Re: Add bms_offset_members() function for bitshifting Bitmapsets

On Sun, Apr 19, 2026, at 7:52 PM, David Rowley wrote:
> On Mon, 20 Apr 2026 at 07:22, Greg Burd <greg@burd.me> wrote:
>> I applied, tested, and reviewed these changes.  Thanks for doing this, only a few small things jumped out.
>
> Many thanks. I took all of those suggestions.

Happy to help.

>> SELECT test_bms_offset_members('(b 1)', -2147483648);
>
> I made that one use member 0 instead of 1.  That'll mean "new_highest"
> goes to INT_MIN rather than INT_MIN + 1.

Perfect, that covers the gap nicely.

Were you planning on writing the optimized non-copy version as well?  I don't think it is strictly necessary, more a curiosity.

bms_offset_members() -> new bms, might repalloc() replaces existing loops you've found
bms_shift_members() -> bms is modified in place and fits your new use case a bit better

best.

-greg


> David
>
> Attachments:
> * v3-0001-Introduce-bms_offset_members-function.patch