486 lines
15 KiB
Markdown
486 lines
15 KiB
Markdown
# NEWS for Ruby 3.0.0
|
|
|
|
This document is a list of user visible feature changes
|
|
since the **2.7.0** release, 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`).
|
|
|
|
## Language changes
|
|
|
|
* Keyword arguments are now separated from positional arguments.
|
|
Code that resulted in deprecation warnings in Ruby 2.7 will now
|
|
result in ArgumentError or different behavior. [[Feature #14183]]
|
|
|
|
* Arguments forwarding (`...`) now supports leading arguments.
|
|
[[Feature #16378]]
|
|
|
|
```ruby
|
|
def method_missing(meth, ...)
|
|
send(:"do_#{meth}", ...)
|
|
end
|
|
```
|
|
|
|
* Procs accepting a single rest argument and keywords are no longer
|
|
subject to autosplatting. This now matches the behavior of Procs
|
|
accepting a single rest argument and no keywords.
|
|
[[Feature #16166]]
|
|
|
|
```ruby
|
|
pr = proc{|*a, **kw| [a, kw]}
|
|
|
|
pr.call([1])
|
|
# 2.7 => [[1], {}]
|
|
# 3.0 => [[[1]], {}]
|
|
|
|
pr.call([1, {a: 1}])
|
|
# 2.7 => [[1], {:a=>1}] # and deprecation warning
|
|
# 3.0 => [[[1, {:a=>1}]], {}]
|
|
```
|
|
|
|
* $SAFE is now a normal global variable with no special behavior.
|
|
C-API methods related to $SAFE have been removed.
|
|
[[Feature #16131]]
|
|
|
|
* yield in singleton class definitions in methods is now a SyntaxError
|
|
instead of a warning. yield in a class definition outside of a method
|
|
is now a SyntaxError instead of a LocalJumpError. [[Feature #15575]]
|
|
|
|
* Find pattern is added. [[Feature #16828]]
|
|
|
|
```ruby
|
|
case ["a", 1, "b", "c", 2, "d", "e", "f", 3]
|
|
in [*pre, String => x, String => y, *post]
|
|
p pre #=> ["a", 1]
|
|
p x #=> "b"
|
|
p y #=> "c"
|
|
p post #=> [2, "d", "e", "f", 3]
|
|
end
|
|
```
|
|
|
|
* When a class variable is overtaken by the same definition in an
|
|
ancestor class/module, a RuntimeError is now raised (previously,
|
|
it only issued a warning in verbose mode. Additionally, accessing a
|
|
class variable from the toplevel scope is now a RuntimeError.
|
|
[[Bug #14541]]
|
|
|
|
* Rightward assignment statement is added. [EXPERIMENTAL]
|
|
[[Feature #15921]]
|
|
|
|
```ruby
|
|
fib(10) => x
|
|
```
|
|
|
|
* Endless method definition is added. [EXPERIMENTAL]
|
|
[[Feature #16746]]
|
|
|
|
```ruby
|
|
def square(x) = x * x
|
|
```
|
|
|
|
* Interpolated String literals are no longer frozen when
|
|
`# frozen-string-literal: true` is used. [[Feature #17104]]
|
|
|
|
* RBS is introduced. It is a type definition language for Ruby programs.
|
|
|
|
## Command line options
|
|
|
|
### `--help` option
|
|
|
|
When the environment variable `RUBY_PAGER` or `PAGER` is present and has
|
|
non-empty value, and the standard input and output are tty, `--help`
|
|
option shows the help message via the pager designated by the value.
|
|
[[Feature #16754]]
|
|
|
|
## Core classes updates
|
|
|
|
Outstanding ones only.
|
|
|
|
* Dir
|
|
|
|
* Modified method
|
|
|
|
* Dir.glob and Dir.[] now sort the results by default, and
|
|
accept `sort:` keyword option. [[Feature #8709]]
|
|
|
|
* ENV
|
|
|
|
* New method
|
|
|
|
* ENV.except, which returns a hash excluding the given keys
|
|
and their values. [[Feature #15822]]
|
|
|
|
* Hash
|
|
|
|
* Modified method
|
|
|
|
* Hash#transform_keys now accepts a hash that maps keys to new
|
|
keys. [[Feature #16274]]
|
|
|
|
* New method
|
|
|
|
* Hash#except, which returns a hash excluding the given keys
|
|
and their values. [[Feature #15822]]
|
|
|
|
* Kernel
|
|
|
|
* Modified method
|
|
|
|
* Kernel#clone when called with `freeze: false` keyword will call
|
|
`#initialize_clone` with the `freeze: false` keyword.
|
|
[[Bug #14266]]
|
|
|
|
* Kernel#clone when called with `freeze: true` keyword will call
|
|
`#initialize_clone` with the `freeze: true` keyword, and will
|
|
return a frozen copy even if the receiver is unfrozen.
|
|
[[Feature #16175]]
|
|
|
|
* Kernel#eval when called with two arguments will use "(eval)"
|
|
for `__FILE__` and 1 for `__LINE__` in the evaluated code.
|
|
[[Bug #4352]]
|
|
|
|
* Kernel#lambda now warns if called without a literal block.
|
|
[[Feature #15973]]
|
|
|
|
* Module
|
|
|
|
* Modified method
|
|
|
|
* Module#include and #prepend now affect classes and modules that
|
|
have already included or prepended the receiver, mirroring the
|
|
behavior if the arguments were included in the receiver before
|
|
the other modules and classes included or prepended the receiver.
|
|
[[Feature #9573]]
|
|
|
|
```ruby
|
|
class C; end
|
|
module M1; end
|
|
module M2; end
|
|
C.include M1
|
|
M1.include M2
|
|
p C.ancestors #=> [C, M1, M2, Object, Kernel, BasicObject]
|
|
```
|
|
|
|
* Range
|
|
|
|
* All Range objects are frozen. [Feature #15504]
|
|
|
|
* Thread
|
|
|
|
* Introduce `Thread#scheduler` for intercepting blocking operations and
|
|
`Thread.scheduler` for accessing the current scheduler. See
|
|
doc/scheduler.md for more details. [[Feature #16786]]
|
|
* `Thread#blocking?` tells whether the current execution context is
|
|
blocking. [[Feature #16786]]
|
|
* `Thread#join` invokes the scheduler hooks `block`/`unblock` in a
|
|
non-blocking execution context. [[Feature #16786]]
|
|
|
|
* Mutex
|
|
|
|
* `Mutex` is now acquired per-`Fiber` instead of per-`Thread`. This change
|
|
should be compatible for essentially all usages and avoids blocking when
|
|
using a scheduler. [[Feature #16792]]
|
|
|
|
* Fiber
|
|
|
|
* `Fiber.new(blocking: true/false)` allows you to create non-blocking
|
|
execution contexts. [[Feature #16786]]
|
|
* `Fiber#blocking?` tells whether the fiber is non-blocking. [[Feature #16786]]
|
|
* `Fiber#backtrace` & `Fiber#backtrace_locations` provide per-fiber backtrace.
|
|
[[Feature #16815]]
|
|
|
|
* Kernel
|
|
|
|
* `Kernel.sleep(...)` invokes the scheduler hook `#kernel_sleep(...)` in a
|
|
non-blocking execution context. [[Feature #16786]]
|
|
|
|
* IO
|
|
|
|
* `IO#nonblock?` now defaults to `true`. [[Feature #16786]]
|
|
* `IO#wait_readable`, `IO#wait_writable`, `IO#read`, `IO#write` and other
|
|
related methods (e.g. `#puts`, `#gets`) may invoke the scheduler hook
|
|
`#io_wait(io, events, timeout)` in a non-blocking execution context.
|
|
[[Feature #16786]]
|
|
|
|
* ConditionVariable
|
|
|
|
* `ConditionVariable#wait` may now invoke the `block`/`unblock` scheduler
|
|
hooks in a non-blocking context. [[Feature #16786]]
|
|
|
|
* Queue / SizedQueue
|
|
|
|
* `Queue#pop`, `SizedQueue#push` and related methods may now invoke the
|
|
`block`/`unblock` scheduler hooks in a non-blocking context.
|
|
[[Feature #16786]]
|
|
|
|
* Ractor
|
|
|
|
* new class to enable parallel execution. See doc/ractor.md for
|
|
more details.
|
|
|
|
* Symbol
|
|
|
|
* Modified method
|
|
|
|
* Symbol#to_proc now returns a lambda Proc.
|
|
[[Feature #16260]]
|
|
|
|
* New method
|
|
|
|
* Symbol#name, which returns the name of the symbol if it is
|
|
named. The returned string cannot be modified.
|
|
[[Feature #16150]]
|
|
|
|
* Warning
|
|
|
|
* Modified method
|
|
|
|
* Warning#warn now supports a category kwarg.
|
|
[[Feature #17122]]
|
|
|
|
## Stdlib updates
|
|
|
|
Outstanding ones only.
|
|
|
|
* RubyGems
|
|
|
|
* Update to RubyGems 3.2.0.rc.1
|
|
|
|
* Bundler
|
|
|
|
* Update to Bundler 2.2.0.rc.1
|
|
|
|
* Net::HTTP
|
|
|
|
* New method
|
|
|
|
* Add Net::HTTP#verify_hostname= and Net::HTTP#verify_hostname
|
|
to skip hostname verification. [[Feature #16555]]
|
|
|
|
* Modified method
|
|
|
|
* Net::HTTP.get, Net::HTTP.get_response, and Net::HTTP.get_print can
|
|
take request headers as a Hash in the second argument when the first
|
|
argument is a URI. [[Feature #16686]]
|
|
|
|
* IRB
|
|
|
|
* Update to IRB 1.2.6
|
|
|
|
* OpenStruct
|
|
|
|
* Initialization no longer lazy [[Bug #12136]]
|
|
* Builtin methods can now be overridden safely. [[Bug #15409]]
|
|
* Implementation uses only methods ending with `!`.
|
|
* Ractor compatible.
|
|
* Improved support for YAML [[Bug #8382]]
|
|
* Use officially discouraged. Read "Caveats" section.
|
|
|
|
* Reline
|
|
|
|
* Update to Reline 0.1.5
|
|
|
|
* Socket
|
|
|
|
* TCPSocket.new now supports `resolv_timeout`. [[Feature #17134]]
|
|
|
|
```ruby
|
|
# it raises SocketError if name resolution is not finished within resolve_timeout.
|
|
tcp_socket = TCPSocket.new("example.com", 80, resolv_timeout: 10)
|
|
```
|
|
|
|
## Compatibility issues
|
|
|
|
Excluding feature bug fixes.
|
|
|
|
* Regexp literals are frozen [[Feature #8948]] [[Feature #16377]]
|
|
|
|
```ruby
|
|
/foo/.frozen? #=> true
|
|
```
|
|
|
|
* EXPERIMENTAL: Hash#each consistently yields a 2-element array [[Bug #12706]]
|
|
|
|
* Now `{ a: 1 }.each(&->(k, v) { })` raises an ArgumentError
|
|
due to lambda's arity check.
|
|
* This is experimental; if it brings a big incompatibility issue,
|
|
it may be reverted until 2.8/3.0 release.
|
|
|
|
* When writing to STDOUT redirected to a closed pipe, no broken pipe
|
|
error message will be shown now. [[Feature #14413]]
|
|
|
|
* `TRUE`/`FALSE`/`NIL` constants are no longer defined.
|
|
|
|
* `Integer#zero?` overrides `Numeric#zero?` for optimization. [[Misc #16961]]
|
|
|
|
## Stdlib compatibility issues
|
|
|
|
* Default gems
|
|
|
|
* The following libraries are promoted the default gems from stdlib.
|
|
|
|
* abbrev
|
|
* base64
|
|
* English
|
|
* erb
|
|
* find
|
|
* io-nonblock
|
|
* io-wait
|
|
* net-ftp
|
|
* net-http
|
|
* net-imap
|
|
* net-protocol
|
|
* nkf
|
|
* open-uri
|
|
* optparse
|
|
* resolv
|
|
* resolv-replace
|
|
* rinda
|
|
* securerandom
|
|
* set
|
|
* shellwords
|
|
* tempfile
|
|
* time
|
|
* tmpdir
|
|
* tsort
|
|
* weakref
|
|
|
|
* Bundled gems
|
|
|
|
* net-telnet and xmlrpc have been removed from the bundled gems.
|
|
If you are interested in maintaining them, please comment on
|
|
your plan to https://github.com/ruby/xmlrpc
|
|
or https://github.com/ruby/net-telnet.
|
|
|
|
* SDBM have been removed from ruby standard library. [[Bug #8446]]
|
|
|
|
* The issues of sdbm will be handled at https://github.com/ruby/sdbm
|
|
|
|
## C API updates
|
|
|
|
* C API functions related to $SAFE have been removed.
|
|
[[Feature #16131]]
|
|
|
|
* C API header file `ruby/ruby.h` was split. [[GH-2991]] Should have no impact
|
|
on extension libraries, but users might experience slow compilations.
|
|
|
|
* Memory view interface [EXPERIMENTAL]
|
|
|
|
* The memory view interface is a C-API set to exchange a raw memory area,
|
|
such as a numeric array and a bitmap image, between extension libraries.
|
|
The extension libraries can share also the metadata of the memory area
|
|
that consists of the shape, the element format, and so on.
|
|
Using these kinds of metadata, the extension libraries can share even
|
|
a multidimensional array appropriately.
|
|
This feature is designed by referring to Python's buffer protocol.
|
|
[[Feature #13767]] [[Feature #14722]]
|
|
|
|
## Implementation improvements
|
|
|
|
* New method cache mechanism for Ractor [[Feature #16614]]
|
|
|
|
* Inline method caches pointed from ISeq can be accessed by multiple Ractors
|
|
in parallel and synchronization is needed even for method caches. However,
|
|
such synchronization can be overhead so introducing new inline method cache
|
|
mehanisms, (1) Disposable inline method cache (2) per-Class method cache
|
|
and (3) new invalidation mechanism. (1) can avoid per-method call
|
|
syncrhonization because it only use atomic operations.
|
|
See the ticket for more details.
|
|
|
|
* The number of hashes allocated when using a keyword splat in
|
|
a method call has been reduced to a maximum of 1, and passing
|
|
a keyword splat to a method that accepts specific keywords
|
|
does not allocate a hash.
|
|
|
|
* `super` is optimized when the same type of method is called in the previous call
|
|
if it's not refinements or an attr reader or writer.
|
|
|
|
### JIT
|
|
|
|
* Native functions shared by multiple methods are deduplicated on JIT compaction.
|
|
|
|
* Decrease code size of hot paths by some optimizations and partitioning cold paths.
|
|
|
|
* Not only pure Ruby methods but also some C methods skip pushing a method frame.
|
|
|
|
* `Kernel#class`, `Integer#zero?`
|
|
|
|
* Always generate appropriate code for `==`, `nil?`, and `!` calls depending on
|
|
a receiver class.
|
|
|
|
* Optimize instance variable access in some core classes like Hash and their subclasses
|
|
|
|
* Eliminate VM register access on a method return
|
|
|
|
* Optimize C method call a little
|
|
|
|
## RBS
|
|
|
|
* RBS is a new language for type definition of Ruby programs.
|
|
It allows writing types of classes and modules with advanced
|
|
types including union types, overloading, generics, and
|
|
_interface types_ for duck typing.
|
|
|
|
* Ruby ships with type definitions for core/stdlib classes.
|
|
|
|
* `rbs` gem is bundled to load and process RBS files.
|
|
|
|
## Miscellaneous changes
|
|
|
|
* Methods using `ruby2_keywords` will no longer keep empty keyword
|
|
splats, those are now removed just as they are for methods not
|
|
using `ruby2_keywords`.
|
|
|
|
* Taint deprecation warnings are now issued in regular mode in
|
|
addition to verbose warning mode. [[Feature #16131]]
|
|
|
|
* When an exception is caught in the default handler, the error
|
|
message and backtrace are printed in order from the innermost.
|
|
[[Feature #8661]]
|
|
|
|
|
|
[Bug #4352]: https://bugs.ruby-lang.org/issues/4352
|
|
[Bug #8382]: https://bugs.ruby-lang.org/issues/8382
|
|
[Bug #8446]: https://bugs.ruby-lang.org/issues/8446
|
|
[Feature #8661]: https://bugs.ruby-lang.org/issues/8661
|
|
[Feature #8709]: https://bugs.ruby-lang.org/issues/8709
|
|
[Feature #8948]: https://bugs.ruby-lang.org/issues/8948
|
|
[Feature #9573]: https://bugs.ruby-lang.org/issues/9573
|
|
[Bug #12136]: https://bugs.ruby-lang.org/issues/12136
|
|
[Bug #12706]: https://bugs.ruby-lang.org/issues/12706
|
|
[Feature #13767]: https://bugs.ruby-lang.org/issues/13767
|
|
[Feature #14183]: https://bugs.ruby-lang.org/issues/14183
|
|
[Bug #14266]: https://bugs.ruby-lang.org/issues/14266
|
|
[Feature #14413]: https://bugs.ruby-lang.org/issues/14413
|
|
[Bug #14541]: https://bugs.ruby-lang.org/issues/14541
|
|
[Feature #14722]: https://bugs.ruby-lang.org/issues/14722
|
|
[Bug #15409]: https://bugs.ruby-lang.org/issues/15409
|
|
[Feature #15575]: https://bugs.ruby-lang.org/issues/15575
|
|
[Feature #15822]: https://bugs.ruby-lang.org/issues/15822
|
|
[Feature #15921]: https://bugs.ruby-lang.org/issues/15921
|
|
[Feature #15973]: https://bugs.ruby-lang.org/issues/15973
|
|
[Feature #16131]: https://bugs.ruby-lang.org/issues/16131
|
|
[Feature #16150]: https://bugs.ruby-lang.org/issues/16150
|
|
[Feature #16166]: https://bugs.ruby-lang.org/issues/16166
|
|
[Feature #16175]: https://bugs.ruby-lang.org/issues/16175
|
|
[Feature #16260]: https://bugs.ruby-lang.org/issues/16260
|
|
[Feature #16274]: https://bugs.ruby-lang.org/issues/16274
|
|
[Feature #16377]: https://bugs.ruby-lang.org/issues/16377
|
|
[Feature #16378]: https://bugs.ruby-lang.org/issues/16378
|
|
[Feature #16555]: https://bugs.ruby-lang.org/issues/16555
|
|
[Feature #16614]: https://bugs.ruby-lang.org/issues/16614
|
|
[Feature #16686]: https://bugs.ruby-lang.org/issues/16686
|
|
[Feature #16746]: https://bugs.ruby-lang.org/issues/16746
|
|
[Feature #16754]: https://bugs.ruby-lang.org/issues/16754
|
|
[Feature #16786]: https://bugs.ruby-lang.org/issues/16786
|
|
[Feature #16792]: https://bugs.ruby-lang.org/issues/16792
|
|
[Feature #16815]: https://bugs.ruby-lang.org/issues/16815
|
|
[Feature #16828]: https://bugs.ruby-lang.org/issues/16828
|
|
[Misc #16961]: https://bugs.ruby-lang.org/issues/16961
|
|
[Feature #17104]: https://bugs.ruby-lang.org/issues/17104
|
|
[Feature #17122]: https://bugs.ruby-lang.org/issues/17122
|
|
[Feature #17134]: https://bugs.ruby-lang.org/issues/17134
|
|
[GH-2991]: https://github.com/ruby/ruby/pull/2991
|