feat(xanthous): Track the volume and density of item types r/2678

Allow the itemType raw to have density and volume fields, both of which
represent *intervals* of both density and volume (because both can
hypothetically vary a bit). The idea here is that when we're making
an *instance* of one of these items, we pick a random value in the
range.

Lots of stuff in this commit is datatype and typeclass instances to
support things like intervals being fields on datatypes that get
serialized to saved games - including a manual definition of Ord for
Item since Ord isn't well-defined for intervals

Change-Id: Ia088f2f75cdce9d00560297e5c269e3310b85bc3
Reviewed-on: https://cl.tvl.fyi/c/depot/+/3225
Reviewed-by: grfn <grfn@gws.fyi>
Tested-by: BuildkiteCI

1 files changed, 2 insertions, 1 deletions

diff --git a/users/grfn/xanthous/src/Data/Aeson/Generic/DerivingVia.hs b/users/grfn/xanthous/src/Data/Aeson/Generic/DerivingVia.hs
index 34f2a9403892..e89fcd621157 100644
--- a/users/grfn/xanthous/src/Data/Aeson/Generic/DerivingVia.hs
+++ b/users/grfn/xanthous/src/Data/Aeson/Generic/DerivingVia.hs
@@ -89,7 +89,8 @@ type TagSingleConstructors  = 'TagSingleConstructors
 class Demotable (a :: k) where
   demote :: proxy a -> Demoted k
 
-type family All (p :: Type -> Constraint) (xs :: [k]) :: Constraint where
+type All :: (Type -> Constraint) -> [Type] -> Constraint
+type family All p xs where
   All p '[] = ()
   All p (x ': xs) = (p x, All p xs)