Add 'users/glittershark/xanthous/' from commit '53b56744f4335c038724a1bcffc27a7eb8cf6a6d' r/978

git-subtree-dir: users/glittershark/xanthous
git-subtree-mainline: 91f53f02d8479303910abfd3f3690d3ef27e6c4b
git-subtree-split: 53b56744f4335c038724a1bcffc27a7eb8cf6a6d

1 files changed, 19 insertions, 0 deletions

diff --git a/users/glittershark/xanthous/src/Xanthous/Util/JSON.hs b/users/glittershark/xanthous/src/Xanthous/Util/JSON.hs
new file mode 100644
index 000000000000..91d1328e4a10
--- /dev/null
+++ b/users/glittershark/xanthous/src/Xanthous/Util/JSON.hs
@@ -0,0 +1,19 @@
+--------------------------------------------------------------------------------
+module Xanthous.Util.JSON
+  ( ReadShowJSON(..)
+  ) where
+--------------------------------------------------------------------------------
+import Xanthous.Prelude
+--------------------------------------------------------------------------------
+import Data.Aeson
+--------------------------------------------------------------------------------
+
+newtype ReadShowJSON a = ReadShowJSON a
+  deriving newtype (Read, Show)
+
+instance Show a => ToJSON (ReadShowJSON a) where
+  toJSON = toJSON . show
+
+instance Read a => FromJSON (ReadShowJSON a) where
+  parseJSON = withText "readable"
+    $ maybe (fail "Could not read") pure . readMay