Add wielded, wieldable items

Split the character's inventory up into wielded items (in one or both
hands) and the backpack, and display wielded items when drawing the
inventory panel. Currently there's no way to actually *wield* items
though, so this is all unused/untested.

Also, add the ability for items to be "wieldable", which gives specific
descriptions for when attacking with them and also modified damage.

src/Xanthous/App.hs

@@ -143,8 +143,8 @@ handleCommand PickUp = do
   uses entities (entitiesAtPositionWithType @Item pos) >>= \case
     [] -> say_ ["pickUp", "nothingToPickUp"]
     [item] -> pickUpItem item
-    items ->
-      menu_ ["pickUp", "menu"] Cancellable (entityMenu_ items)
+    items' ->
+      menu_ ["pickUp", "menu"] Cancellable (entityMenu_ items')
       $ \(MenuResult item) -> pickUpItem item
   continue
   where
@@ -185,7 +185,7 @@ handleCommand Look = do
 handleCommand Wait = stepGame >> continue
 
 handleCommand Eat = do
-  uses (character . inventory)
+  uses (character . inventory . backpack)
        (V.mapMaybe (\item -> (item,) <$> item ^. Item.itemType . edible))
     >>= \case
       Empty -> say_ ["eat", "noFood"]
@@ -197,7 +197,7 @@ handleCommand Eat = do
             menuItems = mkMenuItems $ imap foodMenuItem food
         in menu_ ["eat", "menuPrompt"] Cancellable menuItems
           $ \(MenuResult (idx, item, edibleItem)) -> do
-            character . inventory %= \inv ->
+            character . inventory . backpack %= \inv ->
               let (before, after) = V.splitAt idx inv
               in before <> fromMaybe Empty (tailMay after)
             let msg = fromMaybe (Messages.lookup ["eat", "eat"])
@@ -231,7 +231,7 @@ handleCommand Read = do
             in readAndContinue msgs
   continue
 
-handleCommand Inventory = showPanel InventoryPanel >> continue
+handleCommand ShowInventory = showPanel InventoryPanel >> continue
 
 handleCommand Save = do
   -- TODO default save locations / config file?
@@ -280,8 +280,8 @@ handlePromptEvent _ (Prompt _ SDirectionPrompt _ _ _) _ = continue
 
 handlePromptEvent _ (Prompt _ SContinue _ _ _) _ = continue
 
-handlePromptEvent _ (Prompt _ SMenu _ items cb) (VtyEvent (EvKey (KChar chr) []))
-  | Just (MenuOption _ res) <- items ^. at chr
+handlePromptEvent _ (Prompt _ SMenu _ items' cb) (VtyEvent (EvKey (KChar chr) []))
+  | Just (MenuOption _ res) <- items' ^. at chr
   = cb (MenuResult res) >> clearPrompt
   | otherwise
   = continue
@@ -350,9 +350,9 @@ menu :: forall (a :: Type) (params :: Type).
      -> Map Char (MenuOption a)           -- ^ Menu items
      -> (PromptResult ('Menu a) -> AppM ()) -- ^ Menu promise handler
      -> AppM ()
-menu msgPath params cancellable items cb = do
+menu msgPath params cancellable items' cb = do
   msg <- Messages.message msgPath params
-  let p = mkMenu cancellable items cb
+  let p = mkMenu cancellable items' cb
   promptState .= WaitingPrompt msg p
 
 menu_ :: forall (a :: Type).
@@ -419,7 +419,8 @@ attackAt pos =
         say ["combat", "killed"] msgParams
         entities . at creatureID .= Nothing
       else do
-        say ["combat", "hit"] msgParams
+        -- TODO attack messages
+        say ["combat", "hit", "generic"] msgParams
         entities . ix creatureID . positioned .= SomeEntity creature'
     stepGame -- TODO