Mutable Objects

Info

Assuming we have already implimented RedBlackDbTree as RedBlackDbTree

In this example, we use Part objects.

Utilizing mutable objects:

local START_POSITION = Vector3.new(-1, 0.5, 18) -- The start position for our parts
local PART_OFFSET = Vector3.new(4, 0, 0)

local removePart, movePart
local tree

function createNewPart(name, position)
    local part = Instance.new("Part")
    part.Anchored = true
    part.Position = position
    part.Name = name
    part.Parent = workspace

    return part
end

function partXComparator(part1, part2)
    if part1 == part2 or part1.Position.X == part2.Position.X then
        return 0  -- part1 equal to part2 or they have equal X positions
    elseif part1.Position.X < part2.Position.X then
        return -1 -- part1 is more left than other
    else
        return 1  -- part1 is more right than other
    end
end

tree = RedBlackDbTree.new(partXComparator) -- Instantiate the tree with the comparator

removePart = createNewPart("REMOVEME", START_POSITION)
movePart = createNewPart("MOVEME", START_POSITION + PART_OFFSET * 2)

tree:AddAll(createNewPart("P1", START_POSITION), createNewPart("P2", START_POSITION + PART_OFFSET), movePart, removePart) -- Add objects into the tree
tree:Remove(removePart) -- Remove `removePart`

tree:UpdateObject(movePart, {Position = START_POSITION - PART_OFFSET}) -- Move `movePart` left of P1

tree:InOrderPrint()

When you run your game, the following should be printed to the console:

MOVEME Color B
P1 Color B
P2 Color B

Since we updated movePart to be left of P1, it is now considered the "smallest".