April 2024 - ruby-core - ml.ruby-lang.org

[ruby-core:117714] [Ruby master Bug#20457] Final `return` is eliminated from the AST
by tenderlovemaking (Aaron Patterson) 30 Apr '24

30 Apr '24

Issue #20457 has been reported by tenderlovemaking (Aaron Patterson). ---------------------------------------- Bug #20457: Final `return` is eliminated from the AST https://bugs.ruby-lang.org/issues/20457 * Author: tenderlovemaking (Aaron Patterson) * Status: Open * Backport: 3.1: UNKNOWN, 3.2: UNKNOWN, 3.3: UNKNOWN ---------------------------------------- Given the following code: ```ruby def foo a = 1 return a end ``` If you parse this with RubyVM::AbstractSyntaxTree, the AST will be missing the `return` node. Of course the `return` node isn't necessary for compilation, but would be required for building an LSP for example. Here's a full program to demonstrate: ```ruby ast = RubyVM::AbstractSyntaxTree.parse DATA.read pp ast # Output is like this: # # (SCOPE@1:0-4:3 # tbl: [] # args: nil # body: # (DEFN@1:0-4:3 # mid: :foo # body: # (SCOPE@1:0-4:3 # tbl: [:a] # args: (ARGS@1:7-1:7 pre_num: 0 pre_init: nil opt: nil first_post: nil post_num: 0 post_init: nil rest: nil kw: nil kwrest: nil block: nil) # body: (BLOCK@2:2-3:10 (LASGN@2:2-2:7 :a (INTEGER@2:6-2:7 1)) (LVAR@3:9-3:10 :a))))) __END__ def foo a = 1 return a end ``` Btw, I'm happy to write failing tests for this type of stuff I'm just not sure where to put it! :) -- https://bugs.ruby-lang.org/

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[ruby-core:117706] [Ruby master Bug#20454] IRB echoes excessive input in dumb terminal
by zonuexe (Kenta USAMI) 30 Apr '24

30 Apr '24

Issue #20454 has been reported by zonuexe (Kenta USAMI). ---------------------------------------- Bug #20454: IRB echoes excessive input in dumb terminal https://bugs.ruby-lang.org/issues/20454 * Author: zonuexe (Kenta USAMI) * Status: Open * ruby -v: ruby 3.3.1 (2024-04-23 revision c56cd86388) [arm64-darwin23] * Backport: 3.1: UNKNOWN, 3.2: UNKNOWN, 3.3: UNKNOWN ---------------------------------------- When IRB is started on a terminal with the environment variable TERM=dumb, excessive output is generated as shown below. A simple terminal such as Emacs shell-mode or comint-mode is assumed, but it should be possible to reproduce the following with a rich terminal such as iTerm. Type 1[RET], 12[RET], 123[RET] on your keyboard in this order. % TERM=dumb irb irb(main):001> 1 irb(main):001> 1=> 1 irb(main):002> 12 irb(main):002> 1irb(main):002> 12=> 12 irb(main):003> 123 irb(main):003> 1irb(main):003> 12irb(main):003> 123=> 123 As arton-san says, you can avoid the problem by not using ReadlineInputMethod. https://twitter.com/arton/status/1783008921000804630 -- https://bugs.ruby-lang.org/

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[ruby-core:117733] [Ruby master Bug#20461] Unreadable pipe included in the readable IO of IO.select
by yamam (Masanari Yamamoto) 30 Apr '24

30 Apr '24

Issue #20461 has been reported by yamam (Masanari Yamamoto). ---------------------------------------- Bug #20461: Unreadable pipe included in the readable IO of IO.select https://bugs.ruby-lang.org/issues/20461 * Author: yamam (Masanari Yamamoto) * Status: Open * ruby -v: ruby 3.4.0dev (2024-04-27T12:55:28Z master c844968b72) [x86_64-linux] * Backport: 3.1: UNKNOWN, 3.2: UNKNOWN, 3.3: UNKNOWN ---------------------------------------- When executing the following script, pipe_r is not supposed to be readable because no writing is done to pipe_w, but pipe_r is included in the return value rs of IO.select. Since it is not possible to read from pipe_r, the IO::EAGAINWaitReadable exception is raised. ```ruby pipe_r, pipe_w = IO.pipe 1000.times do |i| File.popen(['seq', '1', '1000']) do |popen_r| j = 0 while true rs, ws, = IO.select([popen_r, pipe_r]) if rs.include?(popen_r) unless popen_r.gets break end end if rs.include?(pipe_r) puts "IO.select BUG pipe_r is not readable! i = #{i} j = #{j}" p pipe_r.read_nonblock(1) end j += 1 end end end ``` ``` $ ruby select.rb IO.select BUG pipe_r is not readable! i = 0 j = 20 <internal:io>:63:in `read_nonblock': Resource temporarily unavailable - read would block (IO::EAGAINWaitReadable) from select.rb:14:in `block (2 levels) in <main>' from select.rb:3:in `popen' from select.rb:3:in `block in <main>' from select.rb:2:in `times' from select.rb:2:in `<main>' [1] 73732 exit 1 ruby select.rb ``` -- https://bugs.ruby-lang.org/

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[ruby-core:117738] [Ruby master Feature#15438] Threads can't switch faster than TIME_QUANTUM_(NSEC|USEC|MSEC)
by jhawthorn (John Hawthorn) 29 Apr '24

29 Apr '24

Issue #15438 has been updated by jhawthorn (John Hawthorn). Status changed from Open to Closed I think this is something we should improve more (I would like even faster switching times), but it does seem possible as of Ruby 3.3 to have threads switch faster than 100ms. ``` def test_switching(priority = 0) done = false started = false busy = Thread.new do Thread.current.priority = priority until done started = true end end Thread.pass until started times = [] while times.length < 10 before = Process.clock_gettime(Process::CLOCK_MONOTONIC) Thread.pass after = Process.clock_gettime(Process::CLOCK_MONOTONIC) times << (after - before) end done = true busy.join times end puts RUBY_VERSION (-3).upto(3) do |priority| print "Priority: #{priority}" times = test_switching(priority) times = times.sort[1..-2] # drop fastest and slowest average = (times.sum / times.length) puts " average: #{average}" end ``` ``` $ ruby test_measure_switching_times.rb 3.2.2 Priority: -3 average: 0.10010529025021242 Priority: -2 average: 0.10010091188087245 Priority: -1 average: 0.10010025675364886 Priority: 0 average: 0.10010364262052462 Priority: 1 average: 0.20017941037440323 Priority: 2 average: 0.4003785701279412 Priority: 3 average: 0.8007820281236491 ``` ``` $ ruby test_measure_switching_times.rb 3.3.1 Priority: -3 average: 0.02040818374371156 Priority: -2 average: 0.03023905074587674 Priority: -1 average: 0.05040335562443943 Priority: 0 average: 0.10088755612378009 Priority: 1 average: 0.20198591962616774 Priority: 2 average: 0.4033456226279668 Priority: 3 average: 0.8073137137507729 ``` ---------------------------------------- Feature #15438: Threads can't switch faster than TIME_QUANTUM_(NSEC|USEC|MSEC) https://bugs.ruby-lang.org/issues/15438#change-108145 * Author: sylvain.joyeux (Sylvain Joyeux) * Status: Closed ---------------------------------------- Thread#priority can be set to negative values, which when looking at the code is meant to reduce the time allocated to the thread. However, as far as I could understand in the codebase, the quantum of time is definitely hard-coded to 100ms (TIME_QUANTUM_...). This means that the "lower allocated time" would only work for threads that would often yield one way or the other (sleep, blocking calls, ...) My projects would definitely benefit from a faster switching period. I was wondering how best to implement this ability ? I thought of the following: 1. globally using an environment variable 2. globally using an API 3. trying to adapt dynamically, using the highest needed period 4. lowering the period when a priority lower than 0 is set, leaving it at the lower period. Obviously (3) would seem to be the best, but I'm not sure I would be able to get it right in a decent amount of time. (4) seem to be a good trade-off between simplicity and performance (nothing changes if you never use priorities lower than 0, and if you were you basically get what you wanted). What do you think ? ---Files-------------------------------- 0001-dynamically-modify-the-timer-thread-period-to-accoun.patch (3.12 KB) 0001-2.6-fix-handling-of-negative-priorities.patch (8.43 KB) -- https://bugs.ruby-lang.org/

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[ruby-core:117735] [Ruby master Feature#18583] Pattern-matching: API for custom unpacking strategies?
by ntl (Nathan Ladd) 28 Apr '24

28 Apr '24

Issue #18583 has been updated by ntl (Nathan Ladd). Could the match operator, `=~`, could be used as a general complement to `===`? Example (following Victor's original sketch): ``` ruby class Matcher def initialize(regexp) @regexp = regexp end def ===(obj) @regexp.match?(obj) end def =~(obj) match_data = @regexp.match(obj) match_data end end case "some string" in ^(Matcher.new(/(?<some_named_capture>some) string/) => match_data some_named_capture = match_data[:some_named_capture] puts "Match: #{some_named_capture}" end ``` This would add `=~` to the pattern matching protocol that's currently comprised of `===`, `deconstruct` and `deconstruct_keys`. It would make `===` significantly more useful, and regular expressions provide a great example of why: when matching a string to a regular expression pattern, the string is already in lexical scope, but the match data is novel and only comes into existence upon a successful match: ``` subject = "some string" case subject in ^(Matcher.new(/(?<some_named_capture>some) string/) => match_data # Capturing the match data variable instead of the original string doesn't make the original string inaccessible: puts "Match subject: #{subject.inspect}" end ``` I also suspect this could be embedded into the pattern syntax itself, and could allow for some interesting possibilities. One example that leaps to mind is reifying primitive data parsed from JSON into a data structure: ``` ruby SomeStruct = Struct.new(:some_attr, :some_other_attr) do def self.===(data) data.is_a?(Hash) && data.key?(:some_attr) && data.key?(:some_other_attr) end def self.=~(data) new(**data) end end # Parse JSON into raw (primitive) data some_data = JSON.parse(<<JSON) { "some_attr": "some value", "some_other_attr": "some other value" } JSON # Reify data structure from raw data case some_data in SomeStruct => some_struct puts some_struct.inspect end ``` ---------------------------------------- Feature #18583: Pattern-matching: API for custom unpacking strategies? https://bugs.ruby-lang.org/issues/18583#change-108142 * Author: zverok (Victor Shepelev) * Status: Open ---------------------------------------- I started to think about it when discussing https://github.com/ruby/strscan/pull/30. The thing is, usage of StringScanner for many complicated parsers invokes some kind of branching. In pseudocode, the "ideal API" would allow to write something like this: ```ruby case <what next matches> in /regexp1/ => value_that_matched # use value_that_matched in /regexp2/ => value_that_matched # use value_that_matched # ... ``` This seems "intuitively" that there *should* be some way of implementing it, but we fall short. We can do some StringScanner-specific matcher object which defines its own `#===` and use it with pinning: ```ruby case scanner in ^(Matcher.new(/regexp1/)) => value_that_matched # ... ``` But there is no API to tell how the match result will be unpacked, just the whole `StringScanner` will be put into `value_that_matched`. So, I thought that maybe it would be possible to define some kind of API for pattern-like objects, the method with signature like `try_match_pattern(value)`, which by default is implemented like `return value if self === value`, but can be redefined to return something different, like part of the object, or object transformed somehow. This will open some interesting (if maybe uncanny) possibilities: not just slicing out the necessary part, but something like ```ruby value => ^(type_caster(Integer)) => int_value ``` So... Just a discussion topic! -- https://bugs.ruby-lang.org/

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[ruby-core:117734] [Ruby master Feature#18915] New error class: NotImplementedYetError or scope change for NotImplementedError
by Quintasan 28 Apr '24

28 Apr '24

Issue #18915 has been updated by Quintasan (Michał Zając). nithinbekal (Nithin Bekal) wrote in #note-18: > > What name candidate do you have? > > What do you think about the name `SubclassResponsibilityError`? As @citizen428 explains [here](https://ruby.social/@citizen428@chaos.social/112239323523258221): > > > Smalltalk had the idiom of implementing abstract methods with the body `self subclassResponsibility` which raises an error. > > The name gives a pretty clear indication of what is wrong, and it seems fitting considering Ruby's Smalltalk heritage. I like this as well as `AbstractMethodError` ---------------------------------------- Feature #18915: New error class: NotImplementedYetError or scope change for NotImplementedError https://bugs.ruby-lang.org/issues/18915#change-108140 * Author: Quintasan (Michał Zając) * Status: Open ---------------------------------------- # Abstract Introduce `NotImplementedYetError` exception that should be used in case when the codepath has not been implemented by the developer for some reason (maybe they're designing an abstract class or are designing some sort of interface to reuse later on) OR extend the meaning of `NotImplementedError` to cover those usecases so we don't have to introduce another exception # Background `NotImplementedError` is supposed to be raised `if the underlying operating system or Ruby runtime does not support them` (https://ruby-doc.org/core-3.1.2/NotImplementedError.html) However it appears that many people are misusing this exception by raising this in a superclass from which they later inherit from. I do realize that Ruby promotes duck-typing (the default RuboCop style guide has a cop for this – https://github.com/rubocop/ruby-style-guide#duck-typing) However I have seen this being discussed numerous times: * https://github.com/rubocop/ruby-style-guide/issues/458 * http://chrisstump.online/2016/03/23/stop-abusing-notimplementederror/ * https://oleg0potapov.medium.com/ruby-notimplementederror-dont-use-it-dff1fd… * https://gitlab.com/gitlab-org/gitlab/-/issues/354314 (which I'm the author of) * https://github.com/rmosolgo/graphql-ruby/issues/2067 (here the author actually confused it with Python's `NotImplementedError`) * https://stackoverflow.com/questions/13668068/how-to-signal-not-implemented-… # Proposal Create `NotImplementedYetError` exception OR Allow raising `NotImplementedError` in cases other than OS or Ruby runtime incompatibilities # Evaluation ### Add `NotImplementedYetError` I think a new exception is a better idea than changing the usage of an existing one just because "everyone is using it". That said it would require people to refactor their code which might prevent wider adoption of the new exception. ### Change scope of `NotImplementedError` This would require the least amount of changes possible (only a documentation change) and I believe there would be no compatibility problems whatsoever. ---Files-------------------------------- not-implemented-error-docs.patch (1.57 KB) -- https://bugs.ruby-lang.org/

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[ruby-core:117732] [Ruby master Bug#20460] Ripper `eval` option
by kddnewton (Kevin Newton) 27 Apr '24

27 Apr '24

Issue #20460 has been reported by kddnewton (Kevin Newton). ---------------------------------------- Bug #20460: Ripper `eval` option https://bugs.ruby-lang.org/issues/20460 * Author: kddnewton (Kevin Newton) * Status: Open * Backport: 3.1: UNKNOWN, 3.2: UNKNOWN, 3.3: UNKNOWN ---------------------------------------- There are a couple of differences when producing syntax trees from the parser/ripper when compiling for eval. Namely, for the eval case it does not raise a syntax error for invalid jumps. It would be nice to be able to pass an `eval: true/false` option to `Ripper.sexp`/`Ripper.sexp_raw`/`Ripper.new` to tell it to parse as if it were an `eval`. Because of some new syntax errors, this had led to bugs like https://bugs.ruby-lang.org/issues/20186. If we provide such an option, it could also be useful for debugging purposes. -- https://bugs.ruby-lang.org/

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[ruby-core:116802] [Ruby master Misc#20272] Ambiguity around Ractor message sending FIFO semantics
by forthoney (Seong-Heon Jung) 26 Apr '24

26 Apr '24

Issue #20272 has been reported by forthoney (Seong-Heon Jung). ---------------------------------------- Misc #20272: Ambiguity around Ractor message sending FIFO semantics https://bugs.ruby-lang.org/issues/20272 * Author: forthoney (Seong-Heon Jung) * Status: Open * Priority: Normal ---------------------------------------- The docs should explicitly state the semantics/properties of Ractor message, especially when it comes to FIFO. For example, assume I have two Ractors, Ractor A and Ractor B. Ractor A sends two messages `"hello"` and `"world"` in this order to Ractor B. If I call `Ractor.receive` on Ractor B, am I guaranteed to see `"hello"` and then `"world"` or is it possible the messages are delivered out of order? -- https://bugs.ruby-lang.org/

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[ruby-core:117646] [Ruby master Bug#20444] Kernel#loop: returning the "result" value of StopIteration doesn't work when raised directly
by esad (Esad Hajdarevic) 26 Apr '24

26 Apr '24

Issue #20444 has been reported by esad (Esad Hajdarevic). ---------------------------------------- Bug #20444: Kernel#loop: returning the "result" value of StopIteration doesn't work when raised directly https://bugs.ruby-lang.org/issues/20444 * Author: esad (Esad Hajdarevic) * Status: Open * ruby -v: ruby 3.3.0 (2023-12-25 revision 5124f9ac75) [arm64-darwin20] * Backport: 3.0: UNKNOWN, 3.1: UNKNOWN, 3.2: UNKNOWN, 3.3: UNKNOWN ---------------------------------------- There was a https://bugs.ruby-lang.org/issues/11498 a while ago which was merged in, but I was surprised to find out that raising `StopIteration` in a loop like `loop { raise StopIteration.new(3) }` returns nil and not 3. -- https://bugs.ruby-lang.org/

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[ruby-core:117711] [Ruby master Bug#20456] Hash can get stuck marked as iterating through process forking
by blowfishpro (Talia Wong) 26 Apr '24

26 Apr '24

Issue #20456 has been reported by blowfishpro (Talia Wong). ---------------------------------------- Bug #20456: Hash can get stuck marked as iterating through process forking https://bugs.ruby-lang.org/issues/20456 * Author: blowfishpro (Talia Wong) * Status: Open * ruby -v: 3.3.0 * Backport: 3.1: UNKNOWN, 3.2: UNKNOWN, 3.3: UNKNOWN ---------------------------------------- # Steps to Reproduce 1. Iterate over a hash 1. While that iteration is happening, fork the process a. This should be done in a way that causes the iteration to never finish from the child process's view, e.g. fork with a block, or iteration is happening in a different thread than fork 1. Attempt to add a new key to the hash in the child process a. This can be before or after the iteration finishes in the parent process, doesn't matter # Observed Behavior The child process can never add a new key to the hash, always fails with `RuntimeError: can't add a new key into hash during iteration` # Desired The hash is no longer iterating in the child process, so it can be modified as needed # Examples ## With threads: ```ruby h = { a: 1 } t = Thread.new do sleep 0.05 pid = fork do sleep 0.1 puts 'child: before' h[:b] = 2 puts 'child: after' end Process.wait2(pid) end puts 'parent: before' h.each do sleep 0.1 end puts 'parent: after' puts t.join.value.inspect ``` produces: ``` parent: before parent: after child: before can't add a new key into hash during iteration (RuntimeError) [34450, #<Process::Status: pid 34450 exit 1>] ``` ## Without threads: ``` ruby h = { a: 1 } pid = nil puts 'parent: before' h.each do pid = fork do sleep 0.05 puts 'child: before' h[:b] = 2 puts 'child: after' end end puts 'parent: after' puts Process.wait2(pid).inspect ``` produces: ``` parent: before parent: after child: before can't add a new key into hash during iteration (RuntimeError) [17809, #<Process::Status: pid 17809 exit 1>] ``` # Platform information This behavior has been observed in the following environments - Ruby 3.3.0 on Mac OS 14.4.1 (Apple M1 Max) installed via [asdf](https://asdf-vm.com/) - Ruby 2.7.5 on Mac OS 14.4.1 (Apple M1 Max) installed via [asdf](https://asdf-vm.com/) - Ruby 3.2.3 on RockyLinux 8.4 (x86_64) installed from [Fullstaq](https://fullstaqruby.org/) -- https://bugs.ruby-lang.org/

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