Visuwesh <visuweshm@gmail.com> writes:

> [செவ்வாய் செப்டம்பர் 27, 2022] Stefan Kangas wrote:
>
>> Could we change `format-spec' to accept functions in the substitutions,
>> that are then only called when actually needed?
>
> +1. I was thinking of raising such a proposal myself.  It seems wasteful to
> pre-calculate all the specifications instead of lazily evaluating them.

The change is just the attached, plus documentation.