Add a drop command

Add a drop command, bound to 'd', which prompts the character for an
item in their inventory, removes it from the inventory, and places it on
the ground. Along the way I had to fix a bug in the
`EntityMap.atPosition` lens, which was always appending to the existing
entities at the position on set, without removing the entities that were
already there - the rabbit hole of quickchecking the lens laws here also
lead to replacing the target of this lens with a newtype called
`VectorBag`, which ignores order (since the entitymap makes no
guarantees about order of entities at a given position).

1 files changed, 11 insertions, 0 deletions

diff --git a/src/Xanthous/messages.yaml b/src/Xanthous/messages.yaml
index 3967a0cba067..9e59f4fb0fa8 100644
--- a/src/Xanthous/messages.yaml
+++ b/src/Xanthous/messages.yaml
@@ -76,6 +76,17 @@ wield:
   # TODO: use actual hands
   wielded : You wield the {{wieldedItem.itemType.name}} in your right hand.
 
+drop:
+  nothing: You aren't carrying anything
+  menu: What would you like to drop?
+  # TODO: use actual hands
+  dropped:
+    - You drop the {{item.itemType.name}}.
+    - You drop the {{item.itemType.name}} on the ground.
+    - You put the {{item.itemType.name}} on the ground.
+    - You take the {{item.itemType.name}} out of your backpack and put it on the ground.
+    - You take the {{item.itemType.name}} out of your backpack and drop it on the ground.
+
 
 ###