Implement zipper for attachment trees

src/Dodge/Default/Item.hs

@@ -26,7 +26,8 @@ defaultHeldItem = Item
         { _itCurseStatus = Uncursed
         , _itType = HELD PISTOL
         , _itEffect = defaultItEffect
-        , _itID = 0
+        , _itID = 0 -- should this return an error ? const $ error "itID not correctly initialised" ?
+        , _itAmmoSlots = mempty
         , _itInvSize = 1
         , _itLocation = InVoid
         , _itDimension = defaultItemDimension
@@ -45,7 +46,7 @@ singleAmmo x = IM.insert 0 x mempty
 
 defaultBulletWeapon :: Item
 defaultBulletWeapon = defaultHeldItem
-        & itUse . heldAmmoTypes .~ singleAmmo BulletAmmo
+        & itAmmoSlots .~ singleAmmo BulletAmmo
         & itUse . heldAim . aimMuzzles .~ [Muzzle (V2 15 0) 0 0.01 0 PistolFlare MuzzleShootBullet]
 
 defaultConsumable :: Item

src/Dodge/Default/Item/Use.hs

@@ -30,7 +30,6 @@ defaultHeldUse = UseHeld
     { _heldDelay = FixedRate{_rateMax = 8, _rateTime = 0}
     , _heldHammer = HammerUp
     , _heldAim = defaultAimParams
-    , _heldAmmoTypes = mempty
     , _heldParams = BulletShooterParams
         { _muzVel = ConstFloat 0.8
         , _rifling = ConstFloat 0.8