Bug #9611: Arithmetic operator following parentheses-less method gives ArgumentError

• Status: Rejected
• Assignee: matz (Yukihiro Matsumoto)
• Target version: -
• ruby -v: 2.0.0p195
• Backport: 1.9.3: UNKNOWN, 2.0.0: UNKNOWN, 2.1: UNKNOWN

[battox (Matías Battocchia)]

It would be better to explain this with an example:

> 'a'.length -1                                                                                                          
ArgumentError: wrong number of arguments (1 for 0)
from (pry):1:in `length'

Other ways of writing this expression work as expected:

> 'a'.length() -1
=> 0

> 'a'.length-1
=> 0

> 'a'.length- 1
=> 0

> 'a'.length - 1                                                                                                         
=> 0

[battox (Matías Battocchia)]

Even though this also happens with +, * and /, I guess it is on purpose to pass negative numbers, not a bug. My mistake.

[usa (Usaku NAKAMURA)]

• Status changed from Open to Rejected

Yes, this is well-known (but often misunderstood) ruby's spec.