doc/NEWS/NEWS-3.2.0.md
This document is a list of user-visible feature changes since the 3.1.0 release, except for bug fixes.
Note that each entry is kept to a minimum, see links for details.
Anonymous rest and keyword rest arguments can now be passed as arguments, instead of just used in method parameters. [Feature #18351]
def foo(*)
bar(*)
end
def baz(**)
quux(**)
end
A proc that accepts a single positional argument and keywords will no longer autosplat. [Bug #18633]
proc{|a, **k| a}.call([1, 2])
# Ruby 3.1 and before
# => 1
# Ruby 3.2 and after
# => [1, 2]
Constant assignment evaluation order for constants set on explicit objects has been made consistent with single attribute assignment evaluation order. With this code:
foo::BAR = baz
foo is now called before baz. Similarly, for multiple assignments
to constants, left-to-right evaluation order is used. With this
code:
foo1::BAR1, foo2::BAR2 = baz1, baz2
The following evaluation order is now used:
foo1foo2baz1baz2"Find pattern" is no longer experimental. [Feature #18585]
Methods taking a rest parameter (like *args) and wishing to delegate keyword
arguments through foo(*args) must now be marked with ruby2_keywords
(if not already the case). In other words, all methods wishing to delegate
keyword arguments through *args must now be marked with ruby2_keywords,
with no exception. This will make it easier to transition to other ways of
delegation once a library can require Ruby 3+. Previously, the ruby2_keywords
flag was kept if the receiving method took *args, but this was a bug and an
inconsistency. A good technique to find the potentially-missing ruby2_keywords
is to run the test suite, for where it fails find the last method which must
receive keyword arguments, use puts nil, caller, nil there, and check each
method/block on the call chain which must delegate keywords is correctly marked
as ruby2_keywords. [Bug #18625] [Bug #16466]
def target(**kw)
end
# Accidentally worked without ruby2_keywords in Ruby 2.7-3.1, ruby2_keywords
# needed in 3.2+. Just like (*args, **kwargs) or (...) would be needed on
# both #foo and #bar when migrating away from ruby2_keywords.
ruby2_keywords def bar(*args)
target(*args)
end
ruby2_keywords def foo(*args)
bar(*args)
end
foo(k: 1)
Note: We're only listing outstanding class updates.
Fiber
Introduce Fiber.[] and Fiber.[]= for inheritable fiber storage.
Introduce Fiber#storage and Fiber#storage= (experimental) for
getting and resetting the current storage. Introduce
Fiber.new(storage:) for setting the storage when creating a
fiber. [Feature #19078]
Existing Thread and Fiber local variables can be tricky to use. Thread-local variables are shared between all fibers, making it hard to isolate, while Fiber-local variables can be hard to share. It is often desirable to define unit of execution ("execution context") such that some state is shared between all fibers and threads created in that context. This is what Fiber storage provides.
def log(message)
puts "#{Fiber[:request_id]}: #{message}"
end
def handle_requests
while request = read_request
Fiber.schedule do
Fiber[:request_id] = SecureRandom.uuid
request.messages.each do |message|
Fiber.schedule do
log("Handling #{message}") # Log includes inherited request_id.
end
end
end
end
end
You should generally consider Fiber storage for any state which you want to be shared implicitly between all fibers and threads created in a given context, e.g. a connection pool, a request id, a logger level, environment variables, configuration, etc.
Fiber::Scheduler
Fiber::Scheduler#io_select for non-blocking IO.select.
[Feature #19060]IO
Introduce IO#timeout= and IO#timeout which can cause IO::TimeoutError to be raised if a blocking operation exceeds the specified timeout. [Feature #18630]
STDIN.timeout = 1
STDIN.read # => Blocking operation timed out! (IO::TimeoutError)
Introduce IO.new(..., path:) and promote File#path to IO#path.
[Feature #19036]
Class
Class#attached_object, which returns the object for which the receiver is the singleton class. Raises TypeError if the receiver is not a singleton class. [Feature #12084]
class Foo; end
Foo.singleton_class.attached_object #=> Foo
Foo.new.singleton_class.attached_object #=> #<Foo:0x000000010491a370>
Foo.attached_object #=> TypeError: `Foo' is not a singleton class
nil.singleton_class.attached_object #=> TypeError: `NilClass' is not a singleton class
Data
New core class to represent simple immutable value object. The class is similar to Struct and partially shares an implementation, but has more lean and strict API. [Feature #16122]
Measure = Data.define(:amount, :unit)
distance = Measure.new(100, 'km') #=> #<data Measure amount=100, unit="km">
weight = Measure.new(amount: 50, unit: 'kg') #=> #<data Measure amount=50, unit="kg">
weight.with(amount: 40) #=> #<data Measure amount=40, unit="kg">
weight.amount #=> 50
weight.amount = 40 #=> NoMethodError: undefined method `amount='
Encoding
Encoding::UTF_16 and Encoding::UTF_32 encodings no longer
try to dynamically guess the endian based on a byte order mark.
Use Encoding::UTF_16BE/UTF_16LE and Encoding::UTF_32BE/UTF_32LE instead.
This change speeds up getting the encoding of a String. [Feature #18949]EncodingError will be raised. [Feature #18949]Enumerator
Exception
Hash
Integer
Kernel
MatchData
Module
Proc
Process
RLIMIT_NPTS constant to FreeBSD platformRegexp
The cache-based optimization is introduced. Many (but not all) Regexp matching is now in linear time, which will prevent regular expression denial of service (ReDoS) vulnerability. [Feature #19104]
Regexp.linear_time? is introduced. [Feature #19194]
Regexp.new now supports passing the regexp flags not only as an Integer,
but also as a String. Unknown flags raise ArgumentError.
Otherwise, anything other than true, false, nil or Integer will be warned.
[Feature #18788]
Regexp.timeout= has been added. Also, Regexp.new new supports timeout keyword. See [Feature #17837]
Refinement
RubyVM::AbstractSyntaxTree
Add error_tolerant option for parse, parse_file and of. [Feature #19013]
With this option
end is complemented when a parser reaches to the end of input but end is insufficientend is treated as keyword based on indent# Without error_tolerant option
root = RubyVM::AbstractSyntaxTree.parse(<<~RUBY)
def m
a = 10
if
end
RUBY
# => <internal:ast>:33:in `parse': syntax error, unexpected `end' (SyntaxError)
# With error_tolerant option
root = RubyVM::AbstractSyntaxTree.parse(<<~RUBY, error_tolerant: true)
def m
a = 10
if
end
RUBY
p root # => #<RubyVM::AbstractSyntaxTree::Node:SCOPE@1:0-4:3>
# `end` is treated as keyword based on indent
root = RubyVM::AbstractSyntaxTree.parse(<<~RUBY, error_tolerant: true)
module Z
class Foo
foo.
end
def bar
end
end
RUBY
p root.children[-1].children[-1].children[-1].children[-2..-1]
# => [#<RubyVM::AbstractSyntaxTree::Node:CLASS@2:2-4:5>, #<RubyVM::AbstractSyntaxTree::Node:DEFN@6:2-7:5>]
Add keep_tokens option for parse, parse_file and of. Add #tokens and #all_tokens
for RubyVM::AbstractSyntaxTree::Node [Feature #19070]
root = RubyVM::AbstractSyntaxTree.parse("x = 1 + 2", keep_tokens: true)
root.tokens # => [[0, :tIDENTIFIER, "x", [1, 0, 1, 1]], [1, :tSP, " ", [1, 1, 1, 2]], ...]
root.tokens.map{_1[2]}.join # => "x = 1 + 2"
Set
require "set". [Feature #16989]
It is currently autoloaded via the Set constant or a call to Enumerable#to_set.String
Struct
A Struct class can also be initialized with keyword arguments
without keyword_init: true on Struct.new [Feature #16806]
Post = Struct.new(:id, :name)
Post.new(1, "hello") #=> #<struct Post id=1, name="hello">
# From Ruby 3.2, the following code also works without keyword_init: true.
Post.new(id: 1, name: "hello") #=> #<struct Post id=1, name="hello">
Thread
Thread::Queue
Thread::SizedQueue
Time
Time#deconstruct_keys is added, allowing to use Time instances in pattern-matching expressions [Feature #19071]
Time.new now can parse a string like generated by Time#inspect and return a Time instance based on the given argument. [Feature #18033]
SyntaxError
TracePoint
nil for c_call/c_return TracePoints.
[Bug #18487]target_thread keyword argument now defaults to the
current thread if a block is given and target and target_line keyword
arguments are not passed. [Bug #16889]UnboundMethod
UnboundMethod#== returns true if the actual method is same. For example,
String.instance_method(:object_id) == Array.instance_method(:object_id)
returns true. [Feature #18798]
UnboundMethod#inspect does not show the receiver of instance_method.
For example String.instance_method(:object_id).inspect returns
"#<UnboundMethod: Kernel#object_id()>"
(was "#<UnboundMethod: String(Kernel)#object_id()>").
GC
need_major_gc via GC.latest_gc_info. GH-6791ObjectSpace
ObjectSpace.dump_all dump shapes as well. GH-6868Bundler
RubyGems
CGI
CGI.escapeURIComponent and CGI.unescapeURIComponent are added.
[Feature #18822]Coverage
Coverage.setup now accepts eval: true. By this, eval and related methods are
able to generate code coverage. [Feature #19008]
Coverage.supported?(mode) enables detection of what coverage modes are
supported. [Feature #19026]
Date
Date#deconstruct_keys and DateTime#deconstruct_keys same as [Feature #19071]ERB
ERB::Util.html_escape is made faster than CGI.escapeHTML.
#to_s method when an argument is already a String.ERB::Escape.html_escape is added as an alias to ERB::Util.html_escape,
which has not been monkey-patched by Rails.ERB::Util.url_encode is made faster using CGI.escapeURIComponent.-S option is removed from erb command.FileUtils
relative: option to FileUtils.ln_s.
[Feature #18925]IRB
debug, break, catch,
next, delete, step, continue, finish, backtrace, info
gem "debug" in your Gemfile.edit and show_cmds (like Pry's help) are added.ls takes -g or -G option to filter out outputs.show_source is aliased from $ and accepts unquoted inputs.whereami is aliased from @.Net::Protocol
Net::BufferedIO performance. [GH-net-protocol-14]Pathname
Pathname#lutime. [GH-pathname-20]Socket
SO_INCOMING_CPUSO_INCOMING_NAPI_IDSO_RTABLESO_SETFIBSO_USER_COOKIETCP_KEEPALIVETCP_CONNECTION_INFOSyntaxSuggest
syntax_suggest formerly dead_end is integrated in Ruby.
[Feature #18159]UNIXSocket
The following default gems are updated.
The following bundled gems are updated.
See GitHub releases like GitHub Releases of Logger or changelog for details of the default gems or bundled gems.
String#to_c currently treat a sequence of underscores as an end of Complex
string. [Bug #19087]
Now ENV.clone raises TypeError as well as ENV.dup [Bug #17767]
The following deprecated constants are removed.
Fixnum and Bignum [Feature #12005]Random::DEFAULT [Feature #17351]Struct::GroupStruct::PasswdThe following deprecated methods are removed.
Dir.exists? [Feature #17391]File.exists? [Feature #17391]Kernel#=~ [Feature #15231]Kernel#taint, Kernel#untaint, Kernel#tainted?
[Feature #16131]Kernel#trust, Kernel#untrust, Kernel#untrusted?
[Feature #16131]Method#public?, Method#private?, Method#protected?,
UnboundMethod#public?, UnboundMethod#private?, UnboundMethod#protected?
[Bug #18729] [Bug #18751] [Bug #18435]Module#include
with the same name, the statement was handled as "open class" in Ruby 3.1 or before.
Since Ruby 3.2, a new class is defined instead. [Feature #18832]Psych no longer bundles libyaml sources. And also Fiddle no longer bundles libffi sources. Users need to install the libyaml/libffi library themselves via the package manager like apt, yum, brew, etc.
Psych and fiddle supported the static build with specific version of libyaml and libffi sources. You can build psych with libyaml-0.2.5 like this.
$ ./configure --with-libyaml-source-dir=/path/to/libyaml-0.2.5
And you can build fiddle with libffi-3.4.4 like this.
$ ./configure --with-libffi-source-dir=/path/to/libffi-3.4.4
Check cookie name/path/domain characters in CGI::Cookie. [CVE-2021-33621]
URI.parse return empty string in host instead of nil. [sec-156615]
The following APIs are updated.
PRNG update
rb_random_interface_t in ruby/random.h updated and versioned.
Extension libraries which use this interface and built for older
versions need to rebuild with adding init_int32 function.
VALUE rb_hash_new_capa(long capa) was added to created hashes with the desired capacity.rb_internal_thread_add_event_hook and rb_internal_thread_add_event_hook were added to instrument threads scheduling.
The following events are available:
RUBY_INTERNAL_THREAD_EVENT_STARTEDRUBY_INTERNAL_THREAD_EVENT_READYRUBY_INTERNAL_THREAD_EVENT_RESUMEDRUBY_INTERNAL_THREAD_EVENT_SUSPENDEDRUBY_INTERNAL_THREAD_EVENT_EXITEDrb_debug_inspector_current_depth and rb_debug_inspector_frame_depth are added for debuggers.The following deprecated APIs are removed.
rb_cData variable.RubyVM.stat(:global_constant_state) was
removed because it was closely tied to the previous caching scheme
where setting any constant invalidates all caches in the system.
New keys, :constant_cache_invalidations and :constant_cache_misses,
were introduced to help with use cases for :global_constant_state.
[Feature #18589]rustc >= 1.58.0
before running ./configure--yjit-exec-mem-size will not be mapped to physical
memory pages until actually utilized by JIT code.--yjit-exec-mem-size.
RubyVM::YJIT.runtime_stats returns Code GC metrics in addition to
existing inline_code_size and outlined_code_size keys:
code_gc_count, live_page_count, freed_page_count, and freed_code_size.RubyVM::YJIT.runtime_stats are now available in release builds.
--yjit-stats to compute and dump stats (incurs some run-time overhead).--yjit-exec-mem-size is changed to 64 (MiB).--yjit-call-threshold is changed to 30.ruby_vm/mjit/compiler.--mjit-min-calls to --mjit-call-threshold.--mjit-max-cache back from 10000 to 100.