bug#71573: Related functions from ts.el

[Stefan Kangas <stefankangas@gmail.com>]

Adam Porter <adam@alphapapa.net> writes:

> ;; See also the built-in function `format-seconds', which I seem to have
> ;; overlooked before writing this.  However, a quick benchmark, run
> ;; 100,000 times, shows that, when controllable formatting is not needed,
> ;; `ts-human-format-duration' is much faster and generates less garbage:
>
> ;; | Form                     | x faster than next | Total runtime | #
> of GCs | Total GC runtime |
> ;;
> |--------------------------+--------------------+---------------+----------+------------------|
> ;; | ts-human-format-duration | 5.82               |      0.832945 |
>     3 |         0.574929 |
> ;; | format-seconds           | slowest            |      4.848253 |
>    17 |         3.288799 |

Is this used a lot in hot loops?  IOW, is it worth optimizing?

If yes, how about adding something like what you have as an optimization
to `format-seconds` for when the format is very simple?  Would that
remove the need for `ts-human-format-duration'?