Bug #19876: Equality chaining

• Status: Closed
• Assignee: -
• Target version: -
• Backport: 3.0: UNKNOWN, 3.1: UNKNOWN, 3.2: UNKNOWN

[kddnewton (Kevin Newton)]

It appears that you cannot chain ==, !=, <=>, =~, !~, ===:

foo == bar == baz

but you can chain all of the other operators:

1 << 2 << 3

I'm not sure if I've missed some. I would just like to know if this is a bug. If it's not, then I need to know which operators cannot be chained. At the moment all of these can be chained in YARP, but if it's desired behavior that that is a syntax error, I need to explicitly disallow this.

[mame (Yusuke Endoh)]

I think it is by design. They are marked as %nonassoc in parse.y.

https://github.com/ruby/ruby/blob/6e64d4370456190541705ec4c6cf3af6bf4ac647/parse.y#L1698

%nonassoc  tCMP tEQ tEQQ tNEQ tMATCH tNMATCH

[kddnewton (Kevin Newton)]

• Status changed from Open to Closed

Okay. I will make this behavior match.