May 2025 - ruby-core - ml.ruby-lang.org

[ruby-core:122343] [Ruby Misc#21385] Namespace: Suggesting a rename
by fxn (Xavier Noria) 20 Sep '25

20 Sep '25

Issue #21385 has been reported by fxn (Xavier Noria). ---------------------------------------- Misc #21385: Namespace: Suggesting a rename https://bugs.ruby-lang.org/issues/21385 * Author: fxn (Xavier Noria) * Status: Open ---------------------------------------- I'd like to suggest a rename of namespaces. The word "namespace" is already taken in Ruby. We say that classes and modules act as or represent. Constant paths nest them in practice. We say that it is a best practice that gems create their own namespace, etc. If the feature goes ahead with this name, the above sentences, well-established in the Ruby community, will start to sound confusing, because that meaning of "namespace" stays. If you look at the index in Matz's book, "namespaces" is indexed in pages 248–250. Title of section 7.5.1 is "Modules as Namespaces". Besides, I have had a few experiences explaining the proposal to people, and quickly realizing they assume this is something like C++ namespaces or Java packages. Then, I have to undo that mental model and start all over saying "forget that mental model". Those are like our constant paths, only more simple and strict. I think it may also be confusing in this sense (though this could be OK if it wasn't for the previous point.) To be constructive: Some alternative names that I have thought about are "isolates", "shields", or "cells". ("sandboxes" is close, but may have security connotations you do not want to suggest.) -- https://bugs.ruby-lang.org/

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[ruby-core:121234] [Ruby master Bug#21168] Prism doesn't require argument parentheses (in some cases) when a block is present but parse.y does
by Earlopain (Earlopain _) 19 Sep '25

19 Sep '25

Issue #21168 has been reported by Earlopain (Earlopain _). ---------------------------------------- Bug #21168: Prism doesn't require argument parentheses (in some cases) when a block is present but parse.y does https://bugs.ruby-lang.org/issues/21168 * Author: Earlopain (Earlopain _) * Status: Open * ruby -v: ruby 3.4.2 (2025-02-15 revision d2930f8e7a) +PRISM [x86_64-linux] * Backport: 3.1: UNKNOWN, 3.2: UNKNOWN, 3.3: UNKNOWN, 3.4: UNKNOWN ---------------------------------------- It's a bit more than that but explaining it in full would be a bit much. Instead, see this: ```rb foo( bar baz do end ) ``` ```sh $ ruby -c --parser=prism test.rb Syntax OK $ ruby -c --parser=parse.y test.rb ruby: test.rb:2: syntax error, unexpected 'do' for block, expecting ')' (SyntaxError) bar baz do ^~ ``` OTOH, this is consistently rejected: ```rb [ foo bar do end, ] # And also foo || bar baz do end ``` -- https://bugs.ruby-lang.org/

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[ruby-core:116083] [Ruby master Feature#20163] Introduce #bit_count method on Integer
by garrison (Garrison Jensen) 18 Sep '25

18 Sep '25

Issue #20163 has been reported by garrison (Garrison Jensen). ---------------------------------------- Feature #20163: Introduce #bit_count method on Integer https://bugs.ruby-lang.org/issues/20163 * Author: garrison (Garrison Jensen) * Status: Open * Priority: Normal ---------------------------------------- This feature request is to implement a method called #bit_count on Integer that returns the number of ones in the binary representation of the absolute value of the integer. ``` n = 19 n.bit_count #=> 3 (-n).bit_count #=> 3 ``` This is often useful when you use an integer as a bitmask and want to count how many bits are set. This would be equivalent to ``` n.to_s(2).count("1") ``` However, this can be outperformed by ``` def bit_count(n) count = 0 while n > 0 n &= n - 1 # Flip the least significant 1 bit to 0 count += 1 end count end ``` I think this would be a useful addition because it would fit alongside the other bit-related methods defined on integer: `#bit_length,` `#allbits?`, `#anybits?`, `#nobits?`. Also, when working with bitmasks, a minor upgrade to performance often results in a significant improvement. Similar methods from other languages: https://docs.python.org/3/library/stdtypes.html#int.bit_count https://doc.rust-lang.org/std/primitive.i32.html#method.count_ones -- https://bugs.ruby-lang.org/

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[ruby-core:122274] [Ruby Bug#21370] `it` can cause ISeq serialization failure
by byroot (Jean Boussier) 16 Sep '25

16 Sep '25

Issue #21370 has been reported by byroot (Jean Boussier). ---------------------------------------- Bug #21370: `it` can cause ISeq serialization failure https://bugs.ruby-lang.org/issues/21370 * Author: byroot (Jean Boussier) * Status: Open * Backport: 3.2: DONTNEED, 3.3: DONTNEED, 3.4: REQUIRED ---------------------------------------- Originally reported at: https://github.com/rails/rails/issues/55108 ```ruby iseq = RubyVM::InstructionSequence.compile(<<~'RUBY') [1].each do rescue => e puts it end RUBY iseq.to_binary # CRASH ``` ``` miniruby(sigsegv) (null):0 miniruby(RB_FL_ANY_RAW+0x20) [0x1010ac504] internal/fl_type.h:507 miniruby(rbimpl_rstring_getmem+0x20) [0x101090674] internal/core/rstring.h:393 miniruby(rb_str_cmp+0x4c) [0x10109920c] string.c:4541 miniruby(outer_variable_cmp+0x3c) [0x100e43b64] compile.c:13381 miniruby(cmp_bsd_qsort+0x3c) [0x1010fe810] util.c:239 miniruby(ruby_qsort+0x5c) [0x1010fe7a8] util.c:248 miniruby(ibf_dump_outer_variables+0x150) [0x100e43708] compile.c:13402 miniruby(ibf_dump_iseq_each+0x19c) [0x100e423cc] compile.c:13527 miniruby(ibf_dump_iseq_list_i+0x38) [0x100e420fc] compile.c:13862 miniruby(apply_functor+0x40) [0x10107bad8] st.c:1644 ``` It is crashing while trying to sort outer variables, and `it` is anonymous. -- https://bugs.ruby-lang.org/

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[ruby-core:121865] [Ruby Bug#21313] `it` in rescue/ensure on prism
by ko1 (Koichi Sasada) 16 Sep '25

16 Sep '25

Issue #21313 has been reported by ko1 (Koichi Sasada). ---------------------------------------- Bug #21313: `it` in rescue/ensure on prism https://bugs.ruby-lang.org/issues/21313 * Author: ko1 (Koichi Sasada) * Status: Open * Assignee: prism * ruby -v: "ruby 3.4.1 (2024-12-25 revision 48d4efcb85) +PRISM [wasm32-wasi]" * Backport: 3.2: UNKNOWN, 3.3: UNKNOWN, 3.4: UNKNOWN ---------------------------------------- ```ruby 1.times do raise rescue p it #=> prism: false #=> parse.y: 0 end ``` `it` should return 0, shouldn't it? demo: parse.y: https://ruby.github.io/play-ruby/?code=p+RUBY_DESCRIPTION%0A%0A1.times+do%0… prism: https://ruby.github.io/play-ruby/?code=p+RUBY_DESCRIPTION%0A%0A1.times+do%0… Same on `ensure`. ```ruby 1.times do raise ensure p it #=> prism: false #=> parse.y: 0 end ``` ```ruby 1.times do begin raise ensure p it #=> prism: false #=> parse.y: 0 end end ``` -- https://bugs.ruby-lang.org/

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[ruby-core:122086] [Ruby Bug#21337] Using `not` on the RHS of a logical operator becomes valid syntax with Prism
by koic (Koichi ITO) 15 Sep '25

15 Sep '25

Issue #21337 has been reported by koic (Koichi ITO). ---------------------------------------- Bug #21337: Using `not` on the RHS of a logical operator becomes valid syntax with Prism https://bugs.ruby-lang.org/issues/21337 * Author: koic (Koichi ITO) * Status: Open * ruby -v: ruby 3.4.3 (2025-04-14 revision d0b7e5b6a0) +PRISM [x86_64-darwin24] * Backport: 3.2: UNKNOWN, 3.3: UNKNOWN, 3.4: UNKNOWN ---------------------------------------- The following syntax behavior differs between Ruby 3.3 (parse.y by default) and Ruby 3.4 (Prism by default). ```ruby if true && not true; end ``` ## Expected In Ruby 3.3 and earlier, the following code results in a syntax error. The default parser is `parse.y`. ```console $ ruby -vce 'if true && not true; end' ruby 3.3.8 (2025-04-09 revision b200bad6cd) [x86_64-darwin24] -e:1: syntax error, unexpected `true', expecting '(' if true && not true; end ruby: compile error (SyntaxError) ``` The key point is that `not` is used on the right-hand side of a logical operator. ## Actual When the default parser is switched to Prism, it is accepted as valid syntax with Ruby 3.4+ (Prism by default): ```console $ ruby -vce 'if true && not true; end' ruby 3.4.3 (2025-04-14 revision d0b7e5b6a0) +PRISM [x86_64-darwin24] Syntax OK $ ruby -vce 'if true && not true; end' ruby 3.5.0dev (2025-05-13T02:05:19Z master 9b8c846bdf) +PRISM [x86_64-darwin24] Syntax OK ``` Specifying parse.y causes a syntax error, as before 3.3 (parse.y by default): ```console $ ruby -vce 'if true && not true; end' ruby 3.3.8 (2025-04-09 revision b200bad6cd) [x86_64-darwin24] -e:1: syntax error, unexpected `true', expecting '(' if true && not true; end ruby: compile error (SyntaxError) $ ruby --parser=parse.y -vce 'if true && not true; end' ruby 3.5.0dev (2025-05-13T02:05:19Z master 9b8c846bdf) [x86_64-darwin24] -e:1: syntax error, unexpected 'true', expecting '(' if true && not true; end ruby: compile error (SyntaxError) ``` The behavior seen in the parse.y producing a syntax error might be probably the expected one. Any case, it is likely that users would not expect such a discrepancy between parsers. This issue was noticed in the context of the following RuboCop issue: https://github.com/rubocop/rubocop/issues/14177 -- https://bugs.ruby-lang.org/

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[ruby-core:121390] [Ruby Bug#21188] PRISM does not end reading from tty with ^D twice
by nobu (Nobuyoshi Nakada) 15 Sep '25

15 Sep '25

Issue #21188 has been reported by nobu (Nobuyoshi Nakada). ---------------------------------------- Bug #21188: PRISM does not end reading from tty with ^D twice https://bugs.ruby-lang.org/issues/21188 * Author: nobu (Nobuyoshi Nakada) * Status: Open * Assignee: prism * Backport: 3.1: DONTNEED, 3.2: DONTNEED, 3.3: DONTNEED, 3.4: REQUIRED ---------------------------------------- When reading from tty, `^D` ends the text without the newline. ```console $ cat a ``` Typing `^D` here, only "a" is sent without a newline, and `cat` echos back it. Then by typing `^D` again, an empty read that means EOF causes `cat` to exit. `ruby --parser=parse.y` behaves in this manner: ```console $ ruby --parser=parse.y p __FILE__"-" ``` Typing `^D` twice just after `__FILE__`, and `p` prints `"-"`. However prism requires `^D` thrice. -- https://bugs.ruby-lang.org/

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[ruby-core:120819] [Ruby master Bug#21097] `x = a rescue b in c` and `def f = a rescue b in c` parsed differently between parse.y and prism
by tompng (tomoya ishida) 13 Sep '25

13 Sep '25

Issue #21097 has been reported by tompng (tomoya ishida). ---------------------------------------- Bug #21097: `x = a rescue b in c` and `def f = a rescue b in c` parsed differently between parse.y and prism https://bugs.ruby-lang.org/issues/21097 * Author: tompng (tomoya ishida) * Status: Open * ruby -v: ruby 3.5.0dev (2025-01-27T08:19:32Z master c3c7300b89) +YJIT +MN +PRISM [arm64-darwin22] * Backport: 3.1: UNKNOWN, 3.2: UNKNOWN, 3.3: UNKNOWN, 3.4: UNKNOWN ---------------------------------------- ~~~ruby x = a rescue b in c (x = (a rescue b)) in c # parse.y, prism(ruby 3.4) x = (a rescue (b in c)) # prism(ruby 3.5) ~~~ ~~~ruby def f = a rescue b in c #=> true(parse.y), :f(prism) (def f = (a rescue b)) in c # parse.y def f = (a rescue (b in c)) # prism ~~~ There is no difference between prism and parse.y parsing these codes ~~~ruby a rescue b in c # a rescue (b in c) x = a rescue b # x = (a rescue b) x = b in c # (x = b) in c def f = a rescue b # def f = (a rescue b) def f = b in c # (def f = a) in b ~~~ -- https://bugs.ruby-lang.org/

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[ruby-core:121389] [Ruby Bug#21187] Strings concatenated with `\` getting frozen with literal hashes (PRISM only)
by LocoDelAssembly 13 Sep '25

13 Sep '25

Issue #21187 has been reported by LocoDelAssembly (Hernán Pereira). ---------------------------------------- Bug #21187: Strings concatenated with `\` getting frozen with literal hashes (PRISM only) https://bugs.ruby-lang.org/issues/21187 * Author: LocoDelAssembly (Hernán Pereira) * Status: Open * ruby -v: ruby 3.4.2 (2025-02-15 revision d2930f8e7a) +PRISM [x86_64-linux] * Backport: 3.1: UNKNOWN, 3.2: UNKNOWN, 3.3: UNKNOWN, 3.4: UNKNOWN ---------------------------------------- When the first elements of a literal hash are strings that are concatenated with `\`, those elements are flagged with `PM_NODE_FLAG_STATIC_LITERAL` and a special optimization that I believe was introduced in https://github.com/ruby/ruby/commit/8080de04be8e99e71309745822a9d436cc4ae37c causes the strings to be frozen. Reproduction === test.rb ``` a = { a: 'one' \ 'two', b: 'three' \ 'four', c: 'five', d: 'six' \ 'seven' } b = { a: 'one', b: 'two' \ 'three' } puts "a = #{a.map { |k,v| {k => v.frozen?} }}" puts "b = #{b.map { |k,v| {k => v.frozen?} }}" ``` With prism: ``` $ ruby test.rb a = [{a: true}, {b: true}, {c: false}, {d: false}] b = [{a: false}, {b: false}] ``` With parse.y: ``` $ ruby --parser=parse.y test.rb a = [{a: false}, {b: false}, {c: false}, {d: false}] b = [{a: false}, {b: false}] ``` (Notice `b` hash is unaffected in both parsers) Not sure if this is just part of undefined behavior or this is indeed a bug. Assigning a string concatenated with `\` to a variable doesn't make it frozen, to the best of my knowledge this seems to be hash-specific. -- https://bugs.ruby-lang.org/

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[ruby-core:122315] [Ruby Bug#21378] variable pinning does not look for method arguments
by shyouhei (Shyouhei Urabe) 13 Sep '25

13 Sep '25

Issue #21378 has been reported by shyouhei (Shyouhei Urabe). ---------------------------------------- Bug #21378: variable pinning does not look for method arguments https://bugs.ruby-lang.org/issues/21378 * Author: shyouhei (Shyouhei Urabe) * Status: Open * Assignee: prism * ruby -v: ruby 3.5.0dev (2025-01-23T15:24:35Z origin/7ed08c4fd31.. 7ed08c4fd3) +PRISM [wasm32-wasi] * Backport: 3.2: UNKNOWN, 3.3: UNKNOWN, 3.4: UNKNOWN ---------------------------------------- Is this intentional? ``` irb(main):001> def x?(y, z) = y in { x: ^z } <internal:kernel>:168:in 'Kernel#loop': (irb):1: syntax error found (SyntaxError) > 1 | def x?(y, z) = y in { x: ^z } | ^ z: no such local variable from eval_async:132:in '<main>' from /bundle/gems/js-2.7.1/lib/js.rb:109:in 'Kernel.eval' from /bundle/gems/js-2.7.1/lib/js.rb:109:in 'block in JS.__eval_async_rb' from /bundle/gems/js-2.7.1/lib/js.rb:120:in 'block in JS.__async' ``` -- https://bugs.ruby-lang.org/

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