Merge reactive scope refactor

src/root.luau

@@ -0,0 +1,38 @@
+if not game then script = require "test/relative-string" end
+
+local throw = require(script.Parent.throw)
+local graph = require(script.Parent.graph)
+type Node<T> = graph.Node<T>
+local create_node = graph.create_node
+local open_scope = graph.open_scope
+local close_scope = graph.close_scope
+local destroy = graph.destroy
+
+local refs = {}
+
+local function root<T...>(fn: (destroy: () -> ()) -> T...): T...
+    local node = create_node(false, false)
+
+    refs[node] = true -- prevent gc of root node
+
+    local destroy = function()
+        if not refs[node] then throw "root already destroyed" end
+        refs[node] = nil
+        destroy(node)
+    end
+
+    open_scope(node)
+
+    local result = { pcall(fn, destroy) }
+
+    close_scope()
+
+    if not result[1] then
+        refs[node] = nil
+        throw(`mount error\n{result}`)
+    end
+
+    return unpack(result :: any, 2)
+end
+
+return root :: (<T...>(fn: (destroy: () -> ()) -> T...) -> T...) & ((fn: (destroy: () -> ()) -> ()) -> ())