changed a couple of failure cases to return nil, message instead of…

… `false, message`, for consistency

src/main/java/li/cil/oc/server/component/AbstractBus.scala

@@ -81,7 +81,7 @@ class AbstractBus(val device: IBusDevice) extends ManagedComponent with IBusDriv
       busInterface.sendAllPackets()
       result(true)
     }
-    else result(false, "not enough energy")
+    else result(Unit, "not enough energy")
   }
 
   @Callback(direct = true, doc = """function():number -- The maximum packet size that can be sent over the bus.""")

src/main/java/li/cil/oc/server/component/GraphicsCard.scala

@@ -53,7 +53,7 @@ abstract class GraphicsCard extends ManagedComponent {
   def bind(context: Context, args: Arguments): Array[AnyRef] = {
     val address = args.checkString(0)
     node.network.node(address) match {
-      case null => result(false, "invalid address")
+      case null => result(Unit, "invalid address")
       case node: Node if node.host.isInstanceOf[Buffer] =>
         screenAddress = Option(address)
         screenInstance = Some(node.host.asInstanceOf[Buffer])
@@ -66,7 +66,7 @@ abstract class GraphicsCard extends ManagedComponent {
           s.background = 0x000000
           result(true)
         })
-      case _ => result(false, "not a screen")
+      case _ => result(Unit, "not a screen")
     }
   }
 
@@ -166,7 +166,7 @@ abstract class GraphicsCard extends ManagedComponent {
         s.set(x, y, value)
         result(true)
       }
-      else result(false)
+      else result(Unit, "not enough energy")
     })
   }
 
@@ -182,7 +182,7 @@ abstract class GraphicsCard extends ManagedComponent {
         s.copy(x, y, w, h, tx, ty)
         result(true)
       }
-      else result(false)
+      else result(Unit, "not enough energy")
     })
   }
 
@@ -200,7 +200,7 @@ abstract class GraphicsCard extends ManagedComponent {
         result(true)
       }
       else {
-        result(false)
+        result(Unit, "not enough energy")
       }
     })
     else throw new Exception("invalid fill value")

src/main/java/li/cil/oc/server/component/InternetCard.scala

@@ -54,12 +54,12 @@ class InternetCard extends ManagedComponent {
     }
     val address = args.checkString(0)
     if (!Settings.get.httpEnabled) {
-      return result(false, "http requests are unavailable")
+      return result(Unit, "http requests are unavailable")
     }
     val post = if (args.isString(1)) Option(args.checkString(1)) else None
     this.synchronized {
       if (request.isDefined || queue.isDefined) {
-        return result(false, "already busy with another request")
+        return result(Unit, "already busy with another request")
       }
       scheduleRequest(address, post)
     }
@@ -137,7 +137,9 @@ class InternetCard extends ManagedComponent {
   def connect(context: Context, args: Arguments): Array[AnyRef] = {
     val address = args.checkString(0)
     val port = if (args.count > 1) args.checkInteger(1) else -1
-    if (!Settings.get.tcpEnabled) return result(false, "tcp connections are unavailable")
+    if (!Settings.get.tcpEnabled) {
+      return result(Unit, "tcp connections are unavailable")
+    }
     if (connections.size >= Settings.get.maxConnections) {
       throw new IOException("too many open connections")
     }

src/main/java/li/cil/oc/server/component/UpgradeGenerator.scala

@@ -27,16 +27,18 @@ class UpgradeGenerator(val owner: TileEntity) extends ManagedComponent {
     val player = context.player
     val stack = player.inventory.getStackInSlot(context.selectedSlot)
     if (stack == null) throw new IllegalArgumentException("selected slot is empty")
-    if (!TileEntityFurnace.isItemFuel(stack)) return result(false, "selected slot does not contain fuel")
+    if (!TileEntityFurnace.isItemFuel(stack)) {
+      return result(Unit, "selected slot does not contain fuel")
+    }
     inventory match {
       case Some(existingStack) =>
         if (!existingStack.isItemEqual(stack) ||
           !ItemStack.areItemStackTagsEqual(existingStack, stack)) {
-          return result(false, "different fuel type already queued")
+          return result(Unit, "different fuel type already queued")
         }
         val space = existingStack.getMaxStackSize - existingStack.stackSize
         if (space <= 0) {
-          return result(false, "queue is full")
+          return result(Unit, "queue is full")
         }
         val moveCount = math.min(stack.stackSize, math.min(space, count))
         existingStack.stackSize += moveCount

src/main/java/li/cil/oc/server/component/robot/Robot.scala

@@ -227,7 +227,7 @@ class Robot(val robot: tileentity.Robot) extends Machine(robot) with RobotContex
     val sneaky = args.isBoolean(2) && args.checkBoolean(2)
     val stack = player.robotInventory.selectedItemStack
     if (stack == null || stack.stackSize == 0) {
-      return result(false, "nothing selected")
+      return result(Unit, "nothing selected")
     }
 
     for (side <- sides) {
@@ -494,16 +494,16 @@ class Robot(val robot: tileentity.Robot) extends Machine(robot) with RobotContex
     if (robot.isAnimatingMove) {
       // This shouldn't really happen due to delays being enforced, but just to
       // be on the safe side...
-      result(false, "already moving")
+      result(Unit, "already moving")
     }
     else {
       val (something, what) = blockContent(robot.player(direction), direction)
       if (something) {
-        result(false, what)
+        result(Unit, what)
       }
       else {
         if (!robot.computer.node.tryChangeBuffer(-Settings.get.robotMoveCost)) {
-          result(false, "not enough energy")
+          result(Unit, "not enough energy")
         }
         else if (robot.move(direction)) {
           context.pause(Settings.get.moveDelay)
@@ -512,7 +512,7 @@ class Robot(val robot: tileentity.Robot) extends Machine(robot) with RobotContex
         }
         else {
           robot.computer.node.changeBuffer(Settings.get.robotMoveCost)
-          result(false, "impossible move")
+          result(Unit, "impossible move")
         }
       }
     }
@@ -529,7 +529,7 @@ class Robot(val robot: tileentity.Robot) extends Machine(robot) with RobotContex
       result(true)
     }
     else {
-      result(false, "not enough energy")
+      result(Unit, "not enough energy")
     }
   }