mirror of https://github.com/ruby/ruby.git synced 2025-08-15 05:29:10 +02:00

Étienne Barrié 12be40ae6b Implement chilled strings

[Feature #20205]

As a path toward enabling frozen string literals by default in the future,
this commit introduce "chilled strings". From a user perspective chilled
strings pretend to be frozen, but on the first attempt to mutate them,
they lose their frozen status and emit a warning rather than to raise a
`FrozenError`.

Implementation wise, `rb_compile_option_struct.frozen_string_literal` is
no longer a boolean but a tri-state of `enabled/disabled/unset`.

When code is compiled with frozen string literals neither explictly enabled
or disabled, string literals are compiled with a new `putchilledstring`
instruction. This instruction is identical to `putstring` except it marks
the String with the `STR_CHILLED (FL_USER3)` and `FL_FREEZE` flags.

Chilled strings have the `FL_FREEZE` flag as to minimize the need to check
for chilled strings across the codebase, and to improve compatibility with
C extensions.

Notes:
  - `String#freeze`: clears the chilled flag.
  - `String#-@`: acts as if the string was mutable.
  - `String#+@`: acts as if the string was mutable.
  - `String#clone`: copies the chilled flag.

Co-authored-by: Jean Boussier <byroot@ruby-lang.org>

2024-03-19 09:26:49 +01:00

3.5 KiB

Raw Blame History

NEWS for Ruby 3.4.0

This document is a list of user-visible feature changes since the 3.3.0 release, except for bug fixes.

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

Language changes

String literals in files without a frozen_string_literal comment now behave as if they were frozen. If they are mutated a deprecation warning is emited. These warnings can be enabled with -W:deprecated or by setting Warning[:deprecated] = true. To disable this change you can run Ruby with the --disable-frozen-string-literal command line argument. [Feature #20205]
it is added to reference a block parameter. [Feature #18980]
Keyword splatting nil when calling methods is now supported. **nil is treated similar to **{}, passing no keywords, and not calling any conversion methods. [Bug #20064]
Block passing is no longer allowed in index. [Bug #19918]
Keyword arguments are no longer allowed in index. [Bug #20218]

Core classes updates

Note: We're only listing outstanding class updates.

Exception
- Exception#set_backtrace now accepts arrays of Thread::Backtrace::Location. Kernel#raise, Thread#raise and Fiber#raise also accept this new format. [Feature #13557]

Stdlib updates

The following default gems are updated.

RubyGems 3.6.0.dev
bundler 2.6.0.dev
erb 4.0.4
fiddle 1.1.3
io-console 0.7.2
irb 1.12.0
net-http 0.4.1
prism 0.24.0
reline 0.4.3
resolv 0.4.0
stringio 3.1.1
strscan 3.1.1

The following bundled gems are updated.

minitest 5.22.3
test-unit 3.6.2
net-ftp 0.3.4
net-imap 0.4.10
net-smtp 0.4.0.1
rbs 3.4.4
typeprof 0.21.11
debug 1.9.1

The following bundled gems are promoted from default gems.

mutex_m 0.2.0
getoptlong 0.2.1
base64 0.2.0
bigdecimal 3.1.7
observer 0.1.2
abbrev 0.1.2
resolv-replace 0.1.1
rinda 0.2.0
drb 2.2.1
nkf 0.2.0
syslog 0.1.2
csv 3.2.8

See GitHub releases like GitHub Releases of Logger or changelog for details of the default gems or bundled gems.

Supported platforms

Compatibility issues

Error messages and backtrace displays have been changed.
- Use a single quote instead of a backtick as a opening quote. Feature #16495
- Display a class name before a method name (only when the class has a permanent name). Feature #19117
- Kernel#caller, Thread::Backtrace::Location's methods, etc. are also changed accordingly.
```
Old:
test.rb:1:in `foo': undefined method `time' for an instance of Integer
        from test.rb:2:in `<main>'

New:
test.rb:1:in 'Object#foo': undefined method 'time' for an instance of Integer
        from test.rb:2:in `<main>'
```

Stdlib compatibility issues

C API updates

rb_newobj and rb_newobj_of (and corresponding macros RB_NEWOBJ, RB_NEWOBJ_OF, NEWOBJ, NEWOBJ_OF) have been removed [Feature #20265].

Implementation improvements

Array#each is rewritten in Ruby for better performance [Feature #20182].

3.5 KiB Raw Blame History