add better server error messages, cbor vs raw hex

agora-scripts/Data/Cache/Cached.hs

@@ -6,7 +6,8 @@
 -}
 module Data.Cache.Cached (
   cached,
-  cachedFor,
+  cachedM,
+  cachedForM,
 ) where
 
 import Control.Monad.IO.Class (MonadIO (liftIO))
@@ -20,7 +21,14 @@ import System.Clock (TimeSpec)
    Uses a HashMap under the hood.
 -}
 cached :: (Monad m, MonadIO m, Hashable k, Ord k) => (k -> v) -> IO (k -> m v)
-cached = cachedFor Nothing
+cached f = cachedForM Nothing (pure . f)
+
+{- | 'cachedFor' but items last forever.
+
+   Uses a HashMap under the hood.
+-}
+cachedM :: (Monad m, MonadIO m, Hashable k, Ord k) => (k -> m v) -> IO (k -> m v)
+cachedM = cachedForM Nothing
 
 {- | Create a cached version of a function tainting result with MonadIO context.
 
@@ -28,13 +36,13 @@ cached = cachedFor Nothing
 
    Uses a HashMap under the hood.
 -}
-cachedFor :: (Monad m, MonadIO m, Hashable k, Ord k) => Maybe TimeSpec -> (k -> v) -> IO (k -> m v)
-cachedFor t f =
+cachedForM :: (Monad m, MonadIO m, Hashable k, Ord k) => Maybe TimeSpec -> (k -> m v) -> IO (k -> m v)
+cachedForM t f =
   Cache.newCache t <&> \cache k -> do
     res <- liftIO $ Cache.lookup cache k
     case res of
       Nothing -> do
-        let v = f k
+        v <- f k
         liftIO $ Cache.insert cache k v
         pure v
       Just v -> do