Struct.new.

ERB
  • Prohibit marshaling ERB instance.

IRB
  • Introduce syntax highlight inspired by pry.gem to Binding#irb source lines, REPL input, and inspect output of some core-class objects.

Net::IMAP
  • Add Server Name Indication (SNI) support. [Feature #15594]

Racc
  • Merge 1.4.15 from upstream repository and added cli of racc.

RSS
RubyGems

Compatibility issues (excluding feature bug fixes)

Stdlib compatibility issues (excluding feature bug fixes)

profile.rb, Profiler__
  • Removed from standard library. No one maintains it from Ruby 2.0.0.

C API updates

Implementation improvements

Thread
  • VM stack memory allocation is now combined with native thread stack, improving thread allocation performance and reducing allocation related failures. ~10x performance improvement was measured in micro-benchmarks.

JIT
  • JIT-ed code is recompiled to less-optimized code when an optimization assumption is invalidated.

  • Method inlining is performed when a method is considered as pure. This optimization is still experimental and many methods are NOT considered as pure yet.

  • Default value of --jit-max-cache is changed from 1,000 to 100

  • Default value of --jit-min-calls is changed from 5 to 10,000

Miscellaneous changes