Prisms

Primsms are opionals where the setter doesn't need a second (whole) argument, which makes them reveresible. They are used for converting back and forth between two reprenstations of the same data, hence the name.

You can create an iso by calling:

prism<Part, Whole>({
	getter,
	mapper,
	setter,
}: {
	getter: (whole: Whole) => Part | undefined
	mapper?: (mod: (p: Part) => Part, w: Whole) => Whole
	setter: (part: Part) => Whole
})

getter function returns the value of the focus, setter updates it and optionally mapper applies a modifying function. When mapper is not provided, it is derived from getter and setter