Minor refactors

Also fixed potential bug with `create()` being called recursively if a
property binding passed as a property to `create()` also calls
`create()`

src/action.luau

@@ -10,14 +10,14 @@ local function is_action(v: any)
 end
 
 local function action(callback: (Instance) -> (), priority: number?): Action
-    local t = {
+    local a = {
         priority = priority or 1,
         callback = callback
     }
 
-    setmetatable(t :: any, ActionMT)
+    setmetatable(a :: any, ActionMT)
 
-    return table.freeze(t)
+    return table.freeze(a)
 end
 
 return function()

src/apply.luau

@@ -13,41 +13,58 @@ type Node<T> = graph.Node<T>
 type Array<V> = { V }
 type Map<K, V> = { [K]: V }
 
--- buffer of event -> callback to connect after properties are set
-local event_buffer = {} :: Map<string, () -> ()>
+local free_caches: {
+    -- event listeners to connect after properties are set
+    events: Map<
+        string, -- event name
+        () -> () -- listener
+    >,
 
--- buffer of priority -> callback to run after events are connected
-local action_buffers = {} :: Map<number, Array<(Instance) -> ()>>
+    -- actions to run after events are connected
+    actions: Map<
+        number, -- priority
+        Array<(Instance) -> ()> -- action callbacks
+    >,
 
--- lazily create buffers on nil index
-setmetatable(action_buffers :: any, {
-    __index = function(_, i: number)
-        action_buffers[i] = {}
-        return action_buffers[i]
-    end
-})
+    -- cache to detect duplicate property setting at same nesting depth
+    nested_debug: Map<
+        number, -- depth
+        Map<string, true> -- set of property names
+    >,
 
--- cache in strict mode to detect duplicate property set at same nesting level
-local nested_debug_cache = {} :: Map<number, Map<string, true>>
-
-setmetatable(nested_debug_cache :: any, {
-    __index = function(_, i: number)
-        nested_debug_cache[i] = {}
-        return nested_debug_cache[i]
-    end
-})
-
--- use stack instead of recursive function to process nested layers one at time
+    -- use stack instead of recursive function to process nesting layers one at time
     -- deeper-nested properties take precedence over shallower-nested ones
     -- each nested layer occupies two indexes: 1. table ref 2. nested depth
     -- e.g. { t1 = { t3 = {} }, t2 = {} } -> { t1, 1, t2, 1, t3, 2 }
-local nested_stack = {} :: { {} | number }
+    nested_stack: { {} | number }
+}?
+
+local function borrow_caches(): typeof(assert(free_caches))
+    if free_caches then
+        local caches = free_caches :: typeof(assert(free_caches))
+        free_caches = nil
+        return caches
+    else
+        return {
+            events = {},
+            actions = setmetatable({} :: any, { -- lazy init
+                __index = function(self, i) self[i] = {}; return self[i] end
+            }),
+            nested_debug = setmetatable({} :: any, {
+                __index = function(self, i: number) self[i] = {}; return self[i] end
+            }),
+            nested_stack = {}
+        }
+    end
+end
+
+local function return_caches(caches: typeof(free_caches) )
+    free_caches = caches
+end
 
--- todo: solution without manual updating of this table
 -- map of datatype names to class default constructor for aggregate init
 local aggregates = {}
-
-for i, v in next, {
+for name, class in {
     CFrame = CFrame,
     Color3 = Color3,
     UDim = UDim,
@@ -55,27 +72,39 @@ for i, v in next, {
     Vector2 = Vector2,
     Vector3 = Vector3,
     Rect = Rect
-} do
-    aggregates[i] = v.new
+} :: Map<string, { [string]: any }> do
+    aggregates[name] = class.new
+end
+
+-- applies table of nested properties to an instance using full vide semantics
+local function apply<T>(instance: T & Instance, properties: { [unknown]: unknown }): T
+    if not properties then
+        throw("attempt to call a constructor returned by create() with no properties")
     end
 
--- processes a potentially nested table of values to assign to an instance
-local function process_props(instance: Instance, properties: Map<unknown, unknown>)
     local strict = flags.strict
 
-    table.clear(nested_stack)
-    if strict then table.clear(nested_debug_cache) end
+    -- queue parent assignment if any for last
+    local parent: unknown = properties.Parent 
 
+    local caches = borrow_caches()
+    local events = caches.events
+    local actions = caches.actions
+    local nested_debug = caches.nested_debug
+    local nested_stack = caches.nested_stack
+
+    -- process all properties
     local depth = 1
-
     repeat
         for property, value in properties do
+            if property == "Parent" then continue end
+
             if type(property) == "string" then
-                if strict then -- check for duplicate prop assignment at nesting layer
-                    if nested_debug_cache[depth][property] then
+                if strict then -- check for duplicate prop assignment at nesting depth
+                    if nested_debug[depth][property] then
                         throw(`duplicate property {property} at depth {depth}`)
                     end
-                    nested_debug_cache[depth][property] = true
+                    nested_debug[depth][property] = true
                 end
 
                 if type(value) == "table" then -- attempt aggregate init
@@ -86,7 +115,7 @@ local function process_props(instance: Instance, properties: Map<unknown, unknow
                     (instance :: any)[property] = ctor(unpack(value :: {}))
                 elseif type(value) == "function" then 
                     if typeof((instance :: any)[property]) == "RBXScriptSignal" then
-                        event_buffer[property] = value  :: () -> () -- add event to buffer
+                        events[property] = value  :: () -> () -- add event to buffer
                     else
                         bind.property(instance, property, value :: () -> ()) -- bind property
                     end
@@ -98,7 +127,7 @@ local function process_props(instance: Instance, properties: Map<unknown, unknow
                     bind.children(instance, value :: () -> Instance | Array<Instance>) -- bind children
                 elseif type(value) == "table" then
                     if is_action(value) then
-                        table.insert(action_buffers[(value :: any).priority], (value :: any).callback :: () -> ()) -- add action to buffer
+                        table.insert(actions[(value :: any).priority], (value :: any).callback :: () -> ()) -- add action to buffer
                     else
                         table.insert(nested_stack, value :: {})
                         table.insert(nested_stack, depth + 1) -- push table to stack for later processing
@@ -109,40 +138,17 @@ local function process_props(instance: Instance, properties: Map<unknown, unknow
             end
         end
 
-        -- pop next nested table off stack
         depth = table.remove(nested_stack) :: number
         properties = table.remove(nested_stack) :: {}
 
     until not properties
+
+    for event, listener in next, events do
+        (instance :: any)[event]:Connect(listener)   
     end
 
--- applies table of nested properties to an instance using full vide semantics
-local function apply<T>(instance: T & Instance, properties: { [unknown]: unknown }): T
-    if not properties then
-        throw("no properties given, did you forget to call the constructor returned by create()?")
-    end
-
-    -- queue parent assignment if any for last
-    local parent: unknown = properties.Parent 
-    if parent then properties.Parent = nil end
-
-    -- reset buffers
-    table.clear(event_buffer)
-    for _, buffer in next, action_buffers do
-        table.clear(buffer)
-    end
-
-    -- process all properties for immediate setting or buffering
-    process_props(instance, properties)
-
-    -- connect buffered events
-    for event, fn in next, event_buffer do
-        (instance :: any)[event]:Connect(fn)   
-    end
-
-    -- run buffered actions
-    for _, buffer in next, action_buffers do
-        for _, callback in next, buffer do
+    for _, queued in next, actions do
+        for _, callback in next, queued do
             callback(instance)
         end
     end
@@ -156,6 +162,14 @@ local function apply<T>(instance: T & Instance, properties: { [unknown]: unknown
         end
     end
 
+    -- clear caches
+    table.clear(events)
+    for _, queued in next, actions do table.clear(queued) end
+    if strict then table.clear(nested_debug) end
+    table.clear(nested_stack)
+
+    return_caches(caches)
+
     return instance
 end
 

src/bind.luau

@@ -5,7 +5,7 @@ local flags = require(script.Parent.flags)
 local graph = require(script.Parent.graph)
 type Node<T> = graph.Node<T>
 local create_node = graph.create_node
-local get_owning_scope = graph.get_owning_scope
+local assert_owning_scope = graph.assert_owning_scope
 local evaluate_node = graph.evaluate_node
 local set_owner = graph.set_owner
 
@@ -31,8 +31,7 @@ function create_binding<T>(updater: (T) -> T, binding: T)
         end
     end
 
-    
-    local owner = get_owning_scope()
+    local owner = assert_owning_scope()
     
     local node = create_node(binding, updater)
 

src/create.luau

@@ -5,9 +5,11 @@ local Instance = game and Instance or require "test/mock".Instance :: never
 local throw = require(script.Parent.throw)
 local defaults = require(script.Parent.defaults)
 local apply = require(script.Parent.apply)
-local memoize = require(script.Parent.memoize)
 
-local function create_instance(class: string)
+local ctor_cache = {} :: { [string]: () -> Instance }
+
+setmetatable(ctor_cache :: any, {
+    __index = function(self, class)
         local ok, instance: Instance = pcall(Instance.new, class :: any)
         if not ok then throw(`invalid class name, could not create instance of class { class }`) end
 
@@ -18,29 +20,37 @@ local function create_instance(class: string)
             end
         end
 
-    return function(properties: { [any]: unknown }): Instance
+        local function ctor(properties: Props): Instance
             return apply(instance:Clone(), properties)    
         end  
-end; create_instance = memoize(create_instance) -- always return same constructor for given class
+
+        self[class] = ctor
+        return ctor
+    end
+})
+
+local function create_instance(class: string)
+    return ctor_cache[class]
+end
 
 local function clone_instance(instance: Instance)
-    return function(properties: { [any]: unknown }): Instance
+    return function(properties: Props): Instance
         local clone = instance:Clone()
-        if not clone then error("Attempt to clone a non-archivable instance", 3) end
+        if not clone then throw "attempt to clone a non-archivable instance" end
         return apply(clone, properties)
     end
 end
 
-local function create(class_or_instance: string|Instance)
+local function create(class_or_instance: string|Instance): (Props) -> Instance
     if type(class_or_instance) == "string" then
         return create_instance(class_or_instance)
     elseif typeof(class_or_instance) == "Instance" then
         return clone_instance(class_or_instance)
     else
         throw("bad argument #1, expected string or instance, got " .. typeof(class_or_instance))
-    end
         return nil :: never
     end
+end
 
 type Props = { [any]: any }
 return (create :: any) :: 

src/derive.luau

@@ -4,11 +4,11 @@ local graph = require(script.Parent.graph)
 local create_node = graph.create_node
 local set_owner = graph.set_owner
 local track = graph.track
-local get_owning_scope = graph.get_owning_scope
+local assert_owning_scope = graph.assert_owning_scope
 local evaluate_node = graph.evaluate_node
 
 local function derive<T>(source: () -> T): () -> T
-    local owner = get_owning_scope()
+    local owner = assert_owning_scope()
 
     local node = create_node(false :: any, source)
 

src/effect.luau

@@ -2,12 +2,12 @@ if not game then script = require "test/relative-string" end
 
 local graph = require(script.Parent.graph)
 local create_node = graph.create_node
-local get_owning_scope = graph.get_owning_scope
+local assert_owning_scope = graph.assert_owning_scope
 local evaluate_node = graph.evaluate_node
 local set_owner = graph.set_owner
 
 local function effect<T>(callback: (T) -> T, initial_value: T)
-    local owner = get_owning_scope()
+    local owner = assert_owning_scope()
 
     local node = create_node(initial_value, callback)
 

src/graph.luau

@@ -40,7 +40,7 @@ local function get_scope(): Node<unknown>?
     return scopes[scopes.n]
 end
 
-local function get_owning_scope(): Node<unknown>
+local function assert_owning_scope(): Node<unknown>
     local scope = get_scope()
 
     if not scope then
@@ -187,7 +187,7 @@ end
 
 local _flushing = false
 local function flush_update_queue()
-    assert(not flushing, "recursive queue flush occured") -- todo
+    assert(not _flushing, "recursive queue flush occured") -- todo
     _flushing = true
 
     local n0 = 0
@@ -266,7 +266,7 @@ return table.freeze {
     close_scope = close_scope,
     evaluate_node = evaluate_node,
     get_scope = get_scope,
-    get_owning_scope = get_owning_scope,
+    assert_owning_scope = assert_owning_scope,
     add_cleanup = add_cleanup,
     set_owner = set_owner,
     destroy = destroy,

src/init.luau

@@ -14,6 +14,7 @@ local effect = require(script.effect)
 local derive = require(script.derive)
 local cleanup = require(script.cleanup)
 local untrack = require(script.untrack)
+local read = require(script.read)
 local batch = require(script.batch)
 local switch = require(script.switch)
 local show = require(script.show)
@@ -60,10 +61,8 @@ local vide = {
     -- util
     cleanup = cleanup,
     untrack = untrack,
+    read = read,
     batch = batch,
-    read = function<T>(value: T | () -> T): T
-        return if type(value) == "function" then value() else value
-    end,
 
     -- animations
     spring = spring,

src/maps.luau

@@ -10,7 +10,7 @@ local create_start_node = graph.create_start_node
 local set_owner = graph.set_owner
 local track = graph.track
 local update = graph.update
-local get_owning_scope = graph.get_owning_scope
+local assert_owning_scope = graph.assert_owning_scope
 local open_scope = graph.open_scope
 local close_scope = graph.close_scope
 local evaluate_node = graph.evaluate_node
@@ -28,7 +28,7 @@ local function check_primitives(t: {})
 end
 
 local function indexes<K, VI, VO>(input: () -> Map<K, VI>, transform: (() -> VI, K) -> VO): () -> { VO }
-    local owner = get_owning_scope()
+    local owner = assert_owning_scope()
 
     local subowner = create_node(false, false)
     set_owner(subowner, owner)
@@ -123,7 +123,7 @@ local function indexes<K, VI, VO>(input: () -> Map<K, VI>, transform: (() -> VI,
 end
 
 local function values<K, VI, VO>(input: () -> Map<K, VI>, transform: (VI, () -> K) -> VO): () -> { VO }
-    local owner = get_owning_scope()
+    local owner = assert_owning_scope()
 
     local subowner = create_node(false, false)
     set_owner(subowner, owner)

src/memoize.luau

@@ -1,17 +0,0 @@
-local function memoize<X, Y>(f: (X) -> Y): (X) -> Y
-    local cache: { [X]: Y? } = {}
-
-    return function(x: X): Y
-        local y = cache[x]
-
-        if not y then
-            y = f(x)
-            cache[x] = y
-        end
-
-        return y :: Y
-    end
-end
-
-return memoize
-

src/read.luau

@@ -0,0 +1,7 @@
+if not game then script = require "test/relative-string" end
+
+local function read<T>(value: T | () -> T): T
+    return if type(value) == "function" then value() else value
+end
+
+return read

src/source.luau

@@ -6,7 +6,7 @@ local create_start_node = graph.create_start_node
 local track = graph.track
 local update = graph.update
 
-export type Source<T> = (() -> T) & ((T) -> T)
+export type Source<T> = (() -> T) & ((value: T) -> T)
 
 local function source<T>(initial_value: T): Source<T>
     local node = create_start_node(initial_value)

src/spring.luau

@@ -27,7 +27,7 @@ type Node<T> = graph.Node<T>
 type StartNode<T> = graph.StartNode<T>
 local create_node = graph.create_node
 local create_start_node = graph.create_start_node
-local get_owning_scope = graph.get_owning_scope
+local assert_owning_scope = graph.assert_owning_scope
 local evaluate_node = graph.evaluate_node
 local update = graph.update
 local set_owner = graph.set_owner
@@ -150,7 +150,7 @@ local springs: { [SpringData<any>]: StartNode<any> } = {}
 setmetatable(springs, { __mode = "v" })
 
 local function spring<T>(source: () -> T, period: number?, damping_ratio: number?): () -> T
-    local owner = get_owning_scope()
+    local owner = assert_owning_scope()
 
     -- https://en.wikipedia.org/wiki/Damping
 

src/switch.luau

@@ -9,14 +9,14 @@ local evaluate_node = graph.evaluate_node
 local set_owner = graph.set_owner
 local track = graph.track
 local destroy = graph.destroy
-local get_owning_scope = graph.get_owning_scope
+local assert_owning_scope = graph.assert_owning_scope
 local open_scope = graph.open_scope
 local close_scope = graph.close_scope
 
 type Map<K, V> = { [K]: V }
 
 local function switch<T, U>(source: () -> T): (map: Map<T, ((() -> U)?)>) -> () -> U?
-    local owner = get_owning_scope()
+    local owner = assert_owning_scope()
 
     return function(map)
         local last_scope: Node<false>?
@@ -35,7 +35,7 @@ local function switch<T, U>(source: () -> T): (map: Map<T, ((() -> U)?)>) -> ()
             if component == nil then return nil end
 
             if type(component) ~= "function" then
-                throw("map must map a value to a function")
+                throw "map must map a value to a function"
             end
 
             local new_scope = create_node(false, false)

test/tests.luau

@@ -942,6 +942,33 @@ TEST("create()", wrap_root(function()
         CHECK(not wref[1])
     end
 
+    do CASE "recursive create"
+        local set_test_to_true = vide.action(function(self) (self :: any).test = true end)
+
+        local f2
+    
+        local to_apply = {
+            { a = 1 },
+            set_test_to_true,
+            b = function() f2 = create "Frame" { a = 2 } end,
+        } :: { [number|string]: unknown }
+
+        -- do -- confirm iteration order
+        --     local t = {}
+        --     for i in to_apply do
+        --         table.insert(t, i)
+        --     end
+        --     assert(t[1] == "a")
+        -- end
+
+        local f = create "Frame" (to_apply)
+
+        CHECK((f :: any).a == 1)
+        CHECK((f :: any).test == true )
+
+        CHECK((f2 :: any).a == 2)
+    end
+
     do CASE "garbage collection test"
         local wref