Issue #20090 has been updated by naruse (Yui NARUSE). Backport changed from 3.0: DONTNEED, 3.1: DONTNEED, 3.2: DONTNEED, 3.3: REQUIRED to 3.0: DONTNEED, 3.1: DONTNEED, 3.2: DONTNEED, 3.3: DONE ruby_3_3 f8f0d342e48a38caac6d32b438c145bb581a51e6 merged revision(s) 3d19409637de1462b6790d2a92344bf0a10d8c52. ---------------------------------------- Bug #20090: Anonymous arguments are now syntax errors in unambiguous cases https://bugs.ruby-lang.org/issues/20090#change-106522 * Author: willcosgrove (Will Cosgrove) * Status: Closed * Priority: Normal * ruby -v: ruby 3.3.0 (2023-12-25 revision 5124f9ac75) [arm64-darwin23] * Backport: 3.0: DONTNEED, 3.1: DONTNEED, 3.2: DONTNEED, 3.3: DONE ---------------------------------------- It looks like the changes that were made in #19370 may have gone further than intended. It's also possible I'm misunderstanding what decision was made. But it was my understanding that the goal was to make ambiguous cases a syntax error. The test cases added are all testing the ambiguous cases: ```rb assert_syntax_error("def b(&) ->(&) {c(&)} end", /anonymous block parameter is also used/) # ... assert_syntax_error("def b(*) ->(*) {c(*)} end", /anonymous rest parameter is also used/) assert_syntax_error("def b(a, *) ->(*) {c(1, *)} end", /anonymous rest parameter is also used/) assert_syntax_error("def b(*) ->(a, *) {c(*)} end", /anonymous rest parameter is also used/) # ... assert_syntax_error("def b(**) ->(**) {c(**)} end", /anonymous keyword rest parameter is also used/) assert_syntax_error("def b(k:, **) ->(**) {c(k: 1, **)} end", /anonymous keyword rest parameter is also used/) assert_syntax_error("def b(**) ->(k:, **) {c(**)} end", /anonymous keyword rest parameter is also used/) ``` However it is now also producing syntax errors in all of these cases: ```rb def b(&) -> { c(&) } end def b(*) -> { c(*) } end def b(a, *) -> { c(1, *) } end def b(*) ->(a) { c(a, *) } end def b(**) -> { c(**) } end def b(k:, **) -> { c(k: 1, **) } end def b(**) ->(k:) { c(k:, **) } end ``` Again, it's possible I misunderstood the scope of the previous change. But it would be sad to lose the unambiguous case, as I've used that pattern quite a bit in my own projects. This is my first time opening an issue here, so I apologize in advance if I've done anything non-standard. -- https://bugs.ruby-lang.org/