From: Kenneth McDonald <kenneth.m.mcdonald@...>
Date: 2007-08-31T10:35:26+09:00
Subject: Re: Why stack overflow with such a small stack?

Daniel DeLorme wrote:
> Kenneth McDonald wrote:
>> I'm getting the following error:
>>
>> sheet.rb:35:in `values': stack level too deep (SystemStackError)
>>        from sheet.rb:35:in `values'
>>        from sheet.rb:53:in `to_s'
>>        from sheet.rb:52:in `to_s'
>>        from sheet.rb:52:in `map'
>>        from sheet.rb:52:in `to_s'
>>        from sheet.rb:52:in `to_s'
>>        from sheet.rb:52:in `map'
>>        from sheet.rb:52:in `to_s'
>>        from sheet.rb:52:in `to_s'
>>        from sheet.rb:52:in `map'
>>        from sheet.rb:52:in `to_s'
>>        from sheet.rb:92
>>
>> The output above is given _in full_. Is Ruby truncating the call 
>> stack in this output? If  so, how I can I see a larger snapshot of 
>> the stack, so I can trace down where the infinite recursion is really 
>> happening? If not, why am I getting this error?
>
> Here's one even shorter:
> >> def x; x; end; x
> SystemStackError: stack level too deep
>         from (irb):2:in `x'
>         from (irb):2:in `x'
>         from (irb):4
>
> Pretty smart of ruby to avoid a gazillion lines of identical output IMHO
>
> Daniel
>
>
To a newcomer, it's sorta nonobvious, however--it turned out the problem 
was that I'd made a circular reference to 'values' instead of '@values', 
and the fact that the stack was full of 'values' frames is certainly not 
obvious from the above.

Ken