[css-animations-2] Add / separator before animation-trigger exit range

[ydaniv]

Animation Triggers allow specifying a default and exit ranges for the specified timeline which currently, in the animation-trigger shorthand, look like 4 (or less) subsequent range definitions.

It was previously suggested to allow separating these 2 ranges using a / to allow specifying the default range with 1 or even 0 values while still be able to unambiguously specify the exit range:

Should we add a / separator between the two ranges to distinguish them more explicitly?
So it would become:

#target {
 animation-trigger: repeat view() contain / cover;
}

And if there's no range on the lefthand side it can be computed to normal.

So, proposing to add a / in the syntax for the animation-trigger shorthand before the animation-trigger-exit-range value(s).

/cc @DavMila @flackr

[bramus]

Seems like a good idea or parsing the shorthand would otherwise be impossible.

[DavMila]

+1 I like the idea