From 905a1117e1850c678ef900d41a34b0cf76104e06 Mon Sep 17 00:00:00 2001
From: Sabine Lim <thesabinelim@gmail.com>
Date: Sun, 14 May 2023 03:18:39 +1000
Subject: [PATCH] Derived

---
 Basalt/plugins/xml.lua | 14 +++++++++++---
 1 file changed, 11 insertions(+), 3 deletions(-)

diff --git a/Basalt/plugins/xml.lua b/Basalt/plugins/xml.lua
index fd77bfd..8d35d2a 100644
--- a/Basalt/plugins/xml.lua
+++ b/Basalt/plugins/xml.lua
@@ -167,6 +167,8 @@ local function registerFunctionEvent(self, data, event, renderContext)
     end
 end
 
+local effectStack = {}
+
 local clearEffectDependencies = function(effect)
     for _, dependency in ipairs(effect.dependencies) do
         for index, backlink in ipairs(dependency) do
@@ -178,10 +180,8 @@ local clearEffectDependencies = function(effect)
     effect.dependencies = {};
 end
 
-local effectStack = {}
-
 return {
-    basalt = function()
+    basalt = function(basalt)
         local object = {
             reactive = function(initialValue)
                 local value = initialValue
@@ -217,6 +217,14 @@ return {
                 end
                 effect.execute = execute
                 effect.execute()
+            end,
+
+            derived = function(computeFn)
+                local getValue, setValue = basalt.reactive();
+                basalt.effect(function()
+                    setValue(computeFn())
+                end)
+                return getValue;
             end
         }
         return object