Bug #21622: Prism wrongly accepts command call to be a key of keyword argument

• Status: Open
• Assignee: -
• Target version: -
• ruby -v: ruby 3.5.0dev (2025-10-02T03:48:32Z master 88222caaa9) +PRISM [x86_64-linux]
• Backport: 3.2: UNKNOWN, 3.3: UNKNOWN, 3.4: UNKNOWN

[tompng (tomoya ishida)]

These are syntax error in parse.y but accepted in Prism

p(p a, x: b => value)
p(p a, x: => value)
p(p a, &block => value)
p(p a, *args => value)
p(p a, **kwargs => value)

Maybe as a result, Prism accepts command call within command call

p p 1, &block => 2, &block
p p p 1 => 2 => 3 => 4