Optimize indexes() and values()

src/derive.luau

@@ -1,6 +1,6 @@
 local graph = require "./graph"
 local create_node = graph.create_node
-local push_child_to_scope = graph.push_child_to_scope
+local push_scope_as_child_of = graph.push_scope_as_child_of
 local assert_stable_scope = graph.assert_stable_scope
 local evaluate_node = graph.evaluate_node
 
@@ -10,7 +10,7 @@ local function derive<T>(source: () -> T): () -> T
     evaluate_node(node)
 
     return function()
-        push_child_to_scope(node)
+        push_scope_as_child_of(node)
         return node.cache
     end
 end

src/graph.luau

@@ -245,7 +245,7 @@ local function update_descendants<T>(root: SourceNode<T>)
     update_queue.n = n0
 end
 
-local function push_child_to_scope<T>(node: SourceNode<T>)
+local function push_scope_as_child_of<T>(node: SourceNode<T>)
     local scope = get_scope()
     if scope and scope.effect then -- do not track nodes with no effect
         push_child(node, scope)
@@ -302,7 +302,7 @@ return table.freeze {
     push_cleanup = push_cleanup,
     destroy = destroy,
     flush_cleanups = flush_cleanups,
-    push_child_to_scope = push_child_to_scope,
+    push_scope_as_child_of = push_scope_as_child_of,
     update_descendants = update_descendants,
     push_child = push_child,
     create_node = create_node,

src/indexes.luau

@@ -0,0 +1,114 @@
+local flags = require "./flags"
+local graph = require "./graph"
+type Node<T> = graph.Node<T>
+type SourceNode<T> = graph.SourceNode<T>
+local create_node = graph.create_node
+local create_source_node = graph.create_source_node
+local push_scope_as_child_of = graph.push_scope_as_child_of
+local update_descendants = graph.update_descendants
+local assert_stable_scope = graph.assert_stable_scope
+local push_scope = graph.push_scope
+local pop_scope = graph.pop_scope
+local evaluate_node = graph.evaluate_node
+local destroy = graph.destroy
+
+type Map<K, V> = { [K]: V }
+
+local function indexes<K, VI, VO>(input: () -> Map<K, VI>, transform: (() -> VI, K) -> VO, delay: number?): () -> { VO }
+    local owner = assert_stable_scope()
+    local subowner = create_node(owner, false, false)
+
+    local input_cache = {} :: Map<K, VI>
+    local output_cache = {} :: Map<K, VO>
+    local input_nodes = {} :: Map<K, SourceNode<VI>>
+    local scopes = {} :: Map<K, Node<unknown>>
+
+    local function update_children(data)
+        local children_need_update = false
+
+        -- remove old indexes
+        for i in input_cache do
+            if data[i] == nil then
+                destroy(scopes[i])
+                input_cache[i] = nil
+                output_cache[i] = nil
+                input_nodes[i] = nil
+                scopes[i] = nil
+                children_need_update = true
+            end
+        end
+
+        push_scope(subowner)
+
+        -- process new or changed values
+        for i, v in data do
+            local cv = input_cache[i]
+
+            if cv ~= v then
+                input_cache[i] = v
+
+                if cv == nil then -- create new scope and run transform
+                    local scope = create_node(subowner, false, false)
+                    scopes[i] = scope :: Node<any>
+
+                    local node = create_source_node(v)
+
+                    push_scope(scope)
+
+                    local ok, result = xpcall(transform, debug.traceback, function()
+                        push_scope_as_child_of(node)
+                        return node.cache
+                    end, i)
+                    
+                    pop_scope()
+
+                    if not ok then
+                        pop_scope() -- subowner scope
+                        error(result, 0)
+                    end
+                    
+                    input_nodes[i] = node
+                    output_cache[i] = result
+                    children_need_update = true
+                else -- update source
+                    input_nodes[i].cache = v
+                    update_descendants(input_nodes[i])
+                end
+            end
+        end
+
+        pop_scope()
+
+        if children_need_update then
+            local output_array_size = #output_cache
+            local output_array
+
+            -- check if the table contains a dictionary section
+            if output_array_size > 0 and next(output_cache, output_array_size) == nil then
+                output_array = table.clone(output_cache)
+            else
+                output_array = table.create(output_array_size)
+                for _, v in output_cache do
+                    table.insert(output_array, v)
+                end
+            end
+            
+            return output_array
+        else
+            return nil
+        end
+    end
+
+    local node = create_node(owner, function(pre_children)
+        return update_children(input()) or pre_children
+    end, {})
+
+    evaluate_node(node)
+
+    return function()
+        push_scope_as_child_of(node)
+        return node.cache
+    end
+end
+
+return indexes

src/lib.luau

@@ -14,10 +14,12 @@ local batch = require "./batch"
 local context = require "./context"
 local switch = require "./switch"
 local show = require "./show"
-local indexes, values = require "./maps"()
+local indexes = require "./indexes"
+local values = require "./values"
 local spring, update_springs = require "./spring"()
 local action = require "./action"()
 local changed = require "./changed"
+local timeout, update_timeouts = require "./timeout"()
 local flags = require "./flags"
 
 export type Source<T> = source.Source<T>
@@ -26,17 +28,17 @@ export type Context<T> = context.Context<T>
 export type context<T> = Context<T>
 
 local function step(dt: number)
-    if game then
-        debug.profilebegin("VIDE STEP")
-        debug.profilebegin("VIDE SPRING")
-    end
+    if game then debug.profilebegin("VIDE STEP") end
 
+    if game then debug.profilebegin("VIDE SPRING") end
     update_springs(dt)
+    if game then debug.profileend() end
 
-    if game then
-        debug.profileend()
-        debug.profileend()
-    end
+    if game then debug.profilebegin("VIDE SCHEDULER") end
+    update_timeouts(dt)
+    if game then debug.profileend() end
+
+    if game then debug.profileend() end
 end
 
 local stepped = game and game:GetService("RunService").Heartbeat:Connect(function(dt: number)

src/maps.luau

@@ -1,216 +0,0 @@
-local flags = require "./flags"
-local graph = require "./graph"
-type Node<T> = graph.Node<T>
-type SourceNode<T> = graph.SourceNode<T>
-local create_node = graph.create_node
-local create_source_node = graph.create_source_node
-local push_child_to_scope = graph.push_child_to_scope
-local update_descendants = graph.update_descendants
-local assert_stable_scope = graph.assert_stable_scope
-local push_scope = graph.push_scope
-local pop_scope = graph.pop_scope
-local evaluate_node = graph.evaluate_node
-local destroy = graph.destroy
-
-type Map<K, V> = { [K]: V }
-
-local function check_primitives(t: {})
-    if not flags.strict then return end
-
-    for _, v in next, t do
-        if type(v) == "table" or type(v) == "userdata" or type(v) == "function" then continue end
-        error("table source map cannot return primitives", 0)
-    end
-end
-
-local function indexes<K, VI, VO>(input: () -> Map<K, VI>, transform: (() -> VI, K) -> VO): () -> { VO }
-    local owner = assert_stable_scope()
-    local subowner = create_node(owner, false, false)
-
-    local input_cache = {} :: Map<K, VI>
-    local output_cache = {} :: Map<K, VO>
-    local input_nodes = {} :: Map<K, SourceNode<VI>>
-    local remove_queue = {} :: { K }
-    local scopes = {} :: Map<K, Node<unknown>>
-
-    local function update_children(data)
-        -- queue removed values
-        for i in next, input_cache do
-            if data[i] == nil then
-                table.insert(remove_queue, i)
-            end
-        end
-
-        -- remove queued values
-        for _, i in next, remove_queue do
-            destroy(scopes[i])
-
-            input_cache[i] = nil
-            output_cache[i] = nil
-            input_nodes[i] = nil
-            scopes[i] = nil
-        end
-
-        table.clear(remove_queue)
-
-        push_scope(subowner)
-
-        -- process new or changed values
-        for i, v in next, data do
-            local cv = input_cache[i]
-
-            if cv ~= v then
-                input_cache[i] = v
-
-                if cv == nil then -- create new scope and run transform
-                    local scope = create_node(subowner, false, false)
-                    scopes[i] = scope :: Node<any>
-
-                    local node = create_source_node(v)
-
-                    push_scope(scope)
-
-                    local ok, result = xpcall(transform, debug.traceback, function()
-                        push_child_to_scope(node)
-                        return node.cache
-                    end, i)
-                    
-                    pop_scope()
-
-                    if not ok then
-                        pop_scope() -- subowner scope
-                        error(result, 0)
-                    end
-                    
-                    input_nodes[i] = node
-                    output_cache[i] = result
-                else -- update source
-                    input_nodes[i].cache = v
-                    update_descendants(input_nodes[i])
-                end
-            end
-        end
-
-        pop_scope()
-
-        local output_array = table.create(#scopes)
-        for _, v in next, output_cache do
-            table.insert(output_array, v)
-        end
-        check_primitives(output_array)
-        
-        return output_array
-    end
-
-    local node = create_node(owner, function()
-        return update_children(input())
-    end, false :: any)
-
-    evaluate_node(node)
-
-    return function()
-        push_child_to_scope(node)
-        return node.cache
-    end
-end
-
-local function values<K, VI, VO>(input: () -> Map<K, VI>, transform: (VI, () -> K) -> VO): () -> { VO }
-    local owner  = assert_stable_scope()
-    local subowner = create_node(owner, false, false)
-    
-    local cur_input_cache_up = {} :: Map<VI, K>
-    local new_input_cache_up = {} :: Map<VI, K>
-    local output_cache = {} :: Map<VI, VO>
-    local input_nodes = {} :: Map<VI, SourceNode<K>>
-    local scopes = {} :: Map<VI, Node<unknown>>
-
-    local function update_children(data: Map<K, VI>)
-        local cur_input_cache, new_input_cache = cur_input_cache_up, new_input_cache_up
-
-        if flags.strict then
-            local cache = {}
-            for _, v in next, data do
-                if cache[v] ~= nil then
-                    error "duplicate table value detected"
-                end
-                cache[v] = true
-            end
-        end
-
-        push_scope(subowner)
-    
-        -- process data
-        for i, v in next, data do
-            new_input_cache[v] = i
-
-            local cv = cur_input_cache[v]
-            
-            if cv == nil then -- create new scope and run transform
-                local scope = create_node(subowner, false, false)
-                scopes[v] = scope :: Node<any>
-
-                local node = create_source_node(i)
-    
-                push_scope(scope)
-                
-                local ok, result = xpcall(transform, debug.traceback, v, function()
-                    push_child_to_scope(node)
-                    return node.cache
-                end)
-                
-                pop_scope()
-
-                if not ok then
-                    pop_scope() -- subowner scope
-                    error(result, 0)
-                end
-
-                input_nodes[v] = node
-                output_cache[v] = result
-            else -- update source
-                if cv ~= i then
-                    input_nodes[v].cache = i
-                    update_descendants(input_nodes[v])
-                end
-
-                cur_input_cache[v] = nil
-            end
-        end
-
-        pop_scope()
-
-        -- remove old values
-        for v in next, cur_input_cache do
-            destroy(scopes[v])
-
-            output_cache[v] = nil
-            input_nodes[v] = nil
-            scopes[v] = nil
-        end
-
-        -- update buffer cache
-        table.clear(cur_input_cache)
-        cur_input_cache_up, new_input_cache_up = new_input_cache, cur_input_cache
-
-        local output_array = table.create(#scopes)
-        for _, v in next, output_cache do
-            table.insert(output_array, v)
-        end
-        check_primitives(output_array)
-
-        return output_array
-    end
-
-    local node = create_node(owner, function()
-        return update_children(input())
-    end, false :: any)
-
-    evaluate_node(node)
-
-    return function()
-        push_child_to_scope(node)
-        return node.cache
-    end
-end
-
-return function() return indexes, values end

src/source.luau

@@ -1,7 +1,7 @@
 local graph = require "./graph"
 type Node<T> = graph.Node<T>
 local create_source_node = graph.create_source_node
-local push_child_to_scope = graph.push_child_to_scope
+local push_scope_as_child_of = graph.push_scope_as_child_of
 local update_descendants = graph.update_descendants
 
 export type Source<T> = (() -> T) & ((value: T) -> T)
@@ -11,7 +11,7 @@ local function source<T>(initial_value: T): Source<T>
 
     local function update_source(...): T
         if select("#", ...) == 0 then -- no args were given
-            push_child_to_scope(node)
+            push_scope_as_child_of(node)
             return node.cache
         end
 

src/spring.luau

@@ -6,7 +6,7 @@ local create_source_node = graph.create_source_node
 local assert_stable_scope = graph.assert_stable_scope
 local evaluate_node = graph.evaluate_node
 local update_descendants = graph.update_descendants
-local push_child_to_scope = graph.push_child_to_scope
+local push_scope_as_child_of = graph.push_scope_as_child_of
 
 local UPDATE_RATE = 120
 local TOLERANCE = 0.001
@@ -202,7 +202,7 @@ local function spring<T>(source: () -> T, period: number?, damping_ratio: number
 
     return function(...)
         if select("#", ...) == 0 then -- no args were given
-            push_child_to_scope(output)
+            push_scope_as_child_of(output)
             return output.cache
         end
 

src/switch.luau

@@ -3,7 +3,7 @@ type Node<T> = graph.Node<T>
 type SourceNode<T> = graph.SourceNode<T>
 local create_node = graph.create_node
 local evaluate_node = graph.evaluate_node
-local push_child_to_scope = graph.push_child_to_scope
+local push_scope_as_child_of = graph.push_scope_as_child_of
 local destroy = graph.destroy
 local assert_stable_scope = graph.assert_stable_scope
 local push_scope = graph.push_scope
@@ -53,7 +53,7 @@ local function switch<T, U>(source: () -> T): (map: Map<T, ((() -> U)?)>) -> ()
         evaluate_node(node)
 
         return function()
-            push_child_to_scope(node)
+            push_scope_as_child_of(node)
             return node.cache
         end
     end

src/timeout.luau

@@ -0,0 +1,27 @@
+local queue = {} :: {
+    { t: number, fn: () -> (), cancel: boolean }
+}
+
+local function timeout(t: number, fn: () -> ())
+    local handle = { t = t, fn = fn, cancel = false }
+    table.insert(queue, handle)
+    return handle
+end
+
+local function update_timeouts(dt: number)
+    for i = #queue, 1, -1 do
+        local handle = queue[i]
+        handle.t -= dt
+        
+        if handle.cancel or handle.t <= 0 then
+            queue[i] = queue[#queue]
+            queue[#queue] = nil
+
+            if not handle.cancel then
+                handle.fn()
+            end
+        end
+    end
+end
+
+return function() return timeout, update_timeouts end

src/values.luau

@@ -0,0 +1,143 @@
+local flags = require "./flags"
+local graph = require "./graph"
+type Node<T> = graph.Node<T>
+type SourceNode<T> = graph.SourceNode<T>
+local create_node = graph.create_node
+local create_source_node = graph.create_source_node
+local push_scope_as_child_of = graph.push_scope_as_child_of
+local update_descendants = graph.update_descendants
+local assert_stable_scope = graph.assert_stable_scope
+local push_scope = graph.push_scope
+local pop_scope = graph.pop_scope
+local evaluate_node = graph.evaluate_node
+local destroy = graph.destroy
+
+type Map<K, V> = { [K]: V }
+
+local function check_primitives(t: {})
+    if not flags.strict then return end
+
+    for _, v in t do
+        if type(v) == "table" or type(v) == "userdata" or type(v) == "function" then continue end
+        error("table source map cannot return primitives", 0)
+    end
+end
+
+local function values<K, VI, VO>(input: () -> Map<K, VI>, transform: (VI, () -> K) -> VO, delay: number?): () -> { VO }
+    local owner  = assert_stable_scope()
+    local subowner = create_node(owner, false, false)
+    
+    local update_count = 0
+
+    local caches = {} :: Map<VI, {
+        count: number,
+        index: K,
+        scope: Node<unknown>,
+        index_source: SourceNode<K>,
+        alive_source: SourceNode<boolean>,
+        result: VO,
+    }>
+
+    local function update_children(data: Map<K, VI>)
+        local count = update_count
+        update_count += 1
+
+        local children_need_update = false
+
+        if flags.strict then
+            local cache = {}
+            for _, v in data do
+                if cache[v] ~= nil then
+                    error "duplicate table value detected"
+                end
+                cache[v] = true
+            end
+        end
+
+        push_scope(subowner)
+    
+        -- process data
+        for i, v in data do
+            local cache = caches[v]
+
+            if cache == nil then -- create new scope and run transform
+                local scope = create_node(subowner, false, false)
+                local index_source = create_source_node(i)
+
+                local new_cache = {
+                    count = count,
+                    index = i,
+                    scope = scope :: Node<unknown>,
+                    index_source = index_source :: SourceNode<K>,
+                    alive_source = nil :: any,
+                    result = false :: any,
+                }
+                -- must be set before transform is run so that the scope can
+                -- be destroyed if the transform itself updates the input
+                -- which lets the strict active scope destruction check work
+                caches[v] = new_cache
+    
+                push_scope(scope)
+                
+                local ok, result = xpcall(transform, debug.traceback, v, function()
+                    push_scope_as_child_of(index_source)
+                    return index_source.cache
+                end)
+                
+                pop_scope()
+
+                if not ok then
+                    pop_scope() -- subowner scope
+                    error(result, 0)
+                end
+
+                new_cache.result = result
+                children_need_update = true
+            else -- update source
+                cache.count = count
+
+                if cache.index ~= i then
+                    cache.index = i
+                    cache.index_source.cache = i
+                    update_descendants(cache.index_source)
+                end
+            end
+        end
+
+        pop_scope()
+
+        -- remove old values
+        for v, cache in caches do
+            if cache.count < count then
+                destroy(cache.scope)
+                caches[v] = nil
+                children_need_update = true
+            end
+        end
+
+        if children_need_update then
+            local output_array = table.create(#data)
+            for _, cache in caches do
+                table.insert(output_array, cache.result)
+            end
+            check_primitives(output_array)
+
+            return output_array
+        else
+            return nil
+        end
+    end
+
+    local node = create_node(owner, function(pre_children) -- todo: add test
+        return update_children(input()) or pre_children
+    end, {})
+
+    evaluate_node(node)
+
+    return function()
+        push_scope_as_child_of(node)
+        return node.cache
+    end
+end
+
+return values

test/tests.luau

@@ -35,7 +35,7 @@ vide.strict = false
 
 TEST("graph", function()
     local create_node = graph.create_node
-    local push_child_to_scope = graph.push_child_to_scope
+    local push_scope_as_child_of = graph.push_scope_as_child_of
     local update_descendants = graph.update_descendants
     local push_child = graph.push_child
     local get_scope = graph.get_scope
@@ -65,8 +65,8 @@ TEST("graph", function()
 
         push_scope(c)
 
-        push_child_to_scope(a)
-        push_child_to_scope(b)
+        push_scope_as_child_of(a)
+        push_scope_as_child_of(b)
 
         pop_scope()
 
@@ -83,8 +83,8 @@ TEST("graph", function()
         local count = 0
 
         local function effect(x)
-            push_child_to_scope(a)
-            push_child_to_scope(b)
+            push_scope_as_child_of(a)
+            push_scope_as_child_of(b)
             count += 1
             return not x
         end
@@ -115,9 +115,9 @@ TEST("graph", function()
         function c.effect(x) c_cnt += 1; return not x end
         function d.effect(x) d_cnt += 1; return not x end
 
-        push_scope(b); push_child_to_scope(a); pop_scope()
-        push_scope(c); push_child_to_scope(a); pop_scope()
-        push_scope(d); push_child_to_scope(b); push_child_to_scope(c); pop_scope()
+        push_scope(b); push_scope_as_child_of(a); pop_scope()
+        push_scope(c); push_scope_as_child_of(a); pop_scope()
+        push_scope(d); push_scope_as_child_of(b); push_scope_as_child_of(c); pop_scope()
 
         update_descendants(a)
 
@@ -131,8 +131,8 @@ TEST("graph", function()
         local a, b, c = node(root), node(root), node(root)
 
         function c.effect(x)
-            push_child_to_scope(a)
-            push_child_to_scope(b)
+            push_scope_as_child_of(a)
+            push_scope_as_child_of(b)
             return not x
         end
 
@@ -171,10 +171,10 @@ TEST("graph", function()
         do push_scope(root) 
             clean "root"
             items_updated = node(root)
-            push_child_to_scope(items_updated) -- should not
+            push_scope_as_child_of(items_updated) -- should not
 
             do push_scope(items_updated)
-                push_child_to_scope(items)
+                push_scope_as_child_of(items)
 
                 do push_scope(root)
                     do push_scope(scope1)
@@ -183,7 +183,7 @@ TEST("graph", function()
 
                         do push_scope(bind1)
                             clean "bind1"
-                            push_child_to_scope(selected)
+                            push_scope_as_child_of(selected)
                         pop_scope() end
                     pop_scope() end
 
@@ -192,7 +192,7 @@ TEST("graph", function()
                         bind2 = node(scope2)
                         do push_scope(bind2)
                             clean "bind2"
-                            push_child_to_scope(selected)
+                            push_scope_as_child_of(selected)
                         pop_scope() end
                     pop_scope() end
                 pop_scope() end
@@ -2345,7 +2345,7 @@ TEST("read()", wrap_root(function()
         CHECK(read(src) == 1)
     end
 
-    do CASE "push_child_to_scope source"
+    do CASE "push_scope_as_child_of source"
         local src = source(0)
 
         local count = 0
@@ -2750,16 +2750,6 @@ TEST("strict", wrap_root(function()
         CHECK(count == 4)
     end
 
-    do CASE "indexes() error if primitive"
-        local src = source { 1 }
-
-        local ok = pcall(function()
-            indexes(src, function() return 1 end)
-        end)
-
-        CHECK(not ok)
-    end
-
     do CASE "values() error if duplicate"
         local src = source { 1, 2, 1 }