--- @internal Lockdown only
--- Priority sets
---
--- PrioritySet can add elements with its priority with all priorities being saved.
--- When removing an element, the elements prior priority will be set.
---
--- **Usage notes**
---
--- 1. The elements stored must be hashable (e.g. strings, numbers, etc.).
type PrioritySet<K> = {
	--- Adds an element to the priority set with priority
	add: (element: K, priority: number) -> (),

	--- Removes an element from the priority set with priority
	remove: (element: K, priority: number) -> (),

	--- Returns the highest priority given element
	highest_priority: (element: K) -> number?,

	--- Returns the lowest priority given element
	lowest_priority: (element: K) -> number?,

	--- Returns if an element exists in the priority set or not
	exists: (element: K) -> boolean,

	-- Metatable
	__iter: (self: PrioritySet<K>) -> () -> (K?, number?)
}

function PrioritySet<K>() -> PrioritySet<K> end