Immutable-js: Set toggle()

[Delapouite]

Hi

I've currently have a util function that does something along these lines :

 function toggle (set, v) {
  return set.includes(v) ? set.delete(v) : set.add(v)
}

What about having it directly on the prototype? Something like :
newSet = set.toggle(value)

[leebyron]

Adding things to the prototype is a slippery slope to a hard to follow API and growing library weight. Especially for simple functions, it's preferred to have an external function provide the functionality.

[frontsideair]

I wished the same today. I agree that simple helpers should not clutter the library, but this seems to be a very common use case of a Set.

While writing a simple helper is not such a big issue, Immutable uses methods in favor of this-less functions so custom helper functions will look very different to builtin methods and it'll create a mixed API. (Adding new methods to the prototype would solve this, but it's almost universally frowned upon.)

[gricey432]

Came here to suggest this idea. Looks like someone else has proposed it in #1742 as well