Bug #21608: 三項演算子と break を組み合わせると SyntaxError

• Status: Rejected
• Assignee: prism
• Target version: -
• ruby -v: ruby 3.4.6 (2025-09-16 revision dbd83256b1) +PRISM [x86_64-linux]
• Backport: 3.2: UNKNOWN, 3.3: UNKNOWN, 3.4: REQUIRED

[ursm (Keita Urashima)]

>> RUBY_VERSION
=> "3.4.5"
>> [1, 2].find {|i| i.even? ? break i : nil }

>> RUBY_VERSION
=> "3.4.6"
>> [1, 2].find {|i| i.even? ? break i : nil }
<internal:kernel>:168:in 'Kernel#loop': (irb):2: syntax error found (SyntaxError)
> 2 | ... i : nil }
    |     ^ unexpected local variable or method, expecting end-of-input

	from /home/ursm/.local/share/mise/installs/ruby/3.4.6/lib/ruby/gems/3.4.0/gems/irb-1.15.2/exe/irb:9:in '<top (required)>'
	from /home/ursm/.local/share/mise/installs/ruby/3.4.6/bin/irb:25:in 'Kernel#load'
	from /home/ursm/.local/share/mise/installs/ruby/3.4.6/bin/irb:25:in '<main>'

[kddnewton (Kevin Newton)]

• Assignee set to prism

Thank you for the report, I will get this fixed.

[k0kubun (Takashi Kokubun)]

• Backport changed from 3.2: UNKNOWN, 3.3: UNKNOWN, 3.4: UNKNOWN to 3.2: UNKNOWN, 3.3: UNKNOWN, 3.4: REQUIRED

[nobu (Nobuyoshi Nakada)]

• Status changed from Open to Rejected

In ruby code, operations with arguments without parentheses have quite lower precedence.
That code is inverting the precedences, so this failure should be an intentional fix.

[Earlopain (Earlopain _)]

To elaborate, if you replace break with a method call, it was already a syntax error. I suspect this was changed with https://bugs.ruby-lang.org/issues/21540. Such code has been rejected since at least ruby 2.0 and was only accidentally accepted since 3.4.0