diff --git a/data-util.lua b/data-util.lua
index 37f09b8..630f4ee 100644
--- a/data-util.lua
+++ b/data-util.lua
@@ -111,11 +111,16 @@ function util.add_effect(technology_name, effect)
   end
 end
 
+-- Add an effect to a given technology to unlock recipe
+function util.add_unlock(technology_name, recipe)
+  util.add_effect(technology_name, {type="unlock-recipe", recipe=recipe})
+end
+
 -- remove recipe unlock effect from a given technology
 function util.remove_recipe_effect(technology_name, recipe_name)
   local technology = data.raw.technology[technology_name]
   local index = -1
-  if technology then
+  if technology and technology.effects then
     for i, effect in pairs(technology.effects) do
       if effect.type == "unlock-recipe" and effect.recipe == recipe_name then
         index = i
@@ -144,6 +149,14 @@ function util.set_enabled(recipe_name, enabled)
   end
 end
 
+function util.set_hidden(recipe_name)
+  if data.raw.recipe[recipe_name] then
+    if data.raw.recipe[recipe_name].normal then data.raw.recipe[recipe_name].normal.hidden = true end
+    if data.raw.recipe[recipe_name].expensive then data.raw.recipe[recipe_name].expensive.hidden = true end
+    if not data.raw.recipe[recipe_name].normal then data.raw.recipe[recipe_name].hidden = true end
+  end
+end
+
 -- Add a given quantity of ingredient to a given recipe
 function util.add_or_add_to_ingredient(recipe_name, ingredient, quantity)
   if me.bypass[recipe_name] then return end
@@ -269,6 +282,29 @@ function add_product(recipe, product)
   end
 end
 
+function util.replace_ingredient_add_to(recipe_name, old, new)
+  if me.bypass[recipe_name] then return end
+  if data.raw.recipe[recipe_name] and (data.raw.item[new] or data.raw.fluid[new]) then
+    me.add_modified(recipe_name)
+    replace_ingredient_add_to(data.raw.recipe[recipe_name], old, new)
+    replace_ingredient_add_to(data.raw.recipe[recipe_name].normal, old, new)
+    replace_ingredient_add_to(data.raw.recipe[recipe_name].expensive, old, new)
+  end
+end
+
+function replace_ingredient_add_to(recipe, old, new)
+	if recipe ~= nil and recipe.ingredients ~= nil then
+    for i, existing in pairs(recipe.ingredients) do
+      if existing[1] == new or existing.name == new then
+        add_to_ingredient(recipe, new, existing[2] and existing[2] or existing.amount)
+        remove_ingredient(recipe, old)
+        return
+      end
+    end
+    replace_ingredient(recipe, old, new)
+	end
+end
+
 -- Replace one ingredient with another in a recipe
 function util.replace_ingredient(recipe_name, old, new, amount)
   if me.bypass[recipe_name] then return end