HTTP/2 200 x-amz-id-2: dRKc3GSTQcnhyycSlM7rRhTnSJOMhkwqPKbo8AIxOV1FiXfyy0Z1whnRZiRrrvWNsEMzfsVoo0zkqfTtPIN+QVc4FDQ5U6tvQWAH9FGPVf0= x-amz-request-id: ZRWZCXS8TH9VYZJJ last-modified: Wed, 14 May 2025 05:02:00 GMT etag: "eea416e305ba75fad0028b8f3ef5082c" x-amz-server-side-encryption: AES256 server: AmazonS3 content-encoding: gzip via: 1.1 varnish, 1.1 varnish content-type: text/plain; charset=utf-8 accept-ranges: bytes age: 0 date: Wed, 23 Jul 2025 20:23:35 GMT x-served-by: cache-tyo11936-TYO, cache-bom-vanm7210046-BOM x-cache: MISS, MISS x-cache-hits: 0, 0 x-timer: S1753302215.268426,VS0,VE318 vary: Accept-Encoding content-length: 1012 From: "koic (Koichi ITO) via ruby-core" Date: 2025-05-14T04:57:44+00:00 Subject: [ruby-core:122086] [Ruby Bug#21337] Using `not` on the RHS of a logical operator becomes valid syntax with Prism 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/ ______________________________________________ ruby-core mailing list -- ruby-core@ml.ruby-lang.org To unsubscribe send an email to ruby-core-leave@ml.ruby-lang.org ruby-core info -- https://ml.ruby-lang.org/mailman3/lists/ruby-core.ml.ruby-lang.org/