Changing argument value depending on slide

[Ekleog]

Hey!

I'm new to touying and typst, so please forgive me if I missed something in the docs.

I'm trying to color a grid cell differently depending on which slide it's on. Here is what I'm currently trying out:

#slide(repeat: 2, self => [
  #grid(
    columns: 1,
    grid.cell(fill: alternatives(blue, red))[#alternatives[Foo][Bar]],
  )
])

The contents alternatives works perfectly, but having the blue/red alternatives seems to completely break compilation:

error: expected color, gradient, pattern, none, or auto, found content
   ┌─ example.typ:67:20
   │
67 │     grid.cell(fill: alternatives(blue, red))[#alternatives[Test][Bar]],
   │                     ^^^^^^^^^^^^^^^^^^^^^^^

As far as I can read, alternatives & co are only supported inside contents.

I also tried the utils.methods(self) variant, but the break seemed even worse, as even the contents-only variant returned this error:

error: expected function, found dictionary
   ┌─ example.typ:68:26
   │
68 │     grid.cell(fill: red)[#alternatives[Test][Bar]],
   │                           ^^^^^^^^^^^^

Is there any way to put alternatives in other places of the AST, like in the value of the fill argument in my case?

Anyway, thank you for your work on touying! I'll just copy-paste the whole slide for now and can most likely live with it, even though it's quite a mastodon with its 50 lines of definition.

[Ekleog]

Actually, I'm also looking for a way to change which cells are in the grid or not, but I guess this can be summed up as a way to alternate non-contents arguments to any typst function :)