Bug #21540: prism allows `foo && return bar` when parse.y doesn't

• Status: Open
• Assignee: -
• Target version: -
• ruby -v: ruby 3.5.0dev (2025-08-08T02:57:23Z master 3ad26d0501) [x86_64-linux]
• Backport: 3.2: DONTNEED, 3.3: DONTNEED, 3.4: REQUIRED

[Earlopain (Earlopain _)]

Code such as foo && return bar has been disallowed in ruby since at least Ruby 2.0. Prism allows it though:

$ ruby -cve "a && return foo"
ruby 3.5.0dev (2025-08-08T02:57:23Z master 3ad26d0501) +PRISM [x86_64-linux]
Syntax OK

$ ruby --parser=parse.y -cve "a && return foo"
ruby 3.5.0dev (2025-08-08T02:57:23Z master 3ad26d0501) [x86_64-linux]
-e:1: syntax error, unexpected local variable or method, expecting end-of-input
a && return foo
ruby: compile error (SyntaxError)

The code seems to behave like I'd expect it to and I wouldn't mind it being accepted but it is inconsistent. Also happens on Ruby 3.4

[Earlopain (Earlopain _)]

• Description updated (diff)

[nobu (Nobuyoshi Nakada)]

It is because of the precedence, and has been since 1.x at least.

[nobu (Nobuyoshi Nakada)]

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

[Earlopain (Earlopain _)]

Right, I understand. foo && (return bar) would be allowed, thanks for clarifying (works as expected in prism and parse.y)