[ruby-core:119467] [Ruby master Bug#20785] Should `a in b, and c` `a in b, or c` `a in b, rescue c` be syntax ok?

["Dan0042 (Daniel DeLorme) via ruby-core" <ruby-core@ml.ruby-lang.org>]

Issue #20785 has been updated by Dan0042 (Daniel DeLorme).


tompng (tomoya ishida) wrote:
> I think these should be accepted like parse.y (prism rejects)
> ~~~ruby
> tap do
>   a in b,
> end
> 
> tap do
>   a in b,
> rescue
> end
> ~~~

Can you explain your reasoning here? I'm guessing that `a in b,` is parsed as `a in [b,]` but a trailing comma like that is just too wild for me; it totally breaks my intuitions about Ruby syntax, and I think it should be rejected.

----------------------------------------
Bug #20785: Should `a in b, and c` `a in b, or c` `a in b, rescue c` be syntax ok?
https://bugs.ruby-lang.org/issues/20785#change-110085

* Author: tompng (tomoya ishida)
* Status: Open
* Assignee: ktsj (Kazuki Tsujimoto)
* ruby -v: ruby 3.4.0dev (2024-10-04T03:22:53Z master 939ec9f080) +YJIT +MN +PRISM [arm64-darwin22]
* Backport: 3.1: UNKNOWN, 3.2: UNKNOWN, 3.3: UNKNOWN
----------------------------------------
This code is accepted in parse.y but rejected in prism
~~~ruby
tap do
  a in b, and c
  a in b, or c
  a in b, rescue c
end

# parsed as
tap do
  (a in b,;) and c
  (a in b,;) or c
  a in b,;
rescue c
end
~~~

I think these should be rejected like prism (parse.y accepts)
~~~ruby
a in b, and c

a in b,
and c

tap do
  a in b, rescue c
end
~~~


I think these should be accepted like parse.y (prism rejects)
~~~ruby
tap do
  a in b,
end

tap do
  a in b,
rescue
end
~~~



-- 
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/