[V4] Defaults for --value() and --modifier()?

[katerlouis]

Imagine the following utility:
.atl = position: absolute; top: 0; left: 0, so far so good
.atl-5 = as above with spacing variables for top and left
.atl-5/10 = same as above but left has spacing 10 instead of 5

@utility atl-* {
  position: absolute;
  top: --spacing(--value(number));
  left: --spacing(--value(number));
  left: --spacing(--modifier(number));
}

This @utility-declaration works perfect for atl and atl-5, as the second left: assignment is just dropped due to no modifier being present.

With a modifier present, however, the output css features 2 left-assignments. This works functionally as the second left overwrites the first left, but the double assignment is bugging me.

What about a way to assign default values to --value() and --modifier() in case they are not present.

This would for one allow atl (without value nor modifier) to default to a desired value, and also allow only one left assignment in this example.

Ideally defaults could be nested like so: left: --spacing(--modifier(number, --value(number, 0)))

Ideally tailwind would be smart enough to recognize, that if there are defaults present for --value, that I don't need to declare a separate @utility atl just for the default-version. Seems like not much of a burden, until you need a lot of utilities with fallbacks. In this example I also want combinations for bottom and right as well, and of course also for fixed.

atl, abl, atr, atl, ftl, fbl, ftr, fbr
alongside their -* valued version.

What do you think?