On 4/25/20 11:46 PM, Andrej Podzimek wrote:
>>> Description:
>>>
>>> While looking for a way to share a "cache" array with a recursive function
>>> call stack (using local -n (nameref)), I hit a well-known problem with
>>> "circular name reference" (which has been around for a long time).
>>
>> Yes, that's how it does loop detection.
>
> There are, however, no loops involved in my $a … $k example; it is merely a
> chain of declare -n references starting from a regular variable $a. The chain
> breaks unexpectedly and silently after 8 links ($j and $k appear to be empty).
>
> Better options, IMHO, would include:
>
> (a) An unlimited number of declare -n resolution steps (as long as there are
> no cycles, i.e., no variable name(*) is encountered twice). This may have
> performance consequences when abused, but it would be better than unexpected
> empty values after >8 steps.
>
> (b) An error message when trying to dereference $j or $k (links No. 9 and 10
> in the chain example), saying e.g. “maximum nameref depth (8) exceeded”. This
> would at least make the problem obvious and easy to debug.
I would welcome patches that did either one of these things.
--
``The lyf so short, the craft so long to lerne.'' - Chaucer
``Ars longa, vita brevis'' - Hippocrates
Chet Ramey, UTech, CWRU c...@case.edu http://tiswww.cwru.edu/~chet/
