>> 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. (*) More precisely, this would be [function context, variable name] pairs in case of local variables referenced by declare -n. Andrej
