Fix an injectivity issue with saving the game

Fix an injectivity issue with JSON-encoding the entity map that was
causing the game saving to not properly round-trip. As part of this,
there's a refactor to the internals of the entity map to use sets
instead of vectors, which should also get us a nice perf boost.

1 files changed, 17 insertions, 0 deletions

diff --git a/src/Xanthous/Prelude.hs b/src/Xanthous/Prelude.hs
index b17fd2897bb1..2f50635e783d 100644
--- a/src/Xanthous/Prelude.hs
+++ b/src/Xanthous/Prelude.hs
@@ -7,6 +7,12 @@ module Xanthous.Prelude
   , module Control.Lens
   , module Data.Void
   , module Control.Comonad
+
+
+    -- * Classy-Prelude addons
+  , ninsertSet
+  , ndeleteSet
+  , toVector
   ) where
 --------------------------------------------------------------------------------
 import ClassyPrelude hiding
@@ -17,3 +23,14 @@ import Control.Lens
 import Data.Void
 import Control.Comonad
 --------------------------------------------------------------------------------
+
+ninsertSet
+  :: (IsSet set, MonoPointed set)
+  => Element set -> NonNull set -> NonNull set
+ninsertSet x xs = impureNonNull $ opoint x `union` toNullable xs
+
+ndeleteSet :: IsSet b => Element b -> NonNull b -> b
+ndeleteSet x = deleteSet x . toNullable
+
+toVector :: (MonoFoldable (f a), Element (f a) ~ a) => f a -> Vector a
+toVector = fromList . toList