Implement saving+loading the game

Implement ToJSON and FromJSON for all of the various pieces of the game
state, and add a pair of functions saveGame/loadGame implementing a
prism to save the game as zlib-compressed JSON. To test this, there's
now Arbitrary, CoArbitrary, and Function instances for all the parts of
the game state - to get around circular imports with the concrete
entities this unfortunately is happening via orphan instances, plus an
hs-boot file to break a circular import that was just a little too hard
to remove by moving things around. Ugh.

1 files changed, 11 insertions, 2 deletions

diff --git a/src/Xanthous/Resource.hs b/src/Xanthous/Resource.hs
index 782fd5040d93..13f7e539679b 100644
--- a/src/Xanthous/Resource.hs
+++ b/src/Xanthous/Resource.hs
@@ -1,8 +1,13 @@
+--------------------------------------------------------------------------------
 module Xanthous.Resource
   ( Name(..)
   ) where
-
+--------------------------------------------------------------------------------
 import Xanthous.Prelude
+--------------------------------------------------------------------------------
+import Test.QuickCheck
+import Test.QuickCheck.Arbitrary.Generic
+--------------------------------------------------------------------------------
 
 data Name = MapViewport
             -- ^ The main viewport where we display the game content
@@ -11,4 +16,8 @@ data Name = MapViewport
           | MessageBox
             -- ^ The box where we display messages to the user
           | Prompt
-  deriving stock (Show, Eq, Ord)
+  deriving stock (Show, Eq, Ord, Generic)
+  deriving anyclass (NFData, CoArbitrary, Function)
+
+instance Arbitrary Name where
+  arbitrary = genericArbitrary