Re: Changing the way bash expands associative array subscripts

[Greg Wooledge]

On Tue, Apr 06, 2021 at 11:28:13PM +0900, Koichi Murase wrote:
> 2) we
> can distinguish the erasure of the element associated with key=@
> `unset -v a[$key]' from the entire array erasure `unset -v a[@]'.

As a counter-proposal, Chet could entirely remove the special meaning
of unset 'a[@]' and introduce a new option to unset which would take
its place.  It appears -a is not yet used, so that would be a good pick.

Under this proposal, unset 'a[@]' would only remove the single element
whose key is '@', and unset -a a would remove all the elements of the
array.

I don't know whether any scripts actually use unset 'a[@]' to clear all
the keys out of an array, but this change would obviously break backward
compatibility if any such scripts exist.  Therefore I only bring it up
because this whole thread is about introducing new behaviors that break
compatibility.