Bug #16050: :@ is not parsed correctly

• Status: Rejected
• Assignee: -
• Target version: -
• Backport: 2.5: UNKNOWN, 2.6: UNKNOWN

[sawa (Tsuyoshi Sawada)]

Symbol literal allows @ as the first character:

:@foo # => :@foo

Nevertheless, it does not allow @ by itself:

:@ # >> SyntaxError: `@' without identifiers is not allowed as an instance variable name

This resembles #10463, but while #10463 is related to placeholder in a method name, the issue here is related to instance variable name, so I think they are different issues.

[jeremyevans0 (Jeremy Evans)]

• Status changed from Open to Rejected

I don't think this is a bug. Just because :@iv is valid syntax does not imply that :@ should also be valid syntax. You should use a quoted symbol (note that Symbol#inspect quotes the symbol):

:'@'
# => :"@"
'@'.to_sym
# => :"@"

[Dan0042 (Daniel DeLorme)]

Ah, but :@1 is not parsed either, even though it's now (unfortunately) valid as a numbered block parameter.

Depending on how #15723 goes, :@1 and/or :@ should be parsed if they are valid identifiers.