Allow serializing arbitrary functions?

[intrnl]

Vanilla Extract currently has this little known feature that allows for serializing calls to a function imported elsewhere (addFunctionSerializer)

I think it would be neat if we could allow serializing arbitrary functions as well. Personally I would use this to make super-optimized functions for recipes

Take the following recipe code

export const Paper = recipe({
  base: {
    backgroundColor: palette.white,
  },

  variants: {
    rounded: {
      true: {
        borderRadius: 4,
      },
    },
    contained: {
      true: {
        contain: 'paint',
      },
    },
    elevation: {
      0: Elevation({level: 0}),
      1: Elevation({level: 1}),
      2: Elevation({level: 2}),
    },
  },

  defaultVariants: {
    rounded: true,
  },
})

This could easily be turned into something like

export const Paper = (options = {}) => {
  const {rounded = true, contained, elevation} = options

  let result = 'paper_Paper__a435gb0'

  if (rounded === true) {
    result += ' paper_Paper_rounded_true__a435gb1'
  }

  if (contained === true) {
    result += ' paper_Paper_contained_true__a435gb2'
  }

  if (elevation === 0) {
    result += ' elevation_Elevation_level_0__1o1i01r0'
  } else if (elevation === 1) {
    result += ' elevation_Elevation_level_1__1o1i01r1'
  } else if (elevation === 2) {
    result += ' elevation_Elevation_level_2__1o1i01r2'
  }

  return result
}