ruby--ruby/NEWS.md

NEWS for Ruby 3.1.0

This document is a list of user visible feature changes since the 3.0.0 release, except for bug fixes.

Note that each entry is kept to a minimum, see links for details.

Language changes

• Pin operator now takes an expression. [Feature #17411]

  Prime.each_cons(2).lazy.find_all{_1 in [n, ^(n + 2)]}.take(3).to_a
  #=> [[3, 5], [5, 7], [11, 13]]
  

Command line options

Core classes updates

Outstanding ones only.

• Enumerable

  • Enumerable#compact is added. [Feature #17312]

• Enumerator::Lazy

  • Enumerator::Lazy#compact is added. [Feature #17312]

• File

  • File.dirname now accepts an optional argument for the level to strip path components. [Feature #12194]

• Module

  • Module#prepend now modifies the ancestor chain if the receiver already includes the argument. Module#prepend still does not modify the ancestor chain if the receiver has already prepended the argument. [Bug #17423]

• Struct

  • Passing only keyword arguments to Struct#initialize is warned. You need to use a Hash literal to set a Hash to a first member. [Feature #16806]

• Queue

  • Queue#initialize now accepts an Enumerable of initial values. [Feature #17327]

• Thread::Backtrace

  • Thread::Backtrace.limit, which returns the value to limit backtrace length set by --backtracse-limit command line option, is added. [Feature #17479]

• $LOAD_PATH

  • $LOAD_PATH.resolve_feature_path does not raise. [Feature #16043]

Stdlib updates

Outstanding ones only.

Compatibility issues

Excluding feature bug fixes.

Stdlib compatibility issues

• ERB#initialize warns safe_level and later arguments even without -w. [Feature #14256]

C API updates

Implementation improvements

JIT

• RubyVM::MJIT is renamed to RubyVM::JIT.

Static analysis

RBS

TypeProf

Miscellaneous changes