Fusion Packed with Maui

README.md

Fusion Packed with Maui

This is the Fusion library (0.2, latest from the repository at the time of writing) packed with Maui, which you can directly loadstring/require in a script.

You can require the module in a script util with:

local Fusion = loadstring(game:HttpGet("https://gist.github.com/regginator/46bb3e44508d6a78595411261664f804/raw/Fusion.maui.lua"))()

This was packed with the following config file:

{
    "FormatVersion": 1,

    "Output": {
        "ScriptType": "ModuleScript",
        "MinifyTable": true
    }
}

Fusion.maui.lua

-- This script was automatically @generated by Maui, it is not intended for manual editing.
local ModuleRoot={{ClassName="ModuleScript",Closure=function() --!strict

--[[
	The entry point for the Fusion library.
]]

local PubTypes = require(script.PubTypes)
local restrictRead = require(script.Utility.restrictRead)

export type StateObject<T> = PubTypes.StateObject<T>
export type CanBeState<T> = PubTypes.CanBeState<T>
export type Symbol = PubTypes.Symbol
export type Value<T> = PubTypes.Value<T>
export type Computed<T> = PubTypes.Computed<T>
export type ForPairs<KO, VO> = PubTypes.ForPairs<KO, VO>
export type ForKeys<KI, KO> = PubTypes.ForKeys<KI, KO>
export type ForValues<VI, VO> = PubTypes.ForKeys<VI, VO>
export type Observer = PubTypes.Observer
export type Tween<T> = PubTypes.Tween<T>
export type Spring<T> = PubTypes.Spring<T>

type Fusion = {
	version: PubTypes.Version,

	New: (className: string) -> ((propertyTable: PubTypes.PropertyTable) -> Instance),
	Hydrate: (target: Instance) -> ((propertyTable: PubTypes.PropertyTable) -> Instance),
	Ref: PubTypes.SpecialKey,
	Cleanup: PubTypes.SpecialKey,
	Children: PubTypes.SpecialKey,
	Out: PubTypes.SpecialKey,
	OnEvent: (eventName: string) -> PubTypes.SpecialKey,
	OnChange: (propertyName: string) -> PubTypes.SpecialKey,

	Value: <T>(initialValue: T) -> Value<T>,
	Computed: <T>(callback: () -> T, destructor: (T) -> ()?) -> Computed<T>,
	ForPairs: <KI, VI, KO, VO, M>(inputTable: CanBeState<{[KI]: VI}>, processor: (KI, VI) -> (KO, VO, M?), destructor: (KO, VO, M?) -> ()?) -> ForPairs<KO, VO>,
	ForKeys: <KI, KO, M>(inputTable: CanBeState<{[KI]: any}>, processor: (KI) -> (KO, M?), destructor: (KO, M?) -> ()?) -> ForKeys<KO, any>,
	ForValues: <VI, VO, M>(inputTable: CanBeState<{[any]: VI}>, processor: (VI) -> (VO, M?), destructor: (VO, M?) -> ()?) -> ForValues<any, VO>,
	Observer: (watchedState: StateObject<any>) -> Observer,

	Tween: <T>(goalState: StateObject<T>, tweenInfo: TweenInfo?) -> Tween<T>,
	Spring: <T>(goalState: StateObject<T>, speed: number?, damping: number?) -> Spring<T>,

	cleanup: (...any) -> (),
	doNothing: (...any) -> ()
}

return restrictRead("Fusion", {
	version = {major = 0, minor = 2, isRelease = false},

	New = require(script.Instances.New),
	Hydrate = require(script.Instances.Hydrate),
	Ref = require(script.Instances.Ref),
	Out = require(script.Instances.Out),
	Cleanup = require(script.Instances.Cleanup),
	Children = require(script.Instances.Children),
	OnEvent = require(script.Instances.OnEvent),
	OnChange = require(script.Instances.OnChange),

	Value = require(script.State.Value),
	Computed = require(script.State.Computed),
	ForPairs = require(script.State.ForPairs),
	ForKeys = require(script.State.ForKeys),
	ForValues = require(script.State.ForValues),
	Observer = require(script.State.Observer),

	Tween = require(script.Animation.Tween),
	Spring = require(script.Animation.Spring),

	cleanup = require(script.Utility.cleanup),
	doNothing = require(script.Utility.doNothing)
}) :: Fusion
 end,Properties={Name="MainModule"},Reference=1,Children={{Children={{Closure=function() --!strict

--[[
	A common interface for accessing the values of state objects or constants.
]]

local Package = script.Parent.Parent
local PubTypes = require(Package.PubTypes)
local xtypeof = require(Package.Utility.xtypeof)

local function unwrap<T>(item: PubTypes.CanBeState<T>, useDependency: boolean?): T
	return if xtypeof(item) == "State" then (item :: PubTypes.StateObject<T>):get(useDependency) else (item :: T)
end

return unwrap end,Properties={Name="unwrap"},Reference=45,ClassName="ModuleScript"},{Closure=function() --!nonstrict

--[[
	Constructs a new ForKeys state object which maps keys of an array using
	a `processor` function.

	Optionally, a `destructor` function can be specified for cleaning up
	calculated keys. If omitted, the default cleanup function will be used instead.

	Optionally, a `meta` value can be returned in the processor function as the
	second value to pass data from the processor to the destructor.
]]

local Package = script.Parent.Parent
local PubTypes = require(Package.PubTypes)
local Types = require(Package.Types)
local captureDependencies = require(Package.Dependencies.captureDependencies)
local initDependency = require(Package.Dependencies.initDependency)
local useDependency = require(Package.Dependencies.useDependency)
local parseError = require(Package.Logging.parseError)
local logErrorNonFatal = require(Package.Logging.logErrorNonFatal)
local logError = require(Package.Logging.logError)
local logWarn = require(Package.Logging.logWarn)
local cleanup = require(Package.Utility.cleanup)
local needsDestruction = require(Package.Utility.needsDestruction)

local class = {}

local CLASS_METATABLE = { __index = class }
local WEAK_KEYS_METATABLE = { __mode = "k" }

--[[
	Returns the current value of this ForKeys object.
	The object will be registered as a dependency unless `asDependency` is false.
]]
function class:get(asDependency: boolean?): any
	if asDependency ~= false then
		useDependency(self)
	end
	return self._outputTable
end


--[[
	Called when the original table is changed.

	This will firstly find any keys meeting any of the following criteria:

	- they were not previously present
	- a dependency used during generation of this value has changed

	It will recalculate those key pairs, storing information about any
	dependencies used in the processor callback during output key generation,
	and save the new key to the output array with the same value. If it is
	overwriting an older value, that older value will be passed to the
	destructor for cleanup.

	Finally, this function will find keys that are no longer present, and remove
	their output keys from the output table and pass them to the destructor.
]]

function class:update(): boolean
	local inputIsState = self._inputIsState
	local newInputTable = if inputIsState then self._inputTable:get(false) else self._inputTable
	local oldInputTable = self._oldInputTable
	local outputTable = self._outputTable

	local keyOIMap = self._keyOIMap
	local keyIOMap = self._keyIOMap
	local meta = self._meta

	local didChange = false


	-- clean out main dependency set
	for dependency in pairs(self.dependencySet) do
		dependency.dependentSet[self] = nil
	end

	self._oldDependencySet, self.dependencySet = self.dependencySet, self._oldDependencySet
	table.clear(self.dependencySet)

	-- if the input table is a state object, add it as a dependency
	if inputIsState then
		self._inputTable.dependentSet[self] = true
		self.dependencySet[self._inputTable] = true
	end


	-- STEP 1: find keys that changed or were not previously present
	for newInKey, value in pairs(newInputTable) do
		-- get or create key data
		local keyData = self._keyData[newInKey]

		if keyData == nil then
			keyData = {
				dependencySet = setmetatable({}, WEAK_KEYS_METATABLE),
				oldDependencySet = setmetatable({}, WEAK_KEYS_METATABLE),
				dependencyValues = setmetatable({}, WEAK_KEYS_METATABLE),
			}
			self._keyData[newInKey] = keyData
		end

		-- check if the key is new
		local shouldRecalculate = oldInputTable[newInKey] == nil

		-- check if the key's dependencies have changed
		if shouldRecalculate == false then
			for dependency, oldValue in pairs(keyData.dependencyValues) do
				if oldValue ~= dependency:get(false) then
					shouldRecalculate = true
					break
				end
			end
		end


		-- recalculate the output key if necessary
		if shouldRecalculate then
			keyData.oldDependencySet, keyData.dependencySet = keyData.dependencySet, keyData.oldDependencySet
			table.clear(keyData.dependencySet)

			local processOK, newOutKey, newMetaValue = captureDependencies(
				keyData.dependencySet,
				self._processor,
				newInKey
			)

			if processOK then
				if self._destructor == nil and (needsDestruction(newOutKey) or needsDestruction(newMetaValue)) then
					logWarn("destructorNeededForKeys")
				end

				local oldInKey = keyOIMap[newOutKey]
				local oldOutKey = keyIOMap[newInKey]

				-- check for key collision
				if oldInKey ~= newInKey and newInputTable[oldInKey] ~= nil then
					logError("forKeysKeyCollision", nil, tostring(newOutKey), tostring(oldInKey), tostring(newOutKey))
				end

				-- check for a changed output key
				if oldOutKey ~= newOutKey and keyOIMap[oldOutKey] == newInKey then
					-- clean up the old calculated value
					local oldMetaValue = meta[oldOutKey]

					local destructOK, err = xpcall(self._destructor or cleanup, parseError, oldOutKey, oldMetaValue)
					if not destructOK then
						logErrorNonFatal("forKeysDestructorError", err)
					end

					keyOIMap[oldOutKey] = nil
					outputTable[oldOutKey] = nil
					meta[oldOutKey] = nil
				end

				-- update the stored data for this key
				oldInputTable[newInKey] = value
				meta[newOutKey] = newMetaValue
				keyOIMap[newOutKey] = newInKey
				keyIOMap[newInKey] = newOutKey
				outputTable[newOutKey] = value

				-- if we had to recalculate the output, then we did change
				didChange = true
			else
				-- restore old dependencies, because the new dependencies may be corrupt
				keyData.oldDependencySet, keyData.dependencySet = keyData.dependencySet, keyData.oldDependencySet

				logErrorNonFatal("forKeysProcessorError", newOutKey)
			end
		end


		-- save dependency values and add to main dependency set
		for dependency in pairs(keyData.dependencySet) do
			keyData.dependencyValues[dependency] = dependency:get(false)

			self.dependencySet[dependency] = true
			dependency.dependentSet[self] = true
		end
	end


	-- STEP 2: find keys that were removed
	for outputKey, inputKey in pairs(keyOIMap) do
		if newInputTable[inputKey] == nil then
			-- clean up the old calculated value
			local oldMetaValue = meta[outputKey]

			local destructOK, err = xpcall(self._destructor or cleanup, parseError, outputKey, oldMetaValue)
			if not destructOK then
				logErrorNonFatal("forKeysDestructorError", err)
			end

			-- remove data
			oldInputTable[inputKey] = nil
			meta[outputKey] = nil
			keyOIMap[outputKey] = nil
			keyIOMap[inputKey] = nil
			outputTable[outputKey] = nil
			self._keyData[inputKey] = nil

			-- if we removed a key, then the table/state changed
			didChange = true
		end
	end

	return didChange
end

local function ForKeys<KI, KO, M>(
	inputTable: PubTypes.CanBeState<{ [KI]: any }>,
	processor: (KI) -> (KO, M?),
	destructor: (KO, M?) -> ()?
): Types.ForKeys<KI, KO, M>

	local inputIsState = inputTable.type == "State" and typeof(inputTable.get) == "function"

	local self = setmetatable({
		type = "State",
		kind = "ForKeys",
		dependencySet = {},
		-- if we held strong references to the dependents, then they wouldn't be
		-- able to get garbage collected when they fall out of scope
		dependentSet = setmetatable({}, WEAK_KEYS_METATABLE),
		_oldDependencySet = {},

		_processor = processor,
		_destructor = destructor,
		_inputIsState = inputIsState,

		_inputTable = inputTable,
		_oldInputTable = {},
		_outputTable = {},
		_keyOIMap = {},
		_keyIOMap = {},
		_keyData = {},
		_meta = {},
	}, CLASS_METATABLE)

	initDependency(self)
	self:update()

	return self
end

return ForKeys end,Properties={Name="ForKeys"},Reference=40,ClassName="ModuleScript"},{Closure=function() --!nonstrict

--[[
	Constructs and returns objects which can be used to model independent
	reactive state.
]]

local Package = script.Parent.Parent
local Types = require(Package.Types)
local useDependency = require(Package.Dependencies.useDependency)
local initDependency = require(Package.Dependencies.initDependency)
local updateAll = require(Package.Dependencies.updateAll)
local isSimilar = require(Package.Utility.isSimilar)

local class = {}

local CLASS_METATABLE = {__index = class}
local WEAK_KEYS_METATABLE = {__mode = "k"}

--[[
	Returns the value currently stored in this State object.
	The state object will be registered as a dependency unless `asDependency` is
	false.
]]
function class:get(asDependency: boolean?): any
	if asDependency ~= false then
		useDependency(self)
	end
	return self._value
end

--[[
	Updates the value stored in this State object.

	If `force` is enabled, this will skip equality checks and always update the
	state object and any dependents - use this with care as this can lead to
	unnecessary updates.
]]
function class:set(newValue: any, force: boolean?)
	local oldValue = self._value
	if force or not isSimilar(oldValue, newValue) then
		self._value = newValue
		updateAll(self)
	end
end

local function Value<T>(initialValue: T): Types.State<T>
	local self = setmetatable({
		type = "State",
		kind = "Value",
		-- if we held strong references to the dependents, then they wouldn't be
		-- able to get garbage collected when they fall out of scope
		dependentSet = setmetatable({}, WEAK_KEYS_METATABLE),
		_value = initialValue
	}, CLASS_METATABLE)

	initDependency(self)

	return self
end

return Value end,Properties={Name="Value"},Reference=44,ClassName="ModuleScript"},{Closure=function() --!nonstrict

--[[
	Constructs a new state object which can listen for updates on another state
	object.

	FIXME: enabling strict types here causes free types to leak
]]

local Package = script.Parent.Parent
local PubTypes = require(Package.PubTypes)
local Types = require(Package.Types)
local initDependency = require(Package.Dependencies.initDependency)

type Set<T> = {[T]: any}

local class = {}
local CLASS_METATABLE = {__index = class}

-- Table used to hold Observer objects in memory.
local strongRefs: Set<Types.Observer> = {}

--[[
	Called when the watched state changes value.
]]
function class:update(): boolean
	for _, callback in pairs(self._changeListeners) do
		task.spawn(callback)
	end
	return false
end

--[[
	Adds a change listener. When the watched state changes value, the listener
	will be fired.

	Returns a function which, when called, will disconnect the change listener.
	As long as there is at least one active change listener, this Observer
	will be held in memory, preventing GC, so disconnecting is important.
]]
function class:onChange(callback: () -> ()): () -> ()
	local uniqueIdentifier = {}

	self._numChangeListeners += 1
	self._changeListeners[uniqueIdentifier] = callback

	-- disallow gc (this is important to make sure changes are received)
	strongRefs[self] = true

	local disconnected = false
	return function()
		if disconnected then
			return
		end
		disconnected = true
		self._changeListeners[uniqueIdentifier] = nil
		self._numChangeListeners -= 1

		if self._numChangeListeners == 0 then
			-- allow gc if all listeners are disconnected
			strongRefs[self] = nil
		end
	end
end

local function Observer(watchedState: PubTypes.Value<any>): Types.Observer
	local self = setmetatable({
		type = "State",
		kind = "Observer",
		dependencySet = {[watchedState] = true},
		dependentSet = {},
		_changeListeners = {},
		_numChangeListeners = 0,
	}, CLASS_METATABLE)

	initDependency(self)
	-- add this object to the watched state's dependent set
	watchedState.dependentSet[self] = true

	return self
end

return Observer end,Properties={Name="Observer"},Reference=43,ClassName="ModuleScript"},{Closure=function() --!nonstrict

--[[
	Constructs a new ForPairs object which maps pairs of a table using
	a `processor` function.

	Optionally, a `destructor` function can be specified for cleaning up values.
	If omitted, the default cleanup function will be used instead.

	Additionally, a `meta` table/value can optionally be returned to pass data created
	when running the processor to the destructor when the created object is cleaned up.
]]

local Package = script.Parent.Parent
local PubTypes = require(Package.PubTypes)
local Types = require(Package.Types)
local captureDependencies = require(Package.Dependencies.captureDependencies)
local initDependency = require(Package.Dependencies.initDependency)
local useDependency = require(Package.Dependencies.useDependency)
local parseError = require(Package.Logging.parseError)
local logErrorNonFatal = require(Package.Logging.logErrorNonFatal)
local logError = require(Package.Logging.logError)
local logWarn = require(Package.Logging.logWarn)
local cleanup = require(Package.Utility.cleanup)
local needsDestruction = require(Package.Utility.needsDestruction)

local class = {}

local CLASS_METATABLE = { __index = class }
local WEAK_KEYS_METATABLE = { __mode = "k" }

--[[
	Returns the current value of this ForPairs object.
	The object will be registered as a dependency unless `asDependency` is false.
]]
function class:get(asDependency: boolean?): any
	if asDependency ~= false then
		useDependency(self)
	end
	return self._outputTable
end

--[[
	Called when the original table is changed.

	This will firstly find any keys meeting any of the following criteria:

	- they were not previously present
	- their associated value has changed
	- a dependency used during generation of this value has changed

	It will recalculate those key/value pairs, storing information about any
	dependencies used in the processor callback during value generation, and
	save the new key/value pair to the output array. If it is overwriting an
	older key/value pair, that older pair will be passed to the destructor
	for cleanup.

	Finally, this function will find keys that are no longer present, and remove
	their key/value pairs from the output table and pass them to the destructor.
]]
function class:update(): boolean
	local inputIsState = self._inputIsState
	local newInputTable = if inputIsState then self._inputTable:get(false) else self._inputTable
	local oldInputTable = self._oldInputTable

	local keyIOMap = self._keyIOMap
	local meta = self._meta

	local didChange = false


	-- clean out main dependency set
	for dependency in pairs(self.dependencySet) do
		dependency.dependentSet[self] = nil
	end

	self._oldDependencySet, self.dependencySet = self.dependencySet, self._oldDependencySet
	table.clear(self.dependencySet)

	-- if the input table is a state object, add it as a dependency
	if inputIsState then
		self._inputTable.dependentSet[self] = true
		self.dependencySet[self._inputTable] = true
	end

	-- clean out output table
	self._oldOutputTable, self._outputTable = self._outputTable, self._oldOutputTable

	local oldOutputTable = self._oldOutputTable
	local newOutputTable = self._outputTable
	table.clear(newOutputTable)

	-- Step 1: find key/value pairs that changed or were not previously present

	for newInKey, newInValue in pairs(newInputTable) do
		-- get or create key data
		local keyData = self._keyData[newInKey]

		if keyData == nil then
			keyData = {
				dependencySet = setmetatable({}, WEAK_KEYS_METATABLE),
				oldDependencySet = setmetatable({}, WEAK_KEYS_METATABLE),
				dependencyValues = setmetatable({}, WEAK_KEYS_METATABLE),
			}
			self._keyData[newInKey] = keyData
		end


		-- check if the pair is new or changed
		local shouldRecalculate = oldInputTable[newInKey] ~= newInValue

		-- check if the pair's dependencies have changed
		if shouldRecalculate == false then
			for dependency, oldValue in pairs(keyData.dependencyValues) do
				if oldValue ~= dependency:get(false) then
					shouldRecalculate = true
					break
				end
			end
		end


		-- recalculate the output pair if necessary
		if shouldRecalculate then
			keyData.oldDependencySet, keyData.dependencySet = keyData.dependencySet, keyData.oldDependencySet
			table.clear(keyData.dependencySet)

			local processOK, newOutKey, newOutValue, newMetaValue = captureDependencies(
				keyData.dependencySet,
				self._processor,
				newInKey,
				newInValue
			)

			if processOK then
				if self._destructor == nil and (needsDestruction(newOutKey) or needsDestruction(newOutValue) or needsDestruction(newMetaValue)) then
					logWarn("destructorNeededForPairs")
				end

				-- if this key was already written to on this run-through, throw a fatal error.
				if newOutputTable[newOutKey] ~= nil then
					-- figure out which key/value pair previously wrote to this key
					local previousNewKey, previousNewValue
					for inKey, outKey in pairs(keyIOMap) do
						if outKey == newOutKey then
							previousNewValue = newInputTable[inKey]
							if previousNewValue ~= nil then
								previousNewKey = inKey
								break
							end
						end
					end

					if previousNewKey ~= nil then
						logError(
							"forPairsKeyCollision",
							nil,
							tostring(newOutKey),
							tostring(previousNewKey),
							tostring(previousNewValue),
							tostring(newInKey),
							tostring(newInValue)
						)
					end
				end

				local oldOutValue = oldOutputTable[newOutKey]

				if oldOutValue ~= newOutValue then
					local oldMetaValue = meta[newOutKey]
					if oldOutValue ~= nil then
						local destructOK, err = xpcall(self._destructor or cleanup, parseError, newOutKey, oldOutValue, oldMetaValue)
						if not destructOK then
							logErrorNonFatal("forPairsDestructorError", err)
						end
					end

					oldOutputTable[newOutKey] = nil
				end

				-- update the stored data for this key/value pair
				oldInputTable[newInKey] = newInValue
				keyIOMap[newInKey] = newOutKey
				meta[newOutKey] = newMetaValue
				newOutputTable[newOutKey] = newOutValue

				-- if we had to recalculate the output, then we did change
				didChange = true
			else
				-- restore old dependencies, because the new dependencies may be corrupt
				keyData.oldDependencySet, keyData.dependencySet = keyData.dependencySet, keyData.oldDependencySet

				logErrorNonFatal("forPairsProcessorError", newOutKey)
			end
		else
			local storedOutKey = keyIOMap[newInKey]

			-- check for key collision
			if newOutputTable[storedOutKey] ~= nil then
				-- figure out which key/value pair previously wrote to this key
				local previousNewKey, previousNewValue
				for inKey, outKey in pairs(keyIOMap) do
					if storedOutKey == outKey then
						previousNewValue = newInputTable[inKey]

						if previousNewValue ~= nil then
							previousNewKey = inKey
							break
						end
					end
				end

				if previousNewKey ~= nil then
					logError(
						"forPairsKeyCollision",
						nil,
						tostring(storedOutKey),
						tostring(previousNewKey),
						tostring(previousNewValue),
						tostring(newInKey),
						tostring(newInValue)
					)
				end
			end

			-- copy the stored key/value pair into the new output table
			newOutputTable[storedOutKey] = oldOutputTable[storedOutKey]
		end


		-- save dependency values and add to main dependency set
		for dependency in pairs(keyData.dependencySet) do
			keyData.dependencyValues[dependency] = dependency:get(false)

			self.dependencySet[dependency] = true
			dependency.dependentSet[self] = true
		end
	end

	-- STEP 2: find keys that were removed
	for oldOutKey, oldOutValue in pairs(oldOutputTable) do
		-- check if this key/value pair is in the new output table
		if newOutputTable[oldOutKey] ~= oldOutValue then
			-- clean up the old output pair
			local oldMetaValue = meta[oldOutKey]
			if oldOutValue ~= nil then
				local destructOK, err = xpcall(self._destructor or cleanup, parseError, oldOutKey, oldOutValue, oldMetaValue)
				if not destructOK then
					logErrorNonFatal("forPairsDestructorError", err)
				end
			end

			-- check if the key was completely removed from the output table
			if newOutputTable[oldOutKey] == nil then
				meta[oldOutKey] = nil
				self._keyData[oldOutKey] = nil
			end

			didChange = true
		end
	end

	for key in pairs(oldInputTable) do
		if newInputTable[key] == nil then
			oldInputTable[key] = nil
			keyIOMap[key] = nil
		end
	end

	return didChange
end

local function ForPairs<KI, VI, KO, VO, M>(
	inputTable: PubTypes.CanBeState<{ [KI]: VI }>,
	processor: (KI, VI) -> (KO, VO, M?),
	destructor: (KO, VO, M?) -> ()?
): Types.ForPairs<KI, VI, KO, VO, M>

	local inputIsState = inputTable.type == "State" and typeof(inputTable.get) == "function"

	local self = setmetatable({
		type = "State",
		kind = "ForPairs",
		dependencySet = {},
		-- if we held strong references to the dependents, then they wouldn't be
		-- able to get garbage collected when they fall out of scope
		dependentSet = setmetatable({}, WEAK_KEYS_METATABLE),
		_oldDependencySet = {},

		_processor = processor,
		_destructor = destructor,
		_inputIsState = inputIsState,

		_inputTable = inputTable,
		_oldInputTable = {},
		_outputTable = {},
		_oldOutputTable = {},
		_keyIOMap = {},
		_keyData = {},
		_meta = {},
	}, CLASS_METATABLE)

	initDependency(self)
	self:update()

	return self
end

return ForPairs end,Properties={Name="ForPairs"},Reference=41,ClassName="ModuleScript"},{Closure=function() --!nonstrict

--[[
	Constructs a new ForValues object which maps values of a table using
	a `processor` function.

	Optionally, a `destructor` function can be specified for cleaning up values.
	If omitted, the default cleanup function will be used instead.

	Additionally, a `meta` table/value can optionally be returned to pass data created
	when running the processor to the destructor when the created object is cleaned up.
]]
local Package = script.Parent.Parent
local PubTypes = require(Package.PubTypes)
local Types = require(Package.Types)
local captureDependencies = require(Package.Dependencies.captureDependencies)
local initDependency = require(Package.Dependencies.initDependency)
local useDependency = require(Package.Dependencies.useDependency)
local parseError = require(Package.Logging.parseError)
local logErrorNonFatal = require(Package.Logging.logErrorNonFatal)
local logWarn = require(Package.Logging.logWarn)
local cleanup = require(Package.Utility.cleanup)
local needsDestruction = require(Package.Utility.needsDestruction)

local class = {}

local CLASS_METATABLE = { __index = class }
local WEAK_KEYS_METATABLE = { __mode = "k" }

--[[
	Returns the current value of this ForValues object.
	The object will be registered as a dependency unless `asDependency` is false.
]]
function class:get(asDependency: boolean?): any
	if asDependency ~= false then
		useDependency(self)
	end
	return self._outputTable
end

--[[
	Called when the original table is changed.

	This will firstly find any values meeting any of the following criteria:

	- they were not previously present
	- a dependency used during generation of this value has changed

	It will recalculate those values, storing information about any dependencies
	used in the processor callback during value generation, and save the new value
	to the output array with the same key. If it is overwriting an older value,
	that older value will be passed to the destructor for cleanup.

	Finally, this function will find values that are no longer present, and remove
	their values from the output table and pass them to the destructor. You can re-use
	the same value multiple times and this will function will update them as little as
	possible; reusing the same values where possible.
]]
function class:update(): boolean
	local inputIsState = self._inputIsState
	local inputTable = if inputIsState then self._inputTable:get(false) else self._inputTable
	local outputValues = {}

	local didChange = false

	-- clean out value cache
	self._oldValueCache, self._valueCache = self._valueCache, self._oldValueCache
	local newValueCache = self._valueCache
	local oldValueCache = self._oldValueCache
	table.clear(newValueCache)

	-- clean out main dependency set
	for dependency in pairs(self.dependencySet) do
		dependency.dependentSet[self] = nil
	end
	self._oldDependencySet, self.dependencySet = self.dependencySet, self._oldDependencySet
	table.clear(self.dependencySet)

	-- if the input table is a state object, add it as a dependency
	if inputIsState then
		self._inputTable.dependentSet[self] = true
		self.dependencySet[self._inputTable] = true
	end


	-- STEP 1: find values that changed or were not previously present
	for inKey, inValue in pairs(inputTable) do
		-- check if the value is new or changed
		local oldCachedValues = oldValueCache[inValue]
		local shouldRecalculate = oldCachedValues == nil

		-- get a cached value and its dependency/meta data if available
		local value, valueData, meta

		if type(oldCachedValues) == "table" and #oldCachedValues > 0 then
			local valueInfo = table.remove(oldCachedValues, #oldCachedValues)
			value = valueInfo.value
			valueData = valueInfo.valueData
			meta = valueInfo.meta

			if #oldCachedValues <= 0 then
				oldValueCache[inValue] = nil
			end
		elseif oldCachedValues ~= nil then
			oldValueCache[inValue] = nil
			shouldRecalculate = true
		end

		if valueData == nil then
			valueData = {
				dependencySet = setmetatable({}, WEAK_KEYS_METATABLE),
				oldDependencySet = setmetatable({}, WEAK_KEYS_METATABLE),
				dependencyValues = setmetatable({}, WEAK_KEYS_METATABLE),
			}
		end

		-- check if the value's dependencies have changed
		if shouldRecalculate == false then
			for dependency, oldValue in pairs(valueData.dependencyValues) do
				if oldValue ~= dependency:get(false) then
					shouldRecalculate = true
					break
				end
			end
		end

		-- recalculate the output value if necessary
		if shouldRecalculate then
			valueData.oldDependencySet, valueData.dependencySet = valueData.dependencySet, valueData.oldDependencySet
			table.clear(valueData.dependencySet)

			local processOK, newOutValue, newMetaValue = captureDependencies(
				valueData.dependencySet,
				self._processor,
				inValue
			)

			if processOK then
				if self._destructor == nil and (needsDestruction(newOutValue) or needsDestruction(newMetaValue)) then
					logWarn("destructorNeededForValues")
				end

				-- pass the old value to the destructor if it exists
				if value ~= nil then
					local destructOK, err = xpcall(self._destructor or cleanup, parseError, value, meta)
					if not destructOK then
						logErrorNonFatal("forValuesDestructorError", err)
					end
				end

				-- store the new value and meta data
				value = newOutValue
				meta = newMetaValue
				didChange = true
			else
				-- restore old dependencies, because the new dependencies may be corrupt
				valueData.oldDependencySet, valueData.dependencySet = valueData.dependencySet, valueData.oldDependencySet

				logErrorNonFatal("forValuesProcessorError", newOutValue)
			end
		end


		-- store the value and its dependency/meta data
		local newCachedValues = newValueCache[inValue]
		if newCachedValues == nil then
			newCachedValues = {}
			newValueCache[inValue] = newCachedValues
		end

		table.insert(newCachedValues, {
			value = value,
			valueData = valueData,
			meta = meta,
		})

		outputValues[inKey] = value


		-- save dependency values and add to main dependency set
		for dependency in pairs(valueData.dependencySet) do
			valueData.dependencyValues[dependency] = dependency:get(false)

			self.dependencySet[dependency] = true
			dependency.dependentSet[self] = true
		end
	end


	-- STEP 2: find values that were removed
	-- for tables of data, we just need to check if it's still in the cache
	for _oldInValue, oldCachedValueInfo in pairs(oldValueCache) do
		for _, valueInfo in ipairs(oldCachedValueInfo) do
			local oldValue = valueInfo.value
			local oldMetaValue = valueInfo.meta

			local destructOK, err = xpcall(self._destructor or cleanup, parseError, oldValue, oldMetaValue)
			if not destructOK then
				logErrorNonFatal("forValuesDestructorError", err)
			end

			didChange = true
		end

		table.clear(oldCachedValueInfo)
	end

	self._outputTable = outputValues

	return didChange
end

local function ForValues<VI, VO, M>(
	inputTable: PubTypes.CanBeState<{ [any]: VI }>,
	processor: (VI) -> (VO, M?),
	destructor: (VO, M?) -> ()?
): Types.ForValues<VI, VO, M>

	local inputIsState = inputTable.type == "State" and typeof(inputTable.get) == "function"

	local self = setmetatable({
		type = "State",
		kind = "ForValues",
		dependencySet = {},
		-- if we held strong references to the dependents, then they wouldn't be
		-- able to get garbage collected when they fall out of scope
		dependentSet = setmetatable({}, WEAK_KEYS_METATABLE),
		_oldDependencySet = {},

		_processor = processor,
		_destructor = destructor,
		_inputIsState = inputIsState,

		_inputTable = inputTable,
		_outputTable = {},
		_valueCache = {},
		_oldValueCache = {},
	}, CLASS_METATABLE)

	initDependency(self)
	self:update()

	return self
end

return ForValues end,Properties={Name="ForValues"},Reference=42,ClassName="ModuleScript"},{Closure=function() --!nonstrict

--[[
	Constructs and returns objects which can be used to model derived reactive
	state.
]]

local Package = script.Parent.Parent
local Types = require(Package.Types)
local captureDependencies = require(Package.Dependencies.captureDependencies)
local initDependency = require(Package.Dependencies.initDependency)
local useDependency = require(Package.Dependencies.useDependency)
local logErrorNonFatal = require(Package.Logging.logErrorNonFatal)
local logWarn = require(Package.Logging.logWarn)
local isSimilar = require(Package.Utility.isSimilar)
local needsDestruction = require(Package.Utility.needsDestruction)

local class = {}

local CLASS_METATABLE = {__index = class}
local WEAK_KEYS_METATABLE = {__mode = "k"}

--[[
	Returns the last cached value calculated by this Computed object.
	The computed object will be registered as a dependency unless `asDependency`
	is false.
]]
function class:get(asDependency: boolean?): any
	if asDependency ~= false then
		useDependency(self)
	end
	return self._value
end

--[[
	Recalculates this Computed's cached value and dependencies.
	Returns true if it changed, or false if it's identical.
]]
function class:update(): boolean
	-- remove this object from its dependencies' dependent sets
	for dependency in pairs(self.dependencySet) do
		dependency.dependentSet[self] = nil
	end

	-- we need to create a new, empty dependency set to capture dependencies
	-- into, but in case there's an error, we want to restore our old set of
	-- dependencies. by using this table-swapping solution, we can avoid the
	-- overhead of allocating new tables each update.
	self._oldDependencySet, self.dependencySet = self.dependencySet, self._oldDependencySet
	table.clear(self.dependencySet)

	local ok, newValue, newMetaValue = captureDependencies(self.dependencySet, self._processor)

	if ok then
		if self._destructor == nil and needsDestruction(newValue) then
			logWarn("destructorNeededComputed")
		end

		if newMetaValue ~= nil then
			logWarn("multiReturnComputed")
		end

		local oldValue = self._value
		local similar = isSimilar(oldValue, newValue)
		if self._destructor ~= nil then
			self._destructor(oldValue)
		end
		self._value = newValue

		-- add this object to the dependencies' dependent sets
		for dependency in pairs(self.dependencySet) do
			dependency.dependentSet[self] = true
		end

		return not similar
	else
		-- this needs to be non-fatal, because otherwise it'd disrupt the
		-- update process
		logErrorNonFatal("computedCallbackError", newValue)

		-- restore old dependencies, because the new dependencies may be corrupt
		self._oldDependencySet, self.dependencySet = self.dependencySet, self._oldDependencySet

		-- restore this object in the dependencies' dependent sets
		for dependency in pairs(self.dependencySet) do
			dependency.dependentSet[self] = true
		end

		return false
	end
end

local function Computed<T>(processor: () -> T, destructor: ((T) -> ())?): Types.Computed<T>
	local self = setmetatable({
		type = "State",
		kind = "Computed",
		dependencySet = {},
		-- if we held strong references to the dependents, then they wouldn't be
		-- able to get garbage collected when they fall out of scope
		dependentSet = setmetatable({}, WEAK_KEYS_METATABLE),
		_oldDependencySet = {},
		_processor = processor,
		_destructor = destructor,
		_value = nil,
	}, CLASS_METATABLE)

	initDependency(self)
	self:update()

	return self
end

return Computed end,Properties={Name="Computed"},Reference=39,ClassName="ModuleScript"}},Properties={Name="State"},Reference=38,ClassName="Folder"},{Children={{Closure=function() --!strict

--[[
	Packs an array of numbers into a given animatable data type.
	If the type is not animatable, nil will be returned.

	FUTURE: When Luau supports singleton types, those could be used in
	conjunction with intersection types to make this function fully statically
	type checkable.
]]

local Package = script.Parent.Parent
local PubTypes = require(Package.PubTypes)
local Oklab = require(Package.Colour.Oklab)

local function packType(numbers: {number}, typeString: string): PubTypes.Animatable?
	if typeString == "number" then
		return numbers[1]

	elseif typeString == "CFrame" then
		return
			CFrame.new(numbers[1], numbers[2], numbers[3]) *
			CFrame.fromAxisAngle(
				Vector3.new(numbers[4], numbers[5], numbers[6]).Unit,
				numbers[7]
			)

	elseif typeString == "Color3" then
		return Oklab.from(
			Vector3.new(numbers[1], numbers[2], numbers[3]),
			false
		)

	elseif typeString == "ColorSequenceKeypoint" then
		return ColorSequenceKeypoint.new(
			numbers[4],
			Oklab.from(
				Vector3.new(numbers[1], numbers[2], numbers[3]),
				false
			)
		)

	elseif typeString == "DateTime" then
		return DateTime.fromUnixTimestampMillis(numbers[1])

	elseif typeString == "NumberRange" then
		return NumberRange.new(numbers[1], numbers[2])

	elseif typeString == "NumberSequenceKeypoint" then
		return NumberSequenceKeypoint.new(numbers[2], numbers[1], numbers[3])

	elseif typeString == "PhysicalProperties" then
		return PhysicalProperties.new(numbers[1], numbers[2], numbers[3], numbers[4], numbers[5])

	elseif typeString == "Ray" then
		return Ray.new(
			Vector3.new(numbers[1], numbers[2], numbers[3]),
			Vector3.new(numbers[4], numbers[5], numbers[6])
		)

	elseif typeString == "Rect" then
		return Rect.new(numbers[1], numbers[2], numbers[3], numbers[4])

	elseif typeString == "Region3" then
		-- FUTURE: support rotated Region3s if/when they become constructable
		local position = Vector3.new(numbers[1], numbers[2], numbers[3])
		local halfSize = Vector3.new(numbers[4] / 2, numbers[5] / 2, numbers[6] / 2)
		return Region3.new(position - halfSize, position + halfSize)

	elseif typeString == "Region3int16" then
		return Region3int16.new(
			Vector3int16.new(numbers[1], numbers[2], numbers[3]),
			Vector3int16.new(numbers[4], numbers[5], numbers[6])
		)

	elseif typeString == "UDim" then
		return UDim.new(numbers[1], numbers[2])

	elseif typeString == "UDim2" then
		return UDim2.new(numbers[1], numbers[2], numbers[3], numbers[4])

	elseif typeString == "Vector2" then
		return Vector2.new(numbers[1], numbers[2])

	elseif typeString == "Vector2int16" then
		return Vector2int16.new(numbers[1], numbers[2])

	elseif typeString == "Vector3" then
		return Vector3.new(numbers[1], numbers[2], numbers[3])

	elseif typeString == "Vector3int16" then
		return Vector3int16.new(numbers[1], numbers[2], numbers[3])
	else
		return nil
	end
end

return packType end,Properties={Name="packType"},Reference=9,ClassName="ModuleScript"},{Closure=function() --!strict

--[[
	Manages batch updating of spring objects.
]]

local RunService = game:GetService("RunService")

local Package = script.Parent.Parent
local Types = require(Package.Types)
local packType = require(Package.Animation.packType)
local springCoefficients = require(Package.Animation.springCoefficients)
local updateAll = require(Package.Dependencies.updateAll)

type Set<T> = {[T]: any}
type Spring = Types.Spring<any>

local SpringScheduler = {}

local EPSILON = 0.0001
local activeSprings: Set<Spring> = {}
local lastUpdateTime = os.clock()

function SpringScheduler.add(spring: Spring)
	-- we don't necessarily want to use the most accurate time - here we snap to
	-- the last update time so that springs started within the same frame have
	-- identical time steps
	spring._lastSchedule = lastUpdateTime
	spring._startDisplacements = {}
	spring._startVelocities = {}
	for index, goal in ipairs(spring._springGoals) do
		spring._startDisplacements[index] = spring._springPositions[index] - goal
		spring._startVelocities[index] = spring._springVelocities[index]
	end

	activeSprings[spring] = true
end

function SpringScheduler.remove(spring: Spring)
	activeSprings[spring] = nil
end


local function updateAllSprings()
	local springsToSleep: Set<Spring> = {}
	lastUpdateTime = os.clock()

	for spring in pairs(activeSprings) do
		local posPos, posVel, velPos, velVel = springCoefficients(lastUpdateTime - spring._lastSchedule, spring._currentDamping, spring._currentSpeed)

		local positions = spring._springPositions
		local velocities = spring._springVelocities
		local startDisplacements = spring._startDisplacements
		local startVelocities = spring._startVelocities
		local isMoving = false

		for index, goal in ipairs(spring._springGoals) do
			local oldDisplacement = startDisplacements[index]
			local oldVelocity = startVelocities[index]
			local newDisplacement = oldDisplacement * posPos + oldVelocity * posVel
			local newVelocity = oldDisplacement * velPos + oldVelocity * velVel

			if math.abs(newDisplacement) > EPSILON or math.abs(newVelocity) > EPSILON then
				isMoving = true
			end

			positions[index] = newDisplacement + goal
			velocities[index] = newVelocity
		end

		if not isMoving then
			springsToSleep[spring] = true
		end
	end

	for spring in pairs(activeSprings) do
		spring._currentValue = packType(spring._springPositions, spring._currentType)
		updateAll(spring)
	end

	for spring in pairs(springsToSleep) do
		activeSprings[spring] = nil
	end
end

RunService:BindToRenderStep(
	"__FusionSpringScheduler",
	Enum.RenderPriority.First.Value,
	updateAllSprings
)

return SpringScheduler end,Properties={Name="SpringScheduler"},Reference=4,ClassName="ModuleScript"},{Closure=function() --!strict

--[[
	Given a `tweenInfo` and `currentTime`, returns a ratio which can be used to
	tween between two values over time.
]]

local TweenService = game:GetService("TweenService")

local function getTweenRatio(tweenInfo: TweenInfo, currentTime: number): number
	local delay = tweenInfo.DelayTime
	local duration = tweenInfo.Time
	local reverses = tweenInfo.Reverses
	local numCycles = 1 + tweenInfo.RepeatCount
	local easeStyle = tweenInfo.EasingStyle
	local easeDirection = tweenInfo.EasingDirection

	local cycleDuration = delay + duration
	if reverses then
		cycleDuration += duration
	end

	if currentTime >= cycleDuration * numCycles then
		return 1
	end

	local cycleTime = currentTime % cycleDuration

	if cycleTime <= delay then
		return 0
	end

	local tweenProgress = (cycleTime - delay) / duration
	if tweenProgress > 1 then
		tweenProgress = 2 - tweenProgress
	end

	local ratio = TweenService:GetValue(tweenProgress, easeStyle, easeDirection)
	return ratio
end

return getTweenRatio end,Properties={Name="getTweenRatio"},Reference=7,ClassName="ModuleScript"},{Closure=function() --!nonstrict

--[[
	Constructs a new computed state object, which follows the value of another
	state object using a tween.
]]

local Package = script.Parent.Parent
local PubTypes = require(Package.PubTypes)
local Types = require(Package.Types)
local TweenScheduler = require(Package.Animation.TweenScheduler)
local useDependency = require(Package.Dependencies.useDependency)
local initDependency = require(Package.Dependencies.initDependency)
local logError = require(Package.Logging.logError)
local logErrorNonFatal = require(Package.Logging.logErrorNonFatal)
local xtypeof = require(Package.Utility.xtypeof)

local class = {}

local CLASS_METATABLE = {__index = class}
local WEAK_KEYS_METATABLE = {__mode = "k"}

--[[
	Returns the current value of this Tween object.
	The object will be registered as a dependency unless `asDependency` is false.
]]
function class:get(asDependency: boolean?): any
	if asDependency ~= false then
		useDependency(self)
	end
	return self._currentValue
end

--[[
	Called when the goal state changes value; this will initiate a new tween.
	Returns false as the current value doesn't change right away.
]]
function class:update(): boolean
	local goalValue = self._goalState:get(false)

	-- if the goal hasn't changed, then this is a TweenInfo change.
	-- in that case, if we're not currently animating, we can skip everything
	if goalValue == self._nextValue and not self._currentlyAnimating then
		return false
	end

	local tweenInfo = self._tweenInfo
	if self._tweenInfoIsState then
		tweenInfo = tweenInfo:get()
	end

	-- if we receive a bad TweenInfo, then error and stop the update
	if typeof(tweenInfo) ~= "TweenInfo" then
		logErrorNonFatal("mistypedTweenInfo", nil, typeof(tweenInfo))
		return false
	end

	self._prevValue = self._currentValue
	self._nextValue = goalValue

	self._currentTweenStartTime = os.clock()
	self._currentTweenInfo = tweenInfo

	local tweenDuration = tweenInfo.DelayTime + tweenInfo.Time
	if tweenInfo.Reverses then
		tweenDuration += tweenInfo.Time
	end
	tweenDuration *= tweenInfo.RepeatCount + 1
	self._currentTweenDuration = tweenDuration

	-- start animating this tween
	TweenScheduler.add(self)

	return false
end

local function Tween<T>(
	goalState: PubTypes.StateObject<PubTypes.Animatable>,
	tweenInfo: PubTypes.CanBeState<TweenInfo>?
): Types.Tween<T>
	local currentValue = goalState:get(false)

	-- apply defaults for tween info
	if tweenInfo == nil then
		tweenInfo = TweenInfo.new()
	end

	local dependencySet = {[goalState] = true}
	local tweenInfoIsState = xtypeof(tweenInfo) == "State"

	if tweenInfoIsState then
		dependencySet[tweenInfo] = true
	end

	local startingTweenInfo = tweenInfo
	if tweenInfoIsState then
		startingTweenInfo = startingTweenInfo:get()
	end

	-- If we start with a bad TweenInfo, then we don't want to construct a Tween
	if typeof(startingTweenInfo) ~= "TweenInfo" then
		logError("mistypedTweenInfo", nil, typeof(startingTweenInfo))
	end

	local self = setmetatable({
		type = "State",
		kind = "Tween",
		dependencySet = dependencySet,
		-- if we held strong references to the dependents, then they wouldn't be
		-- able to get garbage collected when they fall out of scope
		dependentSet = setmetatable({}, WEAK_KEYS_METATABLE),
		_goalState = goalState,
		_tweenInfo = tweenInfo,
		_tweenInfoIsState = tweenInfoIsState,

		_prevValue = currentValue,
		_nextValue = currentValue,
		_currentValue = currentValue,

		-- store current tween into separately from 'real' tween into, so it
		-- isn't affected by :setTweenInfo() until next change
		_currentTweenInfo = tweenInfo,
		_currentTweenDuration = 0,
		_currentTweenStartTime = 0,
		_currentlyAnimating = false
	}, CLASS_METATABLE)

	initDependency(self)
	-- add this object to the goal state's dependent set
	goalState.dependentSet[self] = true

	return self
end

return Tween end,Properties={Name="Tween"},Reference=5,ClassName="ModuleScript"},{Closure=function() --!nonstrict

--[[
	Constructs a new computed state object, which follows the value of another
	state object using a spring simulation.
]]

local Package = script.Parent.Parent
local PubTypes = require(Package.PubTypes)
local Types = require(Package.Types)
local logError = require(Package.Logging.logError)
local logErrorNonFatal = require(Package.Logging.logErrorNonFatal)
local unpackType = require(Package.Animation.unpackType)
local SpringScheduler = require(Package.Animation.SpringScheduler)
local useDependency = require(Package.Dependencies.useDependency)
local initDependency = require(Package.Dependencies.initDependency)
local updateAll = require(Package.Dependencies.updateAll)
local xtypeof = require(Package.Utility.xtypeof)
local unwrap = require(Package.State.unwrap)

local class = {}

local CLASS_METATABLE = {__index = class}
local WEAK_KEYS_METATABLE = {__mode = "k"}

--[[
	Returns the current value of this Spring object.
	The object will be registered as a dependency unless `asDependency` is false.
]]
function class:get(asDependency: boolean?): any
	if asDependency ~= false then
		useDependency(self)
	end
	return self._currentValue
end

--[[
	Sets the position of the internal springs, meaning the value of this
	Spring will jump to the given value. This doesn't affect velocity.

	If the type doesn't match the current type of the spring, an error will be
	thrown.
]]
function class:setPosition(newValue: PubTypes.Animatable)
	local newType = typeof(newValue)
	if newType ~= self._currentType then
		logError("springTypeMismatch", nil, newType, self._currentType)
	end

	self._springPositions = unpackType(newValue, newType)
	self._currentValue = newValue
	SpringScheduler.add(self)
	updateAll(self)
end

--[[
	Sets the velocity of the internal springs, overwriting the existing velocity
	of this Spring. This doesn't affect position.

	If the type doesn't match the current type of the spring, an error will be
	thrown.
]]
function class:setVelocity(newValue: PubTypes.Animatable)
	local newType = typeof(newValue)
	if newType ~= self._currentType then
		logError("springTypeMismatch", nil, newType, self._currentType)
	end

	self._springVelocities = unpackType(newValue, newType)
	SpringScheduler.add(self)
end

--[[
	Adds to the velocity of the internal springs, on top of the existing
	velocity of this Spring. This doesn't affect position.

	If the type doesn't match the current type of the spring, an error will be
	thrown.
]]
function class:addVelocity(deltaValue: PubTypes.Animatable)
	local deltaType = typeof(deltaValue)
	if deltaType ~= self._currentType then
		logError("springTypeMismatch", nil, deltaType, self._currentType)
	end

	local springDeltas = unpackType(deltaValue, deltaType)
	for index, delta in ipairs(springDeltas) do
		self._springVelocities[index] += delta
	end
	SpringScheduler.add(self)
end

--[[
	Called when the goal state changes value, or when the speed or damping has
	changed.
]]
function class:update(): boolean
	local goalValue = self._goalState:get(false)

	-- figure out if this was a goal change or a speed/damping change
	if goalValue == self._goalValue then
		-- speed/damping change
		local damping = unwrap(self._damping)
		if typeof(damping) ~= "number" then
			logErrorNonFatal("mistypedSpringDamping", nil, typeof(damping))
		elseif damping < 0 then
			logErrorNonFatal("invalidSpringDamping", nil, damping)
		else
			self._currentDamping = damping
		end

		local speed = unwrap(self._speed)
		if typeof(speed) ~= "number" then
			logErrorNonFatal("mistypedSpringSpeed", nil, typeof(speed))
		elseif speed < 0 then
			logErrorNonFatal("invalidSpringSpeed", nil, speed)
		else
			self._currentSpeed = speed
		end

		return false
	else
		-- goal change - reconfigure spring to target new goal
		self._goalValue = goalValue

		local oldType = self._currentType
		local newType = typeof(goalValue)
		self._currentType = newType

		local springGoals = unpackType(goalValue, newType)
		local numSprings = #springGoals
		self._springGoals = springGoals

		if newType ~= oldType then
			-- if the type changed, snap to the new value and rebuild the
			-- position and velocity tables
			self._currentValue = self._goalValue

			local springPositions = table.create(numSprings, 0)
			local springVelocities = table.create(numSprings, 0)
			for index, springGoal in ipairs(springGoals) do
				springPositions[index] = springGoal
			end
			self._springPositions = springPositions
			self._springVelocities = springVelocities

			-- the spring may have been animating before, so stop that
			SpringScheduler.remove(self)
			return true

			-- otherwise, the type hasn't changed, just the goal...
		elseif numSprings == 0 then
			-- if the type isn't animatable, snap to the new value
			self._currentValue = self._goalValue
			return true

		else
			-- if it's animatable, let it animate to the goal
			SpringScheduler.add(self)
			return false
		end
	end
end

local function Spring<T>(
	goalState: PubTypes.Value<T>,
	speed: PubTypes.CanBeState<number>?,
	damping: PubTypes.CanBeState<number>?
): Types.Spring<T>
	-- apply defaults for speed and damping
	if speed == nil then
		speed = 10
	end
	if damping == nil then
		damping = 1
	end

	local dependencySet = {[goalState] = true}
	if xtypeof(speed) == "State" then
		dependencySet[speed] = true
	end
	if xtypeof(damping) == "State" then
		dependencySet[damping] = true
	end

	local self = setmetatable({
		type = "State",
		kind = "Spring",
		dependencySet = dependencySet,
		-- if we held strong references to the dependents, then they wouldn't be
		-- able to get garbage collected when they fall out of scope
		dependentSet = setmetatable({}, WEAK_KEYS_METATABLE),
		_speed = speed,
		_damping = damping,

		_goalState = goalState,
		_goalValue = nil,

		_currentType = nil,
		_currentValue = nil,
		_currentSpeed = unwrap(speed),
		_currentDamping = unwrap(damping),

		_springPositions = nil,
		_springGoals = nil,
		_springVelocities = nil
	}, CLASS_METATABLE)

	initDependency(self)
	-- add this object to the goal state's dependent set
	goalState.dependentSet[self] = true
	self:update()

	return self
end

return Spring end,Properties={Name="Spring"},Reference=3,ClassName="ModuleScript"},{Closure=function() --!strict

--[[
	Returns a 2x2 matrix of coefficients for a given time, damping and speed.
	Specifically, this returns four coefficients - posPos, posVel, velPos, and
	velVel - which can be multiplied with position and velocity like so:

	local newPosition = oldPosition * posPos + oldVelocity * posVel
	local newVelocity = oldPosition * velPos + oldVelocity * velVel

	Special thanks to AxisAngle for helping to improve numerical precision.
]]

local function springCoefficients(time: number, damping: number, speed: number): (number, number, number, number)
	-- if time or speed is 0, then the spring won't move
	if time == 0 or speed == 0 then
		return 1, 0, 0, 1
	end
	local posPos, posVel, velPos, velVel

	if damping > 1 then
		-- overdamped spring
		-- solution to the characteristic equation:
		-- z = -ζω ± Sqrt[ζ^2 - 1] ω
		-- x[t] -> x0(e^(t z2) z1 - e^(t z1) z2)/(z1 - z2)
		--		 + v0(e^(t z1) - e^(t z2))/(z1 - z2)
		-- v[t] -> x0(z1 z2(-e^(t z1) + e^(t z2)))/(z1 - z2)
		--		 + v0(z1 e^(t z1) - z2 e^(t z2))/(z1 - z2)

		local scaledTime = time * speed
		local alpha = math.sqrt(damping^2 - 1)
		local scaledInvAlpha = -0.5 / alpha
		local z1 = -alpha - damping
		local z2 = 1 / z1
		local expZ1 = math.exp(scaledTime * z1)
		local expZ2 = math.exp(scaledTime * z2)

		posPos = (expZ2*z1 - expZ1*z2) * scaledInvAlpha
		posVel = (expZ1 - expZ2) * scaledInvAlpha / speed
		velPos = (expZ2 - expZ1) * scaledInvAlpha * speed
		velVel = (expZ1*z1 - expZ2*z2) * scaledInvAlpha

	elseif damping == 1 then
		-- critically damped spring
		-- x[t] -> x0(e^-tω)(1+tω) + v0(e^-tω)t
		-- v[t] -> x0(t ω^2)(-e^-tω) + v0(1 - tω)(e^-tω)

		local scaledTime = time * speed
		local expTerm = math.exp(-scaledTime)

		posPos = expTerm * (1 + scaledTime)
		posVel = expTerm * time
		velPos = expTerm * (-scaledTime*speed)
		velVel = expTerm * (1 - scaledTime)

	else
		-- underdamped spring
		-- factored out of the solutions to the characteristic equation:
		-- α = Sqrt[1 - ζ^2]
		-- x[t] -> x0(e^-tζω)(α Cos[tα] + ζω Sin[tα])/α
		--       + v0(e^-tζω)(Sin[tα])/α
		-- v[t] -> x0(-e^-tζω)(α^2 + ζ^2 ω^2)(Sin[tα])/α
		--       + v0(e^-tζω)(α Cos[tα] - ζω Sin[tα])/α

		local scaledTime = time * speed
		local alpha = math.sqrt(1 - damping^2)
		local invAlpha = 1 / alpha
		local alphaTime = alpha * scaledTime
		local expTerm = math.exp(-scaledTime*damping)
		local sinTerm = expTerm * math.sin(alphaTime)
		local cosTerm = expTerm * math.cos(alphaTime)
		local sinInvAlpha = sinTerm*invAlpha
		local sinInvAlphaDamp = sinInvAlpha*damping

		posPos = sinInvAlphaDamp + cosTerm
		posVel = sinInvAlpha
		velPos = -(sinInvAlphaDamp*damping + sinTerm*alpha)
		velVel = cosTerm - sinInvAlphaDamp
	end

	return posPos, posVel, velPos, velVel
end

return springCoefficients
 end,Properties={Name="springCoefficients"},Reference=10,ClassName="ModuleScript"},{Closure=function() --!strict

--[[
	Unpacks an animatable type into an array of numbers.
	If the type is not animatable, an empty array will be returned.

	FIXME: This function uses a lot of redefinitions to suppress false positives
	from the Luau typechecker - ideally these wouldn't be required

	FUTURE: When Luau supports singleton types, those could be used in
	conjunction with intersection types to make this function fully statically
	type checkable.
]]

local Package = script.Parent.Parent
local PubTypes = require(Package.PubTypes)
local Oklab = require(Package.Colour.Oklab)

local function unpackType(value: any, typeString: string): {number}
	if typeString == "number" then
		local value = value :: number
		return {value}

	elseif typeString == "CFrame" then
		-- FUTURE: is there a better way of doing this? doing distance
		-- calculations on `angle` may be incorrect
		local axis, angle = value:ToAxisAngle()
		return {value.X, value.Y, value.Z, axis.X, axis.Y, axis.Z, angle}

	elseif typeString == "Color3" then
		local lab = Oklab.to(value)
		return {lab.X, lab.Y, lab.Z}

	elseif typeString == "ColorSequenceKeypoint" then
		local lab = Oklab.to(value.Value)
		return {lab.X, lab.Y, lab.Z, value.Time}

	elseif typeString == "DateTime" then
		return {value.UnixTimestampMillis}

	elseif typeString == "NumberRange" then
		return {value.Min, value.Max}

	elseif typeString == "NumberSequenceKeypoint" then
		return {value.Value, value.Time, value.Envelope}

	elseif typeString == "PhysicalProperties" then
		return {value.Density, value.Friction, value.Elasticity, value.FrictionWeight, value.ElasticityWeight}

	elseif typeString == "Ray" then
		return {value.Origin.X, value.Origin.Y, value.Origin.Z, value.Direction.X, value.Direction.Y, value.Direction.Z}

	elseif typeString == "Rect" then
		return {value.Min.X, value.Min.Y, value.Max.X, value.Max.Y}

	elseif typeString == "Region3" then
		-- FUTURE: support rotated Region3s if/when they become constructable
		return {
			value.CFrame.X, value.CFrame.Y, value.CFrame.Z,
			value.Size.X, value.Size.Y, value.Size.Z
		}

	elseif typeString == "Region3int16" then
		return {value.Min.X, value.Min.Y, value.Min.Z, value.Max.X, value.Max.Y, value.Max.Z}

	elseif typeString == "UDim" then
		return {value.Scale, value.Offset}

	elseif typeString == "UDim2" then
		return {value.X.Scale, value.X.Offset, value.Y.Scale, value.Y.Offset}

	elseif typeString == "Vector2" then
		return {value.X, value.Y}

	elseif typeString == "Vector2int16" then
		return {value.X, value.Y}

	elseif typeString == "Vector3" then
		return {value.X, value.Y, value.Z}

	elseif typeString == "Vector3int16" then
		return {value.X, value.Y, value.Z}
	else
		return {}
	end
end

return unpackType end,Properties={Name="unpackType"},Reference=11,ClassName="ModuleScript"},{Closure=function() --!strict

--[[
	Manages batch updating of tween objects.
]]

local RunService = game:GetService("RunService")

local Package = script.Parent.Parent
local Types = require(Package.Types)
local lerpType = require(Package.Animation.lerpType)
local getTweenRatio = require(Package.Animation.getTweenRatio)
local updateAll = require(Package.Dependencies.updateAll)

local TweenScheduler = {}

type Set<T> = {[T]: any}
type Tween = Types.Tween<any>

local WEAK_KEYS_METATABLE = {__mode = "k"}

-- all the tweens currently being updated
local allTweens: Set<Tween> = {}
setmetatable(allTweens, WEAK_KEYS_METATABLE)

--[[
	Adds a Tween to be updated every render step.
]]
function TweenScheduler.add(tween: Tween)
	allTweens[tween] = true
end

--[[
	Removes a Tween from the scheduler.
]]
function TweenScheduler.remove(tween: Tween)
	allTweens[tween] = nil
end

--[[
	Updates all Tween objects.
]]
local function updateAllTweens()
	local now = os.clock()
	-- FIXME: Typed Luau doesn't understand this loop yet
	for tween: Tween in pairs(allTweens :: any) do
		local currentTime = now - tween._currentTweenStartTime

		if currentTime > tween._currentTweenDuration then
			if tween._currentTweenInfo.Reverses then
				tween._currentValue = tween._prevValue
			else
				tween._currentValue = tween._nextValue
			end
			tween._currentlyAnimating = false
			updateAll(tween)
			TweenScheduler.remove(tween)
		else
			local ratio = getTweenRatio(tween._currentTweenInfo, currentTime)
			local currentValue = lerpType(tween._prevValue, tween._nextValue, ratio)
			tween._currentValue = currentValue
			tween._currentlyAnimating = true
			updateAll(tween)
		end
	end
end

RunService:BindToRenderStep(
	"__FusionTweenScheduler",
	Enum.RenderPriority.First.Value,
	updateAllTweens
)

return TweenScheduler end,Properties={Name="TweenScheduler"},Reference=6,ClassName="ModuleScript"},{Closure=function() --!strict

--[[
	Linearly interpolates the given animatable types by a ratio.
	If the types are different or not animatable, then the first value will be
	returned for ratios below 0.5, and the second value for 0.5 and above.

	FIXME: This function uses a lot of redefinitions to suppress false positives
	from the Luau typechecker - ideally these wouldn't be required
]]

local Package = script.Parent.Parent
local PubTypes = require(Package.PubTypes)
local Oklab = require(Package.Colour.Oklab)

local function lerpType(from: any, to: any, ratio: number): any
	local typeString = typeof(from)

	if typeof(to) == typeString then
		-- both types must match for interpolation to make sense
		if typeString == "number" then
			local to, from = to :: number, from :: number
			return (to - from) * ratio + from

		elseif typeString == "CFrame" then
			local to, from = to :: CFrame, from :: CFrame
			return from:Lerp(to, ratio)

		elseif typeString == "Color3" then
			local to, from = to :: Color3, from :: Color3
			local fromLab = Oklab.to(from)
			local toLab = Oklab.to(to)
			return Oklab.from(
				fromLab:Lerp(toLab, ratio),
				false
			)

		elseif typeString == "ColorSequenceKeypoint" then
			local to, from = to :: ColorSequenceKeypoint, from :: ColorSequenceKeypoint
			local fromLab = Oklab.to(from.Value)
			local toLab = Oklab.to(to.Value)
			return ColorSequenceKeypoint.new(
				(to.Time - from.Time) * ratio + from.Time,
				Oklab.from(
					fromLab:Lerp(toLab, ratio),
					false
				)
			)

		elseif typeString == "DateTime" then
			local to, from = to :: DateTime, from :: DateTime
			return DateTime.fromUnixTimestampMillis(
				(to.UnixTimestampMillis - from.UnixTimestampMillis) * ratio + from.UnixTimestampMillis
			)

		elseif typeString == "NumberRange" then
			local to, from = to :: NumberRange, from :: NumberRange
			return NumberRange.new(
				(to.Min - from.Min) * ratio + from.Min,
				(to.Max - from.Max) * ratio + from.Max
			)

		elseif typeString == "NumberSequenceKeypoint" then
			local to, from = to :: NumberSequenceKeypoint, from :: NumberSequenceKeypoint
			return NumberSequenceKeypoint.new(
				(to.Time - from.Time) * ratio + from.Time,
				(to.Value - from.Value) * ratio + from.Value,
				(to.Envelope - from.Envelope) * ratio + from.Envelope
			)

		elseif typeString == "PhysicalProperties" then
			local to, from = to :: PhysicalProperties, from :: PhysicalProperties
			return PhysicalProperties.new(
				(to.Density - from.Density) * ratio + from.Density,
				(to.Friction - from.Friction) * ratio + from.Friction,
				(to.Elasticity - from.Elasticity) * ratio + from.Elasticity,
				(to.FrictionWeight - from.FrictionWeight) * ratio + from.FrictionWeight,
				(to.ElasticityWeight - from.ElasticityWeight) * ratio + from.ElasticityWeight
			)

		elseif typeString == "Ray" then
			local to, from = to :: Ray, from :: Ray
			return Ray.new(
				from.Origin:Lerp(to.Origin, ratio),
				from.Direction:Lerp(to.Direction, ratio)
			)

		elseif typeString == "Rect" then
			local to, from = to :: Rect, from :: Rect
			return Rect.new(
				from.Min:Lerp(to.Min, ratio),
				from.Max:Lerp(to.Max, ratio)
			)

		elseif typeString == "Region3" then
			local to, from = to :: Region3, from :: Region3
			-- FUTURE: support rotated Region3s if/when they become constructable
			local position = from.CFrame.Position:Lerp(to.CFrame.Position, ratio)
			local halfSize = from.Size:Lerp(to.Size, ratio) / 2
			return Region3.new(position - halfSize, position + halfSize)

		elseif typeString == "Region3int16" then
			local to, from = to :: Region3int16, from :: Region3int16
			return Region3int16.new(
				Vector3int16.new(
					(to.Min.X - from.Min.X) * ratio + from.Min.X,
					(to.Min.Y - from.Min.Y) * ratio + from.Min.Y,
					(to.Min.Z - from.Min.Z) * ratio + from.Min.Z
				),
				Vector3int16.new(
					(to.Max.X - from.Max.X) * ratio + from.Max.X,
					(to.Max.Y - from.Max.Y) * ratio + from.Max.Y,
					(to.Max.Z - from.Max.Z) * ratio + from.Max.Z
				)
			)

		elseif typeString == "UDim" then
			local to, from = to :: UDim, from :: UDim
			return UDim.new(
				(to.Scale - from.Scale) * ratio + from.Scale,
				(to.Offset - from.Offset) * ratio + from.Offset
			)

		elseif typeString == "UDim2" then
			local to, from = to :: UDim2, from :: UDim2
			return from:Lerp(to, ratio)

		elseif typeString == "Vector2" then
			local to, from = to :: Vector2, from :: Vector2
			return from:Lerp(to, ratio)

		elseif typeString == "Vector2int16" then
			local to, from = to :: Vector2int16, from :: Vector2int16
			return Vector2int16.new(
				(to.X - from.X) * ratio + from.X,
				(to.Y - from.Y) * ratio + from.Y
			)

		elseif typeString == "Vector3" then
			local to, from = to :: Vector3, from :: Vector3
			return from:Lerp(to, ratio)

		elseif typeString == "Vector3int16" then
			local to, from = to :: Vector3int16, from :: Vector3int16
			return Vector3int16.new(
				(to.X - from.X) * ratio + from.X,
				(to.Y - from.Y) * ratio + from.Y,
				(to.Z - from.Z) * ratio + from.Z
			)
		end
	end

	-- fallback case: the types are different or not animatable
	if ratio < 0.5 then
		return from
	else
		return to
	end
end

return lerpType end,Properties={Name="lerpType"},Reference=8,ClassName="ModuleScript"}},Properties={Name="Animation"},Reference=2,ClassName="Folder"},{Children={{Closure=function() --!strict

--[[
	Utility function to log a Fusion-specific warning.
]]

local Package = script.Parent.Parent
local messages = require(Package.Logging.messages)

local function logWarn(messageID, ...)
	local formatString: string

	if messages[messageID] ~= nil then
		formatString = messages[messageID]
	else
		messageID = "unknownMessage"
		formatString = messages[messageID]
	end

	warn(string.format("[Fusion] " .. formatString .. "\n(ID: " .. messageID .. ")", ...))
end

return logWarn end,Properties={Name="logWarn"},Reference=34,ClassName="ModuleScript"},{Closure=function() --!strict

--[[
	Utility function to log a Fusion-specific error.
]]

local Package = script.Parent.Parent
local Types = require(Package.Types)
local messages = require(Package.Logging.messages)

local function logError(messageID: string, errObj: Types.Error?, ...)
	local formatString: string

	if messages[messageID] ~= nil then
		formatString = messages[messageID]
	else
		messageID = "unknownMessage"
		formatString = messages[messageID]
	end

	local errorString
	if errObj == nil then
		errorString = string.format("[Fusion] " .. formatString .. "\n(ID: " .. messageID .. ")", ...)
	else
		formatString = formatString:gsub("ERROR_MESSAGE", errObj.message)
		errorString = string.format("[Fusion] " .. formatString .. "\n(ID: " .. messageID .. ")\n---- Stack trace ----\n" .. errObj.trace, ...)
	end

	error(errorString:gsub("\n", "\n    "), 0)
end

return logError end,Properties={Name="logError"},Reference=32,ClassName="ModuleScript"},{Closure=function() --!strict

--[[
	An xpcall() error handler to collect and parse useful information about
	errors, such as clean messages and stack traces.

	TODO: this should have a 'type' field for runtime type checking!
]]

local Package = script.Parent.Parent
local Types = require(Package.Types)

local function parseError(err: string): Types.Error
	return {
		type = "Error",
		raw = err,
		message = err:gsub("^.+:%d+:%s*", ""),
		trace = debug.traceback(nil, 2)
	}
end

return parseError end,Properties={Name="parseError"},Reference=36,ClassName="ModuleScript"},{Closure=function() --!strict

--[[
	Utility function to log a Fusion-specific error, without halting execution.
]]

local Package = script.Parent.Parent
local Types = require(Package.Types)
local messages = require(Package.Logging.messages)

local function logErrorNonFatal(messageID: string, errObj: Types.Error?, ...)
	local formatString: string

	if messages[messageID] ~= nil then
		formatString = messages[messageID]
	else
		messageID = "unknownMessage"
		formatString = messages[messageID]
	end

	local errorString
	if errObj == nil then
		errorString = string.format("[Fusion] " .. formatString .. "\n(ID: " .. messageID .. ")", ...)
	else
		formatString = formatString:gsub("ERROR_MESSAGE", errObj.message)
		errorString = string.format("[Fusion] " .. formatString .. "\n(ID: " .. messageID .. ")\n---- Stack trace ----\n" .. errObj.trace, ...)
	end

	task.spawn(function(...)
		error(errorString:gsub("\n", "\n    "), 0)
	end, ...)
end

return logErrorNonFatal end,Properties={Name="logErrorNonFatal"},Reference=33,ClassName="ModuleScript"},{Closure=function() --!strict

--[[
	Stores templates for different kinds of logging messages.
]]

return {
	cannotAssignProperty = "The class type '%s' has no assignable property '%s'.",
	cannotConnectChange = "The %s class doesn't have a property called '%s'.",
	cannotConnectEvent = "The %s class doesn't have an event called '%s'.",
	cannotCreateClass = "Can't create a new instance of class '%s'.",
	computedCallbackError = "Computed callback error: ERROR_MESSAGE",
	destructorNeededValue = "To save instances into Values, provide a destructor function. This will be an error soon - see discussion #183 on GitHub.",
	destructorNeededComputed = "To return instances from Computeds, provide a destructor function. This will be an error soon - see discussion #183 on GitHub.",
	multiReturnComputed = "Returning multiple values from Computeds is discouraged, as behaviour will change soon - see discussion #189 on GitHub.",
	destructorNeededForKeys = "To return instances from ForKeys, provide a destructor function. This will be an error soon - see discussion #183 on GitHub.",
	destructorNeededForValues = "To return instances from ForValues, provide a destructor function. This will be an error soon - see discussion #183 on GitHub.",
	destructorNeededForPairs = "To return instances from ForPairs, provide a destructor function. This will be an error soon - see discussion #183 on GitHub.",
	duplicatePropertyKey = "",
	forKeysProcessorError = "ForKeys callback error: ERROR_MESSAGE",
	forKeysKeyCollision = "ForKeys should only write to output key '%s' once when processing key changes, but it wrote to it twice. Previously input key: '%s'; New input key: '%s'",
	forKeysDestructorError = "ForKeys destructor error: ERROR_MESSAGE",
	forPairsDestructorError = "ForPairs destructor error: ERROR_MESSAGE",
	forPairsKeyCollision = "ForPairs should only write to output key '%s' once when processing key changes, but it wrote to it twice. Previous input pair: '[%s] = %s'; New input pair: '[%s] = %s'",
	forPairsProcessorError = "ForPairs callback error: ERROR_MESSAGE",
	forValuesProcessorError = "ForValues callback error: ERROR_MESSAGE",
	forValuesDestructorError = "ForValues destructor error: ERROR_MESSAGE",
	invalidChangeHandler = "The change handler for the '%s' property must be a function.",
	invalidEventHandler = "The handler for the '%s' event must be a function.",
	invalidPropertyType = "'%s.%s' expected a '%s' type, but got a '%s' type.",
	invalidRefType = "Instance refs must be Value objects.",
	invalidOutType = "[Out] properties must be given Value objects.",
	invalidOutProperty = "The %s class doesn't have a property called '%s'.",
	invalidSpringDamping = "The damping ratio for a spring must be >= 0. (damping was %.2f)",
	invalidSpringSpeed = "The speed of a spring must be >= 0. (speed was %.2f)",
	mistypedSpringDamping = "The damping ratio for a spring must be a number. (got a %s)",
	mistypedSpringSpeed = "The speed of a spring must be a number. (got a %s)",
	mistypedTweenInfo = "The tween info of a tween must be a TweenInfo. (got a %s)",
	springTypeMismatch = "The type '%s' doesn't match the spring's type '%s'.",
	strictReadError = "'%s' is not a valid member of '%s'.",
	unknownMessage = "Unknown error: ERROR_MESSAGE",
	unrecognisedChildType = "'%s' type children aren't accepted by `[Children]`.",
	unrecognisedPropertyKey = "'%s' keys aren't accepted in property tables.",
	unrecognisedPropertyStage = "'%s' isn't a valid stage for a special key to be applied at."
} end,Properties={Name="messages"},Reference=35,ClassName="ModuleScript"}},Properties={Name="Logging"},Reference=31,ClassName="Folder"},{Children={{Closure=function() --!strict

--[[
	A special key for property tables, which adds user-specified tasks to be run
	when the instance is destroyed.
]]

local Package = script.Parent.Parent
local PubTypes = require(Package.PubTypes)

local Cleanup = {}
Cleanup.type = "SpecialKey"
Cleanup.kind = "Cleanup"
Cleanup.stage = "observer"

function Cleanup:apply(userTask: any, applyTo: Instance, cleanupTasks: {PubTypes.Task})
	table.insert(cleanupTasks, userTask)
end

return Cleanup end,Properties={Name="Cleanup"},Reference=22,ClassName="ModuleScript"},{Closure=function() --!strict

--[[
	A special key for property tables, which parents any given descendants into
	an instance.
]]

local Package = script.Parent.Parent
local PubTypes = require(Package.PubTypes)
local logWarn = require(Package.Logging.logWarn)
local Observer = require(Package.State.Observer)
local xtypeof = require(Package.Utility.xtypeof)

type Set<T> = {[T]: boolean}

-- Experimental flag: name children based on the key used in the [Children] table
local EXPERIMENTAL_AUTO_NAMING = false

local Children = {}
Children.type = "SpecialKey"
Children.kind = "Children"
Children.stage = "descendants"

function Children:apply(propValue: any, applyTo: Instance, cleanupTasks: {PubTypes.Task})
	local newParented: Set<Instance> = {}
	local oldParented: Set<Instance> = {}

	-- save disconnection functions for state object observers
	local newDisconnects: {[PubTypes.StateObject<any>]: () -> ()} = {}
	local oldDisconnects: {[PubTypes.StateObject<any>]: () -> ()} = {}

	local updateQueued = false
	local queueUpdate: () -> ()

	-- Rescans this key's value to find new instances to parent and state objects
	-- to observe for changes; then unparents instances no longer found and
	-- disconnects observers for state objects no longer present.
	local function updateChildren()
		if not updateQueued then
			return -- this update may have been canceled by destruction, etc.
		end
		updateQueued = false

		oldParented, newParented = newParented, oldParented
		oldDisconnects, newDisconnects = newDisconnects, oldDisconnects
		table.clear(newParented)
		table.clear(newDisconnects)

		local function processChild(child: any, autoName: string?)
			local kind = xtypeof(child)

			if kind == "Instance" then
				-- case 1; single instance

				newParented[child] = true
				if oldParented[child] == nil then
					-- wasn't previously present

					-- TODO: check for ancestry conflicts here
					child.Parent = applyTo
				else
					-- previously here; we want to reuse, so remove from old
					-- set so we don't encounter it during unparenting
					oldParented[child] = nil
				end

				if EXPERIMENTAL_AUTO_NAMING and autoName ~= nil then
					child.Name = autoName
				end

			elseif kind == "State" then
				-- case 2; state object

				local value = child:get(false)
				-- allow nil to represent the absence of a child
				if value ~= nil then
					processChild(value, autoName)
				end

				local disconnect = oldDisconnects[child]
				if disconnect == nil then
					-- wasn't previously present
					disconnect = Observer(child):onChange(queueUpdate)
				else
					-- previously here; we want to reuse, so remove from old
					-- set so we don't encounter it during unparenting
					oldDisconnects[child] = nil
				end

				newDisconnects[child] = disconnect

			elseif kind == "table" then
				-- case 3; table of objects

				for key, subChild in pairs(child) do
					local keyType = typeof(key)
					local subAutoName: string? = nil

					if keyType == "string" then
						subAutoName = key
					elseif keyType == "number" and autoName ~= nil then
						subAutoName = autoName .. "_" .. key
					end

					processChild(subChild, subAutoName)
				end

			else
				logWarn("unrecognisedChildType", kind)
			end
		end

		if propValue ~= nil then
			-- `propValue` is set to nil on cleanup, so we don't process children
			-- in that case
			processChild(propValue)
		end

		-- unparent any children that are no longer present
		for oldInstance in pairs(oldParented) do
			oldInstance.Parent = nil
		end

		-- disconnect observers which weren't reused
		for oldState, disconnect in pairs(oldDisconnects) do
			disconnect()
		end
	end

	queueUpdate = function()
		if not updateQueued then
			updateQueued = true
			task.defer(updateChildren)
		end
	end

	table.insert(cleanupTasks, function()
		propValue = nil
		updateQueued = true
		updateChildren()
	end)

	-- perform initial child parenting
	updateQueued = true
	updateChildren()
end

return Children :: PubTypes.SpecialKey end,Properties={Name="Children"},Reference=21,ClassName="ModuleScript"},{Closure=function() --!strict

--[[
	A special key for property tables, which stores a reference to the instance
	in a user-provided Value object.
]]

local Package = script.Parent.Parent
local PubTypes = require(Package.PubTypes)
local logError = require(Package.Logging.logError)
local xtypeof = require(Package.Utility.xtypeof)

local Ref = {}
Ref.type = "SpecialKey"
Ref.kind = "Ref"
Ref.stage = "observer"

function Ref:apply(refState: any, applyTo: Instance, cleanupTasks: {PubTypes.Task})
	if xtypeof(refState) ~= "State" or refState.kind ~= "Value" then
		logError("invalidRefType")
	else
		refState:set(applyTo)
		table.insert(cleanupTasks, function()
			refState:set(nil)
		end)
	end
end

return Ref end,Properties={Name="Ref"},Reference=28,ClassName="ModuleScript"},{Closure=function() --!strict

--[[
	A special key for property tables, which allows users to extract values from
	an instance into an automatically-updated Value object.
]]

local Package = script.Parent.Parent
local PubTypes = require(Package.PubTypes)
local logError = require(Package.Logging.logError)
local xtypeof = require(Package.Utility.xtypeof)

local function Out(propertyName: string): PubTypes.SpecialKey
	local outKey = {}
	outKey.type = "SpecialKey"
	outKey.kind = "Out"
	outKey.stage = "observer"

	function outKey:apply(outState: any, applyTo: Instance, cleanupTasks: { PubTypes.Task })
		local ok, event = pcall(applyTo.GetPropertyChangedSignal, applyTo, propertyName)
		if not ok then
			logError("invalidOutProperty", nil, applyTo.ClassName, propertyName)
		elseif xtypeof(outState) ~= "State" or outState.kind ~= "Value" then
			logError("invalidOutType")
		else
			outState:set((applyTo :: any)[propertyName])
			table.insert(
				cleanupTasks,
				event:Connect(function()
					outState:set((applyTo :: any)[propertyName])
				end)
			)
			table.insert(cleanupTasks, function()
				outState:set(nil)
			end)
		end
	end

	return outKey
end

return Out
 end,Properties={Name="Out"},Reference=27,ClassName="ModuleScript"},{Closure=function() --!strict

--[[
	Stores 'sensible default' properties to be applied to instances created by
	the New function.
]]

return {
	ScreenGui = {
		ResetOnSpawn = false,
		ZIndexBehavior = Enum.ZIndexBehavior.Sibling
	},

	BillboardGui = {
		ResetOnSpawn = false,
		ZIndexBehavior = Enum.ZIndexBehavior.Sibling
	},

	SurfaceGui = {
		ResetOnSpawn = false,
		ZIndexBehavior = Enum.ZIndexBehavior.Sibling,

		SizingMode = Enum.SurfaceGuiSizingMode.PixelsPerStud,
		PixelsPerStud = 50
	},

	Frame = {
		BackgroundColor3 = Color3.new(1, 1, 1),
		BorderColor3 = Color3.new(0, 0, 0),
		BorderSizePixel = 0
	},

	ScrollingFrame = {
		BackgroundColor3 = Color3.new(1, 1, 1),
		BorderColor3 = Color3.new(0, 0, 0),
		BorderSizePixel = 0,

		ScrollBarImageColor3 = Color3.new(0, 0, 0)
	},

	TextLabel = {
		BackgroundColor3 = Color3.new(1, 1, 1),
		BorderColor3 = Color3.new(0, 0, 0),
		BorderSizePixel = 0,

		Font = Enum.Font.SourceSans,
		Text = "",
		TextColor3 = Color3.new(0, 0, 0),
		TextSize = 14
	},

	TextButton = {
		BackgroundColor3 = Color3.new(1, 1, 1),
		BorderColor3 = Color3.new(0, 0, 0),
		BorderSizePixel = 0,

		AutoButtonColor = false,

		Font = Enum.Font.SourceSans,
		Text = "",
		TextColor3 = Color3.new(0, 0, 0),
		TextSize = 14
	},

	TextBox = {
		BackgroundColor3 = Color3.new(1, 1, 1),
		BorderColor3 = Color3.new(0, 0, 0),
		BorderSizePixel = 0,

		ClearTextOnFocus = false,

		Font = Enum.Font.SourceSans,
		Text = "",
		TextColor3 = Color3.new(0, 0, 0),
		TextSize = 14
	},

	ImageLabel = {
		BackgroundColor3 = Color3.new(1, 1, 1),
		BorderColor3 = Color3.new(0, 0, 0),
		BorderSizePixel = 0
	},

	ImageButton = {
		BackgroundColor3 = Color3.new(1, 1, 1),
		BorderColor3 = Color3.new(0, 0, 0),
		BorderSizePixel = 0,

		AutoButtonColor = false
	},

	ViewportFrame = {
		BackgroundColor3 = Color3.new(1, 1, 1),
		BorderColor3 = Color3.new(0, 0, 0),
		BorderSizePixel = 0
	},

	VideoFrame = {
		BackgroundColor3 = Color3.new(1, 1, 1),
		BorderColor3 = Color3.new(0, 0, 0),
		BorderSizePixel = 0
	},
	
	CanvasGroup = {
		BackgroundColor3 = Color3.new(1, 1, 1),
		BorderColor3 = Color3.new(0, 0, 0),
		BorderSizePixel = 0
	}
}
 end,Properties={Name="defaultProps"},Reference=30,ClassName="ModuleScript"},{Closure=function() --!strict

--[[
	Applies a table of properties to an instance, including binding to any
	given state objects and applying any special keys.

	No strong reference is kept by default - special keys should take care not
	to accidentally hold strong references to instances forever.

	If a key is used twice, an error will be thrown. This is done to avoid
	double assignments or double bindings. However, some special keys may want
	to enable such assignments - in which case unique keys should be used for
	each occurence.
]]

local Package = script.Parent.Parent
local PubTypes = require(Package.PubTypes)
local cleanup = require(Package.Utility.cleanup)
local xtypeof = require(Package.Utility.xtypeof)
local logError = require(Package.Logging.logError)
local Observer = require(Package.State.Observer)

local function setProperty_unsafe(instance: Instance, property: string, value: any)
	(instance :: any)[property] = value
end

local function testPropertyAssignable(instance: Instance, property: string)
	(instance :: any)[property] = (instance :: any)[property]
end

local function setProperty(instance: Instance, property: string, value: any)
	if not pcall(setProperty_unsafe, instance, property, value) then
		if not pcall(testPropertyAssignable, instance, property) then
			if instance == nil then
				-- reference has been lost
				logError("setPropertyNilRef", nil, property, tostring(value))
			else
				-- property is not assignable
				logError("cannotAssignProperty", nil, instance.ClassName, property)
			end
		else
			-- property is assignable, but this specific assignment failed
			-- this typically implies the wrong type was received
			local givenType = typeof(value)
			local expectedType = typeof((instance :: any)[property])
			logError("invalidPropertyType", nil, instance.ClassName, property, expectedType, givenType)
		end
	end
end

local function bindProperty(instance: Instance, property: string, value: PubTypes.CanBeState<any>, cleanupTasks: {PubTypes.Task})
	if xtypeof(value) == "State" then
		-- value is a state object - assign and observe for changes
		local willUpdate = false
		local function updateLater()
			if not willUpdate then
				willUpdate = true
				task.defer(function()
					willUpdate = false
					setProperty(instance, property, value:get(false))
				end)
			end
		end

		setProperty(instance, property, value:get(false))
		table.insert(cleanupTasks, Observer(value :: any):onChange(updateLater))
	else
		-- value is a constant - assign once only
		setProperty(instance, property, value)
	end
end

local function applyInstanceProps(props: PubTypes.PropertyTable, applyTo: Instance)
	local specialKeys = {
		self = {} :: {[PubTypes.SpecialKey]: any},
		descendants = {} :: {[PubTypes.SpecialKey]: any},
		ancestor = {} :: {[PubTypes.SpecialKey]: any},
		observer = {} :: {[PubTypes.SpecialKey]: any}
	}
	local cleanupTasks = {}

	for key, value in pairs(props) do
		local keyType = xtypeof(key)

		if keyType == "string" then
			if key ~= "Parent" then
				bindProperty(applyTo, key :: string, value, cleanupTasks)
			end
		elseif keyType == "SpecialKey" then
			local stage = (key :: PubTypes.SpecialKey).stage
			local keys = specialKeys[stage]
			if keys == nil then
				logError("unrecognisedPropertyStage", nil, stage)
			else
				keys[key] = value
			end
		else
			-- we don't recognise what this key is supposed to be
			logError("unrecognisedPropertyKey", nil, xtypeof(key))
		end
	end

	for key, value in pairs(specialKeys.self) do
		key:apply(value, applyTo, cleanupTasks)
	end
	for key, value in pairs(specialKeys.descendants) do
		key:apply(value, applyTo, cleanupTasks)
	end

	if props.Parent ~= nil then
		bindProperty(applyTo, "Parent", props.Parent, cleanupTasks)
	end

	for key, value in pairs(specialKeys.ancestor) do
		key:apply(value, applyTo, cleanupTasks)
	end
	for key, value in pairs(specialKeys.observer) do
		key:apply(value, applyTo, cleanupTasks)
	end

	applyTo.Destroying:Connect(function()
		cleanup(cleanupTasks)
	end)
end

return applyInstanceProps end,Properties={Name="applyInstanceProps"},Reference=29,ClassName="ModuleScript"},{Closure=function() --!strict

--[[
	Constructs special keys for property tables which connect property change
	listeners to an instance.
]]

local Package = script.Parent.Parent
local PubTypes = require(Package.PubTypes)
local logError = require(Package.Logging.logError)

local function OnChange(propertyName: string): PubTypes.SpecialKey
	local changeKey = {}
	changeKey.type = "SpecialKey"
	changeKey.kind = "OnChange"
	changeKey.stage = "observer"

	function changeKey:apply(callback: any, applyTo: Instance, cleanupTasks: {PubTypes.Task})
		local ok, event = pcall(applyTo.GetPropertyChangedSignal, applyTo, propertyName)
		if not ok then
			logError("cannotConnectChange", nil, applyTo.ClassName, propertyName)
		elseif typeof(callback) ~= "function" then
			logError("invalidChangeHandler", nil, propertyName)
		else
			table.insert(cleanupTasks, event:Connect(function()
				callback((applyTo :: any)[propertyName])
			end))
		end
	end

	return changeKey
end

return OnChange end,Properties={Name="OnChange"},Reference=25,ClassName="ModuleScript"},{Closure=function() --!strict

--[[
	Processes and returns an existing instance, with options for setting
	properties, event handlers and other attributes on the instance.
]]

local Package = script.Parent.Parent
local PubTypes = require(Package.PubTypes)
local applyInstanceProps = require(Package.Instances.applyInstanceProps)

local function Hydrate(target: Instance)
	return function(props: PubTypes.PropertyTable): Instance
		applyInstanceProps(props, target)
		return target
	end
end

return Hydrate end,Properties={Name="Hydrate"},Reference=23,ClassName="ModuleScript"},{Closure=function() --!strict

--[[
	Constructs and returns a new instance, with options for setting properties,
	event handlers and other attributes on the instance right away.
]]

local Package = script.Parent.Parent
local PubTypes = require(Package.PubTypes)
local defaultProps = require(Package.Instances.defaultProps)
local applyInstanceProps = require(Package.Instances.applyInstanceProps)
local logError= require(Package.Logging.logError)

local function New(className: string)
	return function(props: PubTypes.PropertyTable): Instance
		local ok, instance = pcall(Instance.new, className)

		if not ok then
			logError("cannotCreateClass", nil, className)
		end

		local classDefaults = defaultProps[className]
		if classDefaults ~= nil then
			for defaultProp, defaultValue in pairs(classDefaults) do
				instance[defaultProp] = defaultValue
			end
		end

		applyInstanceProps(props, instance)

		return instance
	end
end

return New end,Properties={Name="New"},Reference=24,ClassName="ModuleScript"},{Closure=function() --!strict

--[[
	Constructs special keys for property tables which connect event listeners to
	an instance.
]]

local Package = script.Parent.Parent
local PubTypes = require(Package.PubTypes)
local logError = require(Package.Logging.logError)

local function getProperty_unsafe(instance: Instance, property: string)
	return (instance :: any)[property]
end

local function OnEvent(eventName: string): PubTypes.SpecialKey
	local eventKey = {}
	eventKey.type = "SpecialKey"
	eventKey.kind = "OnEvent"
	eventKey.stage = "observer"

	function eventKey:apply(callback: any, applyTo: Instance, cleanupTasks: {PubTypes.Task})
		local ok, event = pcall(getProperty_unsafe, applyTo, eventName)
		if not ok or typeof(event) ~= "RBXScriptSignal" then
			logError("cannotConnectEvent", nil, applyTo.ClassName, eventName)
		elseif typeof(callback) ~= "function" then
			logError("invalidEventHandler", nil, eventName)
		else
			table.insert(cleanupTasks, event:Connect(callback))
		end
	end

	return eventKey
end

return OnEvent end,Properties={Name="OnEvent"},Reference=26,ClassName="ModuleScript"}},Properties={Name="Instances"},Reference=20,ClassName="Folder"},{Children={{Closure=function() --!strict

--[[
	Restricts the reading of missing members for a table.
]]

local Package = script.Parent.Parent
local logError = require(Package.Logging.logError)

type table = {[any]: any}

local function restrictRead(tableName: string, strictTable: table): table
	-- FIXME: Typed Luau doesn't recognise this correctly yet
	local metatable = getmetatable(strictTable :: any)

	if metatable == nil then
		metatable = {}
		setmetatable(strictTable, metatable)
	end

	function metatable:__index(memberName)
		logError("strictReadError", nil, tostring(memberName), tableName)
	end

	return strictTable
end

return restrictRead end,Properties={Name="restrictRead"},Reference=53,ClassName="ModuleScript"},{Closure=function() --!strict

--[[
	An empty function. Often used as a destructor to indicate no destruction.
]]

local function doNothing(...: any)
end

return doNothing end,Properties={Name="doNothing"},Reference=50,ClassName="ModuleScript"},{Closure=function() --!strict
--[[
    Returns true if A and B are 'similar' - i.e. any user of A would not need
    to recompute if it changed to B.
]]

local function isSimilar(a: any, b: any): boolean
    -- HACK: because tables are mutable data structures, don't make assumptions
    -- about similarity from equality for now (see issue #44)
    if typeof(a) == "table" then
        return false
    else
        return a == b
    end
end

return isSimilar end,Properties={Name="isSimilar"},Reference=51,ClassName="ModuleScript"},{Closure=function() --!strict

--[[
	A symbol for representing nil values in contexts where nil is not usable.
]]

local Package = script.Parent.Parent
local Types = require(Package.Types)

return {
	type = "Symbol",
	name = "None"
} :: Types.None end,Properties={Name="None"},Reference=48,ClassName="ModuleScript"},{Closure=function() --!strict

--[[
	Extended typeof, designed for identifying custom objects.
	If given a table with a `type` string, returns that.
	Otherwise, returns `typeof()` the argument.
]]

local function xtypeof(x: any)
	local typeString = typeof(x)

	if typeString == "table" and typeof(x.type) == "string" then
		return x.type
	else
		return typeString
	end
end

return xtypeof end,Properties={Name="xtypeof"},Reference=54,ClassName="ModuleScript"},{Closure=function() --!strict

--[[
	Cleans up the tasks passed in as the arguments.
	A task can be any of the following:

	- an Instance - will be destroyed
	- an RBXScriptConnection - will be disconnected
	- a function - will be run
	- a table with a `Destroy` or `destroy` function - will be called
	- an array - `cleanup` will be called on each item
]]

local function cleanupOne(task: any)
	local taskType = typeof(task)

	-- case 1: Instance
	if taskType == "Instance" then
		task:Destroy()

	-- case 2: RBXScriptConnection
	elseif taskType == "RBXScriptConnection" then
		task:Disconnect()

	-- case 3: callback
	elseif taskType == "function" then
		task()

	elseif taskType == "table" then
		-- case 4: destroy() function
		if typeof(task.destroy) == "function" then
			task:destroy()

		-- case 5: Destroy() function
		elseif typeof(task.Destroy) == "function" then
			task:Destroy()

		-- case 6: array of tasks
		elseif task[1] ~= nil then
			for _, subtask in ipairs(task) do
				cleanupOne(subtask)
			end
		end
	end
end

local function cleanup(...: any)
	for index = 1, select("#", ...) do
		cleanupOne(select(index, ...))
	end
end

return cleanup end,Properties={Name="cleanup"},Reference=49,ClassName="ModuleScript"},{Closure=function() --!strict

--[[
    Returns true if the given value is not automatically memory managed, and
    requires manual cleanup.
]]

local function needsDestruction(x: any): boolean
    return typeof(x) == "Instance"
end

return needsDestruction end,Properties={Name="needsDestruction"},Reference=52,ClassName="ModuleScript"}},Properties={Name="Utility"},Reference=47,ClassName="Folder"},{Children={{Closure=function() --!strict

--[[
	If a target set was specified by captureDependencies(), this will add the
	given dependency to the target set.
]]

local Package = script.Parent.Parent
local PubTypes = require(Package.PubTypes)
local sharedState = require(Package.Dependencies.sharedState)

local initialisedStack = sharedState.initialisedStack

local function useDependency(dependency: PubTypes.Dependency)
	local dependencySet = sharedState.dependencySet

	if dependencySet ~= nil then
		local initialisedStackSize = sharedState.initialisedStackSize
		if initialisedStackSize > 0 then
			local initialisedSet = initialisedStack[initialisedStackSize]
			if initialisedSet[dependency] ~= nil then
				return
			end
		end
		dependencySet[dependency] = true
	end
end

return useDependency end,Properties={Name="useDependency"},Reference=19,ClassName="ModuleScript"},{Closure=function() --!strict

--[[
	Given a reactive object, updates all dependent reactive objects.
	Objects are only ever updated after all of their dependencies are updated,
	are only ever updated once, and won't be updated if their dependencies are
	unchanged.
]]

local Package = script.Parent.Parent
local PubTypes = require(Package.PubTypes)

type Set<T> = {[T]: any}
type Descendant = (PubTypes.Dependent & PubTypes.Dependency) | PubTypes.Dependent

-- Credit: https://blog.elttob.uk/2022/11/07/sets-efficient-topological-search.html
local function updateAll(root: PubTypes.Dependency)
	local counters: {[Descendant]: number} = {}
	local flags: {[Descendant]: boolean} = {}
	local queue: {Descendant} = {}
	local queueSize = 0
	local queuePos = 1

	for object in root.dependentSet do
		queueSize += 1
		queue[queueSize] = object
		flags[object] = true
	end

	-- Pass 1: counting up
	while queuePos <= queueSize do
		local next = queue[queuePos]
		local counter = counters[next]
		counters[next] = if counter == nil then 1 else counter + 1
		if (next :: any).dependentSet ~= nil then
			for object in (next :: any).dependentSet do
				queueSize += 1
				queue[queueSize] = object
			end
		end
		queuePos += 1
	end

	-- Pass 2: counting down + processing
	queuePos = 1
	while queuePos <= queueSize do
		local next = queue[queuePos]
		local counter = counters[next] - 1
		counters[next] = counter
		if counter == 0 and flags[next] and next:update() and (next :: any).dependentSet ~= nil then
			for object in (next :: any).dependentSet do
				flags[object] = true
			end
		end
		queuePos += 1
	end
end

return updateAll end,Properties={Name="updateAll"},Reference=18,ClassName="ModuleScript"},{Closure=function() --!strict

--[[
	Registers the creation of an object which can be used as a dependency.

	This is used to make sure objects don't capture dependencies originating
	from inside of themselves.
]]

local Package = script.Parent.Parent
local PubTypes = require(Package.PubTypes)
local sharedState = require(Package.Dependencies.sharedState)

local initialisedStack = sharedState.initialisedStack

local function initDependency(dependency: PubTypes.Dependency)
	local initialisedStackSize = sharedState.initialisedStackSize

	for index, initialisedSet in ipairs(initialisedStack) do
		if index > initialisedStackSize then
			return
		end

		initialisedSet[dependency] = true
	end
end

return initDependency end,Properties={Name="initDependency"},Reference=16,ClassName="ModuleScript"},{Closure=function() --!strict

--[[
	Stores shared state for dependency management functions.
]]

local Package = script.Parent.Parent
local PubTypes = require(Package.PubTypes)

type Set<T> = {[T]: any}

-- The set where used dependencies should be saved to.
local dependencySet: Set<PubTypes.Dependency>? = nil

-- A stack of sets where newly created dependencies should be stored.
local initialisedStack: {Set<PubTypes.Dependency>} = {}
local initialisedStackSize = 0

return {
	dependencySet = dependencySet,
	initialisedStack = initialisedStack,
	initialisedStackSize = initialisedStackSize
} end,Properties={Name="sharedState"},Reference=17,ClassName="ModuleScript"},{Closure=function() --!strict

--[[
	Calls the given callback, and stores any used external dependencies.
	Arguments can be passed in after the callback.
	If the callback completed successfully, returns true and the returned value,
	otherwise returns false and the error thrown.
	The callback shouldn't yield or run asynchronously.

	NOTE: any calls to useDependency() inside the callback (even if inside any
	nested captureDependencies() call) will not be included in the set, to avoid
	self-dependencies.
]]

local Package = script.Parent.Parent
local PubTypes = require(Package.PubTypes)
local parseError = require(Package.Logging.parseError)
local sharedState = require(Package.Dependencies.sharedState)

type Set<T> = {[T]: any}

local initialisedStack = sharedState.initialisedStack
local initialisedStackCapacity = 0

local function captureDependencies(
	saveToSet: Set<PubTypes.Dependency>,
	callback: (...any) -> any,
	...
): (boolean, any)

	local prevDependencySet = sharedState.dependencySet
	sharedState.dependencySet = saveToSet

	sharedState.initialisedStackSize += 1
	local initialisedStackSize = sharedState.initialisedStackSize

	local initialisedSet
	if initialisedStackSize > initialisedStackCapacity then
		initialisedSet = {}
		initialisedStack[initialisedStackSize] = initialisedSet
		initialisedStackCapacity = initialisedStackSize
	else
		initialisedSet = initialisedStack[initialisedStackSize]
		table.clear(initialisedSet)
	end

	local data = table.pack(xpcall(callback, parseError, ...))

	sharedState.dependencySet = prevDependencySet
	sharedState.initialisedStackSize -= 1

	return table.unpack(data, 1, data.n)
end

return captureDependencies
 end,Properties={Name="captureDependencies"},Reference=15,ClassName="ModuleScript"}},Properties={Name="Dependencies"},Reference=14,ClassName="Folder"},{Closure=function() --!strict

--[[
	Stores common type information used internally.

	These types may be used internally so Fusion code can type-check, but
	should never be exposed to public users, as these definitions are fair game
	for breaking changes.
]]

local Package = script.Parent
local PubTypes = require(Package.PubTypes)

type Set<T> = {[T]: any}

--[[
	General use types
]]

-- A symbol that represents the absence of a value.
export type None = PubTypes.Symbol & {
	-- name: "None" (add this when Luau supports singleton types)
}

-- Stores useful information about Luau errors.
export type Error = {
	type: string, -- replace with "Error" when Luau supports singleton types
	raw: string,
	message: string,
	trace: string
}

--[[
	Specific reactive graph types
]]

-- A state object whose value can be set at any time by the user.
export type State<T> = PubTypes.Value<T> & {
	_value: T
}

-- A state object whose value is derived from other objects using a callback.
export type Computed<T> = PubTypes.Computed<T> & {
	_oldDependencySet: Set<PubTypes.Dependency>,
	_callback: () -> T,
	_value: T
}

-- A state object whose value is derived from other objects using a callback.
export type ForPairs<KI, VI, KO, VO, M> = PubTypes.ForPairs<KO, VO> & {
	_oldDependencySet: Set<PubTypes.Dependency>,
	_processor: (KI, VI) -> (KO, VO),
	_destructor: (VO, M?) -> (),
	_inputIsState: boolean,
	_inputTable: PubTypes.CanBeState<{ [KI]: VI }>,
	_oldInputTable: { [KI]: VI },
	_outputTable: { [KO]: VO },
	_oldOutputTable: { [KO]: VO },
	_keyIOMap: { [KI]: KO },
	_meta: { [KO]: M? },
	_keyData: {
		[KI]: {
			dependencySet: Set<PubTypes.Dependency>,
			oldDependencySet: Set<PubTypes.Dependency>,
			dependencyValues: { [PubTypes.Dependency]: any },
		},
	},
}

-- A state object whose value is derived from other objects using a callback.
export type ForKeys<KI, KO, M> = PubTypes.ForKeys<KO, any> & {
	_oldDependencySet: Set<PubTypes.Dependency>,
	_processor: (KI) -> (KO),
	_destructor: (KO, M?) -> (),
	_inputIsState: boolean,
	_inputTable: PubTypes.CanBeState<{ [KI]: KO }>,
	_oldInputTable: { [KI]: KO },
	_outputTable: { [KO]: any },
	_keyOIMap: { [KO]: KI },
	_meta: { [KO]: M? },
	_keyData: {
		[KI]: {
			dependencySet: Set<PubTypes.Dependency>,
			oldDependencySet: Set<PubTypes.Dependency>,
			dependencyValues: { [PubTypes.Dependency]: any },
		},
	},
}

-- A state object whose value is derived from other objects using a callback.
export type ForValues<VI, VO, M> = PubTypes.ForValues<any, VO> & {
	_oldDependencySet: Set<PubTypes.Dependency>,
	_processor: (VI) -> (VO),
	_destructor: (VO, M?) -> (),
	_inputIsState: boolean,
	_inputTable: PubTypes.CanBeState<{ [VI]: VO }>,
	_outputTable: { [any]: VI },
	_valueCache: { [VO]: any },
	_oldValueCache: { [VO]: any },
	_meta: { [VO]: M? },
	_valueData: {
		[VI]: {
			dependencySet: Set<PubTypes.Dependency>,
			oldDependencySet: Set<PubTypes.Dependency>,
			dependencyValues: { [PubTypes.Dependency]: any },
		},
	},
}

-- A state object which follows another state object using tweens.
export type Tween<T> = PubTypes.Tween<T> & {
	_goalState: State<T>,
	_tweenInfo: TweenInfo,
	_prevValue: T,
	_nextValue: T,
	_currentValue: T,
	_currentTweenInfo: TweenInfo,
	_currentTweenDuration: number,
	_currentTweenStartTime: number,
	_currentlyAnimating: boolean
}

-- A state object which follows another state object using spring simulation.
export type Spring<T> = PubTypes.Spring<T> & {
	_speed: PubTypes.CanBeState<number>,
	_speedIsState: boolean,
	_lastSpeed: number,
	_damping: PubTypes.CanBeState<number>,
	_dampingIsState: boolean,
	_lastDamping: number,
	_goalState: State<T>,
	_goalValue: T,
	_currentType: string,
	_currentValue: T,
	_springPositions: {number},
	_springGoals: {number},
	_springVelocities: {number}
}

-- An object which can listen for updates on another state object.
export type Observer = PubTypes.Observer & {
	_changeListeners: Set<() -> ()>,
	_numChangeListeners: number
}

return nil end,Properties={Name="Types"},Reference=46,ClassName="ModuleScript"},{Closure=function() --!strict

--[[
	Stores common public-facing type information for Fusion APIs.
]]

type Set<T> = {[T]: any}

--[[
	General use types
]]

-- A unique symbolic value.
export type Symbol = {
	type: string, -- replace with "Symbol" when Luau supports singleton types
	name: string
}

-- Types that can be expressed as vectors of numbers, and so can be animated.
export type Animatable =
	number |
	CFrame |
	Color3 |
	ColorSequenceKeypoint |
	DateTime |
	NumberRange |
	NumberSequenceKeypoint |
	PhysicalProperties |
	Ray |
	Rect |
	Region3 |
	Region3int16 |
	UDim |
	UDim2 |
	Vector2 |
	Vector2int16 |
	Vector3 |
	Vector3int16

-- A task which can be accepted for cleanup.
export type Task =
	Instance |
	RBXScriptConnection |
	() -> () |
	{destroy: (any) -> ()} |
	{Destroy: (any) -> ()} |
	{Task}

-- Script-readable version information.
export type Version = {
	major: number,
	minor: number,
	isRelease: boolean
}
--[[
	Generic reactive graph types
]]

-- A graph object which can have dependents.
export type Dependency = {
	dependentSet: Set<Dependent>
}

-- A graph object which can have dependencies.
export type Dependent = {
	update: (Dependent) -> boolean,
	dependencySet: Set<Dependency>
}

-- An object which stores a piece of reactive state.
export type StateObject<T> = Dependency & {
	type: string, -- replace with "State" when Luau supports singleton types
	kind: string,
	get: (StateObject<T>, asDependency: boolean?) -> T
}

-- Either a constant value of type T, or a state object containing type T.
export type CanBeState<T> = StateObject<T> | T

--[[
	Specific reactive graph types
]]

-- A state object whose value can be set at any time by the user.
export type Value<T> = StateObject<T> & {
	-- kind: "State" (add this when Luau supports singleton types)
 	set: (Value<T>, newValue: any, force: boolean?) -> ()
}

-- A state object whose value is derived from other objects using a callback.
export type Computed<T> = StateObject<T> & Dependent & {
	-- kind: "Computed" (add this when Luau supports singleton types)
}

-- A state object whose value is derived from other objects using a callback.
export type ForPairs<KO, VO> = StateObject<{ [KO]: VO }> & Dependent & {
	-- kind: "ForPairs" (add this when Luau supports singleton types)
}
-- A state object whose value is derived from other objects using a callback.
export type ForKeys<KO, V> = StateObject<{ [KO]: V }> & Dependent & {
	-- kind: "ForKeys" (add this when Luau supports singleton types)
}
-- A state object whose value is derived from other objects using a callback.
export type ForValues<K, VO> = StateObject<{ [K]: VO }> & Dependent & {
	-- kind: "ForKeys" (add this when Luau supports singleton types)
}

-- A state object which follows another state object using tweens.
export type Tween<T> = StateObject<T> & Dependent & {
	-- kind: "Tween" (add this when Luau supports singleton types)
}

-- A state object which follows another state object using spring simulation.
export type Spring<T> = StateObject<T> & Dependent & {
	-- kind: "Spring" (add this when Luau supports singleton types)
	-- Uncomment when ENABLE_PARAM_SETTERS is enabled
	-- setPosition: (Spring<T>, newValue: Animatable) -> (),
	-- setVelocity: (Spring<T>, newValue: Animatable) -> (),
	-- addVelocity: (Spring<T>, deltaValue: Animatable) -> ()
}

-- An object which can listen for updates on another state object.
export type Observer = Dependent & {
	-- kind: "Observer" (add this when Luau supports singleton types)
  	onChange: (Observer, callback: () -> ()) -> (() -> ())
}

--[[
	Instance related types
]]

-- Denotes children instances in an instance or component's property table.
export type SpecialKey = {
	type: string, -- replace with "SpecialKey" when Luau supports singleton types
	kind: string,
	stage: string, -- replace with "self" | "descendants" | "ancestor" | "observer" when Luau supports singleton types
	apply: (SpecialKey, value: any, applyTo: Instance, cleanupTasks: {Task}) -> ()
}

-- A collection of instances that may be parented to another instance.
export type Children = Instance | StateObject<Children> | {[any]: Children}

-- A table that defines an instance's properties, handlers and children.
export type PropertyTable = {[string | SpecialKey]: any}

return nil end,Properties={Name="PubTypes"},Reference=37,ClassName="ModuleScript"},{Children={{Closure=function() --!strict

--[[
	Provides functions for converting Color3s into Oklab space, for more
	perceptually uniform colour blending.

	See: https://bottosson.github.io/posts/oklab/
]]

local Oklab = {}

-- Converts a Color3 in RGB space to a Vector3 in Oklab space.
function Oklab.to(rgb: Color3): Vector3
	local l = rgb.R * 0.4122214708 + rgb.G * 0.5363325363 + rgb.B * 0.0514459929
	local m = rgb.R * 0.2119034982 + rgb.G * 0.6806995451 + rgb.B * 0.1073969566
	local s = rgb.R * 0.0883024619 + rgb.G * 0.2817188376 + rgb.B * 0.6299787005

	local lRoot = l ^ (1/3)
	local mRoot = m ^ (1/3)
	local sRoot = s ^ (1/3)

	return Vector3.new(
		lRoot * 0.2104542553 + mRoot * 0.7936177850 - sRoot * 0.0040720468,
		lRoot * 1.9779984951 - mRoot * 2.4285922050 + sRoot * 0.4505937099,
		lRoot * 0.0259040371 + mRoot * 0.7827717662 - sRoot * 0.8086757660
	)
end

-- Converts a Vector3 in CIELAB space to a Color3 in RGB space.
-- The Color3 will be clamped by default unless specified otherwise.
function Oklab.from(lab: Vector3, unclamped: boolean?): Color3
	local lRoot = lab.X + lab.Y * 0.3963377774 + lab.Z * 0.2158037573
	local mRoot = lab.X - lab.Y * 0.1055613458 - lab.Z * 0.0638541728
	local sRoot = lab.X - lab.Y * 0.0894841775 - lab.Z * 1.2914855480

	local l = lRoot ^ 3
	local m = mRoot ^ 3
	local s = sRoot ^ 3

	local red = l * 4.0767416621 - m * 3.3077115913 + s * 0.2309699292
	local green = l * -1.2684380046 + m * 2.6097574011 - s * 0.3413193965
	local blue = l * -0.0041960863 - m * 0.7034186147 + s * 1.7076147010

	if not unclamped then
		red = math.clamp(red, 0, 1)
		green = math.clamp(green, 0, 1)
		blue = math.clamp(blue, 0, 1)
	end

	return Color3.new(red, green, blue)
end

return Oklab
 end,Properties={Name="Oklab"},Reference=13,ClassName="ModuleScript"}},Properties={Name="Colour"},Reference=12,ClassName="Folder"}}}}do local a,b='0.4.0',Flags or{}local c,d,e=(b.ContextualExecution==nil and true)or b.ContextualExecution do if c then local f=game:GetService'RunService'd=f:IsServer()e=f:IsClient()end end local f,g,h,i,j,k,l=getfenv(0),{},{},{},{},{},{}local function m(n)local o,p=pcall(Instance.new,n.ClassName)if not o then return end g[n.Reference]=p if n.Closure then i[p]=n.Closure if p:IsA'BaseScript'then table.insert(k,p)end end if n.Properties then for q,r in next,n.Properties do pcall(function()p[q]=r end)end end if n.RefProperties then for q,r in next,n.RefProperties do table.insert(h,{InstanceObject=p,Property=q,ReferenceId=r})end end if n.Attributes then for q,r in next,n.Attributes do pcall(p.SetAttribute,p,q,r)end end if n.Children then for q,r in next,n.Children do local s=m(r)if s then s.Parent=p end end end return p end local n={}do for o,p in next,ModuleRoot do table.insert(n,m(p))end end local function o(p)local q=j[p]if p.ClassName=='ModuleScript'and q then return unpack(q)end local r=i[p]if not r then return end do local s local t={['maui']=table.freeze{Version=a,GetScript=function()return script end,GetShared=function()return l end},['script']=p,['require']=function(t,...)if t and t.ClassName=='ModuleScript'and i[t]then return o(t)end return require(t,...)end,['getfenv']=function(t,...)if type(t)=='number'and t>=0 then if t==0 then return s else local u,v=pcall(getfenv,t)if u and v==f then return s end end end return getfenv(t,...)end,['setfenv']=function(t,u,...)if type(t)=='number'and t>=0 then if t==0 then return setfenv(s,u)else local v,w=pcall(getfenv,t)if v and w==f then return setfenv(s,u)end end end return setfenv(t,u,...)end}s=setmetatable({},{__index=function(u,v)local w=rawget(s,v)if w~=nil then return w end local x=t[v]if x~=nil then return x end return f[v]end})setfenv(r,s)end local s=coroutine.wrap(r)if p:IsA'BaseScript'then local t=(not c or not p.Disabled)and task.defer(s)if c then local u u=p:GetPropertyChangedSignal'Disabled':Connect(function(v)u:Disconnect()if v==false then o(p)else pcall(task.cancel,t)end end)end return else local t={s()}j[p]=t return unpack(t)end end for p,q in next,h do pcall(function()q.InstanceObject[q.Property]=g[q.ReferenceId]end)end for r,s in next,k do if not c or((d and s.ClassName=='Script')or(e and s.ClassName=='LocalScript'))then o(s)end end if b.ReturnMainModule==nil or b.ReturnMainModule then local t do for u,v in next,n do if v.ClassName=='ModuleScript'and v.Name=='MainModule'then t=v break end end end if t then return o(t)end end end