On Mar 1, 2011, at 5:59 PM, Matt Neuburg wrote:

> The ri --help says:
> 
>> Note that shell quoting or escaping may be required for method names 
>> containing punctuation:
>> 
>>    ri 'Array.[]'
> 
> Okay, so let's try it:
> 
> jansen:~ mattleopard$ ri 'Array.[]'
> /Library/Ruby/Gems/1.8/gems/rdoc-3.5.3/lib/rdoc/ri/driver.rb:1001:
> warning: character class has `]' without escape
> /Library/Ruby/Gems/1.8/gems/rdoc-3.5.3/lib/rdoc/ri/driver.rb:1001:in
> `name_regexp': premature end of regular expression: /^Array(#|::)[]$/
> (RegexpError)
>        from
> /Library/Ruby/Gems/1.8/gems/rdoc-3.5.3/lib/rdoc/ri/driver.rb:762:in
> `filter_methods'
>        from
> /Library/Ruby/Gems/1.8/gems/rdoc-3.5.3/lib/rdoc/ri/driver.rb:654:in
> `display_method'
>        from
> /Library/Ruby/Gems/1.8/gems/rdoc-3.5.3/lib/rdoc/ri/driver.rb:695:in
> `display_name'
>        from
> /Library/Ruby/Gems/1.8/gems/rdoc-3.5.3/lib/rdoc/ri/driver.rb:720:in
> `display_names'
>        from
> /Library/Ruby/Gems/1.8/gems/rdoc-3.5.3/lib/rdoc/ri/driver.rb:717:in
> `each'
>        from
> /Library/Ruby/Gems/1.8/gems/rdoc-3.5.3/lib/rdoc/ri/driver.rb:717:in
> `display_names'
>        from
> /Library/Ruby/Gems/1.8/gems/rdoc-3.5.3/lib/rdoc/ri/driver.rb:1072:in
> `run'
>        from
> /Library/Ruby/Gems/1.8/gems/rdoc-3.5.3/lib/rdoc/ri/driver.rb:317:in
> `run'
>        from /Library/Ruby/Gems/1.8/gems/rdoc-3.5.3/bin/ri:5
>        from /usr/bin/ri:19:in `load'
>        from /usr/bin/ri:19
> 
> My guess is that ri is trying to be clever with some sort of regex
> guesswork in case I get the command wrong, but is getting hoist on its
> own petard. m.

You should file a bug if you think this is a bug in RDoc.

Hint: https://github.com/rdoc/rdoc/issues