From 30e3e129c8a619c7240e2e9320e10ad7f3e91bc3 Mon Sep 17 00:00:00 2001
From: Vexatos <Stuarzt@gmx.de>
Date: Sat, 22 Apr 2017 20:16:34 +0200
Subject: [PATCH] I don't trust ItemStack Options. Let's get rid of them.

---
 .../oc/client/gui/DynamicGuiContainer.scala   |  7 +-
 .../scala/li/cil/oc/common/Achievement.scala  | 13 +--
 .../scala/li/cil/oc/common/EventHandler.scala | 15 +--
 .../cil/oc/common/block/Microcontroller.scala |  3 +-
 .../container/DynamicComponentSlot.scala      |  3 +-
 .../cil/oc/common/inventory/Inventory.scala   |  3 +-
 .../provider/DisintegrationProvider.scala     | 12 ++-
 .../cil/oc/common/recipe/ColorizeRecipe.scala |  9 +-
 .../oc/common/recipe/DecolorizeRecipe.scala   |  9 +-
 .../common/recipe/LootDiskCyclingRecipe.scala |  5 +-
 .../cil/oc/common/tileentity/Assembler.scala  | 18 ++--
 .../common/tileentity/Microcontroller.scala   |  8 +-
 .../li/cil/oc/common/tileentity/Printer.scala | 12 ++-
 .../traits/ComponentInventory.scala           | 34 ++++---
 .../jei/ModPluginOpenComputers.scala          |  5 +-
 .../cil/oc/integration/util/ItemSearch.scala  | 11 ++-
 .../li/cil/oc/server/component/Robot.scala    |  6 +-
 .../oc/server/component/UpgradeDatabase.scala |  3 +-
 .../server/component/UpgradeGenerator.scala   | 28 +++---
 .../component/traits/InventoryAnalytics.scala |  5 +-
 .../component/traits/InventoryAware.scala     |  3 +-
 .../component/traits/InventoryControl.scala   | 13 +--
 .../traits/InventoryWorldControl.scala        |  3 +-
 .../traits/WorldInventoryAnalytics.scala      |  5 +-
 .../scala/li/cil/oc/util/InventoryUtils.scala |  9 +-
 .../scala/li/cil/oc/util/StackOption.scala    | 97 +++++++++++++++++++
 26 files changed, 234 insertions(+), 105 deletions(-)
 create mode 100644 src/main/scala/li/cil/oc/util/StackOption.scala

diff --git a/src/main/scala/li/cil/oc/client/gui/DynamicGuiContainer.scala b/src/main/scala/li/cil/oc/client/gui/DynamicGuiContainer.scala
index 90ee35b77..c6d88b14f 100644
--- a/src/main/scala/li/cil/oc/client/gui/DynamicGuiContainer.scala
+++ b/src/main/scala/li/cil/oc/client/gui/DynamicGuiContainer.scala
@@ -9,13 +9,14 @@ import li.cil.oc.integration.Mods
 import li.cil.oc.integration.jei.ModJEI
 import li.cil.oc.integration.util.ItemSearch
 import li.cil.oc.util.RenderState
+import li.cil.oc.util.StackOption
+import li.cil.oc.util.StackOption._
 import net.minecraft.client.gui.Gui
 import net.minecraft.client.renderer.GlStateManager
 import net.minecraft.client.renderer.Tessellator
 import net.minecraft.client.renderer.vertex.DefaultVertexFormats
 import net.minecraft.inventory.Container
 import net.minecraft.inventory.Slot
-import net.minecraft.item.ItemStack
 import net.minecraftforge.fml.common.Optional
 import org.lwjgl.opengl.GL11
 
@@ -25,7 +26,7 @@ import scala.collection.convert.WrapAsScala._
 abstract class DynamicGuiContainer[C <: Container](container: C) extends CustomGuiContainer(container) {
   protected var hoveredSlot: Option[Slot] = None
 
-  protected var hoveredStackNEI: Option[ItemStack] = None
+  protected var hoveredStackNEI: StackOption = EmptyStack
 
   protected def drawSecondaryForegroundLayer(mouseX: Int, mouseY: Int) {
     fontRenderer.drawString(
@@ -127,7 +128,7 @@ abstract class DynamicGuiContainer[C <: Container](container: C) extends CustomG
               ((currentIsInPlayerInventory && slot.getHasStack && isSelectiveSlot(hovered) && hovered.isItemValid(slot.getStack)) ||
                 (hoveredIsInPlayerInventory && hovered.getHasStack && isSelectiveSlot(slot) && slot.isItemValid(hovered.getStack)))
           case _ => hoveredStackNEI match {
-            case Some(stack) => !currentIsInPlayerInventory && isSelectiveSlot(slot) && slot.isItemValid(stack)
+            case SomeStack(stack) => !currentIsInPlayerInventory && isSelectiveSlot(slot) && slot.isItemValid(stack)
             case _ => false
           }
         }
diff --git a/src/main/scala/li/cil/oc/common/Achievement.scala b/src/main/scala/li/cil/oc/common/Achievement.scala
index ce8649c6e..078e8f625 100644
--- a/src/main/scala/li/cil/oc/common/Achievement.scala
+++ b/src/main/scala/li/cil/oc/common/Achievement.scala
@@ -4,6 +4,7 @@ import li.cil.oc.Constants
 import li.cil.oc.OpenComputers
 import li.cil.oc.api.detail.ItemInfo
 import li.cil.oc.common.init.Items
+import li.cil.oc.util.StackOption
 import net.minecraft.entity.player.EntityPlayer
 import net.minecraft.item.ItemStack
 import net.minecraft.stats.StatBase
@@ -241,7 +242,7 @@ object Achievement {
   private class AchievementBuilder(val name: String) {
     var x = 0
     var y = 0
-    var stack: Option[ItemStack] = stackFromName(name)
+    var stack: StackOption = stackFromName(name)
     var parent: Option[MCAchievement] = None
     var crafting = mutable.Set.empty[String]
     var customCrafting = mutable.Set.empty[ItemStack]
@@ -254,7 +255,7 @@ object Achievement {
     }
 
     def withIconOf(stack: ItemStack): AchievementBuilder = {
-      this.stack = Option(stack)
+      this.stack = StackOption(stack)
       this
     }
 
@@ -271,7 +272,7 @@ object Achievement {
 
     def whenCrafting(stack: ItemStack): AchievementBuilder = {
       customCrafting += stack
-      if (this.stack.isEmpty) this.stack = Option(stack)
+      if (this.stack.isEmpty) this.stack = StackOption(stack)
       this
     }
 
@@ -282,7 +283,7 @@ object Achievement {
     }
 
     def add(): MCAchievement = {
-      val achievement = new MCAchievement("oc." + name, "oc." + name, x, y, stack.orNull, parent.orNull)
+      val achievement = new MCAchievement("oc." + name, "oc." + name, x, y, stack.orEmpty, parent.orNull)
 
       if (parent.isEmpty) {
         achievement.asInstanceOf[StatBase].initIndependentStat()
@@ -312,7 +313,7 @@ object Achievement {
       achievement
     }
 
-    private def stackFromName(name: String) = Option(Items.get(name)).map(_.createItemStack(1))
+    private def stackFromName(name: String): StackOption = StackOption(Option(Items.get(name)).map(_.createItemStack(1)))
   }
 
-}
\ No newline at end of file
+}
diff --git a/src/main/scala/li/cil/oc/common/EventHandler.scala b/src/main/scala/li/cil/oc/common/EventHandler.scala
index 8b0fba099..74ee667ac 100644
--- a/src/main/scala/li/cil/oc/common/EventHandler.scala
+++ b/src/main/scala/li/cil/oc/common/EventHandler.scala
@@ -33,6 +33,7 @@ import li.cil.oc.server.machine.Machine
 import li.cil.oc.server.machine.luac.LuaStateFactory
 import li.cil.oc.server.{PacketSender => ServerPacketSender}
 import li.cil.oc.util.ExtendedWorld._
+import li.cil.oc.util.StackOption._
 import li.cil.oc.util._
 import net.minecraft.entity.player.EntityPlayer
 import net.minecraft.entity.player.EntityPlayerMP
@@ -293,29 +294,29 @@ object EventHandler {
     didRecraft = recraft(e, navigationUpgrade, stack => {
       // Restore the map currently used in the upgrade.
       Option(api.Driver.driverFor(e.crafting)) match {
-        case Some(driver) => Option(new ItemStack(driver.dataTag(stack).getCompoundTag(Settings.namespace + "map")))
-        case _ => None
+        case Some(driver) => StackOption(new ItemStack(driver.dataTag(stack).getCompoundTag(Settings.namespace + "map")))
+        case _ => EmptyStack
       }
     }) || didRecraft
 
     didRecraft = recraft(e, mcu, stack => {
       // Restore EEPROM currently used in microcontroller.
-      new MicrocontrollerData(stack).components.find(api.Items.get(_) == eeprom)
+      new MicrocontrollerData(stack).components.find(api.Items.get(_) == eeprom).asStackOption
     }) || didRecraft
 
     didRecraft = recraft(e, drone, stack => {
       // Restore EEPROM currently used in drone.
-      new MicrocontrollerData(stack).components.find(api.Items.get(_) == eeprom)
+      new MicrocontrollerData(stack).components.find(api.Items.get(_) == eeprom).asStackOption
     }) || didRecraft
 
     didRecraft = recraft(e, robot, stack => {
       // Restore EEPROM currently used in robot.
-      new RobotData(stack).components.find(api.Items.get(_) == eeprom)
+      new RobotData(stack).components.find(api.Items.get(_) == eeprom).asStackOption
     }) || didRecraft
 
     didRecraft = recraft(e, tablet, stack => {
       // Restore EEPROM currently used in tablet.
-      new TabletData(stack).items.collect { case item if !item.isEmpty => item }.find(api.Items.get(_) == eeprom)
+      new TabletData(stack).items.collect { case item if !item.isEmpty => item }.find(api.Items.get(_) == eeprom).asStackOption
     }) || didRecraft
 
     // Presents?
@@ -367,7 +368,7 @@ object EventHandler {
     month == Calendar.APRIL && dayOfMonth == 1
   }
 
-  private def recraft(e: ItemCraftedEvent, item: ItemInfo, callback: ItemStack => Option[ItemStack]): Boolean = {
+  private def recraft(e: ItemCraftedEvent, item: ItemInfo, callback: ItemStack => StackOption): Boolean = {
     if (api.Items.get(e.crafting) == item) {
       for (slot <- 0 until e.craftMatrix.getSizeInventory) {
         val stack = e.craftMatrix.getStackInSlot(slot)
diff --git a/src/main/scala/li/cil/oc/common/block/Microcontroller.scala b/src/main/scala/li/cil/oc/common/block/Microcontroller.scala
index d7efa81ca..c81e2d7f9 100644
--- a/src/main/scala/li/cil/oc/common/block/Microcontroller.scala
+++ b/src/main/scala/li/cil/oc/common/block/Microcontroller.scala
@@ -14,6 +14,7 @@ import li.cil.oc.integration.util.ItemBlacklist
 import li.cil.oc.integration.util.Wrench
 import li.cil.oc.util.InventoryUtils
 import li.cil.oc.util.Rarity
+import li.cil.oc.util.StackOption._
 import net.minecraft.block.Block
 import net.minecraft.block.state.BlockStateContainer
 import net.minecraft.block.state.IBlockState
@@ -91,7 +92,7 @@ class Microcontroller(protected implicit val tileTag: ClassTag[tileentity.Microc
             case mcu: tileentity.Microcontroller =>
               val newEeprom = player.inventory.decrStackSize(player.inventory.currentItem, 1)
               mcu.changeEEPROM(newEeprom) match {
-                case Some(oldEeprom) => InventoryUtils.addToPlayerInventory(oldEeprom, player)
+                case SomeStack(oldEeprom) => InventoryUtils.addToPlayerInventory(oldEeprom, player)
                 case _ =>
               }
           }
diff --git a/src/main/scala/li/cil/oc/common/container/DynamicComponentSlot.scala b/src/main/scala/li/cil/oc/common/container/DynamicComponentSlot.scala
index 09f1a8277..612a0e5a7 100644
--- a/src/main/scala/li/cil/oc/common/container/DynamicComponentSlot.scala
+++ b/src/main/scala/li/cil/oc/common/container/DynamicComponentSlot.scala
@@ -7,6 +7,7 @@ import li.cil.oc.util.InventoryUtils
 import li.cil.oc.util.SideTracker
 import net.minecraft.entity.player.EntityPlayer
 import net.minecraft.inventory.IInventory
+import net.minecraft.item.ItemStack
 import net.minecraft.util.ResourceLocation
 
 class DynamicComponentSlot(val container: Player, inventory: IInventory, index: Int, x: Int, y: Int, val info: DynamicComponentSlot => InventorySlot, val containerTierGetter: () => Int) extends ComponentSlot(inventory, index, x, y) {
@@ -38,7 +39,7 @@ class DynamicComponentSlot(val container: Player, inventory: IInventory, index:
   override protected def clearIfInvalid(player: EntityPlayer) {
     if (SideTracker.isServer && getHasStack && !isItemValid(getStack)) {
       val stack = getStack
-      putStack(null)
+      putStack(ItemStack.EMPTY)
       InventoryUtils.addToPlayerInventory(stack, player)
     }
   }
diff --git a/src/main/scala/li/cil/oc/common/inventory/Inventory.scala b/src/main/scala/li/cil/oc/common/inventory/Inventory.scala
index ca25dda28..74fd0e8bd 100644
--- a/src/main/scala/li/cil/oc/common/inventory/Inventory.scala
+++ b/src/main/scala/li/cil/oc/common/inventory/Inventory.scala
@@ -2,6 +2,7 @@ package li.cil.oc.common.inventory
 
 import li.cil.oc.Settings
 import li.cil.oc.util.ExtendedNBT._
+import li.cil.oc.util.StackOption
 import net.minecraft.item.ItemStack
 import net.minecraft.nbt.NBTTagCompound
 import net.minecraftforge.common.util.Constants.NBT
@@ -9,7 +10,7 @@ import net.minecraftforge.common.util.Constants.NBT
 trait Inventory extends SimpleInventory {
   def items: Array[ItemStack]
 
-  def updateItems(slot: Int, stack: ItemStack): Unit = items(slot) = stack
+  def updateItems(slot: Int, stack: ItemStack): Unit = items(slot) = StackOption(stack).orEmpty
 
   // ----------------------------------------------------------------------- //
 
diff --git a/src/main/scala/li/cil/oc/common/nanomachines/provider/DisintegrationProvider.scala b/src/main/scala/li/cil/oc/common/nanomachines/provider/DisintegrationProvider.scala
index 775e0f0fb..f347c5826 100644
--- a/src/main/scala/li/cil/oc/common/nanomachines/provider/DisintegrationProvider.scala
+++ b/src/main/scala/li/cil/oc/common/nanomachines/provider/DisintegrationProvider.scala
@@ -6,6 +6,8 @@ import li.cil.oc.api.nanomachines.DisableReason
 import li.cil.oc.api.prefab.AbstractBehavior
 import li.cil.oc.util.BlockPosition
 import li.cil.oc.util.ExtendedWorld._
+import li.cil.oc.util.StackOption
+import li.cil.oc.util.StackOption._
 import net.minecraft.block.Block
 import net.minecraft.block.state.IBlockState
 import net.minecraft.entity.player.EntityPlayer
@@ -66,7 +68,7 @@ object DisintegrationProvider extends ScalaProvider("c4e7e3c2-8069-4fbb-b08e-74b
                   if (hardness > 0) {
                     val timeToBreak = (1 / hardness).toInt
                     if (timeToBreak < 20 * 30) {
-                      val info = new SlowBreakInfo(now, now + timeToBreak, pos, Option(player.getHeldItemMainhand).map(_.copy()), blockState)
+                      val info = new SlowBreakInfo(now, now + timeToBreak, pos, StackOption(player.getHeldItemMainhand).map(_.copy()), blockState)
                       world.destroyBlockInWorldPartially(pos.hashCode(), pos, 0)
                       breakingMapNew += pos -> info
                     }
@@ -98,14 +100,14 @@ object DisintegrationProvider extends ScalaProvider("c4e7e3c2-8069-4fbb-b08e-74b
     }
   }
 
-  class SlowBreakInfo(val timeStarted: Long, val timeBroken: Long, val pos: BlockPosition, val originalTool: Option[ItemStack], val blockState: IBlockState) {
+  class SlowBreakInfo(val timeStarted: Long, val timeBroken: Long, val pos: BlockPosition, val originalTool: StackOption, val blockState: IBlockState) {
     var lastDamageSent = 0
 
     def checkTool(player: EntityPlayer): Boolean = {
-      val currentTool = Option(player.getHeldItemMainhand).map(_.copy())
+      val currentTool = StackOption(player.getHeldItemMainhand).map(_.copy())
       (currentTool, originalTool) match {
-        case (Some(stackA), Some(stackB)) => stackA.getItem == stackB.getItem && (stackA.isItemStackDamageable || stackA.getItemDamage == stackB.getItemDamage)
-        case (None, None) => true
+        case (SomeStack(stackA), SomeStack(stackB)) => stackA.getItem == stackB.getItem && (stackA.isItemStackDamageable || stackA.getItemDamage == stackB.getItemDamage)
+        case (EmptyStack, EmptyStack) => true
         case _ => false
       }
     }
diff --git a/src/main/scala/li/cil/oc/common/recipe/ColorizeRecipe.scala b/src/main/scala/li/cil/oc/common/recipe/ColorizeRecipe.scala
index 9105a9e8c..16701c544 100644
--- a/src/main/scala/li/cil/oc/common/recipe/ColorizeRecipe.scala
+++ b/src/main/scala/li/cil/oc/common/recipe/ColorizeRecipe.scala
@@ -2,6 +2,7 @@ package li.cil.oc.common.recipe
 
 import li.cil.oc.util.Color
 import li.cil.oc.util.ItemColorizer
+import li.cil.oc.util.StackOption
 import net.minecraft.block.Block
 import net.minecraft.entity.passive.EntitySheep
 import net.minecraft.inventory.InventoryCrafting
@@ -20,9 +21,9 @@ class ColorizeRecipe(target: Item, source: Array[Item] = null) extends Container
   val sourceItems: Array[Item] = if (source != null) source else Array(targetItem)
 
   override def matches(crafting: InventoryCrafting, world: World): Boolean = {
-    val stacks = (0 until crafting.getSizeInventory).flatMap(i => Option(crafting.getStackInSlot(i)))
+    val stacks = (0 until crafting.getSizeInventory).flatMap(i => StackOption(crafting.getStackInSlot(i)))
     val targets = stacks.filter(stack => sourceItems.contains(stack.getItem) || stack.getItem == targetItem)
-    val other = stacks.filterNot(stack => stack.isEmpty || targets.contains(stack))
+    val other = stacks.filterNot(targets.contains(_))
     targets.size == 1 && other.nonEmpty && other.forall(Color.isDye)
   }
 
@@ -32,12 +33,12 @@ class ColorizeRecipe(target: Item, source: Array[Item] = null) extends Container
     var colorCount = 0
     var maximum = 0
 
-    (0 until crafting.getSizeInventory).flatMap(i => Option(crafting.getStackInSlot(i))).foreach { stack =>
+    (0 until crafting.getSizeInventory).flatMap(i => StackOption(crafting.getStackInSlot(i))).foreach { stack =>
       if (sourceItems.contains(stack.getItem)
         || stack.getItem == targetItem) {
         targetStack = stack.copy()
         targetStack.setCount(1)
-      } else if(!stack.isEmpty) {
+      } else {
         val dye = Color.findDye(stack)
         if (dye.isEmpty)
           return ItemStack.EMPTY
diff --git a/src/main/scala/li/cil/oc/common/recipe/DecolorizeRecipe.scala b/src/main/scala/li/cil/oc/common/recipe/DecolorizeRecipe.scala
index b067f1b5e..8f28eaeab 100644
--- a/src/main/scala/li/cil/oc/common/recipe/DecolorizeRecipe.scala
+++ b/src/main/scala/li/cil/oc/common/recipe/DecolorizeRecipe.scala
@@ -1,6 +1,7 @@
 package li.cil.oc.common.recipe
 
 import li.cil.oc.util.ItemColorizer
+import li.cil.oc.util.StackOption
 import net.minecraft.block.Block
 import net.minecraft.init.Items
 import net.minecraft.inventory.InventoryCrafting
@@ -17,20 +18,20 @@ class DecolorizeRecipe(target: Item) extends ContainerItemAwareRecipe {
   val targetItem: Item = target
 
   override def matches(crafting: InventoryCrafting, world: World): Boolean = {
-    val stacks = (0 until crafting.getSizeInventory).flatMap(i => Option(crafting.getStackInSlot(i)))
+    val stacks = (0 until crafting.getSizeInventory).flatMap(i => StackOption(crafting.getStackInSlot(i)))
     val targets = stacks.filter(stack => stack.getItem == targetItem)
-    val other = stacks.filterNot(stack => stack.isEmpty || targets.contains(stack))
+    val other = stacks.filterNot(targets.contains)
     targets.size == 1 && other.size == 1 && other.forall(_.getItem == Items.WATER_BUCKET)
   }
 
   override def getCraftingResult(crafting: InventoryCrafting): ItemStack = {
     var targetStack: ItemStack = ItemStack.EMPTY
 
-    (0 until crafting.getSizeInventory).flatMap(i => Option(crafting.getStackInSlot(i))).foreach { stack =>
+    (0 until crafting.getSizeInventory).flatMap(i => StackOption(crafting.getStackInSlot(i))).foreach { stack =>
       if (stack.getItem == targetItem) {
         targetStack = stack.copy()
         targetStack.setCount(1)
-      } else if (!stack.isEmpty && stack.getItem != Items.WATER_BUCKET) {
+      } else if (stack.getItem != Items.WATER_BUCKET) {
         return ItemStack.EMPTY
       }
     }
diff --git a/src/main/scala/li/cil/oc/common/recipe/LootDiskCyclingRecipe.scala b/src/main/scala/li/cil/oc/common/recipe/LootDiskCyclingRecipe.scala
index 7922ff44b..2712e3081 100644
--- a/src/main/scala/li/cil/oc/common/recipe/LootDiskCyclingRecipe.scala
+++ b/src/main/scala/li/cil/oc/common/recipe/LootDiskCyclingRecipe.scala
@@ -3,6 +3,7 @@ package li.cil.oc.common.recipe
 import li.cil.oc.Settings
 import li.cil.oc.common.Loot
 import li.cil.oc.integration.util.Wrench
+import li.cil.oc.util.StackOption
 import net.minecraft.inventory.InventoryCrafting
 import net.minecraft.item.ItemStack
 import net.minecraft.item.crafting.IRecipe
@@ -14,7 +15,7 @@ import scala.collection.immutable
 class LootDiskCyclingRecipe extends IRecipe {
   override def matches(crafting: InventoryCrafting, world: World): Boolean = {
     val stacks = collectStacks(crafting).toArray
-    stacks.count(!_.isEmpty) == 2 && stacks.exists(Loot.isLootDisk) && stacks.exists(Wrench.isWrench)
+    stacks.length == 2 && stacks.exists(Loot.isLootDisk) && stacks.exists(Wrench.isWrench)
   }
 
   override def getCraftingResult(crafting: InventoryCrafting): ItemStack = {
@@ -31,7 +32,7 @@ class LootDiskCyclingRecipe extends IRecipe {
 
   def getLootFactoryName(stack: ItemStack): String = stack.getTagCompound.getString(Settings.namespace + "lootFactory")
 
-  def collectStacks(crafting: InventoryCrafting): immutable.IndexedSeq[ItemStack] = (0 until crafting.getSizeInventory).flatMap(i => Option(crafting.getStackInSlot(i)))
+  def collectStacks(crafting: InventoryCrafting): immutable.IndexedSeq[ItemStack] = (0 until crafting.getSizeInventory).flatMap(i => StackOption(crafting.getStackInSlot(i)))
 
   override def getRecipeSize: Int = 2
 
diff --git a/src/main/scala/li/cil/oc/common/tileentity/Assembler.scala b/src/main/scala/li/cil/oc/common/tileentity/Assembler.scala
index 69da1b082..c65c8a164 100644
--- a/src/main/scala/li/cil/oc/common/tileentity/Assembler.scala
+++ b/src/main/scala/li/cil/oc/common/tileentity/Assembler.scala
@@ -15,6 +15,8 @@ import li.cil.oc.api.network._
 import li.cil.oc.common.template.AssemblerTemplates
 import li.cil.oc.server.{PacketSender => ServerPacketSender}
 import li.cil.oc.util.ExtendedNBT._
+import li.cil.oc.util.StackOption
+import li.cil.oc.util.StackOption._
 import net.minecraft.item.ItemStack
 import net.minecraft.nbt.NBTTagCompound
 import net.minecraft.util.EnumFacing
@@ -29,7 +31,7 @@ class Assembler extends traits.Environment with traits.PowerAcceptor with traits
     withConnector(Settings.get.bufferConverter).
     create()
 
-  var output: Option[ItemStack] = None
+  var output: StackOption = EmptyStack
 
   var totalRequiredEnergy = 0.0
 
@@ -87,7 +89,7 @@ class Assembler extends traits.Environment with traits.PowerAcceptor with traits
           if (!stack.isEmpty && !isItemValidForSlot(slot, stack)) return false
         }
         val (stack, energy) = template.assemble(this)
-        output = Some(stack)
+        output = StackOption(stack)
         if (finishImmediately) {
           totalRequiredEnergy = 0
         }
@@ -123,16 +125,16 @@ class Assembler extends traits.Environment with traits.PowerAcceptor with traits
 
   override def updateEntity() {
     super.updateEntity()
-    if (output.isDefined && getWorld.getTotalWorldTime % Settings.get.tickFrequency == 0) {
+    if (!output.isEmpty && getWorld.getTotalWorldTime % Settings.get.tickFrequency == 0) {
       val want = math.max(1, math.min(requiredEnergy, Settings.get.assemblerTickAmount * Settings.get.tickFrequency))
       val have = want + (if (Settings.get.ignorePower) 0 else node.changeBuffer(-want))
       requiredEnergy -= have
       if (requiredEnergy <= 0) {
         setInventorySlotContents(0, output.get)
-        output = None
+        output = EmptyStack
         requiredEnergy = 0
       }
-      ServerPacketSender.sendRobotAssembling(this, have > 0.5 && output.isDefined)
+      ServerPacketSender.sendRobotAssembling(this, have > 0.5 && !output.isEmpty)
     }
   }
 
@@ -146,10 +148,10 @@ class Assembler extends traits.Environment with traits.PowerAcceptor with traits
   override def readFromNBTForServer(nbt: NBTTagCompound) {
     super.readFromNBTForServer(nbt)
     if (nbt.hasKey(OutputTag)) {
-      output = Option(new ItemStack(nbt.getCompoundTag(OutputTag)))
+      output = StackOption(new ItemStack(nbt.getCompoundTag(OutputTag)))
     }
     else if (nbt.hasKey(OutputTagCompat)) {
-      output = Option(new ItemStack(nbt.getCompoundTag(OutputTagCompat)))
+      output = StackOption(new ItemStack(nbt.getCompoundTag(OutputTagCompat)))
     }
     totalRequiredEnergy = nbt.getDouble(TotalTag)
     requiredEnergy = nbt.getDouble(RemainingTag)
@@ -157,7 +159,7 @@ class Assembler extends traits.Environment with traits.PowerAcceptor with traits
 
   override def writeToNBTForServer(nbt: NBTTagCompound) {
     super.writeToNBTForServer(nbt)
-    output.foreach(stack => nbt.setNewCompoundTag(OutputTag, stack.writeToNBT))
+    nbt.setNewCompoundTag(OutputTag, output.get.writeToNBT)
     nbt.setDouble(TotalTag, totalRequiredEnergy)
     nbt.setDouble(RemainingTag, requiredEnergy)
   }
diff --git a/src/main/scala/li/cil/oc/common/tileentity/Microcontroller.scala b/src/main/scala/li/cil/oc/common/tileentity/Microcontroller.scala
index 382fd512e..67df23449 100644
--- a/src/main/scala/li/cil/oc/common/tileentity/Microcontroller.scala
+++ b/src/main/scala/li/cil/oc/common/tileentity/Microcontroller.scala
@@ -17,6 +17,8 @@ import li.cil.oc.common.Tier
 import li.cil.oc.common.item.data.MicrocontrollerData
 import li.cil.oc.util.ExtendedArguments._
 import li.cil.oc.util.ExtendedNBT._
+import li.cil.oc.util.StackOption
+import li.cil.oc.util.StackOption._
 import net.minecraft.entity.player.EntityPlayer
 import net.minecraft.item.ItemStack
 import net.minecraft.nbt.NBTTagCompound
@@ -260,17 +262,17 @@ class Microcontroller extends traits.PowerAcceptor with traits.Hub with traits.C
   override def removeStackFromSlot(slot: Int) = ItemStack.EMPTY
 
   // For hotswapping EEPROMs.
-  def changeEEPROM(newEeprom: ItemStack): Option[ItemStack] = {
+  def changeEEPROM(newEeprom: ItemStack): StackOption = {
     val oldEepromIndex = info.components.indexWhere(api.Items.get(_) == api.Items.get(Constants.ItemName.EEPROM))
     if (oldEepromIndex >= 0) {
       val oldEeprom = info.components(oldEepromIndex)
       super.setInventorySlotContents(oldEepromIndex, newEeprom)
-      Some(oldEeprom)
+      SomeStack(oldEeprom)
     }
     else {
       assert(info.components(getSizeInventory - 1).isEmpty)
       super.setInventorySlotContents(getSizeInventory - 1, newEeprom)
-      None
+      EmptyStack
     }
   }
 }
diff --git a/src/main/scala/li/cil/oc/common/tileentity/Printer.scala b/src/main/scala/li/cil/oc/common/tileentity/Printer.scala
index 366b85778..f60e2e2d4 100644
--- a/src/main/scala/li/cil/oc/common/tileentity/Printer.scala
+++ b/src/main/scala/li/cil/oc/common/tileentity/Printer.scala
@@ -16,6 +16,8 @@ import li.cil.oc.api.util.StateAware
 import li.cil.oc.common.item.data.PrintData
 import li.cil.oc.server.{PacketSender => ServerPacketSender}
 import li.cil.oc.util.ExtendedNBT._
+import li.cil.oc.util.StackOption
+import li.cil.oc.util.StackOption._
 import net.minecraft.inventory.ISidedInventory
 import net.minecraft.item.ItemStack
 import net.minecraft.nbt.NBTTagCompound
@@ -40,7 +42,7 @@ class Printer extends traits.Environment with traits.Inventory with traits.Rotat
   var data = new PrintData()
   var isActive = false
   var limit = 0
-  var output: Option[ItemStack] = None
+  var output: StackOption = EmptyStack
   var totalRequiredEnergy = 0.0
   var requiredEnergy = 0.0
 
@@ -248,7 +250,7 @@ class Printer extends traits.Environment with traits.Inventory with traits.Rotat
             amountMaterial -= materialRequired
             amountInk -= inkRequired
             limit -= 1
-            output = Option(data.createItemStack())
+            output = StackOption(data.createItemStack())
             if (limit < 1) isActive = false
             ServerPacketSender.sendPrinting(this, printing = true)
           }
@@ -275,7 +277,7 @@ class Printer extends traits.Environment with traits.Inventory with traits.Rotat
           return
         }
         requiredEnergy = 0
-        output = None
+        output = EmptyStack
       }
       ServerPacketSender.sendPrinting(this, have > 0.5 && output.isDefined)
     }
@@ -319,10 +321,10 @@ class Printer extends traits.Environment with traits.Inventory with traits.Rotat
     isActive = nbt.getBoolean(IsActiveTag)
     limit = nbt.getInteger(LimitTag)
     if (nbt.hasKey(OutputTag)) {
-      output = Option(new ItemStack(nbt.getCompoundTag(OutputTag)))
+      output = StackOption(new ItemStack(nbt.getCompoundTag(OutputTag)))
     }
     else {
-      output = None
+      output = EmptyStack
     }
     totalRequiredEnergy = nbt.getDouble(TotalTag)
     requiredEnergy = nbt.getDouble(RemainingTag)
diff --git a/src/main/scala/li/cil/oc/common/tileentity/traits/ComponentInventory.scala b/src/main/scala/li/cil/oc/common/tileentity/traits/ComponentInventory.scala
index a61d12e5c..af21bd494 100644
--- a/src/main/scala/li/cil/oc/common/tileentity/traits/ComponentInventory.scala
+++ b/src/main/scala/li/cil/oc/common/tileentity/traits/ComponentInventory.scala
@@ -6,6 +6,8 @@ import li.cil.oc.api.network.Node
 import li.cil.oc.common.EventHandler
 import li.cil.oc.common.inventory
 import li.cil.oc.util.ExtendedInventory._
+import li.cil.oc.util.StackOption
+import li.cil.oc.util.StackOption._
 import net.minecraft.item.ItemStack
 import net.minecraft.nbt.NBTTagCompound
 import net.minecraft.util.EnumFacing
@@ -24,8 +26,8 @@ trait ComponentInventory extends Environment with Inventory with inventory.Compo
   // Cache changes to inventory slots on the client side to avoid recreating
   // components when we don't have to and the slots are just cleared by MC
   // temporarily.
-  private lazy val pendingRemovalsActual = mutable.ArrayBuffer.fill(getSizeInventory)(None: Option[ItemStack])
-  private lazy val pendingAddsActual = mutable.ArrayBuffer.fill(getSizeInventory)(None: Option[ItemStack])
+  private lazy val pendingRemovalsActual = mutable.ArrayBuffer.fill(getSizeInventory)(EmptyStack: StackOption)
+  private lazy val pendingAddsActual = mutable.ArrayBuffer.fill(getSizeInventory)(EmptyStack: StackOption)
   private var updateScheduled = false
   def pendingRemovals = {
     adjustSize(pendingRemovalsActual)
@@ -36,7 +38,7 @@ trait ComponentInventory extends Environment with Inventory with inventory.Compo
     pendingAddsActual
   }
 
-  private def adjustSize[T](buffer: mutable.ArrayBuffer[Option[T]]): Unit = {
+  private def adjustSize(buffer: mutable.ArrayBuffer[StackOption]): Unit = {
     val delta = buffer.length - getSizeInventory
     if (delta > 0) {
       buffer.remove(buffer.length - delta, delta)
@@ -44,7 +46,7 @@ trait ComponentInventory extends Environment with Inventory with inventory.Compo
     else if (delta < 0) {
       buffer.sizeHint(getSizeInventory)
       for (i <- 0 until -delta) {
-        buffer += None
+        buffer += EmptyStack
       }
     }
   }
@@ -53,23 +55,23 @@ trait ComponentInventory extends Environment with Inventory with inventory.Compo
     updateScheduled = false
     for (slot <- this.indices) {
       (pendingRemovals(slot), pendingAdds(slot)) match {
-        case (Some(removed), Some(added)) =>
+        case (SomeStack(removed), SomeStack(added)) =>
           if (!removed.isItemEqual(added) || !ItemStack.areItemStackTagsEqual(removed, added)) {
             super.onItemRemoved(slot, removed)
             super.onItemAdded(slot, added)
             markDirty()
           } // else: No change, ignore.
-        case (Some(removed), None) =>
+        case (SomeStack(removed), EmptyStack) =>
           super.onItemRemoved(slot, removed)
           markDirty()
-        case (None, Some(added)) =>
+        case (EmptyStack, SomeStack(added)) =>
           super.onItemAdded(slot, added)
           markDirty()
         case _ => // No change.
       }
 
-      pendingRemovals(slot) = None
-      pendingAdds(slot) = None
+      pendingRemovals(slot) = EmptyStack
+      pendingAdds(slot) = EmptyStack
     }
   }
 
@@ -84,13 +86,13 @@ trait ComponentInventory extends Environment with Inventory with inventory.Compo
     if (isServer) super.onItemAdded(slot, stack)
     else {
       pendingRemovals(slot) match {
-        case Some(removed) if removed.isItemEqual(stack) && ItemStack.areItemStackTagsEqual(removed, stack) =>
+        case SomeStack(removed) if removed.isItemEqual(stack) && ItemStack.areItemStackTagsEqual(removed, stack) =>
           // Reverted to original state.
-          pendingAdds(slot) = None
-          pendingRemovals(slot) = None
+          pendingAdds(slot) = EmptyStack
+          pendingRemovals(slot) = EmptyStack
         case _ =>
           // Got a removal and an add of *something else* in the same tick.
-          pendingAdds(slot) = Option(stack)
+          pendingAdds(slot) = StackOption(stack)
           scheduleInventoryChange()
       }
     }
@@ -100,15 +102,15 @@ trait ComponentInventory extends Environment with Inventory with inventory.Compo
     if (isServer) super.onItemRemoved(slot, stack)
     else {
       pendingAdds(slot) match {
-        case Some(added) =>
+        case SomeStack(added) =>
           // If we have a pending add and get a remove on a slot it is
           // now either empty, or the previous remove is valid again.
-          pendingAdds(slot) = None
+          pendingAdds(slot) = EmptyStack
         case _ =>
           // If we have no pending add, only the first removal can be
           // relevant (further ones should in fact be impossible).
           if (pendingRemovals(slot).isEmpty) {
-            pendingRemovals(slot) = Option(stack)
+            pendingRemovals(slot) = StackOption(stack)
             scheduleInventoryChange()
           }
       }
diff --git a/src/main/scala/li/cil/oc/integration/jei/ModPluginOpenComputers.scala b/src/main/scala/li/cil/oc/integration/jei/ModPluginOpenComputers.scala
index 1ccc851ac..af321394f 100644
--- a/src/main/scala/li/cil/oc/integration/jei/ModPluginOpenComputers.scala
+++ b/src/main/scala/li/cil/oc/integration/jei/ModPluginOpenComputers.scala
@@ -5,6 +5,7 @@ import li.cil.oc.Settings
 import li.cil.oc.api.Items
 import li.cil.oc.integration.util.ItemBlacklist
 import li.cil.oc.integration.util.ItemSearch
+import li.cil.oc.util.StackOption
 import mezz.jei.api.IJeiRuntime
 import mezz.jei.api.IModPlugin
 import mezz.jei.api.IModRegistry
@@ -42,13 +43,13 @@ class ModPluginOpenComputers extends IModPlugin {
     ModJEI.ingredientRegistry = Option(registry.getIngredientRegistry)
   }
 
-  private var stackUnderMouse: (GuiContainer, Int, Int) => Option[ItemStack] = _
+  private var stackUnderMouse: (GuiContainer, Int, Int) => StackOption = _
 
   override def onRuntimeAvailable(jeiRuntime: IJeiRuntime) {
     if (stackUnderMouse == null) {
       ItemSearch.stackFocusing += ((container, mouseX, mouseY) => stackUnderMouse(container, mouseX, mouseY))
     }
-    stackUnderMouse = (container, mouseX, mouseY) => Option(jeiRuntime.getItemListOverlay.getStackUnderMouse)
+    stackUnderMouse = (container, mouseX, mouseY) => StackOption(jeiRuntime.getItemListOverlay.getStackUnderMouse)
 
     ModJEI.runtime = Option(jeiRuntime)
   }
diff --git a/src/main/scala/li/cil/oc/integration/util/ItemSearch.scala b/src/main/scala/li/cil/oc/integration/util/ItemSearch.scala
index a551f642c..8980cf262 100644
--- a/src/main/scala/li/cil/oc/integration/util/ItemSearch.scala
+++ b/src/main/scala/li/cil/oc/integration/util/ItemSearch.scala
@@ -1,14 +1,15 @@
 package li.cil.oc.integration.util
 
+import li.cil.oc.util.StackOption
+import li.cil.oc.util.StackOption._
 import net.minecraft.client.gui.inventory.GuiContainer
-import net.minecraft.item.ItemStack
 
 import scala.collection.mutable
 
 object ItemSearch {
 
   val focusedInput = mutable.Set.empty[() => Boolean]
-  val stackFocusing = mutable.Set.empty[(GuiContainer, Int, Int) => Option[ItemStack]]
+  val stackFocusing = mutable.Set.empty[(GuiContainer, Int, Int) => StackOption]
 
   def isInputFocused: Boolean = {
     for (f <- focusedInput) {
@@ -17,10 +18,10 @@ object ItemSearch {
     false
   }
 
-  def hoveredStack(container: GuiContainer, mouseX: Int, mouseY: Int): Option[ItemStack] = {
+  def hoveredStack(container: GuiContainer, mouseX: Int, mouseY: Int): StackOption = {
     for (f <- stackFocusing) {
-      f(container, mouseX, mouseY).foreach(stack => return Option(stack))
+      f(container, mouseX, mouseY).foreach(stack => return StackOption(stack))
     }
-    None
+    EmptyStack
   }
 }
diff --git a/src/main/scala/li/cil/oc/server/component/Robot.scala b/src/main/scala/li/cil/oc/server/component/Robot.scala
index 2c38af741..0dced123b 100644
--- a/src/main/scala/li/cil/oc/server/component/Robot.scala
+++ b/src/main/scala/li/cil/oc/server/component/Robot.scala
@@ -21,6 +21,8 @@ import li.cil.oc.server.PacketSender
 import li.cil.oc.util.BlockPosition
 import li.cil.oc.util.ExtendedArguments._
 import li.cil.oc.util.ExtendedNBT._
+import li.cil.oc.util.StackOption
+import li.cil.oc.util.StackOption._
 import net.minecraft.nbt.NBTTagCompound
 import net.minecraft.util.EnumFacing
 import net.minecraft.util.EnumParticleTypes
@@ -71,8 +73,8 @@ class Robot(val agent: tileentity.Robot) extends AbstractManagedEnvironment with
 
   @Callback(doc = "function():number -- Get the durability of the currently equipped tool.")
   def durability(context: Context, args: Arguments): Array[AnyRef] = {
-    Option(agent.equipmentInventory.getStackInSlot(0)) match {
-      case Some(item) =>
+    StackOption(agent.equipmentInventory.getStackInSlot(0)) match {
+      case SomeStack(item) =>
         ToolDurabilityProviders.getDurability(item) match {
           case Some(durability) => result(durability)
           case _ => result(Unit, "tool cannot be damaged")
diff --git a/src/main/scala/li/cil/oc/server/component/UpgradeDatabase.scala b/src/main/scala/li/cil/oc/server/component/UpgradeDatabase.scala
index 187f22e4e..13d86017d 100644
--- a/src/main/scala/li/cil/oc/server/component/UpgradeDatabase.scala
+++ b/src/main/scala/li/cil/oc/server/component/UpgradeDatabase.scala
@@ -18,6 +18,7 @@ import li.cil.oc.api.prefab.AbstractManagedEnvironment
 import li.cil.oc.util.DatabaseAccess
 import li.cil.oc.util.ExtendedArguments._
 import li.cil.oc.util.ItemUtils
+import li.cil.oc.util.StackOption
 import net.minecraft.inventory.IInventory
 import net.minecraft.item.ItemStack
 
@@ -40,7 +41,7 @@ class UpgradeDatabase(val data: IInventory) extends AbstractManagedEnvironment w
 
   override def size = data.getSizeInventory
 
-  override def getStackInSlot(slot: Int) = Option(data.getStackInSlot(slot)).map(_.copy()).orNull
+  override def getStackInSlot(slot: Int) = StackOption(data.getStackInSlot(slot)).map(_.copy()).orEmpty
 
   override def setStackInSlot(slot: Int, stack: ItemStack) = data.setInventorySlotContents(slot, stack)
 
diff --git a/src/main/scala/li/cil/oc/server/component/UpgradeGenerator.scala b/src/main/scala/li/cil/oc/server/component/UpgradeGenerator.scala
index c3fa28a10..da4b15bae 100644
--- a/src/main/scala/li/cil/oc/server/component/UpgradeGenerator.scala
+++ b/src/main/scala/li/cil/oc/server/component/UpgradeGenerator.scala
@@ -17,6 +17,8 @@ import li.cil.oc.api.network._
 import li.cil.oc.api.prefab
 import li.cil.oc.api.prefab.AbstractManagedEnvironment
 import li.cil.oc.util.ExtendedNBT._
+import li.cil.oc.util.StackOption
+import li.cil.oc.util.StackOption._
 import net.minecraft.entity.item.EntityItem
 import net.minecraft.item.ItemStack
 import net.minecraft.nbt.NBTTagCompound
@@ -30,7 +32,7 @@ class UpgradeGenerator(val host: EnvironmentHost with internal.Agent) extends Ab
     withConnector().
     create()
 
-  var inventory: Option[ItemStack] = None
+  var inventory: StackOption = EmptyStack
 
   var remainingTicks = 0
 
@@ -55,7 +57,7 @@ class UpgradeGenerator(val host: EnvironmentHost with internal.Agent) extends Ab
       return result(Unit, "selected slot does not contain fuel")
     }
     inventory match {
-      case Some(existingStack) =>
+      case SomeStack(existingStack) =>
         if (!existingStack.isItemEqual(stack) ||
           !ItemStack.areItemStackTagsEqual(existingStack, stack)) {
           return result(Unit, "different fuel type already queued")
@@ -68,7 +70,7 @@ class UpgradeGenerator(val host: EnvironmentHost with internal.Agent) extends Ab
         existingStack.grow(moveCount)
         stack.shrink(moveCount)
       case _ =>
-        inventory = Some(stack.splitStack(math.min(stack.getCount, count)))
+        inventory = StackOption(stack.splitStack(math.min(stack.getCount, count)))
     }
     if (stack.getCount > 0) host.mainInventory.setInventorySlotContents(host.selectedSlot, stack)
     else host.mainInventory.setInventorySlotContents(host.selectedSlot, ItemStack.EMPTY)
@@ -78,7 +80,7 @@ class UpgradeGenerator(val host: EnvironmentHost with internal.Agent) extends Ab
   @Callback(doc = """function():number -- Get the size of the item stack in the generator's queue.""")
   def count(context: Context, args: Arguments): Array[AnyRef] = {
     inventory match {
-      case Some(stack) => result(stack.getCount)
+      case SomeStack(stack) => result(stack.getCount)
       case _ => result(0)
     }
   }
@@ -87,12 +89,12 @@ class UpgradeGenerator(val host: EnvironmentHost with internal.Agent) extends Ab
   def remove(context: Context, args: Arguments): Array[AnyRef] = {
     val count = args.optInteger(0, Int.MaxValue)
     inventory match {
-      case Some(stack) =>
+      case SomeStack(stack) =>
         val removedStack = stack.splitStack(math.min(count, stack.getCount))
         val success = host.player.inventory.addItemStackToInventory(removedStack)
         stack.grow(removedStack.getCount)
         if (success && stack.getCount <= 0) {
-          inventory = None
+          inventory = EmptyStack
         }
         result(success)
       case _ => result(false)
@@ -114,9 +116,9 @@ class UpgradeGenerator(val host: EnvironmentHost with internal.Agent) extends Ab
         stack.shrink(1)
         if (stack.getCount <= 0) {
           if (stack.getItem.hasContainerItem(stack))
-            inventory = Option(stack.getItem.getContainerItem(stack))
+            inventory = StackOption(stack.getItem.getContainerItem(stack))
           else
-            inventory = None
+            inventory = EmptyStack
         }
       }
     }
@@ -140,13 +142,13 @@ class UpgradeGenerator(val host: EnvironmentHost with internal.Agent) extends Ab
     super.onDisconnect(node)
     if (node == this.node) {
       inventory match {
-        case Some(stack) =>
+        case SomeStack(stack) =>
           val world = host.world
           val entity = new EntityItem(world, host.xPosition, host.yPosition, host.zPosition, stack.copy())
           entity.motionY = 0.04
           entity.setPickupDelay(5)
           world.spawnEntity(entity)
-          inventory = None
+          inventory = EmptyStack
         case _ =>
       }
       remainingTicks = 0
@@ -158,9 +160,9 @@ class UpgradeGenerator(val host: EnvironmentHost with internal.Agent) extends Ab
 
   override def load(nbt: NBTTagCompound) {
     super.load(nbt)
-      inventory = Option(new ItemStack(nbt.getCompoundTag("inventory")))
+      inventory = StackOption(new ItemStack(nbt.getCompoundTag("inventory")))
     if (nbt.hasKey(InventoryTag)) {
-      inventory = Option(new ItemStack(nbt.getCompoundTag(InventoryTag)))
+      inventory = StackOption(new ItemStack(nbt.getCompoundTag(InventoryTag)))
     }
     remainingTicks = nbt.getInteger(RemainingTicksTag)
   }
@@ -168,7 +170,7 @@ class UpgradeGenerator(val host: EnvironmentHost with internal.Agent) extends Ab
   override def save(nbt: NBTTagCompound) {
     super.save(nbt)
     inventory match {
-      case Some(stack) => nbt.setNewCompoundTag(InventoryTag, stack.writeToNBT)
+      case SomeStack(stack) => nbt.setNewCompoundTag(InventoryTag, stack.writeToNBT)
       case _ =>
     }
     if (remainingTicks > 0) {
diff --git a/src/main/scala/li/cil/oc/server/component/traits/InventoryAnalytics.scala b/src/main/scala/li/cil/oc/server/component/traits/InventoryAnalytics.scala
index 867ac725d..c8aae3d38 100644
--- a/src/main/scala/li/cil/oc/server/component/traits/InventoryAnalytics.scala
+++ b/src/main/scala/li/cil/oc/server/component/traits/InventoryAnalytics.scala
@@ -8,6 +8,7 @@ import li.cil.oc.server.component.result
 import li.cil.oc.util.DatabaseAccess
 import li.cil.oc.util.ExtendedArguments._
 import li.cil.oc.util.InventoryUtils
+import li.cil.oc.util.StackOption._
 import net.minecraft.item.ItemStack
 import net.minecraftforge.oredict.OreDictionary
 
@@ -23,8 +24,8 @@ trait InventoryAnalytics extends InventoryAware with NetworkAware {
   def isEquivalentTo(context: Context, args: Arguments): Array[AnyRef] = {
     val slot = args.checkSlot(inventory, 0)
     result((stackInSlot(selectedSlot), stackInSlot(slot)) match {
-      case (Some(stackA), Some(stackB)) => OreDictionary.getOreIDs(stackA).intersect(OreDictionary.getOreIDs(stackB)).nonEmpty
-      case (None, None) => true
+      case (SomeStack(stackA), SomeStack(stackB)) => OreDictionary.getOreIDs(stackA).intersect(OreDictionary.getOreIDs(stackB)).nonEmpty
+      case (EmptyStack, EmptyStack) => true
       case _ => false
     })
   }
diff --git a/src/main/scala/li/cil/oc/server/component/traits/InventoryAware.scala b/src/main/scala/li/cil/oc/server/component/traits/InventoryAware.scala
index e977d1015..37dc8a43d 100644
--- a/src/main/scala/li/cil/oc/server/component/traits/InventoryAware.scala
+++ b/src/main/scala/li/cil/oc/server/component/traits/InventoryAware.scala
@@ -2,6 +2,7 @@ package li.cil.oc.server.component.traits
 
 import li.cil.oc.api.machine.Arguments
 import li.cil.oc.util.ExtendedArguments._
+import li.cil.oc.util.StackOption
 import net.minecraft.entity.player.EntityPlayer
 import net.minecraft.inventory.IInventory
 
@@ -24,5 +25,5 @@ trait InventoryAware {
     if (args.count > 0 && args.checkAny(0) != null) args.checkSlot(inventory, 0)
     else selectedSlot
 
-  protected def stackInSlot(slot: Int) = Option(inventory.getStackInSlot(slot))
+  protected def stackInSlot(slot: Int): StackOption = StackOption(inventory.getStackInSlot(slot))
 }
diff --git a/src/main/scala/li/cil/oc/server/component/traits/InventoryControl.scala b/src/main/scala/li/cil/oc/server/component/traits/InventoryControl.scala
index 04ecbe938..3a083fbe0 100644
--- a/src/main/scala/li/cil/oc/server/component/traits/InventoryControl.scala
+++ b/src/main/scala/li/cil/oc/server/component/traits/InventoryControl.scala
@@ -6,6 +6,7 @@ import li.cil.oc.api.machine.Context
 import li.cil.oc.util.ExtendedArguments._
 import li.cil.oc.util.InventoryUtils
 import li.cil.oc.util.ResultWrapper.result
+import li.cil.oc.util.StackOption._
 import net.minecraft.item.ItemStack
 
 trait InventoryControl extends InventoryAware {
@@ -25,7 +26,7 @@ trait InventoryControl extends InventoryAware {
   def count(context: Context, args: Arguments): Array[AnyRef] = {
     val slot = optSlot(args, 0)
     result(stackInSlot(slot) match {
-      case Some(stack) => stack.getCount
+      case SomeStack(stack) => stack.getCount
       case _ => 0
     })
   }
@@ -34,7 +35,7 @@ trait InventoryControl extends InventoryAware {
   def space(context: Context, args: Arguments): Array[AnyRef] = {
     val slot = optSlot(args, 0)
     result(stackInSlot(slot) match {
-      case Some(stack) => math.min(inventory.getInventoryStackLimit, stack.getMaxStackSize) - stack.getCount
+      case SomeStack(stack) => math.min(inventory.getInventoryStackLimit, stack.getMaxStackSize) - stack.getCount
       case _ => inventory.getInventoryStackLimit
     })
   }
@@ -43,8 +44,8 @@ trait InventoryControl extends InventoryAware {
   def compareTo(context: Context, args: Arguments): Array[AnyRef] = {
     val slot = args.checkSlot(inventory, 0)
     result((stackInSlot(selectedSlot), stackInSlot(slot)) match {
-      case (Some(stackA), Some(stackB)) => InventoryUtils.haveSameItemType(stackA, stackB, args.optBoolean(1, false))
-      case (None, None) => true
+      case (SomeStack(stackA), SomeStack(stackB)) => InventoryUtils.haveSameItemType(stackA, stackB, args.optBoolean(1, false))
+      case (EmptyStack, EmptyStack) => true
       case _ => false
     })
   }
@@ -57,7 +58,7 @@ trait InventoryControl extends InventoryAware {
       result(true)
     }
     else result((stackInSlot(selectedSlot), stackInSlot(slot)) match {
-      case (Some(from), Some(to)) =>
+      case (SomeStack(from), SomeStack(to)) =>
         if (InventoryUtils.haveSameItemType(from, to, checkNBT = true)) {
           val space = math.min(inventory.getInventoryStackLimit, to.getMaxStackSize) - to.getCount
           val amount = math.min(count, math.min(space, from.getCount))
@@ -79,7 +80,7 @@ trait InventoryControl extends InventoryAware {
           true
         }
         else false
-      case (Some(from), None) =>
+      case (SomeStack(from), EmptyStack) =>
         inventory.setInventorySlotContents(slot, inventory.decrStackSize(selectedSlot, count))
         true
       case _ => false
diff --git a/src/main/scala/li/cil/oc/server/component/traits/InventoryWorldControl.scala b/src/main/scala/li/cil/oc/server/component/traits/InventoryWorldControl.scala
index 54c42d59f..5c2055695 100644
--- a/src/main/scala/li/cil/oc/server/component/traits/InventoryWorldControl.scala
+++ b/src/main/scala/li/cil/oc/server/component/traits/InventoryWorldControl.scala
@@ -7,6 +7,7 @@ import li.cil.oc.api.machine.Context
 import li.cil.oc.util.ExtendedArguments._
 import li.cil.oc.util.InventoryUtils
 import li.cil.oc.util.ResultWrapper.result
+import li.cil.oc.util.StackOption._
 import net.minecraft.entity.item.EntityItem
 import net.minecraft.item.ItemBlock
 import net.minecraft.item.ItemStack
@@ -22,7 +23,7 @@ trait InventoryWorldControl extends InventoryAware with WorldAware with SideRest
   def compare(context: Context, args: Arguments): Array[AnyRef] = {
     val side = checkSideForAction(args, 0)
     stackInSlot(selectedSlot) match {
-      case Some(stack) => Option(stack.getItem) match {
+      case SomeStack(stack) => Option(stack.getItem) match {
         case Some(item: ItemBlock) =>
           val blockPos = position.offset(side).toBlockPos
           val state = world.getBlockState(blockPos)
diff --git a/src/main/scala/li/cil/oc/server/component/traits/WorldInventoryAnalytics.scala b/src/main/scala/li/cil/oc/server/component/traits/WorldInventoryAnalytics.scala
index f7ec2c32a..4767921f7 100644
--- a/src/main/scala/li/cil/oc/server/component/traits/WorldInventoryAnalytics.scala
+++ b/src/main/scala/li/cil/oc/server/component/traits/WorldInventoryAnalytics.scala
@@ -8,6 +8,7 @@ import li.cil.oc.server.component.result
 import li.cil.oc.util.DatabaseAccess
 import li.cil.oc.util.ExtendedArguments._
 import li.cil.oc.util.InventoryUtils
+import li.cil.oc.util.StackOption
 import net.minecraft.item.ItemStack
 import net.minecraft.util.EnumFacing
 import net.minecraftforge.items.IItemHandler
@@ -23,13 +24,13 @@ trait WorldInventoryAnalytics extends WorldAware with SideRestricted with Networ
   @Callback(doc = """function(side:number, slot:number):number -- Get number of items in the specified slot of the inventory on the specified side of the device.""")
   def getSlotStackSize(context: Context, args: Arguments): Array[AnyRef] = {
     val facing = checkSideForAction(args, 0)
-    withInventory(facing, inventory => result(Option(inventory.getStackInSlot(args.checkSlot(inventory, 1))).fold(0)(_.getCount)))
+    withInventory(facing, inventory => result(StackOption(inventory.getStackInSlot(args.checkSlot(inventory, 1))).fold(0)(_.getCount)))
   }
 
   @Callback(doc = """function(side:number, slot:number):number -- Get the maximum number of items in the specified slot of the inventory on the specified side of the device.""")
   def getSlotMaxStackSize(context: Context, args: Arguments): Array[AnyRef] = {
     val facing = checkSideForAction(args, 0)
-    withInventory(facing, inventory => result(Option(inventory.getStackInSlot(args.checkSlot(inventory, 1))).fold(0)(_.getMaxStackSize)))
+    withInventory(facing, inventory => result(StackOption(inventory.getStackInSlot(args.checkSlot(inventory, 1))).fold(0)(_.getMaxStackSize)))
   }
 
   @Callback(doc = """function(side:number, slotA:number, slotB:number[, checkNBT:boolean=false]):boolean -- Get whether the items in the two specified slots of the inventory on the specified side of the device are of the same type.""")
diff --git a/src/main/scala/li/cil/oc/util/InventoryUtils.scala b/src/main/scala/li/cil/oc/util/InventoryUtils.scala
index 22a1f4279..ce1b2d5c6 100644
--- a/src/main/scala/li/cil/oc/util/InventoryUtils.scala
+++ b/src/main/scala/li/cil/oc/util/InventoryUtils.scala
@@ -2,6 +2,7 @@ package li.cil.oc.util
 
 import li.cil.oc.OpenComputers
 import li.cil.oc.util.ExtendedWorld._
+import li.cil.oc.util.StackOption._
 import net.minecraft.entity.Entity
 import net.minecraft.entity.item.EntityItem
 import net.minecraft.entity.player.EntityPlayer
@@ -328,8 +329,8 @@ object InventoryUtils {
    * the world.
    */
   def dropSlot(position: BlockPosition, inventory: IInventory, slot: Int, count: Int, direction: Option[EnumFacing] = None): Boolean = {
-    Option(inventory.decrStackSize(slot, count)) match {
-      case Some(stack) if stack.getCount > 0 => spawnStackInWorld(position, stack, direction); true
+    StackOption(inventory.decrStackSize(slot, count)) match {
+      case SomeStack(stack) if stack.getCount > 0 => spawnStackInWorld(position, stack, direction); true
       case _ => false
     }
   }
@@ -339,8 +340,8 @@ object InventoryUtils {
    */
   def dropAllSlots(position: BlockPosition, inventory: IInventory): Unit = {
     for (slot <- 0 until inventory.getSizeInventory) {
-      Option(inventory.getStackInSlot(slot)) match {
-        case Some(stack) if stack.getCount > 0 =>
+      StackOption(inventory.getStackInSlot(slot)) match {
+        case SomeStack(stack) if stack.getCount > 0 =>
           inventory.setInventorySlotContents(slot, ItemStack.EMPTY)
           spawnStackInWorld(position, stack)
         case _ => // Nothing.
diff --git a/src/main/scala/li/cil/oc/util/StackOption.scala b/src/main/scala/li/cil/oc/util/StackOption.scala
new file mode 100644
index 000000000..f2f28b2de
--- /dev/null
+++ b/src/main/scala/li/cil/oc/util/StackOption.scala
@@ -0,0 +1,97 @@
+package li.cil.oc.util
+
+import li.cil.oc.util.StackOption._
+import net.minecraft.item.ItemStack
+
+object StackOption {
+
+  //implicit def extendedStack(stack: ItemStack): StackOption = if (stack.isEmpty) Empty else new StackOption(stack)
+
+  implicit def extendedOption(opt: Option[ItemStack]): ExtendedOption = ExtendedOption(opt)
+
+  // Mostly stolen from Option
+  implicit def stack2Iterable(so: StackOption): Iterable[ItemStack] = so.toList
+
+  def apply(stack: ItemStack): StackOption = if (stack == null || stack.isEmpty) EmptyStack else SomeStack(stack)
+
+  def apply(stack: Option[ItemStack]): StackOption = if (stack == null || stack.isEmpty || stack.get.isEmpty) EmptyStack else SomeStack(stack.get)
+
+  def empty: StackOption = EmptyStack
+
+  case object EmptyStack extends StackOption(ItemStack.EMPTY)
+
+  final case class SomeStack(stack: ItemStack) extends StackOption(stack)
+}
+
+final case class ExtendedOption(opt : Option[ItemStack]) {
+  def asStackOption = StackOption(opt)
+}
+
+sealed abstract class StackOption(stack: ItemStack) extends Product with Serializable {
+  self =>
+
+  def isEmpty: Boolean = stack == null || stack.isEmpty
+
+  def get: ItemStack = stack
+
+  def isDefined: Boolean = !isEmpty
+
+  def getOrElse(default: ItemStack): ItemStack = if (isEmpty) default else this.get
+
+  def orEmpty: ItemStack = if(isEmpty) EmptyStack.get else this.get
+
+  def map(f: ItemStack => ItemStack): StackOption = if (isEmpty) EmptyStack else SomeStack(f(this.get))
+
+  //def map[B](f: ItemStack => B): Option[B] = if (isEmpty) None else Some(f(this.get))
+
+  def fold[B](ifEmpty: => B)(f: ItemStack => B): B = if (isEmpty) ifEmpty else f(this.get)
+
+  def flatMap[B](f: ItemStack => Option[B]): Option[B] = if (isEmpty) None else f(this.get)
+
+  def flatten[B](implicit ev: ItemStack <:< Option[B]): Option[B] = if (isEmpty) None else ev(this.get)
+
+  def filter(p: ItemStack => Boolean): StackOption = if (isEmpty || p(this.get)) this else EmptyStack
+
+  def filterNot(p: ItemStack => Boolean): StackOption = if (isEmpty || !p(this.get)) this else EmptyStack
+
+  def nonEmpty: Boolean = isDefined
+
+  def withFilter(p: ItemStack => Boolean): WithFilter = new WithFilter(p)
+
+  class WithFilter(p: ItemStack => Boolean) {
+    //def map[B](f: ItemStack => B): Option[B] = self filter p map f
+
+    //def flatMap[B](f: ItemStack => Option[B]): Option[B] = self filter p flatMap f
+
+    def foreach[U](f: ItemStack => U): Unit = self filter p foreach f
+
+    def withFilter(q: ItemStack => Boolean): WithFilter = new WithFilter(x => p(x) && q(x))
+  }
+
+  def contains[A1 >: ItemStack](elem: A1): Boolean = !isEmpty && this.get == elem
+
+  def exists(p: ItemStack => Boolean): Boolean = !isEmpty && p(this.get)
+
+  def forall(p: ItemStack => Boolean): Boolean = isEmpty || p(this.get)
+
+  def foreach[U](f: ItemStack => U) {
+    if (!isEmpty) f(this.get)
+  }
+
+  def collect[B](pf: PartialFunction[ItemStack, B]): Option[B] = if (!isEmpty) pf.lift(this.get) else None
+
+  def orElse[B >: ItemStack](alternative: => StackOption): StackOption =
+    if (isEmpty) alternative else this
+
+  def iterator: Iterator[ItemStack] =
+    if (isEmpty) collection.Iterator.empty else collection.Iterator.single(this.get)
+
+  def toList: List[ItemStack] =
+    if (isEmpty) List() else new ::(this.get, Nil)
+
+  def toRight[X](left: => X): Either[X, ItemStack] =
+    if (isEmpty) Left(left) else Right(this.get)
+
+  def toLeft[X](right: => X): Either[ItemStack, X] =
+    if (isEmpty) Right(right) else Left(this.get)
+}